Projected change in global fisheries revenues under climate change / by Francisco Blaha

Here is another of those (too many) studies I find interesting that has U. Rashid Sumaila as an author. This one takes an interesting angle since it goes to the business of fishing. As usually I recommend everyone to refer to the original.

 Impacts of climate change on MCP and MRP by the 2050 s (average between 2041–2060) relative to the 2000 s (average between 1991–2010)

Impacts of climate change on MCP and MRP by the 2050 s (average between 2041–2060) relative to the 2000 s (average between 1991–2010)

Global marine fisheries landings are estimated officially at between 80 and 85 million t a year since 1990, with corresponding mean annual gross revenues fluctuating around USD 100 billion annually. Accounting for unreported catches, a recent study estimated the likely “true” annual global catch to be about 130 million t.

The global fisheries sector supports the livelihoods of between 660 to 820 million people, directly or indirectly, which is about 10–12% of the world’s population, if the dependents of fishers are taken into account. Globally, fish also provides more than 2.9 billion people with 20 % of their animal protein needs and is a crucial source of micronutrients. However, along with other non-climatic drivers such as changes in markets, demographics and overexploitation, climate change is considered to be a major challenge that will significantly shape the future of global fisheries.

Several studies suggest that these non-climatic stresses and changes in management regimes may have a greater impact on fisheries than climate change in the short term, while increasing uncertainty in climate poses a major threat to world fisheries in the long run.

Changes in ocean conditions, including temperature, sea ice extent, salinity, pH, oxygen levels and circulation, lead to shifts in the distribution range of marine species, changes in primary and secondary productivity, and shifts in timing of biological events. Warmer temperatures may also lead to decreases in maximum body sizes of marine fishes. The combined effects of the predicted distributional shift and changes in ocean productivity under climate change are expected to lead to changes in species composition and hence global redistribution of maximum catch potential (MCP), with projected increases in MCP in high latitudinal regions and decreases in the tropics. These changes have large implications for people who depend on fish for food and income, and thus the contribution of fisheries to the global economy.

The changes described above under climate change are bound to affect the economics of fishing through changes in revenues (price x landings), costs (fixed + variable costs) and fisheries subsidies.

In this study, they tackle, as a first step in understanding the potential economic impact of climate change, focus on modeling the effects of climate change on revenues through changes in the amount and composition of catches. Price dynamics are affected by the interplay between the supply and demand of seafood products. The preference of consumers and the development of other food supply sectors such as aquaculture may also affect the future price of seafood and therefore have the potential to alter the economic impact under climate change. Here, price dynamics are incorporated as exogenous factors and the effects on revenues are explored by conducting different scenario analysis on prices. These scenarios describe how future development of other production sectors in the economy would likely affect seafood prices.

Specifically, changes in total potential catches may not directly equate to changes in revenues from fisheries. Firstly, climate change may affect catches of species that command different prices in the market. Secondly, even though potential catches are expected to increase in some countries’ exclusive economic zones (EEZs), the fishing sector of these countries may still suffer if they include a substantial Distant Water Fishing fleet (DWF) that operates in foreign waters that are impacted by climate change.

Conclusion

Their study highlights the impacts of climate change on society through its impact on revenues from fishing as a result of the interplay between ecology and fishing patterns. Our results suggest that the negative impact on MRP under the “faster aquaculture expansion” scenario is higher than the change under the “constant price” scenario. This suggests that we have to carefully consider development of aquaculture as a way to adapt to climate change impacts on marine capture fisheries.

The results also indicate that the countries that are most highly exposed to fisheries revenue impacts due to climate change have lower adaptive capacity to absorb these changes. We find that the projected impacts on revenues are relatively robust to climate and structural uncertainty, but not to the range of discount rates and prices explored in this contribution. Future work is needed to assess the full economic effects of mitigating or not mitigating GHG emissions.