August 2, 2011

The World’s Most Important Marine Conservation Hotspots

Researchers, led by ecologist Sandra Pompa from the National Autonomous University of Mexico, have identified 20 of the most important regions of the world's oceans and lakes that are crucial to ensuring the survival of marine mammals such as seals, whales and porpoises, reports the Guardian.

Marine mammals are under constant threat from climate change, ocean acidification, hunting and other perils. Of the 20 important sites chosen, 11 include creatures that are found nowhere else on Earth, according to the study. Researchers dubbed those sites "irreplaceable" and added that the nine other locales include representatives of 84 percent of all marine mammals.

Pompa said that the most endangered marine mammal is currently the vaquita -- a porpoise that lives in the northern region of the Gulf of California. It is thought to number around 250 individuals in the wild.

"The Baikal seal, it's also a very small-numbered population," said Pompa. "Maybe you can think about the vaquita escaping the Gulf into somewhere else but the Baikal seal can't. It's a freshwater endemic mammal species. If any disruption in the lake should happen or a new sickness, they're all packed in one lake."

The 11 irreplaceable sites include the Hawaiian Islands, Galapagos Islands, Amazon River, San Felix and Juan Fernandez Islands off the coast of Chile, Mediterranean Sea, Caspian Sea, Lake Baikal in Russia, Yangtze River, Indus River, Ganges River and the Kerguelen Islands in the southern Indian Ocean.

The 9 sites picked for their mammal diversity were along the coasts of Baja California, much of the eastern coast of the Americas (the Atlantic coast of the U.S. and including coastal areas of Cuba, Hispaniola, Colombia and Venezuela), Peru, Argentina, Northwestern Africa, South Africa, Japan, Australia and New Zealand.

Pompa said that the marine ecosystems around the world are rapidly deteriorating, particularly due to habitat degradation, introduction of exotic species and over-exploitation of natural resources. Many species have experienced severe population losses and several have already become extinct, including the Atlantic gray whale and the Steller's sea cow.

The most recent extinction, declared in 2008, was the baiji, a type of porpoise, from the Yangtze River in China.

The team of researchers tried to identify which regions of the world's oceans were most crucial for the world's 129 marine mammal populations. They reported their results in Monday's issue of the Proceedings of the National Academy of Sciences (PNAS).

To identify which regions were most crucial, Pompa and her team split the ocean up into a grid of roughly 6,200-square-mile boxes and examined which species lived in which boxes. The team also assigned values to the boxes based on whether they contained important feeding grounds or if they were migration routes.

Pompa correlated her map with information on human impacts such as climate disruption, ocean-based pollution and commercial shipping. Areas with no impact from such impacts were scored a zero, while areas with high impact were scored a three.

"Seventy percent of the most impacted areas were near a key conservation site," Pompa said. "We are competing with [the sea mammals] in terms of shipping or ocean pollution. We want to build industry or touristic attractions and it's their home."

Pompa and her team said the maps should be the start of a conservation effort about where to site new conservation areas to preserve the world's most precious marine mammals. "Perhaps you are a government or NGO, you can use this information as a tool depending on the aim you have," said Pompa.

"Marine conservation is barely beginning. Marine mammals are great species because they represent healthy ecosystems so, if you begin to lose the species that give you a clue to a healthy ecosystem then you start with the degradation of all of the oceans," said Pompa.

"A visual projection of where is the richness, where are the endangered species, which corridors we need to protect in order to have all the species present in the world, it's a nice start to know where to focus the effort," she added. 


On the Net: