Fisheries and climate change
Encyclopedia
Rising ocean temperatures
and ocean acidification
are radically altering aquatic ecosystem
s. Climate change
is modifying fish distribution and the productivity of marine and freshwater species. This has impacts on the sustainability of fisheries and aquaculture
, on the livelihoods of the communities that depend on fisheries, and on the ability of the oceans to capture and store carbon (biological pump
). The effect of sea level rise means that coastal fishing communities are in the front line of climate change, while changing rainfall patterns and water use impact on inland (freshwater) fisheries and aquaculture.
Oceans and coastal ecosystems play an important role in the global carbon cycle and have removed about 25% of the carbon dioxide emitted by human activities between 2000 and 2007 and about half the anthropogenic CO2 released since the start of the industrial revolution. Rising ocean temperatures and ocean acidification means that the capacity of the ocean carbon sink will gradually get weaker, giving rise to global concerns expressed in the Monaco and Manado
Declarations. Healthy ocean ecosystems are essential for the mitigation of climate change.
makes it more difficult for marine organisms such as shrimps, oysters, or corals to form their shells – a process known as calcification
. Many important animals, such as zooplankton
, that forms the base of the marine food chain have calcium shells. Thus the entire marine food web is being altered – there are ‘cracks in the food chain’. As a result, the distribution, productivity, and species composition of global fish production
is changing, generating complex and inter-related impacts on oceans, estuaries, coral reefs, mangroves and sea grass beds that provide habitats and nursery areas for fish. Changing rainfall patterns and water scarcity is impacting on river and lake fisheries and aquaculture
production.
Coastal and fishing populations and countries dependent on fisheries are particularly vulnerable to climate change. Low-lying countries such as the Maldives
and Tuvalu
are particularly vulnerable and entire communities may become the first climate refugees. Fishing communities in Bangladesh
are subject not only to sea-level rise, but also flooding and increased typhoons. Fishing communities along the Mekong river produce over 1 million tons of basa fish
annually and livelihoods and fish production will suffer from saltwater intrusion
resulting from rising sea level and dams.
Fisheries and aquaculture
contribute significantly to food security
and livelihoods. Fish provides essential nutrition for 3 billion people and at least 50% of animal protein and minerals to 400 million people from the poorest countries. Over 500 million people in developing countries depend, directly or indirectly, on fisheries and aquaculture for their livelihoods - aquaculture is the world’s fastest growing food production system, growing at 7% annually and fish products are among the most widely traded foods, with more than 37% (by volume) of world production traded internationally.
forests can protect shorelines from erosion and provide breeding grounds for fish while also sequestering carbon.
and the Food and Agriculture Organization
have programs to help countries and communities adapt to global warming
, for example by developing policies to improve the resilience of natural resources, through assessments of risk and vulnerability, by increasing awareness of climate change impacts and strengthening key institutions, such as for weather forecasting and early warning systems. The World Development Report
2010 - Development and Climate Change, Chapter 3 shows that reducing overcapacity in fishing fleet
s and rebuilding fish stocks can both improve resilience to climate change and increase economic returns from marine capture fisheries by US$50 billion per year, while also reducing GHG emissions by fishing fleets. Consequently removal of subsidies on fuel for fishing can have a double benefit by reducing emissions and promoting overfishing
.
Investment in sustainable aquaculture can buffer water use in agriculture while producing food and diversifying economic activities. Algal biofuel
s also show potential as algae
can produce 15-300 times more oil per acre than conventional crops, such as rapeseed, soybeans, or jatropha and marine algae do not require scarce freshwater. Programs such as the GEF
-funded Coral Reef Targeted Research provide advice on building resilience and conserving coral reef
ecosystems, while six Pacific countries recently gave a formal undertaking to protect the reefs in a biodiversity hotspot
– the Coral Triangle
.
The oceans have removed 50% of the anthropogenic CO2, so the oceans have absorbed much of the impact of climate change. The famous White Cliffs of Dover
illustrate how the ocean captures and buries carbon. These limestone cliffs are formed from the skeletons of marine plankton called coccoliths. Similarly, petroleum formation is attributed largely to marine and aquatic plankton further illustrating the key role of the oceans in carbon sequestration.
