Wednesday August 13, 2025
The Cool Down —
Enforcing overfishing rules in key harvest zones gets results, according to a study from the University of Wisconsin.
The team used artificial intelligence coupled with satellite data and radar to monitor fishing vessel traffic in marine protected areas, or MPAs. While vital for thriving oceans, the study from 2017-21 found that monitoring the zones is a challenge.
“We found that MPAs with strict legal fishing bans work better than critics claim,” Wisconsin lead researcher Jennifer Raynor said. “MPAs can help to regenerate fish populations, which creates strong incentives for illegal fishing — and yet, that activity was mostly absent. This is good news for marine conservation.”
The Wisconsin experts teamed with peers from National Geographic Pristine Seas and the University of California, Santa Barbara, to analyze data from 1,380 MPAs — just over 2% of global oceans. The area included the Great Barrier Reef, which is also beleaguered by ocean warming and coral bleaching.
Five billion vessels were tracked using the Automatic Identification System. Satellites, radar, and AI helped to find a significant number of “dark” vessels that, for various reasons, don’t show up on the ID system. Even small ships can be picked up by the radar, spotlighting the need to include the observation method in these types of studies.
Heavily protected MPAs averaged nine times fewer ships in a square kilometer of coastal area than zones without protections. About a quarter of the MPAs had zero fishing vessels during the study timeframe, the report continued.
The experts said that protections are important to give heavily fished areas time to recover. The Environmental Defense Fund called overfishing the “most serious” ocean biodiversity threat. About three billion people globally rely on fishing as a protein source, making sustainability paramount, per the EDF.
Regulating harvests in the waters is better for future bounties, as well. The Wisconsin report cited a study showing that tuna catches increased near the protected Papahānaumokuākea Marine National Monument in Hawai’i. A study off the Mexico Revillagigedo National Park coast had similar results.
Raynor and her team intend for the Wisconsin findings to be a reference point for policymakers. It’s a mission anyone can aid by staying informed about topics that impact our seas and ocean food supply. You can buy products from companies that operate sustainably, and contact your local politicians with concerns about planet-related policy.
The Wisconsin research has shown that the right rule-making can garner outstanding results.
“By using satellites to track fishing vessels, countries can predict the locations of illegal activities and target patrol efforts, saving both manpower and money,” Raynor said. “This is critical for reaching the Global Biodiversity Framework’s 30 by 30 target, which aims to protect 30% of oceans by 2030.”
The Marine Conservation Institute reported that about 2.8% of the “total ocean” is protected.