Endangered African Penguins Rebound in No-Fishing Zone
Conservationists believe closing off or relocating fisheries could help to save top marine predators around the world.
- By Jennifer Viegas | Wed Feb 10, 2010 06:23 AM ET
Researchers outfitted several of the penguins with GPS data loggers that monitored the duration of trips taken by the penguins, the length of their travel paths, diving efforts and their maximum distance from the colony.David Gremillet
THE GIST:
The African penguin population decreased by 90 percent during the 20th century, but conservationists believe they have identified a proven way to save this flightless bird and other endangered seafaring animals.
A new study, published in the latest issue of the journal Biology Letters, reports on the world's first experimental demonstration that a marine protected area closed to fisheries can have immediate benefits for an endangered top marine predator.
The African penguin, Spheniscus demersus, which is endemic toSouthern Africa , was the focus of the study. Its status this month will be upgraded from "vulnerable" to "endangered" by the International Union for Conservation of Nature and Natural Resources, which maintains the IUCN Red List of Threatened Species.
"What is starving the penguin is the spatial shift of their resources -- sardines -- away from their traditional feeding grounds," co-author David Gremillet told Discovery News. "The shift is thought to be due to the late impact of previous overfishing, combined with the consequences of ocean warming."
Gremillet leads the SpatialPopulation Ecology research team at the Center of Functional and Evolutionary Ecology in Montpellier , France. He and his colleagues met with South African government officials to form a "penguin working group" to help save the area's famous local bird. Each year, around 600,000 tourists visit Cape Town 's Boulders Beach African penguin colony. "It is the most visited penguin colony in the world," Gremillet said.
He and the other penguin working group members decided to experimentally close off a 12.5-mile area to purse seine fisheries, which use gigantic nets to encircle entire schools of fish. The closure occurred atSt. Croix Island, Algoa Bay. The waters around Bird Island, 31 miles away within the same bay, were left open to fishermen.
The researchers outfitted several of the penguins with GPS data loggers that monitored the duration of trips taken by the penguins, the length of their travel paths, diving efforts and their maximum distance from the colony. Adult penguins raising chicks were tracked at the two colonies both during the fishing ban in 2008 and the year after, when the ban had lifted.
During the ban period, penguins breeding on St. Croix foraged for food at the site previously occupied by the fisheries. As a result, they were able to decrease their hunting effort by 30 percent, which in turn reduced their daily energy expenditure by 40 percent, in comparison to the following year when the fisheries returned. The Bird Island penguins' foraging efforts remained the same over the study period. "Considering the current situation of the African penguin population (only 26,000 pairs known to exist in the world), I think that such marine protected areas should be permanent," Gremillet said.
Although fisheries might sustain losses, he is hopeful that the plan will go forward and succeed. "South Africa has been one of the world leaders in establishing an ecosystem-based management of its fisheries, miles ahead of many other nations," he said. Ecotourism gains might also help to offset any potential fishing losses.
InNew Zealand , coastal marine reserves have been established within the feeding range of endangered yellow-eyed penguins, one of the most endangered penguin species in the world. The effectiveness of those reserves has yet to be fully documented, however, according to Gremillet.
Conservationists also hope to establish reserves for the rockhopper penguin, whose numbers have declined dramatically since the 1990s.
Penguins aren't the only marine predators that will likely benefit from this proposed solution. The National Oceanic and Atmospheric Administration Fisheries Service recently drafted a proposal to create a marine protected area for killer whales, and other conservationists are working to establish similar areas for additional whale species.
Source
- A new study reports that a marine protected area closed to fisheries can have immediate benefits for an endangered top marine predator.
- The African penguin, which would benefit from the establishment of a permanent no-fishing zone, is being upgraded from "vulnerable" to "endangered."
- Marine protected areas are being considered for other penguin species and additional marine predators, such as whales.
The African penguin population decreased by 90 percent during the 20th century, but conservationists believe they have identified a proven way to save this flightless bird and other endangered seafaring animals.
A new study, published in the latest issue of the journal Biology Letters, reports on the world's first experimental demonstration that a marine protected area closed to fisheries can have immediate benefits for an endangered top marine predator.
The African penguin, Spheniscus demersus, which is endemic to
"What is starving the penguin is the spatial shift of their resources -- sardines -- away from their traditional feeding grounds," co-author David Gremillet told Discovery News. "The shift is thought to be due to the late impact of previous overfishing, combined with the consequences of ocean warming."
Gremillet leads the Spatial
He and the other penguin working group members decided to experimentally close off a 12.5-mile area to purse seine fisheries, which use gigantic nets to encircle entire schools of fish. The closure occurred at
The researchers outfitted several of the penguins with GPS data loggers that monitored the duration of trips taken by the penguins, the length of their travel paths, diving efforts and their maximum distance from the colony. Adult penguins raising chicks were tracked at the two colonies both during the fishing ban in 2008 and the year after, when the ban had lifted.
During the ban period, penguins breeding on St. Croix foraged for food at the site previously occupied by the fisheries. As a result, they were able to decrease their hunting effort by 30 percent, which in turn reduced their daily energy expenditure by 40 percent, in comparison to the following year when the fisheries returned. The Bird Island penguins' foraging efforts remained the same over the study period. "Considering the current situation of the African penguin population (only 26,000 pairs known to exist in the world), I think that such marine protected areas should be permanent," Gremillet said.
Although fisheries might sustain losses, he is hopeful that the plan will go forward and succeed. "
In
Conservationists also hope to establish reserves for the rockhopper penguin, whose numbers have declined dramatically since the 1990s.
Penguins aren't the only marine predators that will likely benefit from this proposed solution. The National Oceanic and Atmospheric Administration Fisheries Service recently drafted a proposal to create a marine protected area for killer whales, and other conservationists are working to establish similar areas for additional whale species.
Source
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