Concentration of Global Fishing Effort with Climate Change

Fishing has a heavy global footprint: we harvest fish from all corners of the oceans and fishing fleets from a host of countries vie for access to key stocks. These international fishing fleets provide food and income to millions of people around the world, but also directly impact the biodiversity of our oceans. This is the challenge of Sustainable Development Goal 14: Life Below Water. Furthermore, the proximity of vessels from different nations can act as a geopolitical risk, with the potential to create region-wide disputes and even armed conflict. There is a need to quantify where international fleets operate, why they operate where they do, and then to use this information to project where these fleets will move to in the coming decades as climate change alters the spatial distribution of fish stocks. To address this challenge, the research questions we aim to answer are: 1) What are global patterns of fishing fleet diversity? 2) What are the relationships between fishing fleet diversity and oceanographic variables (measured from space)? 3) How will global patterns of fishing fleet diversity change in the coming decades under climate change? 4) Will these changes concentrate fishing fleets to (potentially under-governed) areas?

To answer these questions we have developed models of the spatial distribution of fishing fleets. These models leverage machine learning, global data on the location of vessels, satellite observations of oceanographic variables, and climate change projections from Earth System models. Results highlight several regions of fishing fleet congestion: places where many fleets from different nations operate in close proximity. These areas consistently experience relatively high levels of illegal, unreported and unregulated fishing, and fisheries disputes. Projections of future fishing fleets activity highlight regions of future concern, as the effort of fishing fleets are concentrated to particular areas, and as fishing effort moves across transnational boundaries.