Marine protected areas may hold the key to keeping global fishing industries healthy and profitable, a new scientific study in Madagascar reveals.
The study looked at a community-run marine protected area (MPA) in southwest Madagascar that implemented seasonal fishing closures for octopus, the major economic resource for villagers in the region. When the closed areas were reopened to fishing after seven months, the study found, the number of octopus caught by villagers increased 13 times while the total weight of octopus caught jumped 25 times.
“The increase in octopus numbers and weight was far greater than we ever expected,” said Alasdair Harris, scientific director of Blue Ventures, the marine conservation group that conducted the study. “This study shows that MPAs not only serve as a powerful conservation tool helping species thrive, but can also be a powerful economic tool helping fisheries remain productive and profitable.”
Overfishing poses a major threat to the world’s oceans, causing many economically-important marine species to disappear. Various studies have estimated that between 60 to 70 percent of the world’s fisheries are depleted or nearly depleted even as more and more people depend on fish stocks for food and livelihoods.
The study, authored by Blue Ventures scientist Frances Humber, looked at an MPA that was launched in 2004 in coordination with Blue Ventures, the Wildlife Conservation Society, the village of Andavadoaka and the IHSM, Madagascar’s principle marine institute.
The groups worked together to implement the MPA after local fishermen reported drops in their octopus catch in the wake of the arrival of international fishing companies that were collecting octopus for the global market.
The study looked at the size of octopus caught by villagers following the reopening of two closed fishing periods implemented by the MPA, the first between November 2004 and June 2005, the second between December 2005 and April 2006.
The increase in octopus catch following the opening of the second closure more than quadrupled compared to the number caught immediately before the second closure. The weight of octopus caught after the second closure was seven times greater.
The increased size and weight of octopus catch continued for one month following the opening of the first closure and for two months following the opening of the second closure, before dropping to pre-closure levels.
“While the results of the MPA were extraordinary in the initial months, local fishermen also turned out in greater numbers on the opening day of the closures, reducing the long-term benefits,” Harris said. “This shows the need for ongoing management plans in addition to MPAs in order to reap continuing benefits.”
Harris said village leaders from Andavadoaka placed tighter restrictions on the amount of fishing following the second reopening, which resulted in longer-term benefits. Andavadoaka is still developing plans to ensure long-term benefits from future closures on octopus fishing.
African nations are increasingly becoming major suppliers of octopus to the global market. But as international demand continues to grows, many of Africa’s octopus fisheries have peaked and are beginning to decline. For example, the artisanal fishery of Mauritania exported 9,000 tonnes of octopus in 1993, but only 4,500 tonnes in 2001, despite twice as many active boats within the fishery.
Madagascar’s fishing industry is relatively undeveloped compared to other countries in East Africa and the Western Indian Ocean region. But the country has seen a rapid increase in fisheries production and export over the last 20 years with a doubling in the number of fishers in Madagascar.
While there are growing threats from overfishing, Madagascar currently is one of the few African nations that are increasing its octopus fishery output. Between 2002 and 2003 there was a 35 percent increase in octopus exports to France.
“The success of Andavadoaka’s MPA shows there is hope that well-managed fishery practices, such as MPAs, can prevent Madagascar from suffering the damaging effects of overfishing that so many other African nations are dealing with today,” Harris said.
To see the entire study, visit
http://www.blueventures.org/research/BV%20report%20Frans%20Octopus_web.pdf