The 21st century hasn’t been kind to fish. While overfishing was largely halted in U.S. waters thanks to a 2006 fishery law, we’re a long way from repopulating already-depleted species, and most nations don’t have legally-mandated fishery management.
Add that to the effects of climate change heating up and acidifying oceans, and the world’s fish populations aren’t exactly thriving. A 2009 study by Dr. Boris Worm et al. (2009) found that most of the world’s assessed fish stocks are either fully or over-exploited.
In an article on the decline of fisheries in the Sea of Cortez off of Mexico, Harper’s Magazine’s Erik Vance describes the way fishing has moved straight down the food chain after depopulating species after species. Trawlers scoop up hundreds of pounds of “bycatch” fish along with the shrimp they’re after, the often-unlicensed “pangas” then catch the rest, and divers go ever-deeper to find the remaining callao mussels.
But two towns on Mexico’s Gulf of California are doing more than just limiting commercial fishing — they’re banning it. Cabo Pulmo, on the Southern Tip of the Baja Peninsula, worked with the Scripps Institute of Oceanography to close their waters off entirely from fishing in 1995. The town counted on its coral reef and replenished ocean life to draw tourists that would make up for lost fishing revenue and it seems to have worked.
“We could have never dreamt of such an extraordinary recovery of marine life at Cabo Pulmo,” said National Geographic Explorer-in-Residence Enric Sala to Scripps. It reported a 463 percent increase in biomass from 1995 to 2009.
Loreto, 150 miles away, tried a similar ban on commercial fishing, while allowing sport fishing, which, when well-regulated, is much less of a harm to fish populations. They’ve seen increases in tourism, while maintaining a steady level of biomass. Even commercial fishers in nearby communities get improved catches from replenished stocks of fish leaving the protected zones.
Marine Protected Areas (MPAs) like those in the Gulf of California are a way to both mitigate the effects of, and fight back against, climate change according to a report from the Commission for Environmental Cooperation. MPAs are especially resistant to the impacts of climate change, compared with already weakened and depleted ecosystems. And they protect habitats that serve as essential carbon sinks, absorbing the output of the rest of the planet.
But as Vance mentions, MPAs will not work everywhere. Not every community has the beautiful beach or coral reef necessary to depend on tourism to replace lost fishing revenue. And while they are a step toward ocean revitalization, MPA’s are not guaranteed to return fish to surrounding waters, and they will not single-handedly address climate change.