In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.
|EPBC Act Listing Status||
Listed as Critically Endangered
as Aipysurus apraefrontalis
Listed marine as Aipysurus apraefrontalis
|Listing and Conservation Advices||
Commonwealth Listing Advice on Aipysurus apraefrontalis (Short-nosed Seasnake) (Threatened Species Scientific Committee (TSSC), 2011b) [Listing Advice].
Commonwealth Conservation Advice on Aipysurus apraefrontalis (Short-nosed Seasnake) (Threatened Species Scientific Committee (TSSC), 2011d) [Conservation Advice].
|Recovery Plan Decision||
Recovery Plan not required, further research is required to fully understand the threats and ecological requirements of the species in order to determine the most appropriate management strategies. The actions covered by the conservation advice are considered to be sufficient at this time (23/12/2010).
|Adopted/Made Recovery Plans|
|Policy Statements and Guidelines||
Marine bioregional plan for the North-west Marine Region (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012y) [Admin Guideline].
Federal Register of
Declaration under section 248 of the Environment Protection and Biodiversity Conservation Act 1999 - List of Marine Species (Commonwealth of Australia, 2000c) [Legislative Instrument] as Aipysurus apraefrontalis.
Inclusion of species in the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (113) (23/12/10) (Commonwealth of Australia, 2010b) [Legislative Instrument] as Aipysurus apraefrontalis.
|State Listing Status||
|Non-statutory Listing Status||
|Scientific name||Aipysurus apraefrontalis |
|Species author||M.A. Smith, 1926|
|Other names||Smithohydrophis apraefrontalis |
This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.
The Short-nosed Seasnake is a fully aquatic, small, rather slender snake with a small head and pointed snout. The head is generally brown, as is the body, with 2427 purplish brown crossbands over the body. The head scales are mostly symmetrical. The prefrontal scales are absent thus enabling the nasal scales to touch the frontal scale. The body scales are extremely imbricate (overlapping), or leaf-like and are in 17 rows at the mid-body. The 142160 ventral scales are broad with 1825 subcaudal scales. The Short-nosed Seasnake grows to 60 cm in total length (Cogger 2000; Ehmann 1992b; Smith 1926; Storr et al. 2002).
All seasnakes are air breathing reptiles and must come to the surface to breathe, however they can spend from 30 minutes to two hours diving between breaths. Nostril valves, which prevent air entering the lung while underwater, open inwards and are held shut from behind by erectile tissue engorged with blood (Heatwole 1999). Seasnakes have one elongated cylindrical lung that extends for almost the entire length of their body which is very efficient for gas exchange. Seasnakes also carry out cutaneous respiration where oxygen diffuses from sea water across the snake's skin into tiny blood vessels and carbon dioxide diffuses out (Heatwole 1999).
Seasnakes are able to avoid excess salt accumulation from sea water using a salt excreting gland that sits under the tongue. Seasnakes shed their skin every 26 weeks, which is more frequently than land snakes and more often than needed for growth alone. The process involves rubbing their lips against coral, or other hard substrate, to loosen the skin. The seasnake then catches the skin against something to anchor it and moves slowly forward, leaving the skin turned inside out behind it. Skin shedding allows seasnakes to rid themselves of fouling marine organisms such as algae, barnacles and bryozoans (Heatwole 1999).
The Short-nosed Seasnake is endemic to Western Australia, and has been recorded from Exmouth Gulf, Western Australia (Storr et al. 2002) to the reefs of the Sahul Shelf, in the eastern Indian Ocean. Most specimens have been collected from Ashmore and Hibernia Reefs (Minton & Heatwole 1975), although some are from the Arafura Sea (Shuntov 1971). The current extent of occurrence is 160 000 km2 and the current area of occupancy is 227 km2 (Guinea 2003).
The Short-nosed Seasnake was the third most common species encountered, on the reef flat, at Ashmore Reef by Guinea and Whiting (2005). It was relatively common in reef surveys from 1994–1998 but has become scarce at Ashmore Reef and has not been recorded there since the late 1990s despite a five fold increase in survey effort (DEWHA 2008b; Guinea 2006, 2007; Lukoschek et al. 2013).
The species features in surveys of the Sahul Shelf seasnakes in 1974 (Minton & Heatwole 1975), in biological resource surveys of Cartier Island and Hibernia Reef (Russell & Hanley 1993) and surveys of Ashmore Reef, Cartier Island and Hibernia Reef between 1994 and 2007 (Guinea 1995, 2006; Guinea & Whiting 2005) but has not been seen in surveys of Ashmore Reef and Hibernia Reef since 1998 (DEWHA 2008b; Guinea 2007).
