This Conservation Advice was approved by the Minister on 23 December 2010

Approved Conservation Advice for foliosquama (Leaf-scaled Sea )

(s266B of the Environment Protection and Biodiversity Conservation Act 1999)

This Conservation Advice has been developed based on the best available information at the time this Conservation Advice was approved; this includes existing plans, records or management prescriptions for this species.

Description Aipysurus foliosquama, Family Hydrophiidae, also known as the Leaf-scaled , is a small viviparous, slender snake (Cogger, 1983) with an average length of 60 cm, although individuals have been recorded up to 90 cm in length (DEWHA, 2010). The species has a small head with large and usually symmetrical scales and pointed snout (Cogger, 1983). The species is dark blackish-brown or purplish in colour with paler cross bands and scattered pale spots with smooth imbricate scales (Cogger, 1983).

Conservation Status The Leaf-scaled Sea Snake is listed as a marine species under the EPBC Act. This species is eligible for listing as critically endangered under the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) (EPBC Act) as it has a restricted geographic distribution and has undergone a very severe reduction in numbers in the past 10 years (TSSC, 2010).

Distribution and Habitat The Leaf-scaled Sea Snake is known from Ashmore and Hibernia Reefs, off the north-west coast of Western Australia. There is a report of a single specimen of the species from the Arafura Sea, off the northern coast of the Northern Territory in the 1970s; however this individual was likely to be a vagrant, possibly transported by cyclonic activity (Guinea pers. comm., 2009). The Leaf-scaled Sea Snake occurs primarily on the reef flats or in shallow waters of the outer reef edges to depths of 10 m (Minton and Heatwole, 1975). The species is known to shelter under coral or rubble at low tide (McCosker, 1975), predating on small coral reef fish that it catches by poking its head into burrows in the sand and then striking at prey (Lukoschek pers. comm., 2009). This species occurs within the North Western Marine Bioregion. The distribution of this species also falls within the Ashmore and Cartier Reef Marine Reserve, managed by the Commonwealth Government.

Threats The main threat to the Leaf-scaled 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 (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). Reported changes to the inner region of Ashmore Reef include sand encroachment, which has caused coral outcrops that previously supported high densities of sea snakes to be filled in with sand (Guinea, 2008). There are also reported changes to the reef flats and drainage

Aipysurus foliosquama Conservation Advice Page 1 of 4 This Conservation Advice was approved by the Minister on 23 December 2010 channels as sand has moved. While natural variability in water temperatures at Ashmore and Hibernia Reefs has not been studied, increases in water temperatures have been observed in Ashmore and the surrounding reefs associated with El Niño events (DEWHA, 2002). Major El Niño events have occurred in Australia in 1998 (coinciding with severe coral bleaching), 2002, 2006 and 2009 (BOM, 2010) which may have impacted the species directly or indirectly through contributing to further habitat degradation. Oil and gas exploration, including seismic surveys and exploration drilling, which commenced in the 1990s, also coincided with the species’ decline although the potential impact of these activities on sea snakes has not been quantified (Guinea pers. comm., 2009). Unsustainable and illegal fishing practices are currently recognised as the most significant direct and indirect threat to natural processes and biological diversity in the Ashmore region (DEWHA, 2002). Indonesian fishers have historically fished Ashmore and surrounding reefs for sea cucumbers and shark fin (DEWHA, 2002), which may have led to impacts on the species as a result of bycatch.

Research Priorities Research priorities that would inform future regional and local priority actions include:  More precisely assess population size, distribution and ecological requirements of this species.  Clearly define past, current and future threats which have impacted the species and the relative impacts of threatening processes.  Undertake survey work in suitable habitat and potential habitat to locate any additional populations or remnants, including identification of possible populations outside Australian waters.  Conduct more research to determine how the species or similar species respond to reef degradation and shifts in prey abundance.  Investigate the potential impacts on the species from diseases and parasites.

Regional Priority Actions The following regional priority recovery and threat abatement actions can be undertaken to support the recovery of the Leaf-scaled Sea Snake. Habitat Loss, Disturbance and Modification  Identify remnant populations of high conservation priority.  Monitor known populations to identify key threats.  Ensure there is no disturbance in areas where the Leaf-scaled Sea Snake occurs, excluding necessary actions to manage the conservation of the species.  Monitor changes to sea water temperatures and sea levels. Conservation Information  Raise awareness of the Leaf-scaled Sea Snake within the local community and commercial fisheries, in particular fisheries activities off the Western Australian coast. Enable Recovery of Additional Populations  Investigate options for enhancing or establishing additional populations such as captive breeding and release.

This list does not necessarily encompass all actions that may be of benefit to the Leaf-scaled Sea Snake, but highlights those that are considered to be of highest priority at the time of preparing the Conservation Advice.

