Climate Change Impacts on Fisheries and Aquaculture

Climate Change Impacts on Fisheries and Aquaculture A Global Analysis Edited by Bruce F. Phillips and Mónica Pérez-Ramírez

9781119154044 1104 pages October 2017 Hardback £250.00 | €300.00 | $315.00 The first comprehensive review of the current and future effects of climate change on the world’s fisheries and aquaculture operations The first book of its kind, Climate Change Impacts on Fisheries and Aquaculture explores the impacts of climate change on global fisheries resources and on marine aquaculture. It also offers expert suggestions on possible adaptations to reduce those impacts. The world’s climate is changing more rapidly than scientists had envisioned just a few years ago, wand the potential impact of climate change on world food production is quite alarming. Nowhere is the sense of alarm more keenly felt than among those who study the warming of the world’s oceans. Evidence of the dire effects of climate change on fisheries and fish farming has now mounted to such an extent that the need for a book such as this has become urgent. A landmark publication devoted exclusively to how climate change is affecting and is likely to affect commercially vital fisheries and aquaculture operations globally, Climate Change Impacts on Fisheries and Aquaculture provides scientists and fishery managers with a summary of and reference point for information on the subject which has been gathered thus far.

Covers an array of critical topics and assesses

Also available as an eBook

Reviews the spread of diseases, economic and social

reviews of climate change impacts on fisheries and

impacts, marine aquaculture and adaptation in

aquaculture from many countries, including Japan,

aquaculture under climate change

Mexico, South Africa, Australia, Chile, US, UK, New Zealand, Pacific Islands, India and others

Includes special reports on the Antarctic Ocean,

Features chapters on the effects of climate

the Caribbean Sea, the Arctic Ocean and the Mediterranean Sea

change on pelagic species, cod, lobsters, plankton, macroalgae, seagrasses and coral reefs

Extensive references throughout the book make this volume both a comprehensive text for general study and a reference/ guide to further research for fisheries scientists, fisheries managers, aquaculture personnel, climate change specialists, aquatic invertebrate and vertebrate biologists, physiologists, marine biologists, economists, environmentalist biologists and planners.

For further information please go to

www.wiley.com/buy/9781119154044

Climate Change Impacts on Fisheries and Aquaculture A Global Analysis Edited by Bruce F. Phillips and Mónica Pérez-Ramírez

Volume 1

Volume 2

Chapter 1 Climate Change: The Physical Picture

Chapter 15 South Africa

Chapter 2 Future Physical Changes

Chapter 16 The Seychelles Tuna Fishery and Climate Change

Chapter 3 Climate Change Implications for Fisheries

Chapter 17 The Impact of Climate Change on Marine and Inland Fisheries and Aquaculture in India

Chapter 4 Biodiversity and Climate Change in the Oceans

Chapter 18 Management Adaptation to Climate Change Effect on Fisheries in Western Australia

Chapter 5 Impacts of Climate Change on New Zealand Fisheries and Aquaculture

Chapter 19 Climate Change and Fisheries in the Caribbean

Chapter 6 Impacts of Climate Change on the Marine Resources of Japan

Chapter 20 Impacts of Climate Change on the Southern Ocean

Chapter 7 Impacts of Climate Change on Eastern Australia Fisheries

Chapter 21 Regional Assessment of Climate Change Impacts on Arctic Marine Ecosystems

Chapter 8 Climate Change Impacts on Fisheries and Aquaculture of the United States

Chapter 22 Seagrasses and Macroalgae: Importance, Vulnerability and Impacts

Chapter 9 Impacts of Climate Change on Mexican Pacific Fisheries

Chapter 23 Impacts of Climate Change on Pelagic Fish and Fisheries

Chapter 10 Impacts of Climate Change on Marine Fisheries and Aquaculture in Chile Chapter 11 The Pacific Islands: Fisheries, Aquaculture and Climate Change

Chapter 24 Lobsters in a Changing Climate Chapter 25 Climate Change, Zooplankton and Fisheries Chapter 26 Tropical Marine Fishes and Fisheries and

Chapter 12 Impacts of Climate Change in the United Kingdom and Ireland

Climate Change Chapter 27 The Impacts of Climate Change on Marine

Chapter 13 Canadian Fisheries and Aquaculture: Prospects under a Changing Climate

Phytoplankton Chapter 28 Socioeconomic Impacts of Changes to

Chapter 14 Potential Impacts of Climate Change in

Marine Fisheries and Aquaculture that are

Brazilian Marine Fisheries and Aquaculture

brought about through Climate Change Chapter 29 Conclusions

For further information please go to

www.wiley.com/buy/9781119154044

17 - 302702 / MITM040351

and Aquaculture

17 The Impact of Climate Change on Marine and Inland Fisheries and Aquaculture

in India

Bimal Mohantyl, Elayaperumal Vivekanandan 2, Sasmita Mohantx3, Arabinda Mahantyl, Raman Irivedi", Manoj Tripathy5 and Jnanendra Sahu5 , ICAR·Centrallnland 1ICAR.Central J

KilT School

4

Faculty

Marine

Fisheries Research Institute,

FREM Division,

Fisheries Research Institute,

of Biotechnology,

of Fisheries, University

KilT University, af Animal

Bhubaneswar.

West Bengal, India

Odisha, India

& Fishery Sciences, Pancnasoyet;

s COllege of Fisheries, Orissa University of Agriculture

17.1

Barrackpore,

Cochin, Kerola, India

& Technology,

Kolkata,

Rangeilunda,

West Bengal, India

Odisha, India

Introduction

Contribution of Fisheries and Aquaculture Towards Food and Nutritional Security Aquaculture earned its fame as a fast growing food sector which continues to grow more rapidly than all other animal food producing sectors, with an average global growth rate of 8.8% per year since 1970, compared to 2.8% for terrestrial farmed meat production systems. The fisheries and aquaculture sector contribution to Gross Domestic Product (GDP) typically ranges from around 0.5 to 2.5%, but may exceed 7% in some countries, which often compares very significantly with agricultural sector GDP. Aquatic foods have high nutritional quality, contributing 20% or more of average per capita animal protein intake for more than 2.8 billion people, mostly from developing countries. Millions of people around the world depend on fisheries and aquaculture, directly or indirectly, for their livelihoods. Worldwide, fish products provide 15% or more of the protein consumed by nearly 3 billion people and support the livelihoods of 520 million people, many of them women (World Fish Center, 2008; FAO, 2009). Currently, an estimated 42 million people work full or part-time as fishers and fish farmers, with the great majority in developing countries, principally in Asia. Hundreds of millions of other people work in the sector as occasional fishers or in associated activities including supply and post-harvest services, marketing and distribution. Growth in sector employment, largely outpacing that of agriculture, has been mainly in small-scale fisheries and in the aquaculture sector in the developing world where it has important seasonal income, food supply and security impacts (FAO, 2008). 17.1.1

Indian Marine Fisheries Overview

India has a coastline of 8,129 km and an Exclusive Economic Zone (EEZ) of 2.02 million krn" The continental shelf area is 0.51 million krn '. On the eastern side it is bound by the Bay of Bengal and on the western side by the Arabian Sea (Figure 17.1). On the south, India projects into the Indian Ocean. The Andaman & Nicobar Islands are scattered at a distance of 1,200-1,800 km from the east coast of the mainland and Lakshadweep Islands at a distance

Climate Change Impacts on Fisheries and Aquaculture: A Global Analysis, Volume Il, First Edition. Edited by Bruce F.Phillips and M6nica Perez-Rarnirez. © 2018 John Wiley & Sons Ltd. Published 2018 by John Wiley & Sons Ltd.

570

I

Climate Change Impacts on Fisheries and Aquaculture:

A Global Analysis

I

30'

~ PAKISTAN

25'

20'

15'

10'

-1

5'

O'~

Exclusive Economic Zone (EEZ)

~

~

~ 75'

80'

~ 85'

~

~ __~ 95'

Figure 17.1 Map of India and its Exclusive Economic Zone.

of 200-400 km from the west coast. Marine fisheries is important to nutritional security, income and employment generation and foreign exchange earnings for the country. In 2014, the marine fish landings were 3.59 million t, valued at US$5.6 billion at landing center price (CMFRI, 2014). The country exported fish worth US$5 billion (which includes produce from aquaculture, contributing >50% to the export). India has 3,288 marine fishing villages and 1,511 marine fish landing centers distributed along the coastline (CMFRI, 2012). The full-time, part-time and fishery-dependent fisher population was about 4 million. On an average, a fishing village and a landing center is distributed every 2.0 km and 4.3 km, respectively along the coastal mainland of India. The Indian coastal areas support about 30% of the total 1.2 billion human population. The average population density is 455 persons per km". At least 25 major craft-gear combinations are in operation on the continental shelf of India EEZ. The marine fish landings have increased from 0.5 million t in 1950 to 3.94 million t in 2012, but declined to 3.59 million tin 2014. The 7-fold increase in 65 years was made possible by enhancing infrastructure facilities and technological advancements in craft and gear. These advancements enabled extension of fishing activity to offshore and deeper grounds. The fishing fleet is now able to access the entire continental shelf area. The average depth of operation of bottom-contact gears has increased from 20 m in the 1960s to 40 m in the last two decades. These developments have increased the landings, employment opportunities, income and export earnings, but have masked several negative effects. There is evidence of decline of several fish stocks, indicated by declining catch-per-unit effort, reduction in the mean size of fish in the catches, fishing down the food web and severe conflicts within the sector in sharing the resources (Vivekanandan, 2011). The. potential yield (PY) from marine fisheries has been estimated as 4.4 million t (DADF, 2012). With the yield approaching the PY,any further increase


in India

in yield should be viewed with caution. While the country is moving from open access towards regulated access by implementing boat registration, limiting the number of boats, observing seasonal closure, protected areas and species, there are still several challenges in implementing other effective management measures. In addition to overfishing, there are concerns about habitat degradation and pollution affecting the fisheries. The coastal ecosystems extend to 42,808 km2 comprising mudflats 2 ? 2 2 (23,621 km ), sandy beaches (4,210 km"), estuaries (1,711 km ), mangroves (4,445 km ), coral reefs (2,375 km"), marshes (1,611 krrr') and lagoons (1,564 km '), in addition to sandy and rocky beaches, creeks and sea grass meadows (MoEF, 2005). In spite of their ecological and economic importance and existence of a policy and regulatory framework, India's coastal and marine ecosystems are under increasing threat. Numerous direct and indirect pressures arising from different types of economic development and associated activities are having adverse impacts on coastal and marine biodiversity across the country. Climate change adds to the prevailing concerns. If the impact of climate change is not reduced. the potential outcome for fisheries may be a decrease in production and value of coastal fisheries, and a decline in the economic returns from fishing operations. The changes will affect not only the fish trade of the country, but even more importantly, the food security in a country where fish is one of the major contributors of animal protein intake.