Exactly how the oceans capture and bury CO2 is the subject of intense research by scientists worldwide, such as the Carboocean Project. The current level of GHG emissions means that ocean acidity will continue to increase and aquatic ecosystem
s will continue to degrade and change. There are feedback mechanisms involved here. For example, warmer waters can absorb less CO2, so as ocean temperatures rise some dissolved CO2 will be released back into the atmosphere. Warming also reduces nutrient levels in the mesopelagic zone (about 200 to 1000 m deep). This in turn limits the growth of diatom
s in favour of smaller phytoplankton
that are poorer biological pump
s of carbon. This inhibits the ability of the ocean ecosystems to sequester carbon as the oceans warm. What is clear, is that healthy ocean and coastal ecosystems are necessary to continue the vital role of the ocean carbon sinks, as indicated, for example, by the Blue Carbon assessment prepared by UNEP and the coastal carbon sinks report of IUCN and growing evidence of the role of fish biomass in the transport of carbon from surface waters to the deep ocean.
While the various carbon finance
instruments include restoration of forests (REDD) and producing clean energy (emissions trading
), few address the need to finance healthy ocean and aquatic ecosystems although these are essential for continued uptake of CO2 and GHGs. The scientific basis for ocean fertilization – to produce more phytoplankton to increase the uptake of CO2 – has been challenged, and proposals for burial of CO2 in the deep ocean have come under criticism from environmentalists. The debate on these issues has underlined the need to increase scientific understanding of how the ocean sequesters carbon.
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
and ocean acidification
Ocean acidification
Ocean acidification is the name given to the ongoing decrease in the pH and increase in acidity of the Earth's oceans, caused by the uptake of anthropogenic carbon dioxide from the atmosphere....
are radically altering aquatic ecosystem
Aquatic ecosystem
An aquatic ecosystem is an ecosystem in a body of water. Communities of organisms that are dependent on each other and on their environment live in aquatic ecosystems. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems....
s. Climate change
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...
is modifying fish distribution and the productivity of marine and freshwater species. This has impacts on the sustainability of fisheries and aquaculture
Aquaculture
Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the...
, on the livelihoods of the communities that depend on fisheries, and on the ability of the oceans to capture and store carbon (biological pump
Biological pump
In oceanic biogeochemistry, the biological pump is the sum of a suite of biologically-mediated processes that transport carbon from the surface euphotic zone to the ocean's interior.-Overview:...
). The effect of sea level rise means that coastal fishing communities are in the front line of climate change, while changing rainfall patterns and water use impact on inland (freshwater) fisheries and aquaculture.
Role of oceans
Declarations. Healthy ocean ecosystems are essential for the mitigation of climate change.
Impact on fish production
The rising ocean acidityOcean acidification
Ocean acidification is the name given to the ongoing decrease in the pH and increase in acidity of the Earth's oceans, caused by the uptake of anthropogenic carbon dioxide from the atmosphere....
makes it more difficult for marine organisms such as shrimps, oysters, or corals to form their shells – a process known as calcification
Calcification
Calcification is the process in which calcium salts build up in soft tissue, causing it to harden. Calcifications may be classified on whether there is mineral balance or not, and the location of the calcification.-Causes:...
. Many important animals, such as zooplankton
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
, that forms the base of the marine food chain have calcium shells. Thus the entire marine food web is being altered – there are ‘cracks in the food chain’. As a result, the distribution, productivity, and species composition of global fish production
World fish production
Fish are harvested through commercial fishing and aquaculture.According to the Food and Agriculture Organization , the world harvest in 2005 consisted of 93.2 million tonnes captured by commercial fishing in wild fisheries, plus 48.1 million tonnes produced by fish farms...
is changing, generating complex and inter-related impacts on oceans, estuaries, coral reefs, mangroves and sea grass beds that provide habitats and nursery areas for fish. Changing rainfall patterns and water scarcity is impacting on river and lake fisheries and aquaculture
Aquaculture
Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the...
production.