The Short-nosed Seasnake occurs at Ashmore Reef National Nature Reserve, (Guinea & Whiting 2005), which is a Commonwealth Marine Park Area and is also part of the North-west Bioregion (DEWHA 2008b).
The species prefers the reef flats or shallow waters along the outer reef edge in water depths to 10 m (Cogger 2000; Guinea 1993, 1995; McCosker 1975). The species has been observed during daylight hours, resting beneath small coral overhangs or coral heads in 12 m of water (McCosker 1975). Guinea and Whiting (2005) reported that very few Short-nosed Seasnakes moved even as far as 50 m away from the reef flat.
Generally, seasnakes are long-lived and slow-growing with small broods and high juvenile mortality. Little is known of the age at which seasnakes reach sexual maturity (DEWHA 2008b).
All phases of the reproductive cycle of seasnakes takes place in the sea and reproductive seasonality varies among the species. All members of the Hydrophiidae family are viviparous (giving birth to live young), with a gestational period of 6-7 months, indicating that females are unlikely to breed every year (Cogger 1996; DEWHA 2008b).
Male seasnakes have two penises (hemipenes), each is an autonomous, independently functioning penis, but only one is used during mating. Mating takes place for long periods and seasnakes must surface for air during that time. The female controls breathing and as she swims to the surface the male is pulled along attached via the hemipenis. At the surface the male needs to gulp for air or he has to wait until the next time the female comes up the surface to breathe. Males are unable to disengage until mating is finished (Heatwole 1999).
Stomach contents reveals that the Short-nosed Seasnake eats fish (Gobiidae: Eviota sp.) (Voris 1972) and eels (Smith 1926).
The Short-nosed Seasnake is distinctive because of its small and pointed head shape and the darker banding along its slender body (Cogger 2000).
Seasnakes that inhabit coral reefs and lagoons can be surveyed by travelling slowly along transects (for example at about four knots) in a small boat, and visually identifying snakes observed within 3 m of the path of the boat. Species can be distinguished by this method if the water is up to 3 m deep. A Manta board with an observer can be towed at a speed of 2 knots over transects of the reef during high and low tide. A thin tow rope 25 m in length enables surveys to be conducted on snorkel to depths in excess of 12 m when the bottom is not visible from the surface (Francis 2006; Guinea 2007).
At low tide, surveys can be done on foot, for example by searching the reef flat along transects that are 1000 m long and 20 m wide (Guinea & Whiting 2005). The Short-nosed Seasnake comprised 14% of observations of sea snakes during low tide surveys of the reef flat at Ashmore Reef (Guinea & Whiting 2005).
Seasnakes that are swimming on the surface of the water can be captured using a dip net (Porter et al. 1997). In shallow water such as estuaries, they can also be captured in a seine net (Limpus 1975). Snakes that are underwater and either active or resting can also be hand-netted by someone who is snorkelling or SCUBA diving, using a cylindrical net 300 mm in diameter and 1700 mm long, with 10 mm mesh. The catcher wears protective gloves and a wet suit, and gently grasps the snake through the mesh at the base of the net, drawing the snake in until the top of the net can be twisted shut (Guinea 2003; Guinea & Whiting 2005). Alternatively, snakes that are resting can be captured by grasping the snake both behind the head and by the mid-body at once. Pillstrom tongs and gloves can be used for this, although mechanical restraint may injure the snake and increase its aggressiveness (Heatwole 1975).
Indirectly, human activities can interact with seasnakes through the degradation of seasnake habitat. Seasnakes may be affected by oil spills and other contamination, dredging activities and increased boat traffic causing boat strikes and disruption of feeding behaviour (Cogger 2000; Hobday et al. 2006).
The long-term effect of climate change on seasnakes is unclear but an increase in the water temperature, frequency of bleaching events, reduced rates of calcification, increased sediment loads, higher sea levels and changes in the intensity and frequency of storm activity are also likely to have a negative effect on coral reef habitats, which are used by Short-nosed Seasnakes (Cogger 2000; Hobday et al. 2006).
Commercial fish and prawn trawling
While the Short-nosed Seasnake inhabits coral reefs, and is rare in the by-catch of trawling operations (M. Guinea 2001, pers. comm.), trawling for fish now occurs closer to reefs than it did a decade ago (Milton 2001). Wassenberg and colleagues (2001) reported that around a quarter to three-quarters of seasnakes caught during trawling operations drowned or died from injuries, depending on the duration of trawling.