17.1.2

Indian Inland Fisheries Overview

Climate change is an issue of great environmental concern OPCc, 2007; Mohanty & Mohanty, 2009). Climate change is already having a profound effect on marine and inland fisheries and aquaculture in India. There is no doubt that fisheries are already a highly vulnerable sector facing widespread and often profound changes (Mohanty et al., 2010). The marine ecosystems are profoundly affected by processes like ocean acidification, coral bleaching and altered river flows with obvious impacts on fisher folk, but it is not just about what happens to the fish; fishing communities are vulnerable to sea level rise and their livelihoods are threatened by storms and extreme weather. Meanwhile, the social and economic context of fisheries will be disrupted by impacts on security, migration, transport and markets. Fisheries are already rapidly evolving due to overexploitation and globalization. They will suffer from wide range of different impacts from climate change, which may be unpredictable and surprising. The poorest will be least able to adapt to these impacts. India has vast inland fisheries resources which include rivers, estuaries, reservoirs, floodplain wetlands, lakes, coastal lagoons which play important roles in fish production in the country. India's fresh water resources consist of 195,210 km of rivers and canals, 2.9 million ha of minor and major reservoirs, 2.4 million ha of ponds and lakes, and about 0.8 million ha of flood plain wetlands and water bodies (FAO, 2014). The river system of the country comprises 14 major rivers, 44 medium rivers and innumerable small rivers and desert streams. Reservoirs constitute one of the largest inland fishery resource, both in terms of resource size and production potential. Besides, the ponds and tanks also contribute to the aquaculture production. It has been estimated that the area available under ponds and tanks category is 2.36 million ha out of which only 40% has been utilized for fisheries production (FAO, 2014). India is the second largest fish producing country with an annual fish production of about 9 million t and the inland fisheries and aquaculture has contributed immensely to the total fish production the country. Besides fulfilling the domestic needs, and contributing to the livelihood of over 14 million people, aquaculture sector has contributed in foreign exchange earnings to the tune of US$3.51 billion (2012-2013). In recent years, the inland fisheries and aquaculture production system has shown exponential growth e.g., the share of inland fisheries and aquaculture has gone up from 46% in the 1980s to over 85% in recent years in total fish

1571

5721

Climate Change Impacts on Fisheries and Aquaculture: A Global Analysis

production (FAO, 2014). The inland water resources harbour the original germplasm of one of the richest and diversified fish fauna of the world, comprising 930 fish species belonging to 326 genera. Three major carps (Catla catla, Labeo rohita and Cirrhinus mrigala) accounting for most of the aquaculture production in India. In spite of exponential growth in recent times, like other food production systems, inland fisheries and aquaculture system has also been predicted to be affected by climate change. Sea level rise over the next decades would increase salinity intrusion further upstream of rivers and consequently impact on fresh water culture practices (De Silva & Soto, 2009). The major river systems of India which will be impacted in a climate alteration scenario are the Himalayan glacier-supported, rivers like Ganga and Brahmaputra and other rivers of mid Deccan plateau of India like the Narmada, Mahi, Tapi, Godavari and Mahanadi. These rivers will have either acute or regular water shortages or face excessive flood conditions due to climate change (Vass et al., 2009). These changes can have variable impacts on the fish production. depending on the species, locality and other factors. 17.1.3

Regional Climate and Environment Trends

The Indian landmass divides the north Indian Ocean into two tropical basins, namely the Arabian Sea and the Bay of Bengal. Indian seas extend to a vast area in the tropical zones from 8°_23°N, and from 69°-90 E. The Bay of Bengal and Arabian Sea occupy the same latitudinal range, but the oceanographic characteristics exhibit wide differences. The Arabian Sea has high salinity whereas the salinity of the Bay of Bengal is much lower due to the contrast in freshwater forcing of the two basins. The fresh water received by the Bay in large amounts during the summer monsoon through river discharge is flushed out annually by ocean circulation. During the pre-monsoon months of February-April, a warm pool, which is distinctly warmer than the rest of the Indian Ocean, takes shape. In fact, this is the warmest region in the world oceans during this period (Vinayachandran & Shetye, 1991). The climate is affected by tropical monsoon. Strong northeast winds blow from October until February, and south-west winds prevail from May until October. When the monsoon winds change, cyclones strike the coasts of, especially Bay of Bengal. These marginal seas are forced by the above wind systems, solar heating owing to lower latitudes, immense evaporation, precipitation, and huge river runoff, particularly in the Bay of Bengal. Changes in the important oceanic weather systems such as sea surface temperature, pH, salinity, El Nifio Southern Oscillation (ENSO), precipitation, sea level, frequency and intensity of cyclones and droughts are becoming evident as a result of climate change (for example, see Prasannakumar et al., 2009, 2010). Observed changes in the climate and environment trend in the Indian seas may be summarized as follows: 0

(i)

Analyzing the data set (on sea surface temperature, SST) obtained from International Comprehensive Ocean - Atmosphere Data Set (ICOADS) (www.cdc.noaa.gov) and 9-l5.3°C. The annual average SST in different months and latitudes in the Indian seas ranges from 24.8° to 30.1°C. A few hundred species are common and contribute regularly to fisheries along the entire latitudinal range in all the seasons. For example, the Indian mackerel, Rastrelliger kanagurta, which is a small pelagic fish, and the demersal fish the threadfin bream Nemipterus japonicus occur along the entire Indian coast in varying abundance in all seasons, implying that these fish have the ability to establish populations in a wide range of tropical temperatures. Evidence is accumulating that a few species of fish are adapting to seawater warming by increasing their geographic distribution ranges. The oil sardine Sardinella longiceps and the Indian mackerel R. kanagurta are coastal small pelagics, forming massive fisheries in India (catch during 2014: 0.8 million t valued at about US$150 million). They are governed by vagaries of ocean climatic conditions, and have a high population doubling time within 15 to 24 months. They are a major source of protein, and form a staple, sustenance and nutritional food for millions of coastal people. They are known for their restricted distribution between 8°-14°N

17 The Impact of Climate Change on Marine and Inland Fisheries andAquaculture

in India

and 75°-77°£ (Malabar upwelling zone along the south-west coast of India) where the annual average SST ranges from 2r to 28SC. Until 1985, almost the entire catch of S. longiceps was from the Malabar upwelling zone and the catch was either very low or there was no catch from latitudes of 14°N. In the last three decades, however, the catches from 14°-22° have been increasing, reaching 150,000 t (19% of all-India catch during 2014). During the last three decades, the landings along the east coast have also increased. For example, the landings along Tamil Nadu coast (southeast coast) increased from 28SC) of the surface waters expanded to latitudes north of 14°N, enabling the oil sardine and Indian mackerel to extend their distributional boundary to northern latitudes. It was also found that the catches from the Malabar upwelling zone had not decreased indicating distributional "extension" and not distributional "shift': Considering the catch as a surrogate of distribution and abundance, it was also found that the two most dominant .fish have been able to find temperature to their preference in the northern latitudes in recent years, thereby establishing fisheries in extended coastal areas. However, if the SST in the southern latitude (8°_14° ) increases beyond the physiological optimum of the fish, it is possible that the populations may "shift" from the southern latitudes sooner or later. Vertical expansion of distribution range. The Indian mackerel, R. kanagurta, in addition to extension of its northern boundary, has been found to descend to deeper waters over the last three decades. The fish normally occupies surface and subsurface waters. During 1985-1989, only 2% of mackerel catch was from bottom trawlers, and the rest of the catch was contributed by pelagic gear such as drift gillnet. During 2010-2014, about 18.5% of the mackerel catch was contributed by bottom trawlers along the Indian coast. The Indian trawlers operate at a depth ranging from 20 m to 80 m by employing high opening bottom trawlnets. In the last 30 years, the specifications of trawlnet such as mouth opening, headrope length, otterboard and mesh size have not been modified, and hence the increase in the contribution of trawlers to the mackerel catch is not gear-related. As the subsurface waters are also warming up, it appears that the mackerel, being a tropical fish, has extended its vertical boundary to deeper waters. The changes in distribution will lead to changes in composition of communities and large-scale ecological restructuring. For fishers, the implications are that they will have to adapt to catch and utilize the new resources by introducing new gear or altering the existing gear to take the new resources, and find markets for the new resources. This will incur economic cost to them. 17.2.2

Growth

Growth is one of the important factors that determines productivity of fish in terms of biomass. Growth of fish is faster at higher temperatures within the optimal temperature window. Instantaneous daily growth rate increases approximately 0.01 per 1°C increase in water temperature (Vivekanandan & Pandian, 1977). There have been several estimates of growth of marine fish by collecting samples from natural populations in the Indian seas. For a few commercially important fish species such as S. longiceps, R. kanagurta and N. japonicus, growth has been estimated from time to time by different researchers based on length frequency analysis from samples collected at landing centers. Vivekanandan (2013) has compiled this information and has reported that the growth rate of the three species has increased over long time periods. For example, from the von Bertalanffy growth equation, it is estimated that S. longiceps attained around 100 mm during 1950-1965, but 158 mm during 2010-2014 at age 1 year (Table 17.2). These data suggest that growth has been at an enhanced level in recent years. This is likely to continue until the optimum temperature limit is reached. Increase in growth rate at elevated

I

577

5781

Climate Change Impacts on Fisheries and Aquaculture: A Global Analysis Table 17.2 Growth estimates of three fish species along Indian coast: length (mm) attained at age 1 (Vivekanandan, 2013). Nemipterus japonicus

Decade

Sardinella longiceps

Rastrelliger kanaqurta

1950s

100

100-119

1960s

100

142

19705

126-139

142-144 128-248

163-165

19905

145-158

230-234

170

2000s

145

215-230

173-174

2010s

158

19805

temperature must be supported by increased food consumption, but not necessarily growth efficiency. The tropical freshwater fish Ophiocephalus striatus consumes 50% more food at higher water temperatures to maintain growth efficiency at about 20% (Vivekanandan & Pandian, 1977). The metabolic rate increases corresponding to consumption rate, implying that the mortality rate also would be higher at a higher temperature (Houde, 1989). Thus food utilization operates at a faster rate in elevated temperatures, indicating higher food requirement at the population level. It is also possible that the turnover of generations would be at a faster pace within the optimal temperature window. 17.2.3

Phenology

Tropical marine fish species exhibit a wide range of life-history strategies. Most tropical marine fish are oviparous serial spawners with high per-capita fecundity. The process of spawning is known to be triggered by pivotal temperatures. The annually recurring life-cycle events such as timing of spawning can provide particularly important indicators of climate change. Though sparsely investigated, phenological changes such as shift in spawning season are now evident in the Indian seas. The threadfin breams N. japonicus and N. mesoprion are distributed along the entire Indian coast at depths ranging from 10 to 100 m. They are short-lived (longevity: about 3 years), fast growing, highly fecund (annual egg production around 0.2 million per adult female) and medium-sized fishes (maximum length: 35 cm). Data on the number of female spawners collected every month off Chennai (southeast coast of India) from 1981 to 2004 indicated wide monthly fluctuations. However, a trend in the shifting of spawning season from warmer to cooler months was discernible. Whereas 35.3% of the annual number of spawners of N. japonicus occurred during warm months (April-September) during 1981-1985, the number of spawners gradually reduced and only 5.0% of the spawners occurred during the warm season during 20002004. During 1981-1985, it was observed that 64.7% of the spawners occurred during cooler months (October-March), whereas as many as 95.0% of the spawners occurred during the same season in 2000-2004. A similar trend was observed in N. mesoprion also. It appears that SST between 28° and 29°C may be the optimum and when the SST exceeds 29°C, the fish are adapted to shift spawning activity to seasons when the temperature is around the preferred optimum. Owing to elevated temperature and faster rate of warming in the warm season, these species are shifting spawning to the relatively cooler season, which is within the optimum window. Elevated temperature and shift in the timing of spawning are likely to result in a series of several other changes such as egg production (Kurita et al., 2011), and rate of egg development and

17 The Impact of Climate Change on Marine and Inland Fisheries and Aquaculture in India

larval emergence (Warren et al., 2012). Temporal changes in spawning can contribute to variations in year-class strength by influencing the spatial and temporal coexistence of larvae, prey availability, predator abundance, and favorable environmental conditions (Houde, 1989). Future investigations on spawning strength indicators such as delayed or diminishing gonad development, fecundity and ova diameter in relation to seawater temperature, synchrony of male spawning activity with that of females, and food availability for the emerging larvae in the summer months, will be helpful to gain an insight into the response of the fish at population level.

