Risks to large marine protected areas posed by drifting fish aggregation devices.

Area of Science:

• Marine conservation science
• Fisheries management
• Oceanography and modeling

Background:

• Large marine protected areas (MPAs) are crucial for conserving fish biomass but face challenges due to low management capacity.
• Drifting fish aggregating devices (dFADs) are effective fishing tools but cause bycatch and can damage sensitive coastal habitats.
• Understanding the interaction between dFADs and MPAs is vital for effective conservation and enforcement.

Purpose of the Study:

• To map and predict the risk of fishing activities, specifically dFADs, to large marine protected areas (MPAs).
• To quantify the risk of dFADs beaching on sensitive coastal areas within the Chagos Archipelago MPA.
• To assess the potential for dFADs to transit, accumulate, and export biomass from the MPA.

Main Methods:

• Utilized Lagrangian particle modeling to simulate dFAD movement within and around the Chagos Archipelago MPA.
• Quantified the risk of dFADs beaching on reefs and atolls.
• Analyzed dFAD transit times and potential for biomass export from the MPA.

Main Results:

• Over one-third of modeled dFADs posed a risk of beaching or transiting the MPA for over 14 days.
• A significant percentage (13.11%) of dFADs posed a risk for over 40 days.
• The Great Chagos Bank is identified as the most vulnerable atoll to dFAD beaching; dFADs deployed on the MPA perimeter pose the highest risk.

Conclusions:

• Drifting fishing gears like dFADs present a substantial risk to the integrity and function of large MPAs.
• Effective management plans are needed to address the challenges posed by drifting fishing gear to MPA boundaries and biomass.
• Understanding dFAD dynamics is essential for enforcing MPA regulations and ensuring the sustainability of marine resources.