13 June 2017 - The central African nation of Gabon announced Monday the creation of Africa’s largest network of marine protected areas, home to a diverse array of threatened marine life, including the largest breeding populations of leatherback and olive ridley sea turtles and 20 species of dolphins and whales.
The network of 20 marine parks and aquatic reserves will protect 26 percent of Gabon’s territorial seas and extend across 20,500 square miles (53,000 square kilometres). In creating the protected areas, the Gabon government also set up what scientists call the most sustainable fisheries management plan for West Africa—an area long known for rampant overfishing and abuses by foreign fleets. Separate zones have been established for commercial and artisanal fishing fleets, in an effort to restore sustainable fishing.
“West Africa is an area which has incredibly rich oceans, but it is being bled dry by international fishing fleets,” says Callum Roberts, a marine conservation biologist at the University of York in Great Britain. “In the space of a few decades, the waters of West Africa have moved from being a cornucopia of marine life to something that is far reduced from that. Protection is urgently needed to rebalance fish resources.”
Roberts, who has spent more than three decades studying ocean health, argues in a new paper, published Monday in the Proceedings of the National Academy of Sciences, that marine protected areas, which already help restore fish populations, also help marine ecosystems adapt to the impacts of climate change. Large, fully intact ecosystems are healthier and better armed to adapt to what Roberts calls the “killer cocktail” of ocean acidification, intense storms, sea-level rise, shifts in species distribution, and decreased oxygen availability in the deep ocean. Reduced oxygen is already visible in the Pacific and Atlantic, Roberts says, where nutrient-poor “ocean deserts” increased by 15 percent between 1998 and 2006.
“Fishing has had the greatest impact on the ocean ecosystems,” Roberts says. “But climate change is rapidly catching up, and in some ecosystems, has taken the lead.”
Roberts doesn’t claim marine protected areas help marine habitats resist climate change. Rather, he says that healthier habitats makes them more resilient. Coral reefs, for example, can’t be protected from rising ocean temperatures. But protecting reefs from overfishing, dredging, and runoff pollution can decrease the sensitivity of corals to ocean warming and help them recover from floods or bleaching events. The Chagos Marine Protected Area in the remote Indian Ocean now has a reef free from human-caused stresses that, in turn, contributed to a remarkable capacity to recover. More than 90 percent of the reef died in a 1998 bleaching event. But by 2010, the reef had recovered.
Likewise, a marine protected area in Baja, California saw a ten-fold increase of predatory fish within a decade after a marine protection area was established.
Networks of marine protected areas can also provide stepping stones, or safe “landing zones” for colonising species as they move northward to cooler waters, he says. The Papahanaumokuakea Marine National Monument in the north-west Hawaiian Islands provided a “strategic refuge” for coral reef ecosystems that may be forced poleward by climate change.
“When we introduce protection, the only way to go is up,” he says. “We see it in recoveries of big species that grow to very old ages. The bigger and older things get in the sea, the more productive they begin to be in terms of offspring. They are like fountains, pouring offspring, like larvae, into the water, which then gets transported by ocean currents and reseeds other areas. This is a positive way to counter climate change.”
LESS THAN THREE PERCENT CURRENTLY PROTECTED
The world has 11,212 marine protected areas. But combined, they protect just 2.98 percent of the oceans, according to the Marine Conservation Institute, a marine science nonprofit based in Seattle.
Two other measures fill in the picture. If the high seas is discounted, the remaining marine reserves protect 7.29 percent of marine habitats that lie within the 200-nautical mile exclusive economic zones of all countries. And if only no-take protected areas are counted, where fishing and all other extraction, such as mining, is prohibited, only 1.63 percent of the world’s oceans are covered.
The no-take reserves are the strongest, but not well distributed across the globe, says Russell Moffitt, the institute’s conservation analyst. There are only about a dozen very large protected areas, including those in offshore territories of the Pacific Remote Islands Marine National Monuments, and Great Britain’s Pitcairn, and Chagos marine reserves.