17.3 17.3.1

Impact on Marine Ecosystems Coastal Upwelling and Chlorophyll Concentration

The Malabar upwelling zone along Kerala coast (south-west coast of India) is an import-ant upwelling system, contributing about 20% to the marine fish catch of India. During the summer monsoon (south-west monsoon), an intense low-level wind jet (Findlater Jet) blows diagonally across the Arabian Sea producing coastal upwelling along Somalia, Oman and the south-west coast of India. UpweUing occurs during Iune-August, elevating chlorophyll a concentration, which is a proxy for higher phytoplankton productivity. In the context of climate change, Manjusha et al. (2013) have correlated the trends in coastal upwelling index (CUI), chlorophyll-a concentration and small pelagic catches in the Malabar upwelling zone. While the intensity of annual coastal upwelling fluctuates between years, it has been found that the CUI in the monsoon season constantly increased from 301 m3/sec in 1998 3 to 713 m /sec in 2009. While it is known that chlorophyll concentration is influenced by climatic factors such as SST and wind, the mechanism by which the CUI increases during summer monsoon in the Malabar upwelling zone is not clear. Manjusha et al. (2013) also found that increase in CUI elevated the chlorophyll a concentration from 2.25 mg/rn ' to 8.50 rng/rn ' during the corresponding years. The increasing CUI and chlorophyll a during the monsoon sustained an increasing catch of the oil sardine S. longiceps during the post-rnonsoon season. Changes in chlorophyll concentration can change food availability and influence fish populations. "The responses of lesser sardines and Indian mackerel, which are midlevel carnivores, were different. The population increases of the oil-sardine appear to replace the lesser sardines and Indian mackerel during the post-rnonsoon season" (Manjusha et al., 2013). This indicator provides proxy information on the amount of primary production occurring in the Malabar upwelling zone during the summer monsoon, which may influence ecosystem-wide productivity.

17.3.2

Coral Reefs

Coral reefs are the most diverse marine habitat, which support an estimated one million species globally. They are highly sensitive to climatic influences and are among the most sensitive of all ecosystems to temperature changes, exhibiting bleaching when stressed by higher than normal sea temperatures. Reef-building corals are highly dependent on a symbiotic relationship with microscopic algae (a type of dinoflagellate known as zooxanthellae), which live within the coral tissues. The corals are dependent on the algae for nutrition and coloration. Bleaching results from the ejection of zooxanthellae by the coral polyps and/or by the loss of chlorophyll by the zooxanthellae themselves at higher than normal temperatures. Corals usually recover from bleaching, but die in extreme cases. In the Indian seas, coral reefs are found in the Gulf of Mannar, Gulf of Kachchh, Palk Bay, the Andaman Seas and Lakshadweep Seas. Indian coral reefs have experienced 29 widespread

1579

- ---------------

580

I Climate Change Impacts on Fisheries and Aquaculture:

A Global Analysis

bleaching events since 1989 and intense bleaching occurred in 1998 when the SST was higher than the usual summer maxima. By using the relationship between past temperatures and bleaching events and the predicted SST for another 100 years, Vivekanandan et al. (2009) projected the vulnerability of corals in the Indian Seas. The outcome of this analysis suggests that if the projected increase in seawater temperature follows the trajectory suggested by the HadCM3 for an SRES A2 scenario, reefs should soon start to decline in terms of coral cover and appearance. The number of decadallow bleaching events will remain between 0 and 3 during 2000-2099, but the number of catastrophic events will increase from 0 during 2000-2009 to 10 during 2000-2099. Given the implication that reefs will not be able to sustain catastrophic events more than three times a decade, reef building corals are likely to disappear as dominant organisms on coral reefs between 2020 and 2040 and the reefs are likely to become remnant between 2030 and 2040 in the Lakshadweep region and between 2050 and 2060 in other regions in the Indian seas. These projections on coral reef vulnerability have taken into consideration only the warming of seawater. Other factors such as increasing acidity of seawater would slow down formation of exoskeleton of the reefs, and if acidification continues as it is now, all the coral reefs would be dead sooner. The loss of coral reefs is likely to have several ramifications for fisheries, as coral reefs provide habitats for a large number of commercially important fishes, crustaceans and molluscs. It has been estimated that reefs contribute up to 25% to the total marine fish catch of India. This includes a large variety of organisms caught elsewhere, but which would have spent part of their life in the reefs. 17.3.3

Ecosystem Structure and Function

The ecosystem response to climate change will depend on the response of individual species and the resulting effect on trophodynamic interactions among species (Rijnsdorp et al., 2009). As different species and regions respond differently to climate change, those species having the capacity to adapt will become dominant and those vulnerable will begin to disappear. Similarly, regions experiencing high impact will lose several species. Thus there will be a novel mix of organisms in the ecosystems. If small-sized, low value fish species with rapid turnover of generations such as oil sardine, Indian mackerel and threadfin breams are able to cope with changing climate; they may replace large-sized high value species, which are already showing declining trends due to fishing. This will change the food webs as well as the fish catch. These changes will make species adjust to new prey, predators, parasites, diseases and competitors (Kennedy et al., 2002), and result in considerable changes in ecosystem structure and function. Analyzing 50 years of fish landings data, Vivekanandan et al. (2005) detected occurrence of fishing down the marine food web along the Indian coast. They quantified that the trophic level of catches is reducing by 0.03 per decade, and cautioned about changes in structure and function of marine ecosystems due to fishing. Later, Vivekanandan & Krishnakumar (2010) suggested that the cause for reduction in the trophic level of fish catches is not by fishing alone, but a combination of fishing and climate change. They pointed out that seawater warming will increase the abundance of small pelagics with low trophic level in relation to high trophic level groups, thereby reducing the trophic level in the fishery. The changes in ecosystem structure and function are likely to alter the services provided by the ecosystems. These alterations will have economic consequences and there is a need to examine economic policies that may be adopted in response to these changes. To save coastal and marine ecosystems, emphasis has been given in recent years on economic valuation of ecosystem services. This process makes the economic case for protection and sustainable use


of natural resources by showing the monetary, employment, and infrastructure benefits ecosystems provide - metrics that are easily understood by decision-makers. While there are not many economic valuations of coastal and marine ecosystem services in India, BOBLME (2015) has recently estimated the annual economic value of provisioning, regulating, cultural and supporting services of coastal marine ecosystems of the east coast of India. The annual value has been estimated as US$4,060 million, which includes annual value of US$1,803 million from capture fisheries and US$1,033 million from aquaculture. It has been projected that in the business-as-usual scenario, the ecosystem services of the east coast of India will reduce by 25% in 25 years, resulting in cumulative loss of US$17 billion. This loss is due to a combination of factors such as overexploitation, habitat degradation, pollution and climate change. As marine fisheries management in India needs vast improvements to achieve sustain ability, the country is not well-positioned to immediately respond to the vagaries of climate change. It is important to respond much more proactively to disruptive changes resulting from climate change, so that the values of ecosystem services are restored. Efforts should be made to estimate the economic costs of adapting fisheries to climate change and the means of absorbing these costs. Some important marine ecosystems such as mangrove, seagrass, and coral reefs are under great stress due to habitat destruction by human interference, pollution etc. and so climate change may add more stress, and may completely bring about structural and behavioral change in the ecosystem. Lakshmi & Ramya (2009) have reported that climate change is also expected to increase the number of extreme events such as tropical cyclones. For example, tropical cyclone Nargis reportedly caused the destruction of some 17,000 ha of natural forest. It is predicted that ecosystem changes would be rapid in the future. Brander (2007) has cited three reasons: (i) the rate of future climate change is predicted to be more rapid than previous natural changes; (ii) the resilience of species and systems is being compromised by concurrent pressures, including fishing, loss of genetic diversity, habitat destruction, pollution, introduced and invasive species, and pathogens; and (iii) rising CO2 levels are lowering the pH of the oceans, with consequences that are largely unknown.

17.4 Impact of Climate Change on Fragile Coastal Ecosystems - The Indian Sundarban as a Case Study Climate change is projected to impact broadly across ecosystems, societies and economies, increasing pressure on all livelihoods and food supplies, including those in the fisheries and aquaculture sector (Cochrane et al., 2009). In recent years, climate variability manifested by rise of sea level, increased incidence of flood, drought, tropical cyclones and increasing water stress in various countries of the world have adversely affected the aquatic ecosystems, fisheries and fishers' livelihood (Cruz et al., 2007; Csaszar et al., 2009; Badjeck et al., 2010). These projections are important from the viewpoint of Asia, as the majority of fishers live in anthropogenically disturbed areas where the aquatic resources are vulnerable to climate variations. The multiple benefits that fisheries and aquaculture provide for the alleviation of poverty in these countries are threatened by climate change. Small-scale fisheries, and especially inland fisheries, have also often been marginalized and poorly recognized in terms of contribution to food security and poverty reduction. The Intergovernmental Panel on Climate Change (IPCC) in its several assessment reports has made strong assertions about the occurrence of accelerated sea level rise (SLR) and more frequent extreme events such as coastal flooding, cyclones, storm surges and salinity intrusion. Low-lying deltaic and small island countries (SICs) are particularly vulnerable to the SLR and its associated extreme events (IPCC, 2007) which in turn have

1581

5821


a strong negative impact on freshwater fisheries and aquaculture. The IPCC fifth Assessment Report (AR5) (IPCC. 2014) has predicted that sea level rise will exacerbate inundation, storm surge, erosion and other coastal hazards. 17.4.1

The Sundarban Eeo-Region and its Natural Setting

The Indian Sundarban delta (between 21°40'-22°40'N and 88°03'-89°07'E) is a UNESCO declared World Heritage Site, and lies on the southern fringes of the state of West Bengal, where the Gangetic plain meets the Bay of Bengal. This river-mouth ecosystem has been formed mainly by the continuous deposition of silt carried down by the Ganges, Brahmaputra and Meghna river system (Allison et al., 2003) as well as its tributaries like Mayurakshi, Damodar, Ajay, and Kansai rivers (Danda et al., 2011). The site of the world's largest mangrove ecosystem, the Sundarban is an archipelago of several hundred islands, spread across 9,630 sq km in India and 16,370 sq km in Bangladesh. The Sundarban Estuarine System (SES) is the largest monsoonal, macro-tidal, delta-front, estuarine system in India and the most complex of. the lOO-odd estuaries that exist along the Indian coast. Its 9,630 km2 area is spread over the entire South 24 Parganas and the southern parts of the adjoining North 24 Parganas, the two southern most districts of the state of West Bengal. River Hooghly, the western most estuary of the SES, is the first deltaic offshoot of the Ganga. River Raimangal forms the eastern boundary of the SES. This trans-boundary river is a tributary of the river Ichhamati, easterly distributaries of the Ganga situated in the orth 24 Parganas. The northern limit of the Sundarban is defined by the Dampier-Hodges Line, an imaginary line that is based on a survey conducted during 1829-1832 (Chatterjee et al., 2013). The principal estuaries of the Sundarban lying east of the Hooghly are the north-south flowing rivers: the Saptamukhi, Thakuran, Matla, Bidya, Gomdi (Gomor), Gosaba, Gona, Harinbhanga and Raimangal (Chatterjee et al., 2013). Interconnecting these estuaries and forming the complex estuarine network are numerous west-east flowing channels, canals and creeks. Some of these interlinking channels are wide and strong enough to be considered as estuaries by themselves. In the eastern sector, five major rivers namely Saptarnukhi, Thakuran, Matla, Gosaba and Harinbhanga have lost their upstream connections with the Ganges due to heavy siltation, whereas rivers in the western part, namely HooghIy and Muriganga, are connected to the Himalayan glaciers through the Ganges originating at the Gangotri Glacier, collectively known as the Hooghly-Matla estuarine complex (Choudhuri & Choudhury, 1994). This ecosystem comprises about 55% forest land and 45% water spread area. The delta comprises of 102 low-lying islands, of which 48 are inhabited and all habitation is on reclaimed land, which amounts to an area of 5,363 sq km. On the Indian side, it extends over two districts; 13 blocks in South 24 Parganas and six blocks in the orth 24 Parganas districts with a total of 190 Gram Panchayats and 1,064 villages. 17.4.2

People and Livelihood in Indian Sundarban

The Sundarban contains over 4.4 million of the most impoverished and vulnerable people in India. About half of this population lives below the poverty line (BPL), with poverty incidence highest in the blocks close to the vast mangrove forest. Per capita income in the region is about 50 cents (US$) per day, which is half of that commonly used as an indicator of extreme poverty. Along with abject poverty, there is a lack of basic food security; around 6% of all households reported that they consumed less than one square meal a day, with around 19%consuming only one meal a day. All 19 blocks of the Sundarban region have more poor households than the corresponding averages for India and West Bengal, and the percentage of BPL households ranges from 31% to 65% in these blocks (World Bank, 2014). Nearly 80% of the households


pursue livelihood options that involve inefficient production methods in agriculture, fishing, and aquaculture (World Bank, 2014). Agriculture followed by aquaculture is an important source of livelihood in the Sundarban economy. Nearly 60% of the total working population depends on agriculture as a primary occupation (World Bank, 2014). 17.4.3

Climate Change

Scenarios

in Sundarban

Delta

Recent studies have indicated that South Asian countries including India will be particularly vulnerable to climate change impacts (Hijioka et al., 2014). In 20l3, India ranked third in the Global Climate Risk Index, a ranking of 170 countries that are most vulnerable to climate change, and the countries affected most in 2013 were the Philippines, Cambodia and India (Kreft & Eckstein, 20l3). The coastal region ofIndia is perhaps one of the most productive and ecologically diverse landscapes covering over 7,500 km of coastline. Erratic weather and mensoon patterns, along with frequent extreme climatic events are major threats to the Indian coastline (Patwardhan et al., 2003). The anthropogenic activities coupled with climate variability pose serious hazards on the biotic as well as abiotic integrity of the deltaic ecosystem. Being served as a "bio-wall" of the coastal region, the Indian Sundarban is now the most visible victim of climate change. The major combination of climatic variables include: 0) coastal flooding: (ii) cyclone; (iii) drought; (iv) rainfall; (v) salinity; (vi) sea-level rise; and (vii) SST. Air temperature over the Bay of Bengal is rising at a rate of 0.0 19°C per year. If this trend continues, the air temperature in this area is expected to rise by 1°C by 2050 (Hazra et al., 2010). It is also observed that the period 1993-2007 had a higher rate of temperature increase as compared to 1980-1992 (Hazra et al., 2010). SST in the Bay of Bengal is increasing more rapidly than in the global oceans. The average SST over the Sundarban region has increased from 31° to 32.6°C between 1980 and 2007 in the pre-rnonsoon periods, an increase ofOSC per decade (Mitra et al., 2009). Another study estimated the annual composite SST of Bay of Bengal near Sagar Island during the period 2003-2009 and it varied from 28.023°C in the year 2004 to 29.381°C in the year 2009, with a rising trend of 0.0453°C per year (Hazra et al., 2002) and SST over northern and southern sectors of Bay of Bengal increased by 0.8 and l.O°C respectively over 102 years (Dash et aL., 2007) Rainfall of monsoon and post-rnonsoon months showed a decreasing trend in the Sundarban region (-3.84 to -4.42 mm/year), while pre-rnonsoon rainfall showed an increasing trend (+0.98 mm/year) (Mandal et al., 20l3). It is also evident that the monsoonal rainfall has significantly increased at the rate of 0.0041 rnrn/h along with SST (Hazra et al., 2010). The most important aspect of rainfall with specific relevance to agriculture and aquaculture is the erratic nature of its distribution. There is remarkable change in the onset and recession of monsoon in South Bengal, very specifically in Sundarban. There is a trend of delayed monsoon and heavy rains at the beginning as well as late recession and sometimes heavy precipitation during the khariff harvest. In the eastern sector, the increase of 6 psu in salinity over the past three decades (-2 psu/ decade) is much higher than the documented average in the Indian Ocean (0.01-0.02 psu/ decade). Furthermore, much of the salinity increase (3.67 psu/decade) occurred during the last 15 years (Mitra et al., 2009). In some areas, soil salinity has increased beyond the safe threshold for agriculture (for growing rice, the safe limit is 4-6 ppt). The northern part, which is a low salinity zone, witnessed salinity of up to 8 ppt, while the southern part contends with 8 to 20 ppt. In many areas, soil salinity has markedly increased from 0.1 to 5.25 ppt and had reached a depth of about 1.5 m after Aila in 2009 (Haldar & Debnath, 2014). Although the Bay of Bengal accounts for less than 6% of the total number of tropical cyclones occurring globally, it accounts for 18 of the top 25 most fatal tropical cyclones. Pre- and

1583

5841


A Global Analysis

post-monsoonal storms are more violent than the storms of the monsoon season. According to Singh (2007), severe cyclonic storms over the Bay of Bengal registered a 26% increase over the last 120 years, intensifying post-monsoon. The number of severe cyclonic storms crossing the east coast in the decade 1891-1900 was lo, which increased to 19 in the decade 1971-1980 and became l3 in the last decade 1991-2000 (Dash et al., 2007). Over 3 million individuals were affected, on average, by cyclones each year (World Bank, 2014). In the recent decade (2005-2013) the entire Bay of Bengal region of Indian Ocean experienced more than 22 such events. Most tropical cyclones end with great damage through inundation from storm surges and subsequent rains causing widespread flooding. Cyclone Nargis (April-May 2008) resulted in the death of around 14.0,000 people with an economic loss ofUS$10 billion in Myanmar (Webster, 2008). Cyclone Sidr (November 2007) smashed coastal Bangladesh with an economic loss ofUS$1.7 billion and about 10,000 lives (World Bank, 2014). In cyclone Aila (May 2009), over 5 million people were affected in India, and over 3 million in Bangladesh (World Bank, 2014). The impact associated in the Indian Sundarban delta was about US$550 million with a loss of more than 300 lives, with over 8,000 persons missing (World Bank, 2014). The average mean sea-level rise along the Indian coasts is estimated to be about 1.3 mm/year which is lower than the global average sea level rise. Earlier, during 1991 and 1999, relative mean sea level rise in the Sundarban and adjoining Bay of Bengal was 3.14 mm/year (Hazra et al., 2002). The sea level rise of 17.8 mm/year between 2000 and 2009 was recorded from the tide gauge data of Sagar Island, the largest island in the delta, and also the western most point of the Sundarban (Hazra et al., 2010). Considering the average tidal gauge data of the past 25 years across four locations of the delta, the rate of relative mean sea level rise was about 8 mm/year, and the same for the period between 2002 and 2009 was 12 mm/year (Hazra et al., 2002, 2010; CSE, 2012). This value is significantly higher than the rate observed during the previous decade. The current rate of sea level increase in Sundarban is far higher than the global average rise in sea level which was in the range 1.7 mm/year (1.5 to 1.9) between 1901 and 20lO, 2.0 mm/year (1.7 to 2.3) between 1971 and 2010, and 3.2 mm/year (2.8 to 3.6) between 1993 and 2010 (IPCe, 2014). In fact, the mean tidal amplitude of the Sundarbans area (from 3.14 to 5.22 mm ) is much higher than the national average (between 1.06 and 1.75 mm) (Unnikrishnan et al., 2015). Tidal waves are a regular phenomenon and may reach up to 7.5 m high, which may further increase during cyclone and extreme weather events. Relative sea levels are rising in the Sundarban partly from eustatic processes, but mainly due to land subsidence caused by various natural and anthropogenic processes (Bhattacharjee et al., 20l3). Embankments play a key role in the Sundarbans as systems of defense against cyclonic storms and sea level rise, but the structural integrity of many embankments is poor, as they were built in 19th century. The rate rate of coastal erosion in the Indian Sundarban has been found to be about 5.50 sq km/year in the last decade. The total land area which was 6,402,090 km2 in 2001 2 has been found to be reduced to 6,358,048 km2 in 2009, registering a net loss of 44,042 km land (Hazra, 2010). The total length of the embankments in the Indian Sundarban has been found to be 3,638,182 km2 of which the length of vulnerable embankments was 470,962 km2 (before Aila) (Hazra, 2010). However, after the Aila, the vulnerable patches have reportedly gone up to 1,000 km2 (World Bank, 2014). Sea level rise and subsequent erosion have inundated four islands (Bedford, Lohachara, Kabasgadi and Suparibhanga) in the Sundarban over the past two decades, and about 6,000 families from those islands have been rendered homeless. Severe cyclonic storm Aila in 2009 brought vast changes in physico-chemical properties of Sundarbans' water masses in many ways (Mitra et al., 2011). The average salinity of surface water increased from l3.64 ± 6.24 ppt to 17.08 ± 8.03 ppt with a rise of 25.2%. Average pH was increased from 7.99 ± 0.20 to 8.01 ± 0.21 which is an increase of 25%. Average DO decreased from 5.24 ± 0.70 ppm to 4.95 ± 0.51 ppm (Mitra et al., 2011). A sharp increment in water


turbidity, chemical oxygen demand (COD), phytopigment chlorophyll-b (chI b) and rnicronutrients (nitrate, phosphate, silicate) were observed in the post-Aila period with a corresponding decrease in water transparency, chlorophyll-a (chI a) and mesozooplankton community (Bhattachyarya et al., 2014).

17.4.4

Impact of Climate Change on Fisheries and Aquaculture in Sundarban

In Sundarban, inhabited islands are protected by man-made embankments against the ingression of saline water. This makes agriculture and aquaculture possible in the islands (Danda, 2007). Increase in the incidence of cyclone, storm surge and sea level rise are causing erosion of land mass and saline water ingression in the inhabited areas, resulting in loss of life, agriculture and fish crops (Chand et al., 2012). In brief, aquaculture is also the victim of climate change. According to Chand et al. (2012), saline water inundation is putting enormous risk on aquaculture, especially freshwater farming through breach of pond dykes, escape of fish stock, l11ass mortality, entry of other unwanted species, retardation of growth, deterioration of water quality and disease in Sundarban. In the changed situation, the salination of lands and water in the inhabited areas ofSundarban may bring more areas under brackish water aquaculture, given the decreasing viability of freshwater aquaculture and agriculture sectors, thus presenting an opportunity for this sector to capitalize on the changes posed by climate change (Chand et al., 2012).

17.4.5

Farmers' Perceptions on the Changing Climate of Sundarban Delta

Sarkar & Padaria (2010) studied farmers' awareness and risk perception about climate change in the coastal ecosystem of the South 24 Parganas district of West Bengal. The study depicted that nearly 38% of the respondents had heard about climate change. Most of the respondents perceived climate change as being due to rapid industrialization by humans. People are more aware about such phenomena as increase in temperature, reduction in agricultural and livestock production, increase in diseases, increase in sea level etc. than the phenomena like frequent cyclones, occurrence of cold waves, heavy fog and precipitation. The mean score on the awareness about perceived consequences due to climate change was very high on the item "Reduction in agricultural production" followed by "There will be a large scale migration or exodus of people and animals from Sundarban" Increase in diseases due to climate change was the major perceived risk by the respondents in agriculture, animal husbandry, fishery and the human health sector. Increase in poverty was the major perceived risk under socioeconomic and cultural life by the respondents (Sarkar & Padaria, 2010). Islam et al. (2014) studied the vulnerability of fishery-based livelihoods to the impacts of climate variability from coastal Bangladesh. According to Islam et al. (2014), the most important climate-related elements of exposure are floods and cyclones, while the key factor determining sensitivity of an individual household is the dependence on marine fisheries for livelihoods. Adaptive capacity is underpinned by the combination of physical, natural, and financial capital and is influenced by the diversity of livelihood strategies. All fish farmers surveyed were well aware about climatic variability in the Sundarban ecoregion. The respondents described their observed changes in temperature in many ways, of which the most common changes experienced included hotter summers characterized by more intense heat (62%), abnormal seasonal changes (40%), and a short winter period (7%). A few farmers (2%) were aware about rise in river salinity due to changes in temperature. The erratic nature of the monsoon and low rainfall (25%) were observed by many farmers of Sundarban, with delayed onset of monsoon. Some farmers expressed their concern about heavy rainfall in onset and offset of monsoon (16%) and shortening of the monsoon period (7%).

