Marine reserves do not aid in the recovery of fish populations

Fish populations in Caribbean marine reserves have not recovered, according to a 12-year study. Researchers say poor enforcement of marine protection regulations, coastal development and rising water temperatures are likely to blame.

Stretching for more than 1,000 kilometers along the Caribbean coasts of Belize, Guatemala, Honduras, and Mexico, the Mesoamerican Reef is home to a wide range of wildlife, including more than 500 species of fish and 65 species of coral.

Over the past few decades, governments in these countries have created many marine protected areas (MPAs) with the aim of protecting the precious biodiversity of coral reefs and restoring fish populations that have declined due to overfishing. I did. These areas may prohibit fishing during certain times of the year, prohibit certain types of fishing gear, and restrict other activities such as tourism and mining.

To evaluate the effectiveness of these MPAs, stephen canty Researchers from the Smithsonian Environmental Research Center in Maryland analyzed changes in fish biomass in 111 protected lands and 28 non-protected lands from 2006 to 2018. The data was collected during a survey by a scuba diver as part of the investigation. Initiatives for healthy coral reefs.

The researchers found that adult fish biomass increased in only 11 of the marine protected areas during the study period, indicating an increase in adult fish populations. Meanwhile, adult fish populations declined in 28 of the reserves and remained unchanged in the remaining locations. Less protected sites did see declines, but the declines were often smaller than the most protected sites.

The study found that 11 areas where fish populations have recovered have well-enforced MPA regulations and less fluctuation in sea surface temperatures. Sites with poor recovery showed opposite trends, including poor implementation of conservation measures, increased human activity in coastal areas, and increased temperature anomalies.

“Enforcement plays a huge role in whether some of these areas are successful or not,” Canty says. He suggests that local residents, who make a living from adult fish, should be given a greater role in managing MPAs. It's also important to ensure MPAs are located in areas that are better protected from climate change and easier to manage, he says.

“There's still a lot we don't know about marine protected areas,” team members say Justin Nowakowski, also located at the Smithsonian Environmental Research Center. “Therefore, it is important to be able to look to the past to optimize how he positions and manages his MPAs in the future.”