In the past 50 years, the number of marine extreme warming events, are estimated to have already increased by more than 50%Nowadays fisheries and aquaculture not only represent a pillar of the world’s economy but are also recognized as fundamental for the food security of 12% of the world’s population, a percentage that goes up to almost 36% if we consider how many people rely, as a source of protein, on food coming from the ocean (FAO, 2020). In that sense, the situation is alarming, if we think that fishery is an industry that is already suffering the impacts of climate change. Indeed, the processes of acidification, changes in currents, deoxygenation, rising temperatures and pollution of the ocean are all already affecting fisheries, and are expected to be increasing in the coming years. The growth and the reproduction of certain organisms are affected by these changes in the marine environment, with a resulting reduction in the available populations of many commercial species. In the past 50 years, the number of marine extreme warming events, are estimated to have already increased by more than 50% (Smale, DA, et al, 2019), and these heat-waves are not only much more frequent but also heavier as individual events. Furthermore, all around the world, ocean temperatures are predicted to increase, by the end of the century, even 4°C above the current average temperatures (Laffoley, D. et al, 2016).
The global levels of ocean productivity are expected to decrease rapidly in the tropical and inter-tropical areas, affecting the possibility to fish locally, with the local fishing operations that have already been reduced by up to 40% (FAO, 2018.) Significant repercussions are expected for small islands and countries highly dependent on fisheries, such as Bangladesh, India, Vietnam, Indonesia, Angola, and Peru. This is also increasing inequalities between states. The ocean’s productivity could increase in the Polar regions, but an increase of the fishing activities in northern countries such as Norway, Iceland, Alaska, and Russia, as well as around the North Pole, could overheat and pollute the area, leading to much more rapid melting of permanent glaciers, and therefore to even more changes to the natural ecosystem. The state of world fisheries and aquaculture — Meeting the sustainable development goals It is not just fish stocks safety that is at risk, coral reefs are also at risk due to climate change and pollution effects on the ocean, with nearly all tropical coral ecosystems that are expected to disappear by 2050. At first instance, one may think that coral reefs are not a part of the human food chain, and therefore do not affect our food security. However, by functioning as nurseries for many species, protecting coasts from erosion, absorbing carbon and nitrogen, they are vital to many ecosystems, economies and food systems in the world, especially – but not limited to — those of small islands.
Bacterial and phytoplankton communities, even though also not directly related to human food security, are fundamental for the maintenance of the marine ecosystem, and are another thing highly at risk due to climate change impacts on the marine ecosystems. Adaptation measures in fishery and aquaculture are very much needed but, in current times, due to a lack of a targeted analyses of the sector’s vulnerabilities to climate change and of those that are the risks associated to the impact of climate change, not many responses options have been thoroughly studied and even less have been implemented. This article, of course, is not intended to fill in that gap, but just to shed a light on the current and future issues regarding fishery. Moreover, not only we are not implementing strategies to reduce the impacts of climate change on oceans, and therefore on the fishery, but in many parts of the world we are also supporting an irresponsible, intensive, unsustainable, and oftentimes illegal fishing industry, which is contributing to oceans’ pollution and to the devastation of fish stocks, coral reefs, seabeds, and is bringing, or has already brought, species to extinction.
Globally, the total amount of fish caught is nearly three times larger than what the oceans can handle; the fish that remain are unable, with reproduction alone, to replace all the specimens caught. 53% of the world’s fishing areas are fully exploited, and 32% are in many cases over-exploited (FAO, 2020), impoverished or unusable because they are in a period of recovery from previous exhaustion, even if it is not certain that this recovery is possible. Mitigation and adaptation strategies for climate change impacts on fishery are very much needed, but also a shift in our diets, away from unsustainable produce, is essential to combat climate change and environmental degradation at a personal level.