1585

5861


A Global Analysis

The observed pattern of tropical cyclones and sea level rise was also described by the farmers with impacts on their local physical environment. The vast majority of farmers (87%) reported that the frequency and intensity of cyclones has increased in recent times. Heavy inundation and prolonged flood were reported by some farmers (18%) during cyclonic storms. Some respondents observed the higher tidal water above the normal high tide level along the coasts, estuaries and rivers than previous decades. Most reported the depletion of mangroves and wildlife (16%) due to climatic events. The cyclones led to high tidal surge that caused river embankment failure (15%) and coastal erosion (12%) as reported by the aquaculture farmers of the Sundarban area. The aggravated natural hazards forced island dwellers to migrate in other places due to lack of ecosystem services (15%) and caused an increased number of disease outbreaks (2%). Respondents (19%) contend that as a result of cyclonic storm-induced coastal flooding and sea level rise, inland brackish water area has been extending day by day and thus could prove an opportunity for shrimp and crab farms. Climate change has dramatic effects on freshwater aquaculture (pond-fish culture) in the study area. All surveyed farmers expressed their concern about the effects of different climatic variables on freshwater aquaculture. According to the survey, cyclone and storm surge are the most significant climatic phenomena that severely affect freshwater aquaculture, subsequently coastal flooding, and sea level rise that cumulatively lead to salinity intrusion, followed by rising temperature and drought. Cyclones with tidal surges devastate aquaculture farms as most cyclones often occur during the peak season of grow-out operations. When the cyclone bombards the area with increased height of storm surge, the surge water breaches the earthen pond dykes (21%) and inundates the entire pond with saline water (28%), which allows existing fish stocks to escape to the floodplains. Preventing the escape of culture species is very difficult during sudden or prolonged floods as farmers are unable to raise their low and narrow embankments encircling the ponds (41 %). The farmers who have farms in the proximity of the river and outside the coastal embankment are slightly exposed to rising high tide causing damage to the farms. The coastal flooding and surge water also allow predatory and other trash fish to invade (23%) which further hampers the natural continuity of the culture system. Farmers also reported that salinity inundation causes mass mortality of freshwater fish due to the inability to cope with the sudden salinity stress (26%). Growth retardation and altered feeding habits of the survived fishes were also noticed by the some farmers of Sundarban after the salinity flooding event (16%). All participants were concerned about the alteration of the physico-chemical conditions of the ponds due to cyclones. Farmers reported that due to cyclones and coastal flooding, huge volumes of debris, dead organisms, toxic substances and land-based pollutants such as plastics are washed into ponds, which severely affects the pond ecosystem (14%). Water quality of the farms sharply deteriorates after 'cyclones, because of the decomposition of dead organisms and plant debris which lowers the water pH and deteriorates the overall water quality of the pond. This has detrimental effects on the survival, growth, feeding and production of the fish. Some farmers perceived that increasing summer temperatures and drought (dry seasons mainly November to March) may have increased pond salinity due to evaporation (16%), which augmented disease outbreaks for fish (10%). Earthen embankments encompassing the Sundarban islands keep the brackish water away and make freshwater aquaculture viable within the islands. Saline water inundation due to breach of river embankment, sea level rise and subsequent erosion coupled with frequent extreme weather events, affect the freshwater fish culture inside the island of Sundarban which is basically a freshwater ecosystem. During group discussions, farmers shared their observations on the natural adaptation of fish to climate change in the Indian Sundarban region. Farmers contend that the common culture fish, notably Indian major carps, survive


and grow in low saline water (up to 5 ppt salinity) and a few brackish water fish and shellfish also survive and grow in fresh water. However, the breeding periodicity and spawning nature of self-recruiting indigenous fish species has altered due to deficient rainfall and high temperature. to Climate Change for Freshwater Aquacufture. Among the surveyed farmers, 73% were affected during cyclonic events. The vast majority of farmers (37%) reported that they had repaired or re-constructed the pond dykes through earth filling to make the dyke stronger and wider. Farmers had also raised dyke height around the ponds (31 %) in order to prevent fish escaping as well as to prevent entry of predator fish during inundation caused by cyclones and intense rainfall. In order to make this intervention more effective, 17% of the respondents planted various types of tress (fruit and wood trees) on the pond dykes for strengthening the dykes. About 17% respondents reported that they dewatered the saline water during the flood recovery period and added fresh water from a ground source (10%) (water exchange). To improve pond water quality and prevent further disease outbreak after flooding, farmers often applied lime (11%) and chemicals, and fertilizer (6%) to minimize their loss. However, approximately 17% respondents did not employ any coping measures against climatic events that affect fish cultivation. In attempting to understand the reason, respondents were asked whether they were concerned about the climatic events and the reasons for their inaction. The respondents were concerned about the climate impacts, but said that they could not afford to take coping measures due to financial constraints.

Farmer's Coping Capacity/Adaptation

17.5

Impact of Climate Change on Fish Production

Currently, it is difficult to find out how much fish production and catch fluctuation is due to changes in fish distribution, growth and phenology. The direction of this change is also uncertain; it may be negative for a few species and positive for others. However, it is certain that there will be instability and fluctuations over long time periods. The impacts listed in Table 17.1 for Indian marine fish and fisheries show only coincidences of biological events with seawater warming in the Indian seas over a reasonably long time period. These coincidences need to be validated and confirmed for integrating these results into models to predict fish production. It is also a challenge to resolve the effect of climate change and link it to changes in fish production for to the following reasons: (i) Commercial fishery affects the distribution and abundance of fish and masks the impact of climate change. Fishing interacts with climate change and the degree of interaction depends on the species affected. It is hard to delineate the impact of climate change from that of fishing and other stressors as well. (ii) The climate-driven abiotic changes differ between locations, and these changes determine the distribution and production of fish populations. (iii) Responses of species to climate change are influenced by their habitat (pelagic, demersal, dependence of critical habitats such as mangroves, seagrasses, coral reefs), biological characteristics (short-lived, long-lived, turnover of generations) and trophic level (herbivores, carnivores, top predators). As the response differs between species, it is almost impossible to arrive at generalities in the response of populations of different species. (iv) Even if the effect of changes in environmental factors on a species is known, it is difficult to scale-up and understand the changes to population or ecosystem level. (v) Fish have several distinct life-history stages such as eggs, larvae, juveniles and adults, each of which may be affected in different ways by climate change (Rijnsdorp et al., 2009). Possibly, the most serious concern about climate change will be regional climate variability. Productivity and specific species resources in the region may be varied. This eventually may

I

587

5881


A Global Analysis

decrease the catch per unit effort and compel the fishers to go further for harvest which would demand more effort and cost. Moreover, changing environmental conditions such as cyclones and rough weather will make the whole scenario more risk-prone. Allison et at. (2009) used an indicator-based approach to compare the vulnerabilities of 132 nations to potential climate change impacts on their capture fisheries. They found that countries in central and western Africa as well as some in Asia were most vulnerable. Indirect economic impacts will depend on the extent to which local economies are able to adapt to new conditions in terms of labor and capital mobility. Change in natural fisheries production is often compounded by decreased harvest capacity and reduced access to markets (FAO, 2006).

17.6

The Way Forward

India has long-term data on marine fish catches from commercial fisheries, but suffers from lack of long-term information on fish availability. Often, catches are considered as a surrogate of abundance, but this assumption has severe limitations. As commercial fisheries operate in grounds where high-value resources are abundant, catches are selective of economically valuable resources. Assessment based on fishery-independent sampling is available, but discontinuous. This hinders research on climate change impacts, despite decades of commercial exploitation. For India, it is important to regularly estimate, on an annual basis, the fish stock status of all commercially important species/groups to understand the impact of climate change. 17.6.1

Potential Adaptation Options

Fisheries management in India is categorized into management of fisheries in the EEZ and in the territorial waters. According to the Constitution ofIndia, the Central (Federal) government has jurisdiction over the fisheries in the EEZ, while the State (Provincial) governments have jurisdiction over fisheries in the territorial waters. Fisheries management is undertaken mainly through licensing, prohibitions on certain fishing gear, regulations on mesh size and establishment of closed seasons and areas, under the Marine Fishing Regulation Act (MFRA) and Comprehensive Marine Fishing Policy. The present Acts mainly aim at control/regulation of fishing by craft/gear and spatial restrictions for maximizing/sustaining production. However, fishery resources are seriously degraded with many issues. The current Acts fall considerably short of fulfilling the objective of sustainable fisheries, and are insufficient to address climate change. While climate change exacerbates the fluctuations and uncertainties in fish production, it is imperative to mainstream climate change into the Acts and incorporate adaptation options, a few of which are indicated in Table 17.3. Adaptation measures should consider the response of fish species and make amends. For example, seasonal closure of fishing is an important management measure implemented on both the east and west coasts of India for a period of 47 to 65 days every year. The seasonal fishing closure is followed for the last 15 to 28 years in certain months (April-May along the east coast and June-July along the west coast) that are considered as the peak spawning season of several species of fish. In the context of changes in spawning season, it may be necessary to make the Act sensitive to consider and revise the months of closure if evidence for phenological changes are accumulated for a large number of species. 17.6.2

Code of Conduct for Responsible Fisheries (CCRF)

Fishing and climate change are strongly interrelated pressures on fish production and must be addressed jointly. Moderately-fished stocks are likely to be more resilient to climate change


Table 17.3 Potential fishery adaptations. Impact

Implication to fisheries

Potential fishery adaptation

Changes in fish distribution

Occurrence fishery

Use of new/modified

Phenological changes in spawning

Changes in months of recruitment

Change the season of fishing closure

Precocious maturity

Smaller eggs and larvae; poor survival

Reduce fishing stress

Reduction in number of eggs

Reduction in recruitment

Reduce fishing stress

Faster growth

Higher food requirement; higher metabolism; faster turnover of generations

Reduce fishing stress; adopt ecosystem approach to fisheries management

Reduction in mean length in fishery

Growth overfishing

Prescribe mean legal size

Reduction in mean trophic level in fishery

Decline in long-lived, predatory, high value fish biomass

Adopt ecosystem approach to fisheries management

Coral bleaching

Coral-dependent fish species will be devoid of habitat

Adopt ecosystem approach to fisheries management; and habitat restoration programme

of new species in the

to fishery

gear

impacts than heavily-fished ones. Reducing fishing mortality in the majority of fisheries, which are currently fully exploited or overexploited, is the principal means of reducing the impacts of climate change (Brander, 2007). Reduction of fishing effort (i) maximizes sustainable yields; (ii) helps adaptation of fish stocks and marine ecosystems to climate impacts; and (iii) reduces greenhouse gas emission by fishing boats (Brander, 2008). Though CO2 emission by marine fishing boats of India is considerably lower than the global average, it has doubled from 0.50 t to 1.02 t per tonne of fish caught in 50 years (Vivekanandan et al., 20l3). Hence, some of the most effective actions by which we can tackle climate impacts are to deal with the familiar problems such as over fishing (Brander 2008), and adopt the Code of Conduct for Responsible Fisheries and Integrated Ecosystem approach to Fisheries Management. In India, mechanisms for managing large-scale commercial fisheries such as total allowable catch (TAC) or total allowable effort (TAE) do not exist. The challenge becomes severe considering the poverty prevalent among the small-scale fishermen and the lack of suitable alternate income generating options for them. These factors make these communities highly vulnerable to climate change, as their capacity to adapt is very limited. Efforts to reduce dependence on fishing by these vulnerable communities are essential. It is also essential to adopt the ecosystem approach to fisheries management by integrating fisheries management into coastal areas management. 17.6.3

Ecosystem Approach to Fisheries Management

(EAFM)

Effective management of marine fisheries inclusive of overexploitation, habitat degradation, pollution and climate change could be achieved by following an ecosystem approach, in which multiple regulatory measures and management actions would be agreed upon and applied, in a participatory manner. It is beneficial to use the framework of the ecosystem approach for addressing the inevitable but unclear impacts of climate change on coastal fisheries. In the ecosystem approach, it is crucial to obtain the commitment of governments, fishery managers,

