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Post by Melanie on Aug 25, 2011 15:21:47 GMT
The main threat to the Short-nosed Sea Snake appears to be degradation of reef habitat, primarily as a result of coral bleaching. Severe bleaching events are known to cause changes in the assemblages of associated fish species resulting in a likely decrease in fish prey species for sea snakes (Graham et al., 2007). Observed changes in reef ecology since 1998 correspond to the disappearance of the Leaf-scaled Sea Snake at Ashmore Reef, but have not been quantified. A high surface water temperature stress event was experienced in early 2003 at Ashmore Reef that resulted in widespread coral mortality, with some areas that had coral cover of 50–60 per cent during 2000 showing rare coral coverage in 2003 (Rees et al., 2003). Approved Conservation Advice for Aipysurus apraefrontalis (Short-nosed Sea Snake) www.environment.gov.au/biodiversity/threatened/species/pubs/1115-conservation-advice.pdf |
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Post by surroundx on Dec 1, 2013 5:23:59 GMT
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Post by Sebbe on Apr 13, 2014 10:23:49 GMT
Enigmatic declines of Australia’s sea snakes from a biodiversity hotspotDeclines in the abundance of marine vertebrates are of considerable concern, especially when they occurin isolated locations relatively protected from most major anthropogenic disturbances. This paper reportson sustained declines in the abundance and diversity of sea snakes at Ashmore Reef, a renowned biodi-versity hotspot in Australia’s Timor Sea. Surveys conducted in eight years between 1973 and 2010recorded the highest abundances (average 42–46 snakes day1) and species richness (nine species) in1973 and 1994. In 2002 abundance had declined by more than 50% (21 snakes day1) and only five spe-cies were recorded. Since 2005 abundances have been consistently low (1–7 snakes day1), with just twospecies,Aipysurus laevisandEmydocephalus annulatus, recorded in significant numbers. Despite extensivesearches since 2005 (especially in 2010) five species of sea snake historically abundant at Ashmore Reefhave not been sighted and are presumed to have become locally extinct. These species include threeTimor Sea endemicsAipysurus apraefrontalis,Aipysurus foliosquama,Aipysurus fuscus, and one AustralasianendemicAipysurus duboisii. Declines in the abundance and diversity of sea snakes at Ashmore Reef cannotbe attributed to differences in survey methods among years. Ashmore Reef was declared a National Nat-ure Reserve (IUCN Category 1a) in 1983 and, although the causes for the declines are not known, this pro-tection has not prevented their occurrence. We discuss possible causes for these enigmatic declineshowever, in order to implement effective management strategies, studies are needed to determinewhy sea snakes have disappeared from Ashmore Reef. www.dulvy.com/uploads/2/1/0/4/21048414/snakes.pdf
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Post by surroundx on Feb 20, 2015 11:42:37 GMT
Molecules and Morphology Reveal Overlooked Populations of Two Presumed Extinct Australian Sea Snakes (Aipysurus: Hydrophiinae)Abstract The critically endangered leaf-scaled (Aipysurus foliosquamaI) and short-nosed (A. apraefrontalis) sea snakes are currently recognised only from Ashmore and Hibernia reefs ~600km off the northwest Australian coast. Steep population declines in both species were documented over 15 years and neither has been sighted on dedicated surveys of Ashmore and Hibernia since 2001. We examine specimens of these species that were collected from coastal northwest Australian habitats up until 2010 (A.foliosquama) and 2012 (A. apraefrontalis) and were either overlooked or treated as vagrants in conservation assessments. Morphological variation and mitochondrial sequence data confirm the assignment of these coastal specimens to A. foliosquama (Barrow Island, and offshore from Port Hedland) and A.apraefrontalis (Exmouth Gulf, and offshore from Roebourne and Broome). Collection dates, and molecular and morphological variation between coastal and offshore specimens, suggest that the coastal specimens are not vagrants as previously suspected, but instead represent separate breeding populations. The newly recognised populations present another chance for leaf-scaled and short-nosed sea snakes, but coastal habitats in northwest Australia are widely threatened by infrastructure developments and sea snakes are presently omitted from environmental impact assessments for industry. Further studies are urgently needed to assess these species’ remaining distributions, population structure, and extent of occurrence in protected areas. Source: Sanders, K. L., Schroeder, T., Guinea, M. L. and Rasmussen, A. R. (2015). Molecules and Morphology Reveal Overlooked Populations of Two Presumed Extinct Australian Sea Snakes (Aipysurus: Hydrophiinae). PLoS ONE 10(2): e0115679.
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Post by Melanie on Feb 20, 2015 11:55:39 GMT
Rediscovered in 2012
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Post by Melanie on Apr 11, 2015 14:41:24 GMT
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Post by Melanie on Dec 21, 2015 9:47:00 GMT
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Post by surroundx on Apr 22, 2021 13:21:24 GMT
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Post by koeiyabe on May 17, 2021 0:50:05 GMT
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