tuna

POSEIDON: Process-based ocean-system simulation for evolving integrated domains and operational needs

About

Fisheries worldwide are currently managed such that human behavior is the only thing being controlled; managers can implement policies that dictate how many fish an individual can catch, but they have no control over the dynamics of the populations being fished. While setting controls on human behavior is the standard for fisheries management, there are still many unknowns when it comes to the human aspect of management. Because it is impossible to experiment with people and fishery policies in real time, evaluating these knowledge gaps can be difficult. 

Alongside research partners, we developed a series of adaptive ecosystem-based fisheries management (EBFM) approaches that can be applied in diverse contexts. A major component of this project was the development of an agent-based modeling (ABM) tool, which was used to simulate fisher behavior and inform management strategy evaluations. We forecasted vessel behavior using the ABM under a range of policy and ecological scenarios. We applied the ABM to design ecosystem-based fishery management strategies for both industrial and small-scale fisheries in developing countries that are faster, simpler, and more cost effective, with built-in resilience to environmental changes.

Approach

We provided expert advice to project partners who led the construction of the ABM while developing hypotheses and assisting in model validation. Our research contributions to this project included incorporating behavioral economics into fisheries science, evaluating tradeoffs between objectives, and developing approaches to prioritize new data collection efforts. We hypothesized that an ABM, when coupled with an ecosystem model, can simulate realistic scenarios under a suite of potential management strategies, including those that involve complex combinations of policies. By combining the ABM development with basic research on EBFM, we aimed to advance a mix of simplistic, applied solutions to the EBFM challenge in both developed and developing world contexts.

Key Findings

The POSEIDON model has been applied in Eastern Pacific tropical tuna fisheries and the Indonesian deep water snapper grouper fishery to help managers anticipate how fisherman and tuna stocks will respond to new management measures. We believe this capability will provide managers and stakeholders a picture of what may happen in the future and identify the unintended consequences of management decisions in advance–resulting in healthy, sustainably managed stocks.

Partners

This project was a collaborative effort alongside partners at The Ocean Conservancy, Oxford University, and George Mason University.