1589

590

I Climate Change Impacts

on Fisheries and Aquaculture: A Global Analysis

scientists, fishers, traders and other stakeholders to develop, apply and strictly enforce the management measures to sustain fish populations for current and future generations. The ecosystem approach attempts to achieve ecological well-being and human well-being through good governance. The seven principles of EAFM are: (i) good governance; (ii) appropriate scale; (iii) increased participation; (iv) multiple objectives; (v) cooperation and coordination; (vi) adaptive management; and (vii) a precautionary approach (BOBLME, 2014). The five steps of EAFM are (i) define and scope the management unit and geographical area; (ii) identify and prioritize issues and threats; (Hi) develop the EAFM plan; (iv) implement the plan; and (v) monitor, evaluate and adapt the plan. Uncertainties of climate change impacts make it imperative to follow EAFM, which incorporates a precautionary approach within integrated management across all sectors. The EAFM plan can include an assessment (even a very general assessment) of the expected impacts of climate change on fisheries and marine ecosystems and allow for additional management measures to be considered to address these impacts. A fisheries risk assessment should. be linked to a climate vulnerability assessment, which can be conducted at a national or local level (Pomeroy et al., 2013). The EAFM approach will not only build resilience to the ecological and fisheries effects of climate change, but will also help address habitat degradation and overfishing. 17.6.4

Integrated Prediction Models for Climate Change

As the physical, ecological and social nature of marine systems is complex, developing adaptation strategies from realistic forecasts is a challenge. However, opportunities exist for quantification of the biophysical environment (climate and oceanography and species biodiversity) and socioeconomics (marine communities, market drivers and policy and governance arrangements) to gain an insight into marine system health, resilience and productivity. Monitoring at spatial and temporal scales will capture processes that drive marine systems and identify links between the biophysical and socioeconomic changes and advance modeling capabilities. Understanding boundary currents, chlorophyll and upwelling using remote sensing information in a targeted zone and link to fish productivity is necessary for integrated monitoring and modeling. 17.6.5

AssessingVulnerability of Fish Species

While climate change is impacting some species positively and some others negatively, it is not clear which species are most vulnerable to continued changes in climate. This is because most studies are spatially and temporally specific, and often a single species or a single issue have been focused upon. The capacity to predict species responses is limited even for commonly occurring, commercially important fish species. Vulnerable species are susceptible to and will be unable to cope with adverse effects of climate change. They are indicators of ecosystem change and identifying vulnerable species in the fishery will provide an early warning to the managers and stakeholders and provide an opportunity to devise adaptation. For this, it is important to find out which species are sensitive and vulnerable; and why they are vulnerable. To identify these species, it is necessary to understand the sensitivity of species to the physical exposure (e.g., temperature, acidification, ocean currents) and their potential for adaptation. The task is to develop tools from current understanding on the exposure of fish species to climate variability and to develop conservation strategies. It is also essential that vulnerability assessments capture the vulnerability of a human system that is dependent on these exploitable populations. Thus social and economic implications of changes in those species vulnerable to climate change need to be assessed together with policy and management options.


17.6.6

in India

Blue Carbon from the Marine Sector

The role of coastal ecosystems such as coral reefs, seagrass meadows, mangrove forests and marshy coastal wetlands in trapping and storing vast quantities of carbon, known as blue carbon, has created interest for exploring the role of these ecosystems in climate change adaptation and mitigation schemes. Damage and destruction of these habitats will lead to greater emissions of carbon dioxide back into the atmosphere, thus increasing emissions of this greenhouse gas, and thereby significantly contributing to the main cause of climate change. In spite of the availability of a vast expanse of critical coastal habitats in India, the opportunity for using blue carbon has not been adequately realized. It is, therefore, important to seriously examine the role and potential of blue carbon at a national level. Understanding the opportunity blue carbon presents is important to India in the long term. This may lead to financial incentives through carbon trading to protect and sustainably manage all blue carbon ecosystems as part of wider climate change adaptation, and mitigation strategies with a core focus on communities. The objectives of blue carbon assessment are to (i) evaluate the opportunities with regard to blue carbon; and (ii) make recommendations on best ways to realize the opportunity. 17.6.7

Marine Protected Areas (MPAs)

MPAs are a primary management approach in attempts to alleviate anthropogenic pressures. Evidence from MPAs, particularly No-take Zones, show that protection can increase average size, diversity, abundance and biomass of species. MPAs can also play an important role in climate change adaptation, enhancing ecosystem resilience and protecting vital ecosystem services. In India, 31 locations covering an area of 6,271 km2 have been designated as MPAs. Considering the long coastline, it is necessary to increase the number and extent of MPAs. MPAs will experience the same types of climate change impacts, including changes in water temperature, oceanic circulation, rising sea levels, ocean acidification, precipitation and storms, and their associated effects. However, protected areas help reduce impact of other stressors like overexploitation, habitat degradation and pollution, thereby providing a stable, legal and management infrastructure to protect the resources. Selection of sites is an important aspect for achieving effectiveness of MPAs. To develop climate-informed MPAs, it is important to locate them in climate-sensitive sites. Locating MPAs in critical habitats such as mangroves, coral reefs and seagrass meadows will help conserve resources as well as enhance storage of blue carbon. It is also recognized that the MPAs reduce the risks of uncertainties about which species, habitats and ecosystems are most vulnerable. 17.6.8

Thermal Adaptation - Taking Clues from Nature for Sustainable Aquaculture

and Fisheries

The ecological systems supporting fisheries and aquaculture are already known to be sensitive to climate variability. The effects of increasing temperature on both marine and freshwater ecosystems are already evident, with rapid pole-ward shifts in distribution of fish and plankton in regions such as the North East Atlantic, where temperature change has been rapid (Brander, 2007). Relatively small temperature changes alter fish metabolism and physiology, which results in alteration in growth, fecundity, feeding behavior, distribution, migration and abundance of fish species (Marcogliese, 2008). Climate changes could also increase the vulnerability of fish to diseases and affect aquaculture productivity. In recent years the climate is showing perceptible changes in the Indian subcontinent, where the average temperature has been on the rise over the last few decades.

1591

5921


Studies on the physiological, biochemical and molecular adaptations in Antarctic animals have contributed to the mechanistic understanding of how they cope with extreme environmental conditions (Duman & DeVries 1974; Sicheri & Yang, 2005) and what makes them different from their temperate counterparts. It has been seen that in some highly cold adapted species like Trematomus bernacchii, the capability to regulate their hsp gene expression, even if sensitized by heat stress and metal exposure, have been lost (Hofmann et al., 2000). Such apparent absence of a heat-shock response in this highly stenothermal species has been attributed to loss of physiological capacity as a result of the absence of positive selection during evolution at stable sub-zero temperatures. In organisms constantly exposed to high temperature stress, like fishes inhabiting the hot spring runoffs or thermal discharge sites, specific biochemical and molecular adaptive mechanisms could possibly be operating, similar to coldadaptation in Antarctic fishes, for survival. It is necessary to understand such mechanisms, which may be of use for devising mitigation. The Atri Hot Spring in Odisha - A Natural Ecosystem for Global Warming Research. The thermal springs (hot springs) are sites that discharge hot ground water, the temperature of which is . notably higher than the ground water. The springs usually emerge along the deep faults or fissure of the earth along which the ground water comes out. The high temperature of hot spring water is because of geothermal energy, exothermic reactions and disintegration of radioactive elements (Mahala et al., 2013). There are about 340 hot springs in India, of which eight are present in the state of Odisha. The water temperature of these hot springs ranges from 32°-67°C (Bisht et al., 2011). We surveyed many hot springs in eastern India, especially in West Bengal and Odisha, with the objective of identifying a natural system for investigating acclimation and adaptation to thermal stress in eukaryotes. Out of the springs surveyed, the Atri hot spring appeared to be an ideal ecosystem for this purpose. The Atri hot spring is located in the Khurda district of Odisha (20 09'N and 85°18'E) in eastern India. The hot spring takes its name from the village Atri where it is located and according to the revenue records has existed for many centuries. As this area is a low seismic zone, there has been no change in its flow and existence. The hot spring has a religious dimension also; its water is considered holy, and there are some temples located nearby. The main source of the spring at Atri has a circular tank, the temperature of which has been recorded to be 57°-58°C, except in the rainy season. The temperature of the spring water is 58°C which always remains steady (Figure 17.2b), and is believed to have medicinal properties for curing skin diseases. The bathing complex, located close to the spring provides steam bathing facilities for the tourists. For this, water of the hot spring is collected in a reservoir with a depth of around 4.5 meters and a circumference of 3 meters (Figure 17. 2c); it is provided to the tourists with outlets to prevent stagnation (Figure 17.2d). The outlet which carries the hot-spring run-off water, connects to a nearby rivulet (Figure 17.2e) a branch of the river Rananadi. The temperature of the confluence and immediate periphery remains at about 36°-38°C, and fish are present in this hot water (Figure 17.2f): Channa striatus, Puntius sophore and Cirrhinus reba were some of the fish found in the confluence water (Mohanty et al., 2014). Stress protein (heat shock protein, hsp) gene expression in Channa striatus and Puntius sophore is used for heat stress monitoring and evaluation (Purohit et al., 2014; Mahanty et al., 2016a). The cellular heat stress response (HSR) is one component of the acute systemic response to heat stress. The HSR is a highly conserved cellular response which involves the transcription and translation of heat shock proteins (Hsps) (Feder & Hofmann, 1999). Heat shock proteins are involved in a variety of activities, including protein folding, withstanding thermal stress, scavenging oxygen radicals, induction of apoptosis, and mounting of the immune response. 0


Figure 17.2 Atri hot spring, Odisha: the Atri hot spring located in a small village called Atri is about 42 km from Bhubaneswar, and is famed for its hot sulfur water spring (a). The temperature of the spring water is 58°-600( which always remains steady (b), and is believed to have medicinal properties for curing skin diseases. The bathing complex, located close to the spring provides steam bathing facilities for the tourists. For this, water of the hot spring is collected it is provided

in a reservoi r with a depth of around

to the tourist with outlets to prevent stagnation

15 feet and a circumference

of 10 feet (cl. and

(d). This outlet which carries the hot-spring

run-

off water, connects to a nearby rivulet, a branch of the river Rananadi (e). The temperature of the confluence and immediate periphery remains at about 36°-38°( and fish are present in this hot water (0.

In an unstressed cell, these proteins have constitutive functions; however when a cell is subjected to a stress, there is a multifold increase in their transcription and translation. Hsps are classified into different families according to their molecular size: hsp27, hsp47, hsp60, hsp70, hsp90, and hspllO (Hofmann et al., 2000; Mohanty et al., 2010). In order to find out which of Hsps play a central role in providing survivability to heat-stressed fish, we have analyzed the

I

593

5941


expression of a battery of hsps in two Indian fish: Channa striatus (Family: Channidae) and Puntius sophore (Cyprinus). In Channa it was observed that hsp90 and hspllO play an important role in short-term thermal acclimation, whereas hsp60, hsp70 and hsp78 are needed for both thermal acclimation and adaptation response. Similarly, in Puntius sophore, it was observed that hsp90 and hsp47 play important role in providing survivability to the fish in hot spring runoff environment. The species belong to two different families and largely differ in their biology and behavior. However, up-regulation of hsp90 appeared as a common phenomenon in both fish. Trends in hsp gene expression in liver tissues of Channa striatus were studied in response to heat stress. The hsps have been grouped into three clusters (a), (b), and (c) based on their similarity/near similarity in response to the heat stress (Figure 17.3); (a) hsp70, hsp78, and hsp60; (b) hsp90 and hspll 0; and (c) hsp27 and hsp47. In order to find out what other proteins are in

14 12

•.............•

·.•. ·Hsp70

!

-a· Hsp78

50 '.

/

45

..•.

.

-+-.