Incidental catch and death in commercial prawn trawling fisheries appears to be the biggest threat to seasnakes in the North-west Marine Bioregion (Guinea 2007). High catch rates are exacerbated by the high death rate of snakes caught in trawl nets. Even when retained aboard to recuperate, seasnakes seldom survive (Guinea 2007). Seasnakes may be more vulnerable to overfishing than other species because of their longevity and low reproductive rates. In addition, females appear to be caught more often than males (Fry et al. 2001).
The Northern Prawn Fishery (NPF) extends into the easternmost part of the North-west Marine Bioregion to Cape Londonderry and has historically had high levels of interaction with seasnakes. However, due to the small area and shorter season of the Northern Prawn Fishery in the North-west Marine Region, the number of seasnakes caught in the region is likely to be much lower (DEWHA 2008b).
Other prawn fisheries in the North-west Bioregion, such as the Pilbara Trawl Fishery, the Exmouth Gulf Prawn Fishery and the Shark Bay Prawn Fishery, also occasionally catch small numbers of seasnakes, however, their impact on seasnake populations is considered negligible (DEWHA 2008b).
The decline of sea snakes at Asmore Reef are likely to be multi faceted and possibly related to overall ecosystemdecline. If habitat degradation has driven declines at the reefm than increases in live coral cover in the late 2000s may point to a potential recovery of sea snakeas (Lukoschek et al. 2013). Nevertheless, declines of this species at that reef preceeded major bleaching events in late 1990s (Lukoschek et al. 2013).
Seasnakes are becoming rare at Ashmore Reef and no Short-nosed Seasnakes have been recorded at Ashmore Reef for several years (DEWHA 2008b). The reason for this decline has not been identified but is likely to be environmental. A close examination of long term data sets of physical and remotely sensed data may reveal long term environmental changes that are underway on the Sahul Shelf (Francis 2006; Guinea 2007).
Turtle Excluder Devices and Bycatch Reduction Devices
Turtle Excluder Devices (TEDS) are hard grids placed in trawl nets to exclude turtles and other large animals, and Bycatch Reduction Devices (BRDs) are escape grids designed to enable smaller animals to swim out of trawl nets. The NPF has a legal obligation to avoid captures of threatened and protected species such as seasnakes, by using TEDs and BRDs. Between 2003–2006, Milton and colleagues (2008, 2009) examined the performance of different types of BRDs in the NPF and found that catches of seasnakes were reduced by 43% on those vessels where a Fisheye BRD was positioned less than 70 meshes from the codend. A separate study with a scientific observer undertook trials with a 'popeye' Fishbox BRD. This BRD reduced seasnake catch by 85%. All species had almost 100% survival in trawls of less than two hours.
Fishing vessel numbers
In 2007, there was a major reduction in the size of the NPF fleet and, by 2008, there were only 56 vessels operating, compared with 96 vessels in 2006. This change in the level of fishing effort is likely to further reduce the impact of trawling on seasnakes (Milton et al. 2008).
Marine bioregional plans have been developed for four of Australia's marine regions - South-west, North-west, North and Temperate East. Marine Bioregional Plans will help improve the way decisions are made under the EPBC Act, particularly in relation to the protection of marine biodiversity and the sustainable use of our oceans and their resources by our marine-based industries. Marine Bioregional Plans improve our understanding of Australia's oceans by presenting a consolidated picture of the biophysical characteristics and diversity of marine life. They describe the marine environment and conservation values of each marine region, set out broad biodiversity objectives, identify regional priorities and outline strategies and actions to address these priorities. Click here for more information about marine bioregional plans.
The Short-nosed Seasnake has been identified as a conservation value in the North-west (DSEWPaC 2012y) Marine Region. See Schedule 2 of the North-west Marine Bioregional Plan (DSEWPaC 2012y) for regional advice. The "species group report card - marine reptiles" for the North-west (DSEWPaC 2012y) Marine Region provides additional information.
The following documents may inform on protection and management of the Short-nosed Seasnake:
- Ashmore Reef National Nature Reserve and Cartier Island Marine Reserve Management Plans (EA 2002a)
- Final Report: Survey 2005: Sea Snakes of Ashmore Reef, Hibernia Reef and Cartier Island (Guinea 2006)
- Northern Prawn Fishery Bycatch Action Plan. (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 2008b)
- The Action Plan for Australian Reptiles(Cogger et al. 1993).
