Abstract
In a report by FAO (2017) it is indicated that globally there would be a decline in fish production value of 21% by 2050 resulting in annual losses of USD 311 million for the fishing sector due to increased ocean water temperature. As per the report, fisheries and aquaculture provide livelihoods for 10-12% of the world population[3] .Currently the blue economy is contributing 5% (USD 2.5 trillion) to the world’s economy. Aquaculture, fishing, mariculture, tourism, maritime transport and offshore gas production are some of the activities which contribute the most. Coral reefs, predominantly located in tropical waters, contribute approximately $375 billion annually to the global economy through tourism, fisheries, and coastal protection . The (IPCC) reports that up to 30% of species are at risk of extinction if global temperatures rise by 1.5°C to 2°C. In addition to that around 3 billion people live near coastal areas and almost 300 million people are depending on marine related activities for their livelihood. More than 70% of earth’s surface is water and almost 90% of anthropogenic emission of greenhouse gas is absorbed by the ocean. The underwater ecosystem which includes biotic components like fishes, marine animals, coral reefs are impacted due to effects of climate change. The rising atmospheric CO2 and climate change will impact marine ecosystems in many ways, such as rise in temperatures, circulation, stratification, nutrient input, ocean acidification, leading to a range of biological effects such as coral bleaching eventually impacting overall ecosystem functioning and services. Warming, deoxygenation, acidification, and changes in primary productivity by marine phytoplankton can be considered as four major stressors of open ocean ecosystems that are intensified by climate change.
