No-fishing zones protect species and possibly lead to increases in catch rates
Recently created Large-Scale Marine Protected Areas (LSMPAs) like Revillagigedo in Mexico are potentially large enough to protect highly migratory species like tuna, especially bigeye tuna, possibly leading to increases in catch rates for tuna fisheries operating outside their boundaries. The findings were published in Science on Dec. 12, 2024.
Key findings:
- The research team found multiple examples from around the world of spillover benefits, resulting in an increase in catch rates outside of marine protected areas. On average, this spillover benefit resulted in a 12 to 18 percent increase in catch-per-unit-of-fishing-effort in the waters near protected areas.
- Results across tuna species are relatively consistent, with all species showing some evidence of positive spillover ranging from 2 to 11 percent, with the strongest benefits for bigeye tuna.
- The research finds nations that engage in conservation are also reaping most of the economic benefits. For example, close to 100% of the spillover benefits from the Revillagigedo protected area in Mexican waters flow to Mexican fishing vessels.
"We found that the spillover benefits, measured as the change in catch rates, are strongest just outside the boundaries of these MPAs and get stronger over time," said Juan Carlos Villaseñor-Derbez, a co-author of the study and an assistant professor in the Department of Environmental Science and Policy at the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science, and a core faculty member at the Frost Institute for Data Science and Computing . "The effects were strongest for the MPAs that were heavily fished prior to protection and are now well-enforced."
Understanding the interactions between Large-Scale MPAs, tuna stocks and tuna fisheries is timely given international goals to protect 30 percent of the world's ocean area by 2030 and the United Nations' Biodiversity Beyond National Jurisdiction Agreement, an international treaty aimed at protecting biodiversity on the high seas.
The authors reviewed data from 9 LSMPAs across the Pacific and Indian oceans.
"A unique aspect of this research is that we built a global database on tuna catch using only publicly available data," said Villaseñor-Derbez. "That hasn't been possible with previous studies on large-scale MPA impacts."
"In 2004, there was only one Large-Scale MPA in the world, the Galápagos Marine Reserve in Ecuador. Today there are more than 20, including Papahānaumokuākea in the Northwest Hawaiian Islands. Most of these protected areas are in waters where tuna fisheries operate," said co-author John Lynham, a professor in the Department of Economics at UH Mānoa's College of Social Sciences. "This means that we can now test, for the first time, the impact of these marine protected areas, especially on tuna species like ʻahi and skipjack, which support a global industry worth over $40 billion."
While protected areas in Hawaiʻi were not the main focus of the study, the research also reveals that the Papahānaumokuākea Marine National Monument, the world's largest no-fishing zone, has caused a 10% increase in bigeye tuna (ʻahi) catch rates near the monument, in line with a recent finding of a 13% increase by researchers from the University of Washington and the Western Pacific Regional Fisheries Management Council.
The research was funded by the National Science Foundation.
About the University of Miami and Rosenstiel School of Marine, Atmospheric and Earth Science
The University of Miami is a private research university and academic health system with a distinct geographic capacity to connect institutions, individuals, and ideas across the hemisphere and around the world. The University's vibrant and diverse academic community comprises 12 schools and colleges serving more than 19,000 undergraduate and graduate students in more than 180 majors and programs. Located within one of the most dynamic and multicultural cities in the world, the University is building new bridges across geographic, cultural, and intellectual borders, bringing a passion for scholarly excellence, a spirit of innovation, a respect for including and elevating diverse voices, and a commitment to tackling the challenges facing our world. With more than $413 million in research and sponsored program expenditures annually, the University of Miami is a member of the prestigious Association of American Universities (AAU).
Founded in 1943, the Rosenstiel School of Marine, Atmospheric, and Earth Science is one of the world's premier research institutions in the continental United States. The school's basic and applied research programs seek to improve understanding and prediction of Earth's geological, oceanic, and atmospheric systems by focusing on four key pillars:
*Saving lives through better forecasting of extreme weather and seismic events.
*Feeding the world by developing sustainable wild fisheries and aquaculture programs.
*Unlocking ocean secrets through research on climate, weather, energy and medicine.
*Preserving marine species, including endangered sharks and other fish, as well as protecting and restoring threatened coral reefs.