The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.
|Threat Class||Threatening Species||References|
|Biological Resource Use:Fishing and Harvesting Aquatic Resources:Harvesting of shark body parts||Commonwealth Listing Advice on Aipysurus apraefrontalis (Short-nosed Seasnake) (Threatened Species Scientific Committee (TSSC), 2011b) [Listing Advice].|
|Biological Resource Use:Fishing and Harvesting Aquatic Resources:Illegal take||Commonwealth Listing Advice on Aipysurus apraefrontalis (Short-nosed Seasnake) (Threatened Species Scientific Committee (TSSC), 2011b) [Listing Advice].|
|Biological Resource Use:Fishing and Harvesting Aquatic Resources:Incidental capture and death due to trawling fishing activities||Commonwealth Listing Advice on Aipysurus apraefrontalis (Short-nosed Seasnake) (Threatened Species Scientific Committee (TSSC), 2011b) [Listing Advice].|
|Biological Resource Use:Fishing and Harvesting Aquatic Resources:Mortality due to capture, entanglement/drowning in nets and fishing lines|
|Climate Change and Severe Weather:Habitat Shifting and Alteration:Coral bleaching|
|Climate Change and Severe Weather:Habitat Shifting and Alteration:Habitat loss, modification and/or degradation|
|Climate Change and Severe Weather:Habitat Shifting and Alteration:Habitat modification, destruction and alteration due to changes in land use patterns|
|Climate Change and Severe Weather:Temperature Extremes:Elevated water temperatures|
|Energy Production and Mining:Oil and Gas Drilling:Exploration drilling|
|Energy Production and Mining:Oil and Gas Drilling:Seismic survey activities|
Australian Fisheries Management Authority (AFMA) (2007). Northern Prawn Fishery Bycatch Action Plan 2007. [Online]. Prepared in conjunction with the Northern Prawn Fishery Management Advisory Committee. Available from: http://www.afma.gov.au/information/publications/fishery/baps/docs_reports/npf_final_2007.pdf.
Brewer, D., N. Rawlinson, S. Eayres & C. Burridge (1998). An assessment of bycatch reduction devices in a tropical Australian prawn trawl fishery. Fisheries Research. 36:195-215.
Cogger, H.G. (2000). Reptiles and Amphibians of Australia - 6th edition. Sydney, NSW: Reed New Holland.
Cogger, H.G., E.E. Cameron & H.M. Cogger (1983). Amphibia and Reptilia. In: Walton, D.W., ed. Zoological Catalogue of Australia. 1. Netley, South Australia: Griffin Press Limited.
Cogger, H.G., E.E. Cameron, R.A. Sadlier & P. Eggler (1993). The Action Plan for Australian Reptiles. [Online]. Canberra, ACT: Australian Nature Conservation Agency. Available from: http://www.environment.gov.au/biodiversity/threatened/action/reptiles/index.html.
Department of the Environment, Water, Heritage and the Arts (DEWHA) (2008b). North-West Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the North-West Marine Region. [Online]. Canberra: DEWHA. Available from: http://www.environment.gov.au/coasts/mbp/publications/north-west/bioregional-profile.html.
Ehmann, H. (1992b). Reptiles. In: Strahan, R., ed. Encyclopedia of Australian Animals. Sydney: Angus & Robertson.
Environment Australia (EA) (2002a). Ashmore Reef National Nature Reserve and Cartier Island Marine Reserve Management Plans. [Online]. Available from: http://www.environment.gov.au/coasts/mpa/publications/cartier-plan.html.
Francis, E.J. (2006). The Morphology, Population and Distribution of the Dusky Sea Snake Aipysurus fuscus (Tschudi, 1837). Hons. Thesis. Darwin: School of Science and Primary Industries, Charles Darwin University.
Fry, G.C., A. Milton & T.J. Wassenberg (2001). The reproductive biology and diet of sea snake bycatch of prawn trawling in northern Australia: characteristics important for assessing the impacts on populations. Pacific Conservation Biology. 7:55-73.
Golay, P., H.M. Smith, D.G. Broadley, J.R. Dixon, C. McCarthy, J-C. Rage, B. Schatti & M. Toriba (1993). Endoglyphs and Other Major Venomous Snakes of the World a Checklist. Page(s) 478. Aire-Geneva, Switzerland: Azemiops.
Guinea, M.L. (1993). Reptilia, Aves and Mammalia. In: in Russell, B.C. & J.R. Hanley, eds. Survey of Marine Biological and Heritage Resources of Cartier and Hibernia Reefs, Timor Sea. Page(s) 74 - 83. Darwin: Northern Territory Museum of Arts and Sciences.
Guinea, M.L. (1995). The sea turtles and sea snakes of Ashmore Reef Nature Reserve. Page(s) 67. Darwin: Northern Territory University.