Existing Plans/Management Prescriptions that are Relevant to the Species

The following documents may inform protection and management of the Leaf-scaled Snake:

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 ‘Ashmore Reef National Nature Reserve and Cartier Island Marine Reserve (Commonwealth Waters) Management Plans (DEWHA, 2002). This management plan expired on 25 June 2009. Ashmore has since been managed under interim management arrangements which will continue until a new management plan is developed at the conclusion of the marine bioregional planning process for the north-west region. Interim management information is available in ‘Ashmore Reef National Nature Reserve and Cartier Island Marine Reserve Information for Visitor’s (DEWHA, 2009).  ‘Northern Prawn Fishery Bycatch Action Plan. Australian Fisheries Management Authority’ (AFMA, 2007)  ‘North-West Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the North-West Marine Region’ (DEWHA, 2008)  ‘The Action Plan for Australian ’ (Cogger et al., 1993)

These prescriptions were current at the time of publishing; please refer to the relevant agency’s website for any updated versions.

Information Sources: AFMA (Australian Fisheries Management Authority) (2007). Northern Prawn Fishery Bycatch Action Plan 2007. Prepared in conjunction with the Northern Prawn Fishery Management Advisory Committee. Viewed 9 August 2010. Available on the Internet at: http://www.afma.gov.au/information/publications/fishery/baps/docs_reports/npf_final_ 2007.pdf.

BOM (Australian Bureau of Meteorology) (2010). ENSO Wrap-up. Viewed 12 March 2010. Available on the Internet at: http://www.bom.gov.au/climate/enso/

Chin A, Sweatman H, Forbes S, Perks H, Walker R, Jones G, Williamson D, Evans R, Hartley F, Armstrong S, Malcolm H, Edgar G (2008). Status of the Coral Reefs in Australia and Papua New Guinea. In Status of Coral Reefs of the World (ed Wilkinson C. Global Coral Reef Monitoring Network and Reef and Rainforest Research Centre, Townsville.

Cogger HG, Cameron EE, Sadlier RA and Eggler P (1993). The Action Plan for Australian Reptiles. Australian Nature Conservation Agency, Canberra ACT. Viewed 12 March 2010. Available on the Internet at: http://www.environment.gov.au/biodiversity/threatened/action/reptiles/index.html.

DEWHA (Australian Government Department of the Environment, Water, Heritage and the Arts – formerly Environment Australia) (2002). Ashmore Reef National Nature Reserve and Cartier Island Marine Reserve (Commonwealth Waters) Management Plans. Viewed 5 March 2010. Available on the Internet at: http://www.environment.gov.au/coasts/mpa/publications/pubs/cartier-plan.pdf

DEWHA (Department of the Environment, Water, Heritage and the Arts) (2008). North- West Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the North-West Marine Region. Viewed 9 August 2010

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Available on the Internet at: http://www.environment.gov.au/coasts/mbp/publications/north-west/bioregional- profile.html.

DEWHA (Australian Government Department of the Environment, Water, Heritage and the Arts) (2009). Interim management information is available in Ashmore Reef National Nature Reserve and Cartier Island Marine Reserve Information for Visitors. Viewed 9 August 2010. Available on the Internet at: http://www.environment.gov.au/coasts/mpa/publications/pubs/ashmore-visitors- information.pdf

DEWHA (Australian Government Department of the Environment, Water, Heritage and the Arts) (2010). Species Profile and Threats Database: Aipysurus foliosquama – Leaf-scaled Sea Snake. Viewed 9 August 2010. Available on the Internet at: http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=1118

Graham N, Wilson SK, Hennings S, Polunin N, Robinson J, Bijoux JP and Daw T (2007). Lag Effects in the Impacts of Mass Coral Bleaching on Coral Reef Fish, Fisheries, and Ecosystems. Conservation Biology 21: 1291- 1300.

Guinea ML (2006). Final Report Survey 2005: Sea Snakes of Ashmore Reef, Hibernia Reef and Cartier Island. Charles Darwin University.

Guinea ML (2008). An assessment of Sea Snake Abundance at Ashmore Reef National Nature Reserve, Ashmore Reef and Cartier Island Territory, Stage Three. Charles Darwin University.

Guinea ML (2009). Personal communication by email, 2 November 2009. Lecturer Zoology, Charles Darwin University.

Lukoschek V (2009). Personal communication by email, 23 March 2009; 2 November 2009. University of California.

McCoster JE (1975). Feeding behaviour of Indo-Australian Hydrophiidae. In The Biology of Sea Snakes (ed WA Dunson). University Park Press, Baltimore.

Minton SA and Heatwole H (1975). Sea Snakes from Reefs of the Sahul Shelf. In The Biology of Sea Snakes (ed WA Dunson). University Park Press, Baltimore.

Rees M, Colquhoun J, Smith L and Heyward A, (2003). Surveys of Trochus, Holothuria, Giant Clams and the Coral Communities at Ashmore Reef, Cartier Reef and Mermaid Reef Northwestern Australia: 2003. The Australian Institute of Marine Science.

Smith LD, Gilmore JP and Heyward AJ (2008). Resilience of coral communities on an isolated system of reefs following catastrophic mass-bleaching. Coral Reefs 27: 197–205.

TSSC (Threatened Species Scientific Committee) (2010). Listing advice for Aipysurus foliosquama (Leaf-scaled Sea Snake).

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