CAIRNS, Australia, Dec. 21 (UPI) -- Biologists in Australia assumed both the short-nose sea snake and leaf-scaled sea snake were extinct. Not so fast, scientists.
The critically endangered species hadn't been seen in at least 15 years. But as they recently recounted in the journal Biological Conservation, scientists located both snakes unexpectedly off the coast of Western Australia.
The rare short-nose sea snake's only known habitat was the water surrounding the Ashmore Reef in the Timor Sea. But the species hadn't been seen there in nearly two decades.
Earlier this year, however, Grant Griffin, an officer with Western Australia Parks and Wildlife, spotted a pair courting near Ningaloo Reef. Griffin snapped a photo of the snakes, and biologists back on the mainland confirmed the sighting.
"This discovery is really exciting, we get another chance to protect these two endemic Western Australian sea snake species," study author Blanche D'Anastasi, a researcher with the ARC Centre of Excellence for Coral Reef Studies at Jame Cook University, said in a press release.
The other species, the leaf-scaled sea snake, is also endemic to Ashmore Reef. But their most recent sighting, the first in years, occurred more than 1,050 miles south in the thick seagrass beds of Shark Bay. There, scientists found a significant population.
"We had thought that this species of sea snake was only found on tropical coral reefs. Finding them in seagrass beds at Shark Bay was a real surprise," said D'Anastasi.
Unfortunately, this unexpected but positive news was paired with bad news. A number of sea snake species are declining along the Ashmore Reef, and researchers aren't sure why. Sea snakes are vulnerable to trawling, a destructive commercial fishing technique, but fishing is off-limits among the marine sanctuaries surrounding the reef.
"The disappearance of sea snakes from Ashmore Reef could not be attributed to trawling and remains unexplained," said co-author Vimoksalehi Lukoschek, also wtih the Centre of Excellence for Coral Reef Studies.
"Clearly we need to identify the key threats to their survival in order to implement effective conservation strategies if we are going to protect these newly discovered coastal populations," he added.