WASHINGTON (CN) - The National Marine Fisheries Service has finalized its listing of the Tanzanian distinct population segment of African coelacanth as a threatened species under the Endangered Species Act. No critical habitat has been designated because the geographical area occupied by the fish is outside U.S. jurisdiction, and no unoccupied areas in U.S. waters have been identified as essential for the species' conservation, according to the action published Tuesday. The listing was spurred by a petition from the WildEarth Guardians conservation group in 2013.
"Coelacanths swam the oceans when dinosaurs ruled the earth, but they are facing serious threats in the modern world," Taylor Jones, endangered species advocate for WildEarth Guardians, said. "We're thrilled this incredible living fossil is receiving stronger protections."
The coelacanth was known through the fossil record, but was thought to have become extinct 65 million years ago until a living specimen was discovered in 1938 off the coast of South Africa. The living species bears a "strong morphological resemblance to fossils that date back over 400 million years," the agency said. As one of only a few surviving species of lobe-finned fish, it is believed to fit somewhere in the evolutionary gap between aquatic and terrestrial species. Lobe-finned fish, like coelacanths and lungfish, are closely related to modern tetrapods, or four-limbed vertebrates, according to the agency's status report on the species.
The Tanzanian population is one of only three small isolated populations of African coelacanth, and the loss of any one of these populations from natural disasters could threaten the survival of the entire species, the agency said. According to last year's listing proposal, the Tanzanian population, in particular, faces fishing threats as bycatch in shark gillnets and from warming oceans due to climate change, and faces a potential threat from construction of a planned deep water port at Mwambami Bay.
"Our oceans are facing serious threats, and we are losing species at an unprecedented rate," Jones said. "More than half of marine species may be at risk of extinction by 2100 without significant conservation efforts. Despite this grave situation, the U.S. largely fails to protect marine species under the ESA. Of the 2,216 species protected under the Act, only 125 (roughly 5 percent) are marine species," the WildEarth Guardians said in their reaction statement to the listing.
The unique characteristics of this fish also contribute to its vulnerability. These large deep water bony fish, which appear to be dark blue in the water, can descend to depths of 2300 feet to feed, and are thought to live in deep submarine caves and canyons for protection from predators. They need very cold water to maintain the correct oxygen saturation levels in their blood, which limits their distribution. They are long-lived, perhaps up to 100 years, but slow to reproduce, with a 3 year gestation rate, which limits their ability to recover from sudden population declines. The Tanzanian population has low genetic diversity, and could be at an increased risk of "random genetic drift" and "the fixing of recessive detrimental genes" that could increase the species' extinction risk, the agency said.
Listing under the Endangered Species Act (ESA) for foreign species means there are restrictions on harming or killing the species for parties subject to U.S. jurisdiction, and the listing increases recognition of the species' plight. Conservation efforts are promoted for "federal and state agencies, foreign entities and private groups and individuals," the agency said.
"Scientists estimate that 227 species would have gone extinct by 2006 if not for ESA protections. Listing species with global distribution helps focus U.S. resources toward enforcement of international regulation and recovery of the species," the WildEarth Guardians said.
The final rule is effective April 28.