Impact on fishing communities
Maldives
The Maldives , , officially Republic of Maldives , also referred to as the Maldive Islands, is an island nation in the Indian Ocean formed by a double chain of twenty-six atolls oriented north-south off India's Lakshadweep islands, between Minicoy Island and...
and Tuvalu
Tuvalu
Tuvalu , formerly known as the Ellice Islands, is a Polynesian island nation located in the Pacific Ocean, midway between Hawaii and Australia. Its nearest neighbours are Kiribati, Nauru, Samoa and Fiji. It comprises four reef islands and five true atolls...
are particularly vulnerable and entire communities may become the first climate refugees. Fishing communities in Bangladesh
Bangladesh
Bangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
are subject not only to sea-level rise, but also flooding and increased typhoons. Fishing communities along the Mekong river produce over 1 million tons of basa fish
Basa fish
The basa fish, Pangasius bocourti, is a type of catfish in the family Pangasiidae. Basa are native to the Mekong River Delta in Vietnam and Chao Phraya basin in Thailand. These fish are important food fish with an international market. They are often labeled in North America and Australia as "basa...
annually and livelihoods and fish production will suffer from saltwater intrusion
Saltwater intrusion
Saltwater intrusion is the movement of saline water into freshwater aquifers. Most often, it is caused by ground-water pumping from coastal wells, or from construction of navigation channels or oil field canals. The channels and canals provide conduits for salt water to be brought into fresh...
resulting from rising sea level and dams.
Fisheries and aquaculture
Aquaculture
Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the...
contribute significantly to food security
Food security
Food security refers to the availability of food and one's access to it. A household is considered food-secure when its occupants do not live in hunger or fear of starvation. According to the World Resources Institute, global per capita food production has been increasing substantially for the past...
and livelihoods. Fish provides essential nutrition for 3 billion people and at least 50% of animal protein and minerals to 400 million people from the poorest countries. Over 500 million people in developing countries depend, directly or indirectly, on fisheries and aquaculture for their livelihoods - aquaculture is the world’s fastest growing food production system, growing at 7% annually and fish products are among the most widely traded foods, with more than 37% (by volume) of world production traded internationally.
Adaptation and mitigation
The impacts of climate change can be addressed through adaptation and mitigation. The costs and benefits of adaptation are essentially local or national, while the costs of mitigation are essentially national whereas the benefits are global. Some activities generate both mitigation and adaptation benefits, for example, the restoration of mangroveMangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
forests can protect shorelines from erosion and provide breeding grounds for fish while also sequestering carbon.
Adaptation
Several international agencies, including the World BankWorld Bank
The World Bank is an international financial institution that provides loans to developing countries for capital programmes.The World Bank's official goal is the reduction of poverty...
and the Food and Agriculture Organization
Food and Agriculture Organization
The Food and Agriculture Organization of the United Nations is a specialised agency of the United Nations that leads international efforts to defeat hunger. Serving both developed and developing countries, FAO acts as a neutral forum where all nations meet as equals to negotiate agreements and...
have programs to help countries and communities adapt to global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
, for example by developing policies to improve the resilience of natural resources, through assessments of risk and vulnerability, by increasing awareness of climate change impacts and strengthening key institutions, such as for weather forecasting and early warning systems. The World Development Report
World Development Report
The World Development Report is an annual report published since 1978 by the World Bank. Each WDR provides in-depth analysis of a specific aspect of economic development. Past reports have considered such topics as agriculture, youth, equity, public services delivery, the role of the state,...
2010 - Development and Climate Change, Chapter 3 shows that reducing overcapacity in fishing fleet
Fishing fleet
A fishing fleet is an aggregate of commercial fishing vessels. The term may be used of all vessels operating out of a particular port, all vessels engaged in a particular type of fishing , or all fishing vessels of a country or region.Although fishing vessels are not formally organized as if they...
s and rebuilding fish stocks can both improve resilience to climate change and increase economic returns from marine capture fisheries by US$50 billion per year, while also reducing GHG emissions by fishing fleets. Consequently removal of subsidies on fuel for fishing can have a double benefit by reducing emissions and promoting overfishing
Overfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....
.
