Call to save Australia's disappearing sea snakes

May 04, 2012

Australia’s sea snakes may be more in danger of extinction than previously thought, marine scientists say.

New research on turtleheaded that frequent coral reefs in Australia and nearby New Caledonia has found they are strongly attached to their home reef and rarely venture even a few kilometres to neighboring reefs.

Researchers from the ARC Centre of Excellence for Coral Reef Studies (CoECRS) and The University of Sydney used genetic ‘fingerprinting’ to show that this behavior has resulted in significant genetic differentiation in populations of the turtleheaded sea snake, Emydocephalus annulatus, living on adjacent reefs. These snakes occur in shallow-water coral reef habitats from the Philippines to the Great Barrier Reef and from New Caledonia to north western Australia.

“The genetic divergence we found confirms that snakes rarely travel to other locations to mate, regardless of the distance, and means that if one population were to decline or disappear, it is unlikely to be ‘replenished’ by neighboring snakes, because snakes rarely move between reefs,” says lead researcher Dr. Vimoksalehi Lukoschek from CoECRS and James Cook University.

“For eight years, sea snakes on two reefs that are adjacent to each other in New Caledonia have been captured, tagged with a microchip device and released,” says Prof. Rick Shine from the University of Sydney. “In almost all instances, the snakes were repeatedly re-captured on the same reef during summers and winters.

“This finding matches with the genetic dataset, which showed that snakes on their home reefs were more closely related to each other genetically, than they were to snakes on the neighboring reef. Similar genetic patterns have also been documented for other coral reef sea snake species.”

“The implications are that coral reef sea snakes are extremely vulnerable to disturbances in their local habitats, which could be caused by human activities or environmental changes,” says Dr Lukoschek. “This is of great concern, given that some Australian populations of turtleheaded and other reef-associated sea snakes have undergone massive declines or local extinctions in recent years, particularly at Ashmore Reef in the Timor Sea, and also on some reefs in the southern Great Barrier Reef.”

While the reasons for this behavior of sea snakes are still unknown, physical barrier is not one of them, the researchers say.

“Although movement between reefs by sea snakes can be hindered by deep-water channels, our study sites were in close proximity and connected by shallow-water reef. These sea snakes can swim well and could easily have travelled to the neighbouring reef but they didn’t.”

“It is possible that they don’t move far because they forage exclusively on the eggs of reef fishes that are laid in nests on reefs, so they stick to reefs where they know the locations of those nests. Land snakes have been shown to have memory and the same may also be true for sea snakes. It is also possible that they like to stay close to their ‘relatives’.”

The findings raise doubts on the ability of Australia’s coral reef sea snake populations to recover from serious setbacks and highlight the need for greater awareness about the conservation status of these species.

“Perhaps because they are snakes, sea snakes have a very low profile on the conservation agenda. Some populations of coral reef sea snakes have declined sharply over the past ten years, but this has gone largely unnoticed and almost no effort has been made to find out why,” Dr. Lukoschek says. “We need to pay more attention to these species, particularly because most of the coral reef species that have disappeared from Ashmore Reef are endemic to Australia.”

Explore further: Five anthropogenic factors that will radically alter northern forests in 50 years

More information: Ecology and Evolution, DOI: 10.1002/ece3.256

add to favorites email to friend print save as pdf

Related Stories

Isolated reefs regenerate faster: study

Nov 28, 2011

A recent study published in CSIRO’s Marine & Freshwater Research reveals isolated reefs may have a better ability to regenerate compared to those closer to human activity.

Ongoing collapse of coral reef shark populations

Dec 04, 2006

Investigators have revealed that coral reef shark populations are in the midst of rapid decline, and that "no-take zones" -- reefs where fishing is prohibited -- do protect sharks, but only when compliance with no-take regulations ...

Sea cucumbers could be key to preserving coral reefs

Jan 31, 2012

(PhysOrg.com) -- Tropical sea cucumbers could play a key role in saving coral reefs from the devastating effects of climate change, say scientists at One Tree Island, the University of Sydney's research station ...

Coral rehab finding offers hope for Great Barrier Reef

Sep 05, 2011

Coral ecosystems cope much better than was first thought when the reef habitat is fragmented, a new study has found, meaning that efforts to restore even small parts of the damaged Great Barrier Reef could ...

Recommended for you

More, bigger wildfires burning western US, study shows

3 hours ago

Wildfires across the western United States have been getting bigger and more frequent over the last 30 years – a trend that could continue as climate change causes temperatures to rise and drought to become ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

gregor1
1 / 5 (1) May 04, 2012
Perhaps the genetic diversity of the populations is too low to sustain them. If so, physically mixing them may help

More news stories

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

Clean air: Fewer sources for self-cleaning

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...

There's something ancient in the icebox

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Researchers discover target for treating dengue fever

Two recent papers by a University of Colorado School of Medicine researcher and colleagues may help scientists develop treatments or vaccines for Dengue fever, West Nile virus, Yellow fever, Japanese encephalitis and other ...