The increasing concentration of carbon dioxide gas due to ongoing human activities such as combustion of fossil fuels, deforestation, and urbanisation leading to land degradation have been causing a global rise in temperature. This has led to the declining health of marine and aquatic ecosystems. The process of ocean acidification, deoxygenation and weakening ocean currents threaten a significant reduction in fisheries and aquaculture output which will hurt the coastal communities affecting their food security, livelihood and nutritional requirements, especially for proteins. Unless we adopt measures to mitigate global warming, prepare coastal communities to enhance their adaptive capacity and resilience toward impending climate change associated fisheries and aquaculture challenges, we may risk facing social, economic and political unrest and chaos in not so distant future.
With an increase in carbon dioxide in oceans, the basicity of seawater has lowered which has resulted in the weakening of shells of animals like oysters, shrimps and clams. Even the coral reefs have been bleaching and this, in turn, has led to the destruction of the natural habitat of several other marine creatures. Warming seawater and increasing nutrients from the fertilisers runoff from the farms pouring into the oceans have reduced oxygen-carrying capacity in some parts of the oceans worldwide. This has resulted in the creation of dead zones where any life form ceases to exist. Changes in the circulation of ocean currents have made the fish on the move in search of optimum water temperature. This has impacted their growth and development and in some cases have even changed their reproductive patterns. Moreover, over-fishing is another concern which has made climate change challenges worse.
Global warming would lead to a change in rainfall patterns and water scarcity, drying up many lakes and rivers around the world. This will impact fisheries and aquaculture production drastically. By 2100, the fish catch is estimated to decline by 6 per cent. Coastal communities including fishermen and the general population are most vulnerable to these changes. Nations like the Maldives, Tuvalu and Bangladesh would be some of the worst-affected countries. Saltwater intrusion in the Mekong river will affect the production of basa fish. The food security and nutritional value which fisheries and aquaculture provide to billions of people are at risk due to warming ocean and other water bodies.
To mitigate these risks, coastal communities need new policies that can improve their resilience. An assessment report of risk and vulnerability by governments should be made accessible to these communities. With increased awareness, better weather forecasting and state of the art warning systems for floods, cyclones and drought, the communities could lessen the impact of climate change-induced food and economic insecurity. There should be stringent rules to reduce overcapacity in fishing fleets and subsidies on fossil fuel usage for fishing should be removed. For the rural and poor population around the world, infrastructural changes are needed to be strengthened. For the fishermen, who risk losing their livelihood, alternate work opportunities should be explored. Overall, fossil fuel consumption should be reduced significantly to mitigate global warming and climate change consequences.