Leaf scaled sea snake (Aipysurus foliosquama)
Photo by: Blanche D’Anastasi
While the re-discovery of these two snakes is a huge deal, there is still
much to be done. True Sea Snakes still face many threats. Human
expansion, development of the coasts, pesticide contamination, overfishing,
and global climate change are all likely chipping away at sea snake populations.
Global climate change is a major threat to sea snakes. Record increases in sea
surface temperature in Western Australia in 2010 caused a marine heatwave.
This caused seagrass declines of over 90% in large areas of Shark Bay, a sea
snake hotspot. Sea snakes also declined dramatically after the heatwave.
“We need to find ways to buffer sea snake populations from heat waves, which
are projected to become more severe and frequent as the global climate warms”,
Sea snakes are also susceptible to overfishing, especially due to shrimp trawling.
“A great deal of effort has gone into reducing the impact of shrimp trawling on
sea snakes in Australia, especially in the Northern Prawn Fishery and in
Western Australia”, said D’Anastasi.
"Death By 1000 Cuts"
D'Anastasi conducting field work
Short nose sea snake (Aipysurus apraefrontalis)
Photo by: Grant Griffin, WA Parksand Wildlife Service
Discovering that an animal species is not actually gone for good is exciting news for anyone
concerned about Earth’s biodiversity. Discovering that there are two is a game changer.
Blanche D’Anastasi of James Cook University in Queensland, Australia along with scientists
from the Western Australian Department of Parks and Wildlife, Western Australia Department
of Fisheries, Miami University, Stanford University/NASA, Florida International University and
the Australian Institute of Marine Science are to thank for this amazing discovery.
Through her research D’Anastasi has re-discovered not one but two species of true sea snake
(those belonging to the subfamily Hydrophiinae) previously thought to be extinct. The Short-nosed Sea Snake (Aipysurus apraefrontalis) was discovered for the first time on Ningaloo Reef, while the Leaf-scaled Sea Snake (Aipysurus foliosquama) was re-discovered in Shark Bay, Western Australia by D’Anastasi and her research team.
Both species used to be found at the Ashmore Reef Complex in the Timor Sea, off of the Westcoast of Australia, which has been a marine reserve since 1983. By 2002, both species had disappeared.
Professor Mick Guinea, who has been documenting the sea snake declines in the Timor Sea for over a decade, referred to Ashmore Reef as the “Sea Snake Capital of the World”. Sadly, sea snakes had vanished from Ashmore by 2012.
“Mick had been asking for support for more research to understand the causes of these declines at Ashmore Reef, but he did not get to causal mechanism in time” D’Anastasi said. “Lukoschek et al. 2013 investigated the possible causes of the decline, but there is simply not enough data to tell us what happened.”
While impacts are ongoing, Australia is testing new bycatch reduction devices to cut their impact on non-target species including sea snakes, turtles, sharks, rays, pipefish and mantis shrimps.
“There is still a lot of work to be done, but industry is leading positive and innovative change and that is incredible,” said D’Anastasi. “If we can protect water quality, habitat, and work to rapidly reduce global carbon emissions that lead to global climate change, we can maximize the resilience of sea snake populations.”
Marine reserves are a critical conservation tool, but they are not the sole answer to protecting sea snakes. To conserve sea snakes it is necessary to find new and innovative solutions to the cumulative impacts they are experiencing and to prevent sea snake populations from being lost one by one, suffering a death by 1000 cuts.
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Two sea snake species re-discovered off Australia’s Coast still face the perils of
earth’s changing climate and human neglect.
By Luke Basulto