No doubt IUU is a big issue with many facets… and it fits in the bigger picture of better fisheries management. And a lot of scorn is given to these doing it, but also to those that are working against it for not for not being good enough, fast enough, or for being political and industry puppets, and so on…
And most of the criticism comes from surely well intended folks that are very fast at pointing fingers, but may not know how technical the issue can get particular when adding other elements around subsidies, social responsibility and the economical vulnerability of the nations that have the fish against the DWFN that catch it.
Yet, people keep pointing the finger at these issues, while forgetting that there is a topic where we all need to have a much bigger impacts ourselves… this recent paper by Lotze et al. 2019 (Global ensemble projections reveal trophic amplification of ocean biomass declines with climate change - I never read a paper with so many authors!), is a groundbreaking study predicts that life in the ocean will decrease by about 5% per degree of global warming.
Climate change studies and the gloomy figures they produce can be discouraging, but the figure here can be interpreted positively: Reducing warming by any amount will move up the scale and prevent the deaths of countless marine animals, where we can work better on IUU and management.
Lotze and his co authors from across the world incorporated climate models into ecosystem models to determine how rising global and ocean temperatures (and their associated impacts) will affect animal populations over time.
There are two major takeaways concerning fisheries:
1. The composition of fish in the ocean will change dramatically and
2. Fishing has very little impact on what will happen.
Large marine animals higher in the food chain will suffer disproportionately to animals lower in the food chain. Climate change effects will start low in the food chain and amplify through the food web, leaving higher trophic level animals most vulnerable—a phenomenon known as trophic amplification.
According to the models, much of the biomass lost in the ocean will be due to a sharp decrease in organisms larger than 30cm. This has obvious implications for fishermen and women and seafood consumers.
Fishing impact is virtually non-existent
According to the study’s models, fishing had no impact on future biomass in the ocean:
“The fact that the estimated climate-change impacts are independent of fishing provides an added incentive to develop sustainable and adaptive fishing, responsive to climate change, which we need to feed a world of 9 billion humans” says co-author Manuel Barange, Director of Fisheries and Aquaculture at the Food and Agriculture Organisation (FAO).
However, the fished and unfished scenarios used in the models were basic—the next step in this analysis is to incorporate more realistic fishing scenarios.
In any case the conclusion is quite “conclusive”:
Our ensemble projections demonstrate that global ocean animal biomass consistently declines with climate change, and that impacts are amplified at higher trophic levels. Our hindcasts support recent empirical work that shows ongoing climate impacts on fish biomass and project elevated climate-driven declines in ocean ecosystems, with magnitudes dependent on emission pathways. Amplification of biomass declines for higher trophic levels represents a particular challenge for human society, including meeting the SDGs for food security (SDG2), livelihoods (SDG1), and well-being (SDG3) for a growing human population while also sustaining life below water (SDG14).
Our ensemble projections indicate the largest decreases in animal biomass at middle to low latitudes, where many nations depend on seafood and fisheries, and where marine biodiversity is already threatened by multiple human activities. In turn, the largest increases are projected at high latitudes, highlighting new opportunities for—and potential conflict over—resource use, but also an urgent need for protecting sensitive species and rapidly changing ecosystems. Overall, our results clearly highlight the benefits to be gained from climate change mitigation, as all impacts were substantially reduced under a strong mitigation (RCP2.6) compared with the business-as-usual (RCP8.5) scenario.
More simply, the conclusion remains that reducing emissions is the most important thing society can do to protect the ocean.