Hsp90 ...• Hspl10

40

10 - '- Hsp60/

35 30

8

25

6

20 15

4

10 2

5

O+------.~~-.-----,r-----._----,O+-~~.-----~~L--.-----.-----, Control

4days

15 days

30 days

Atri'

Control

4 days

30 days

Atri'

(a) 1.6

-+- Hsp47 1.4

-a· Hsp27

1.2

a 0.8

0.6 0.4 0.2

0+------.-----.-----.------.-----. Control

4 days

15 days

30 days

Atri'

(c) Figure 17.3 Trends in hsp gene expression in liver tissues of Channa striatus in response to heat stress. The hsps have been grouped into three clusters (a), (b), and (c) based on their similarity/near similarity in response to the heat stress. (a) hsp70, hsp78 and hsp60; (b) hsp90 and hsp 110; (c) hsp27 and hsp47. Atri-fish were collected from the Atri hot spring runoff. hsp90 and hsp 110, besides hsp70, are required for immediate survival of the fish at high temperature; hsp60, hsp70 and hsp78 are needed for long·term survival at high temperature in Channa.


crosstalk with HSPs that provide survivability to fish during heat stress, we studied the liver proteomic changes in Channa striatus exposed at 36°C for 4 days with a 2D-gel based proteomic approach. The study showed, besides others, increased abundance of two sets of proteins, the anti-oxidative enzymes SOD, ferritin, CRBP, GST and the chaperones HSP60, PDl. Pathway analysis showed that the up-regulations of the anti-oxidant enzymes as well as molecular chaperones are induced by the transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2) which could be a possible molecule to trigger HSR in Channa striatus (Mahanty et al., 2016b). Superoxide dismutase, cellular retinol binding protein, glutathione-S-transferase, heat shock protein 60, protein disulphide isomerase, 3-hydroxyanthranilate 3,4-dioxygenase; glyceraldehyde-3-phosphate dehydrogenase, enolase, fumaryl acetoacetase, ferritin, hemoglobin subunit p were among the up-regulated proteins. The majority of the proteins that were found to be up-regulated were anti-oxidative enzymes, chaperones and proteins of energy metabolism. The major pathways influenced by the upregulated proteins in the heat-stressed fish were NRF-2 induced oxidative stress response, 'gluconeogenesis, glycolysis, proline biosynthesis and tryptophan degradation. Thermal stress is often associated with oxidative stress and common stress markers for both these stresses have been observed in many organisms. Besides their crucial role for many physiological functions, ROS such as superoxide radicals (02-), singlet oxygens (102), hydrogen peroxides (H202) and hydroxyl radicals (HO.) can disrupt vital biological functions via lipid peroxidation, protein oxidation and DNA degradation. Proteins like SOD, PDl, GST, and CRBP act as anti-oxidative enzymes and at the same time these are also responsible for generation of ROS for activating the innate immunity at the time of infection. Pathway analysis showed that the Nrf2-mediated response to oxidative stress is one of the major pathways influenced during the heat stress condition. Nrf2, a basic leucine zipper transcription factor, under basal conditions, is found mainly sequestered in the cytoplasm. When challenged by oxidative stress derived from accumulation of ROS or reactive nitrogen species, Nrf2 quickly translocates into the nucleus and elicits the anti-oxidant response by binding to the anti-oxidant response element (ARE), and recruiting the general transcriptional machinery for expression of ARE-regulated genes. A closer look at the Nrf2 mediated downstream pathways indicated that this single molecule not only influences the synthesis of anti-oxidative proteins SOD, GST and ferritin, but also influences the activity of the molecular chaperones required for stabilization of the other proteins. These anti-oxidative proteins are thus the major proteins that protect the cells during thermal stress and inhibit cell death. Thus in cases where the internal mechanism of an organism fails to augment its anti-oxidative capacity, supplementation with anti-oxidants can be a possible way of managing thermal stress in animals.

17.6.9

Increased Awareness and Management

by Local Communities

Fishermen have excellent knowledge of climatic factors and fish catch. Their knowledge should be utilized for scientific understanding on climate change. Partnership between fishermen and scientists will be a win-win combination for a better understanding of climate impacts on fisheries, and to evolve adaptation options and mitigation measures. Fishermen are of the opinion that fishery-dependent activities, rather than climate change, are responsible for decline in fish catches. While this may be true for now, awareness building is necessary to educate the fishermen on the future impacts of climate change on fisheries. Most of them are aware of climate change, but are confused between annual climate variability and climate change. Resilience of fishing communities needs to be enhanced by supporting existing adaptive livelihood strategies. Effort is also required to raise awareness of the impact, vulnerability, adaptation and

1595

5961


mitigation related to climate change among the decision-makers, managers and other stakeholders in the fishing sector. The relative risk of climate change also needs to be understood in the context of impacts on other hazards such as poverty, food insecurity, epidemic diseases, inequality and intrasectoral conflicts. Throughout the world's oceans, there is growing evidence that marine conservation works best when local communities are responsible for fisheries management. Non-compliance, costs of enforcing compliance, increasing conflicts, and limited effectiveness in addressing complexity and uncertainty are persistent problems of the top-down approach of governance. In India, management of coastal ecosystems, resources and biodiversity should be divested to local communities with the government acting as a facilitator. In the context of climate change adaptation too, it is important to consider eo-management as an important tool of fisheries governance.

17.7

Conclusions

Adverse impacts of climate change are putting enormous stresses on lives and livelihoods of the people engaged in fisheries. The extreme events like recurring cyclones, floods need to be better tackled by enhancing risk preparedness and adaptive capacity of vulnerable communities. Developing policies and programs to improve the resilience of natural resources, through assessments of risk and vulnerability, by increasing awareness of climate change impacts and strengthening key institutions, would help the communities adapt to climate change. In this context, adoption of climate-resilience as an adaptation strategy will help in meeting the livelihood security of stakeholders associated with fisheries and aquaculture. Selection of species that are more resistant to climatic fluctuations, their breeding and propagation in aquaculture will safeguard aquaculture production, and sustainable fisheries. Feed-based strategies and other management strategies need to be devised to ameliorate the impact of climate change on fish to ensure sustainable fisheries and aquaculture production for both nutritional and livelihood security.

References Allison, E.H., Perry, A.L., Badjeck, M.C., Adger, W.N., et al. (2009) Vulnerability of national economies to the impacts of climate change on fisheries. Fish and Fisheries, 10, 173-196. Allison, M.A., Khan, S.R., Goodbred, S.L. & Kuehl, S.A. (2003) Stratigraphic evolution of the late Holocene Ganges-Brahmaputra lower delta plain. Sediment Geology, 155,317-342. Annarnalai, H., Hafner, J., Sooraj, K.P. & Pillai, P. (2013) Global warming shifts the monsoon circulation, drying South Asia. Journal of Climate, 26, 2701-2718. Badjeck, M.-C., Allison, E., Halls, A. & Dulvy, N. (2010) Impacts of climate variability and change on fishery-based livelihoods. Marine Policy, 34, 375-383. Bhattacharjee, A.K., Sufia, Z., Bhattacharyya, S.B., Pramanick, P., Raha, A.K. & Mitra, A. (2013) How mangroves respond to hypersaline condition? Preparedness for predicted sea level rise. International Journal of Scientific Research, 2, 360-364. Bisht, S.P.S., Das, N. & Tripathy, N.K. (2011) Indian hot-water springs: a bird's eye view. Journal of Energy, Environment & Carbon Credits, 1,1-15. BOBLME (2014) Handbook on Essential EAFM. Bay of Bengal Large Marine Ecosystem Project, FAO, Rome.


BOBLME (2015) Assessing, demonstrating and capturing the economic value of marine and coastal ecosystem services in the Bay of Bengal Large Marine Ecosystem. Bay of Bengal Large Marine Ecosystem Project, FAO, Rome. Brander, K.M. (2007) Global fish production and climate change. Proceedings of the National Academic of Sciences USA, 104, 19709-19714. Brander, K.M. (2008) Tackling the old familiar problems of pollution, habitat alteration and overfishing will help with adapting to climate change. Marine Pollution Bulletin, 56, 1957-1958. Chand, B.K., Trivedi, R.K., Dubey, S.K. & Beg, M.M. (2012) Aquaculture in changing climate of Sundarban survey report on climate change vulnerabilities, aquaculture practices and coping measures in Sagar and Basanti Blocks of Indian Sundarban. West Bengal University of Animal & Fishery Sciences, Kolkata, India. Chatterjee, M., Shankar, D., Sen, G.K., Sanyal, P. & Sundar, D. (2013) Tidal variation in the Sundarbans Estuarine System, India. Journal of Earth System Science, 122, 899-933. Chaudhuri, A.B. & Choudhury, A. (1994) Mangroves of the Sundarbans. Vol. 1. India, The IUCN Wetlands Programme. IUCN, Bangkok. Church, J.A., Clark, P.u., Cazenave, A., Gregory, J.M., et at. (2013) Sea level change. In: T.F. Stocker, Qin, D., Plattner, G.-K., Tignor, M., et al. (Eds) Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. pp. 1137-1216. CMFRI (2012) Marine Fisheries Census 2010. Central Marine Fisheries Research Institute, Co chin, India. CMFRI (2014) Annual Report. Central Marine Fisheries Research Institute, Kochi, India. Cochrane, K, De Young, C, Soto, D. & Bahri, T. (2009) Climate Change Implications for Fisheries and Aquaculture: Overview of Current Scientific Knowledge. Fisheries and Aquaculture Technical Paper No. 530. FAO, Rome. Convention on Biological Diversity (2014) An Updated Synthesis of the Impacts of Ocean Acidification on Marine Biodiversity. S. Hennige, Roberts, J.M. & Williamson, P. (Eds) Technical Series, Montreal. Cruz, RV., Harasawa, H., Lal, M., Wu, S., et al. (2007) Asia. In: M.L. Parry, Canziani, O.E, Palutikof, J.P., van der Linden, PJ. & Hanson, CE. (Eds) Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK. pp. 471-506. Csaszar, N.B.M., Seneca, EO. & van Oppen, M.J.H. (2009) Variation in anti-oxidant gene expression in the scleractinian coral Acropora millepora under laboratory thermal stress. Marine Ecology Progress Series, 392, 93-102. DADF (2012) Revalidation of Potential Yield Estimates of Indian EEZ. Report of Department of Animal Husbandry, Dairying and Fisheries, Ministry of Agriculture, Government of India, New Delhi. Danda, A.A. (2007) Surviving in the Sundarbans: Threats and responses. PhD thesis. University of Twente, Netherlands. Danda, A.A., Gayathri, S., Gosh, A., Bandyopadhyay, J. & Hazara, S. (2011) Indian Sunderbans Delta: A Vision. World Wide Fund for Nature-India, New Delhi, India. Dash, S.K., [enamani, R.K., Kalsi, S.R. & Panda, S.K. (2007) Some evidence of climate change in twentieth-century India. Climatic Change, 85, 299-321. De Silva, S.S. & Soto, D. (2009) Climate change and aquaculture: potential impacts, adaptation and mitigation. In: K. Cochrane, De Young, C, Soto, D. & Bahri, T. (Eds) Climate Change Implications for Fisheries and Aquaculture: Overview of Current Scientific Knowledge. FAO Fisheries and Aquaculture Technical Paper. No. 530. Rome, FAO. pp. 151-212.

