Last month, the United Nations’ Food and Agriculture Organization (FAO) released a technical paper entitled “Impacts of climate change on fisheries and aquaculture.” The 28-chapter, 654-page paper took nearly three years to write with over 100 contributors.
One of the most significant findings is that climate change will have a negative impact on the catch potential of the world’s fisheries in the range of 2.8% to 12.1%. As the atmospheric concentration of greenhouse gasses (GHGs) has increased, the ocean has absorbed over 90% of the extra energy that has been generated. Additionally, 30% of the carbon dioxide created by humans has been absorbed by the ocean. These factors have contributed to an increase in surface water temperature (.7% per century), which has in turn led to decreased levels of dissolved oxygen. Other changes include ocean acidification which leads to a decrease in water pH and saturation of calcium carbonate; these changes have a negative impact on the ability of crustaceans to form shells. Sea level has risen by an average of 3.1 mm per annum in recent years due to climate change. Extreme weather events attributed to climate change (flooding, hurricane, drought, etc.) impact fisheries, as well. In addition to ocean fisheries, inland fisheries will also feel the effects. As will food safety and biosecurity.
According to FAO’s summary of the paper (click HERE to read the summary):
Case studies provide unequivocal evidence of the significant impacts that climate change has already had on marine fisheries in some regions and the need to take steps to adapt to current (in many regions) and future (in all regions) climate change.
Aquaculture (the fastest growing food production sector worldwide) will also be impacted by climate change. Extreme weather events can increase risk of parasites and harmful algal blooms and negatively impact farming conditions in the short term. In the long term, decreased access to freshwater and lower amounts of wild stocks are among the factors affecting aquaculture. To mitigate these items, the summary suggests:
- Improved management of farms and choice of farmed species;
- Improved spatial planning of farms that takes climate change-related risks into account;
- Improved environmental monitoring involving users; and
- Improved local, national, and international coordination of prevention and mitigation.
The report states that approximately 200 million people are either directly or indirectly employed in fisheries or aquaculture. The impacts of climate change can be very hard-felt by small fishing operations both because of where they are located geographically and their socio-economic status. Aquaculture may be an alternative for those fishers as a way to maintain their livelihoods when their capture fisheries decline.
The report also suggests ways capture fisheries and aquaculture can reduce their creation of GHGs. Even though energy usage for fish production is much lower than that of beef or pork, improvements can still be made including using more efficient fishing vessels and renewable energy sources employed for land-based operations.
To view the full report click HERE.