Investment in sustainable aquaculture can buffer water use in agriculture while producing food and diversifying economic activities. Algal biofuel
Biofuel
Biofuel is a type of fuel whose energy is derived from biological carbon fixation. Biofuels include fuels derived from biomass conversion, as well as solid biomass, liquid fuels and various biogases...
s also show potential as algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
can produce 15-300 times more oil per acre than conventional crops, such as rapeseed, soybeans, or jatropha and marine algae do not require scarce freshwater. Programs such as the GEF
Global Environment Facility
The Global Environment Facility unites 182 member governments — in partnership with international institutions, nongovernmental organizations, and the private sector — to address global environmental issues....
-funded Coral Reef Targeted Research provide advice on building resilience and conserving coral reef
Coral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
ecosystems, while six Pacific countries recently gave a formal undertaking to protect the reefs in a biodiversity hotspot
Biodiversity hotspot
A biodiversity hotspot is a biogeographic region with a significant reservoir of biodiversity that is under threat from humans.The concept of biodiversity hotspots was originated by Norman Myers in two articles in “The Environmentalist” , revised after thorough analysis by Myers and others in...
– the Coral Triangle
Coral Triangle
The Coral Triangle is a geographical term so named as it refers to a roughly triangular area of the tropical marine waters of Indonesia, Malaysia, Papua New Guinea, Philippines, Solomon Islands and Timor-Leste that contain at least 500 species of reef-building corals in each ecoregion...
.
Mitigation
White cliffs of Dover
The White Cliffs of Dover are cliffs which form part of the British coastline facing the Strait of Dover and France. The cliffs are part of the North Downs formation. The cliff face, which reaches up to , owes its striking façade to its composition of chalk accentuated by streaks of black flint...
illustrate how the ocean captures and buries carbon. These limestone cliffs are formed from the skeletons of marine plankton called coccoliths. Similarly, petroleum formation is attributed largely to marine and aquatic plankton further illustrating the key role of the oceans in carbon sequestration.
Exactly how the oceans capture and bury CO2 is the subject of intense research by scientists worldwide, such as the Carboocean Project. The current level of GHG emissions means that ocean acidity will continue to increase and aquatic ecosystem
Aquatic ecosystem
An aquatic ecosystem is an ecosystem in a body of water. Communities of organisms that are dependent on each other and on their environment live in aquatic ecosystems. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems....
s will continue to degrade and change. There are feedback mechanisms involved here. For example, warmer waters can absorb less CO2, so as ocean temperatures rise some dissolved CO2 will be released back into the atmosphere. Warming also reduces nutrient levels in the mesopelagic zone (about 200 to 1000 m deep). This in turn limits the growth of diatom
Diatom
Diatoms are a major group of algae, and are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons , fans , zigzags , or stellate colonies . Diatoms are producers within the food chain...
s in favour of smaller phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
that are poorer biological pump
Biological pump
In oceanic biogeochemistry, the biological pump is the sum of a suite of biologically-mediated processes that transport carbon from the surface euphotic zone to the ocean's interior.-Overview:...
s of carbon. This inhibits the ability of the ocean ecosystems to sequester carbon as the oceans warm. What is clear, is that healthy ocean and coastal ecosystems are necessary to continue the vital role of the ocean carbon sinks, as indicated, for example, by the Blue Carbon assessment prepared by UNEP and the coastal carbon sinks report of IUCN and growing evidence of the role of fish biomass in the transport of carbon from surface waters to the deep ocean.
While the various carbon finance
Carbon finance
Carbon finance is a new branch of Environmental finance. Carbon finance explores the financial implications of living in a carbon-constrained world, a world in which emissions of carbon dioxide and other greenhouse gases carry a price....
instruments include restoration of forests (REDD) and producing clean energy (emissions trading
Emissions trading
Emissions trading is a market-based approach used to control pollution by providing economic incentives for achieving reductions in the emissions of pollutants....
), few address the need to finance healthy ocean and aquatic ecosystems although these are essential for continued uptake of CO2 and GHGs. The scientific basis for ocean fertilization – to produce more phytoplankton to increase the uptake of CO2 – has been challenged, and proposals for burial of CO2 in the deep ocean have come under criticism from environmentalists. The debate on these issues has underlined the need to increase scientific understanding of how the ocean sequesters carbon.