While it might sound counterintuitive, new research suggests that protected marine reserves where fishing is prohibited might actually help fishermen to bring in larger hauls. As originally reported by Science Daily, marine protected areas (MPAs) actually do increase fish stocks, despite reducing fishing grounds. This is great news, as MPA designation is among the best conservation tools at our disposal today.
In recent years, the fishing industry has demonstrated considerable scepticism on this subject, largely due to the lack of specific research surrounding sustainable fisheries and the use of MPAs. In the past, few studies have been conducted on the buildup of individual populations within reserves and the subsequent spillover into commercial fishing grounds. What has been lacking was evidence that the increase in yield from this overflow actually balances the loss of fishing grounds. But, new studies indicate that MPAs don't just make up for the lost area - they actually enhance the entire fishery.
One project compared lobster populations and catch records from the waters off California's coast around Santa Barbara and Goleta. Between 2012 and 2018, scuba divers conducted surveys of the size and number of lobsters at five specific sites. Three of the chosen reefs were open to fishing throughout the study, while two of them were incorporated into marine reserves in 2012. The researchers also used the same six years' worth of data from local commercial fishing efforts to build their case. Specifically, the number of traps pulled and quantity of catch in each trap. These records gave the scientists a sizable window to examine the impact that the newly established reserves had on the region's lobster catch.
Throughout the study, the team observed that the population of lobsters increased both in and around the marine reserves once fishing was prohibited. This suggests that the lobsters were indeed proliferating inside the MPAs, and spilling out into the surrounding areas - exactly as predicted by the project's initial theory. The team also found that annual lobster catches more than doubled in the surrounding waters over the course of their study, despite the 35% reduction in the fishing area. By contrast, regions without MPAs showed little to no change during the same period.
This is one of the first studies to conclusively prove that the establishment of marine reserves actually enhances catch, despite reducing the area that fishermen could actually work in. Of course, the increase in catch was met with an increase in fishing activity just outside the reserve. This practice, called "fishing the line", targeted lobsters that spilt over from the reserves into fishable areas. This data suggests that MPAs do, in fact, have the potential to yield a higher and more sustainable catch.
In addition to these efforts, the team has tagged over 17,000 lobsters and relied on local fishermen to report where they were eventually caught. This provided valuable insight into the animals' movements in and out of the newly established parks' limits, and helps fishermen learn about lobster behaviour, increasing their yield and inspiring professional lobstermen to work alongside researchers. Ultimately, this relationship is benefitting the region hugely, allowing for improved science, better fishery management, and increased conservation efforts.