1597

5981


Duman, J.G. & DeVries, A.L. (1974) Freezing resistance in winter flounder, Pseudopleuronectes americanus. Nature, 274,237-238. FAO (2006) Building Adaptive Capacity to Climate Change: Policies to Sustain Livelihoods and Fisheries. New Directions in Fisheries, A Series of Policy Briefs on Development Issues. FAO, Rome. FAO (2008) Climate Change for Fisheries and Aquaculture. Technical Background Document From the Expert Consultation. FAO, Rome. FAO (2009) The State of World Fisheries and Aquaculture 2008. FAO, Rome. FAO (2014) Fisheries and Aquaculture Department National Aquaculture Sector Overview. India. National Aquaculture Sector Overview Fact Sheets. Text by Ayyappan, S. [online]. Updated 4 April 2014. http://www.fao.org/fishery /countrysector /naso_india/en. Feder, M.£. & Hofmann, G.£. (1999) Heat-shock proteins, molecular chaperones, and the stress response: evolutionary and ecological physiology. Annual Reviews of Physiology, 61, 243-282. Fine, R.A., Smethie, W.M.J., Bullister, J.L., Rhein, M., Min, D. H., Warner, M.J., Poisson, A. & Weiss., R.E (2008) Decadal ventilation and mixing of Indian Ocean waters. Deep Sea Research I Oceanographic Research Papers, 55, 20-37. Guhathakurta, P., Sreejith, O.P. & Menon, P.A. (2011) Impact of climate change on extreme rainfall events and flood risk in India. Journal of Earth System Science, 120,359-373. Haldar, A. & Debnath, A. (2014) Assessment of climate induced soil salinity conditions of Gosaba Island, West Bengal and its influence on local livelihood. In: M. Singh (Ed) Climate Change and Biodiversity: Proceedings of IGU Rohtak Conference. Advances in Geographical and Environmental Sciences, doi:1O.1007/978-4-431-54838-6_3. Han, W., Meehl, G., Rajagopalan, B., Fasullo, J., et al. (2010) Patterns of Indian Ocean sea-level change in a warming climate. Nature Geoscience, 3, 546-550. Hazra, S., Ghosh, T., Dasgupta, R. & Sen, G. (2002) Sea level and associated changes in Sundarbans. Science and Culture, 68, 309-32l. Hazra, S., Sarnanta, K., Mukhopadhyay, A. & Akhand, A. (2010) Temporal change detection (2001-2008) of the Sundarban. Unpublished Report. WWF-India, New Delhi. Hijioka, Y, Lin, E., Pereira, J.]., Corlett, R.T., et al. (Eds) Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part B: Regional Aspects. Contribution of Working Group 1l to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. pp. 1327-1370. Hofmann, G.£., Buckley, B.A., Airaksinen, S., Keen, J.E. & Somero, G.N. (2000) Heat-shock protein expression is absent in the antarctic fish Trematomus bernacchii (family Nototheniidae). Journal of Experimental Biology, 203, 2331-2339. Houde, E.D. (1989) Comparative growth, mortality, and energetic of marine fish larvae: temperature and implied latitudinal effects. Fisheries Bulletin, 87, 471-495. IPCC (2007) Fourth Assessment Report - Climate Change 2007: Synthesis Report. IPCC, Geneva, Switzerland. IPCC (2014) Fifth Assessment Report - Climate Change 2014: Synthesis Report. IPCC, Geneva, Switzerland. Islam, M.M., Sallu, S.M., Hubacek, K. & Paavola, J. (2014) Vulnerability of fishery-based livelihoods to the impacts of climate variability and change: insights from coastal Bangladesh. Regional Environmental Change, 14,281-294. Keeling, R.E, Kortzinger, A. & Gruber, N. (2010) Ocean deoxygenation in a warming world. Annual Reviews in Marine Science, 2,463-493. Kennedy, V.S., Twilley, R.R., Kleypas, J.A., Cowan, J.H.J. & Hare, S.R. (2002) Coastal and Marine Ecosystems and Global Climate Change. Pew Center on Global Climate Change, Arlington, USA.


s.r., Raja, S., Gupta, K.S., Vivekanandan, E., Kizhakudan, ).K., Sethi, S.N. & Geetha, R. (2014) Correlation between changes in sea surface temperature and fish catch along Tamil Nadu coast of India - an indication of impact of climate change on fisheries'? Indian Journal of Fisheries, 61,111-115. Kreft, S. & Eckstein, D. (2013) Global Climate Risk Index 2014. available at http://germanwatch. org/de/download/8551.pd£. Kurita, Y, Fujinami, Y & Amano, M. (2011) The effect of temperature on the duration of spawning markers - migratory-nucleus and hydrated oocytes and postovulatory follicles - in the multiple-batch spawner Japanese flounder (Paralichthys olivaceuss. Fisheries Bulletin, 109,79-89. Lakshmi, A. & Ramya, R. (2009) Fisheries and climate change. Coasttrack, 8, 1-5, Mahala, S,c., Singh, P., Das, M. & Acharya, S, (2013) Genesis of Thermal Springs of Odisha, India, International lournal of Earth Sciences and Engineering, 5, 1572-1577. Mahanty, A" Purohit, G.K., Yadav, R.P., Mohanty, S. & Mohanty, B.P. (2016a) hsp90 and hsp47 • appear to play important role in minnow Puntlus sophore for surviving in the hot spring runoff aquatic ecosystem, Fish Physiology and Biochemistry, doi:l0,1007/s10695-016-0270-y, Mahanty, A" Purohit, G.K., Banerjee, S., Karunakaran, D" Mohanty. S. & Mohanty, B.P. (2016b) Proteomic changes in the liver of Channa striatus in response to high temperature stress, Electrophoresis, 37, 1704-1717. Mandal, B., Mukherjee, A. & Banerjee, S, (2013) A review on the ichthyofaunal diversity in mangrove based estuary of Sundarbans. Reviews in Fish Biology and Fisheries, 23, 365-374, Manjusha, U, Iayasankar, J., Remya, R., Ambrose, TV & Vivekanandan. E, (2013) Influence of coastal upwelling on the fishery of small pelagics off Kerala, south-west coast of India, Indian Journal of Fisheries, 60, 37 -42, Marcogliese, D.J. (2008) The impact of climate change on the parasites and infectious diseases of aquatic animals. Reviews in Science and Technology, 27, 467-484. McBride, J,L. (1995) Tropical cyclone formation: Global perspectives on tropical cyclones, World Meteorological Organization. WMO/TD-No, 693. Mishra, A. (2014) Temperature rise and trend of cyclones over the eastern coastal region of India, Journal of Earth Science and Climate Change, 5, 227, Mitra, A., Banerjee, K., Sengupta, K. & Gangopadhyay, A. (2009) Pulse of climate change in Indian Sundarbans: A myth or reality, National Academy of Science Letters, 32, 19-25. Mitra, A., Sengupta, K. & Banerjee K. (2011) Standing biomass and carbon storage of aboveground structures in dominant mangrove trees in the Sundarbans. Forest Ecology and Management, 261,1325-1335. MoEF (2005) Report of the Committee to Review the Coastal Regulation Notification 1991, Ministry of Environment and Forests, New Delhi, India, Moffitt, S.£., Moffitt, R.A., Sauthoff, w., Davis, CV, Hewett, K. & Hill T.M. (2015) Paleoceanographic insights on recent oxygen minimum zone expansion: Lessons for modern oceanography. PLoS ONE, 10, e01l5246. Mohanty, B.P., Mohanty, S., Sahoo, J, & Sharma, A. (2010) Climate change: impacts on fisheries and aquaculture. In: S. Simard (Ed) Climate Change and Variability. InTech, Rijeka, Croatia. Mohanty, S. & Mohanty, B.P. (2009) Global climate change: a cause of concern. National Academy Science Letters, 32, 149-156. Mohanty, S., Mahanty, A., Yadav, R.P., Purohit, G.K., Mohanty, B.N. & Mohanty, B.P. (2014) The Atri hot spring in Odisha - a natural ecosystem for global warming research. International Journal of Geology Earth and Environmental Science, 4,85-90. Naqvi, S.W.A, Naik, H., Jayakumar, D.A., Shailaja, M.s. & Narvekar, RV (2006) Seasonal oxygen deficiency over the western continental shelf of India. In: L. Neretin (Ed) Past and Present Water Kizhakudan,

1599

600

I


A Global Analysis

Column Anoxia. NATO Science Series, IV. Earth and Environmental Sciences. Springer, Amsterdam. pp. 195-224. Patwardhan, A., Schneider, S.H. & Semenov, S.M. (2003) Assessing the science to address LlNFCCC Article 2: a concept paper relating to cross cutting theme number four. IPCC, Geneva. Porneroy, R., Brainard, R., Moews, M., Heenan, A., Shackeroff, J. & Armada, N. (20l3) Coral Triangle Regional Ecosystem Approach to Fisheries Management (EAFM) Guidelines. The USAID Coral Triangle Support Partnership, Honolulu, Hawaii. Prasannakumar, S., Roshin, R.P., Narvekar, J., Kurnar P.K.D. & Vivekanandan, E. (2010) What drives the increased phytoplankton biomass in the Arabian Sea? Current Science, 99, 101-106. Prasannakumar, S., Roshin, R.P., Narvekar, J., Kurnar, P.K.D. & Vivekanandan, E. (2009) Response of the Arabian Sea to global warming and associated regional climate shift. Marine Environment Research, 68, 217-222. Purohit, G.K., Mahanty, A., Sharrna, A., Sharma, A.P., Mohanty, B.P. & Mohanty, S. (2014) Investigating hsp gene expression in liver of Channa striatus under heat stress for understanding the upper thermal acclimation. Blomed Research International, 381719. Rashid, T., Hoque, S. & Akter, F. (20l3) Ocean acidification in the Bay of Bengal. Open Access Science Report, 2, 699. Rijnsdorp, A.D., Peck, M.A., Engelhard, G.H., Mollmann, C. & Pinnegar, J.K. (2009) Resolving the effect of climate change on fish populations. ICES Journal of Marine Science, 66, 1570-1583. Sarkar, S. & Padaria, R.N. (2010) Farmers' awareness and risk perception about climate change in coastal ecosystem of West Bengal. Indian Research Journal of Extension Education, 10, 32-38. Shaji, c., Kar, S.K. & Vishal, T (2014) Storm surge studies in the north Indian Ocean: a review. Indian Journal ofGeo-Marine Science, 43,125-147. Sicheri, F. & Yang, D.S. (2005) Ice-binding structure and mechanism of an antifreeze protein from winter flounder. Nature, 375, 427-43l. Singh, O.P. (2007) Long-term trends in the frequency of severe cyclones of Bay of Bengal: observations and simulations. Mausam, 58, 59-66. Takahashi, T & Sutherland, S.c. (20l3) Climatological mean distribution of pH and carbonate concentration in global ocean surface waters in the unified pH scale and mean rate of their changes in selected areas. The National Science Foundation, Washington DC. Turner, A.G. & Annamalai, H. (2012) Climate change and the South Asian summer monsoon. Nature Climate Change, 2, 587 -595. Unnikrishnan, A.S., Nidheesh, A.G. & Lengaigne, M. (2015) Sea-level-rise trends off the Indian coasts during the last two decades. Current Science, 108, 966-97l. Vass, K.K., Das, M.K., Srivastava, P.K. & Dey, S. (2009) Assessing the impact of climate change on inland fisheries in River Ganga and its plains in India. Aquatic Ecosystem Health & Management, 12, 138-15l. Vinayachandran, P.N. & Shetye, S.R. (1991) The warm pool in the Indian Ocean. Proceedings of Indian Academy of Sciences (Earth Planetary Science), lOO, 165-175. Vivekanandan, E. & Krishnakumar, P.K. (2010) Spatial and temporal differences in the coastal fisheries along the east coast of India. Indian Journal of Marine Science, 39, 380-387. Vivekanandan, E. & Pandian, TJ. (1977) Surfacing activity and food utilization in a tropical airbreathing fish exposed to different temperatures. Hydrobiologia, 54, 145-160. Vivekanandan, E. (2011) Climate Change and Indian Marine Fisheries. CMFRl Special Publication, India. Vivekanandan, E. (2013) Climate change: challenging the sustainability of marine fisheries and ecosystems. Journal Aquatic Biology and Fisheries, 1, 58-7l. Vivekanandan, E., Ali, M.H., Jasper, B. & Rajagopalan, M. (2009) Vulnerability of corals to warming of the Indian seas: a projection for the 21st century. Current Science, 97, 1654-1658.


Vivekanandan, E., Singh, V.v. & Kizhakudan, J.K. (20l3) Carbon footprint by marine fishing boats of India. Current Science, 105, 361-366. Vivekanandan, E., Srinath, M. & Kuriakose S. (2005) Fishing the food web along the Indian coast. Fisheries Research, 72, 241-252. Warren, D.R., Robinson, J.M. & Iosephson, D.e. (2012) Elevated summer temperatures delay spawning and reduce redd construction for resident brook trout Salvelinus [ontinalis. Global Climate Change, doi: 10.1111/j.1365- 2486.2012.02670.x. Webster, P.J. (2008) Myanmar's deadly "Daffodil': Nature Geoscience, 1,488-490. World Bank (2014) Poverty head count ratio. http://data.worldbank.org/topic/poverty. World Fish Center (2008) Small-scale capture fisheries: A global overview with emphasis on developing countries. Preliminary report of the Big Numbers Project. Penang, Malaysia: Food and Agriculture Organization of the United Nations, PRO FISH World Bank and World Fish Center, Penang, Malaysia.

\601