Guinea, M.L. (2001). Personal Communication.
Guinea, M.L. (2003). Ecology, Systematics and Biogeography of Sea Snakes. Ph.D. Thesis. Darwin: Northern Territory University.
Guinea, M.L. (2006). Final Report Survey 2005: Sea snakes of Ashmore Reef, Hibernia Reef and Cartier Island. Consultant's report to the Department of the Environment and Water Resources, Canberra. [Online]. Canberra: Department of the Environment and Water Resources. Available from: http://www.afma.gov.au/information/publications/fishery/baps/docs_reports/npf_final_2007.pdf.
Guinea, M.L. (2007). Survey March 16 - April 2 2007: Sea snakes of Ashmore Reef, Hibernia Reef and Cartier Island with comments on Scott Reef. Final Report to the Department of the Environment and Water Resources, Canberra. Darwin: Charles Darwin University.
Guinea, M.L. & S.D. Whiting (2005). Insights into the distribution and abundance of sea snakes at Ashmore Reef. The Beagle (Supplement 1). Page(s) 199-206.
Heatwole, H. (1975). Attacks by sea snakes on divers. In: Dunson, W.A, ed. The Biology of Sea Snakes. Page(s) 501-515. Baltimore: University Park Press.
Heatwole, H. (1999). Sea Snakes. In: Australian Natural History Series. Page(s) 148. Sydney, NSW: UNSW Press.
Hobday, A.J., T.A. Okey, E.S. Poloczanska, T.J. Kunz & A.J. Richardson (2006). Impacts of climate change on Australian Marine Life.
Limpus, C.J. (1975). Coastal sea snakes of subtropical Queensland waters (23° to 28° South Latitude). In: Dunson, W. A., ed. The Biology of Sea Snakes. Page(s) 173-182. Baltimore: University Park Press.
Lukoschek, V., M. Beger, D. Ceccarelli, Z. Richards & M. Pratchett (2013). Enigmatic declines of Australia’s sea snakes from a biodiversity hotspot. Biological Conservation. 166:191-202.
McCosker, J.E. (1975). Feeding behaviour of Indo-Australian Hydrophiidae. In: Dunson, W. A., ed. The Biology of Sea Snakes. Page(s) 217-232. Baltimore: University Park Press.
Milton, D, S. Zhou, G. Fry & Q. Dell (2008). Risk assessment and mitigation for sea snakes caught in the Northern Prawn Fishery. FRDC Project 205/051. Final Report. CSIRO Marine and Atmospheric Research. Cleveland, Queensland: CSIRO Marine and Atmospheric Research.
Milton, D.A. (2001). Assessing the susceptibility to fishing of populations of rare trawl bycatch: sea snakes caught by Australia's Northern Prawn Fishery. Biological Conservation. 101:281-290.
Milton, D.A., G.C. Fry & Q. Dell (2009). Reducing impacts of trawling on protected sea snakes: by-catch reduction devices improve escapement and survival. Marine and Freshwater Research. 60:824-832.
Minton, S.A. & H. Heatwole (1975). Sea snakes from three reefs of the Sahul Shelf. In: Dunson, W. A., ed. The Biology of Sea Snakes. Page(s) 141-144. Baltimore: University Park Press.
Porter, R., S. Irwin, T. Irwin & K. Rodrigues (1997). Records of the marine snake species from the Hey-Embley and Mission Rivers, Far N Qld. Herpetofauna. 27 (2): 2-7.
Russell, B.C. & J.R. Hanley (1993). Survey of the marine biological resources and heritage values of Cartier and Hibernia Reefs, Timor Sea. Darwin, Northern Territory: Department of Music, Arts & Sciences.
Shuntov, V.P. (1971). Sea snakes of the North Australian Shelf. Ekologiya. 4:65-72.
Smith, M.A. (1926). Monograph of the sea-snakes (Hydrophiidae). In: British Museum Natural History. Page(s) 130. London: British Museum.
Storr, G.M., L.A. Smith & R.E. Johnstone (2002). Snakes of Western Australia. Page(s) 309. Perth, Western Australia: Western Australian Museum.
Voris, H.K. (1972). The role of sea snakes (Hydrophiidae) in the trophic structure of coastal oceanic communities. Journal of the Marine Biological Association of India. 14(2):429-442.
Ward, T.M. (1996a). Sea snake bycatch of fish trawlers on the Northern Australian continental shelf. Marine and Freshwater Research. 47:625-630.
Wassenberg, T.J., D.A. Milton & C.Y. Burridge (2001). Survival rates of sea snakes caught by demersal trawlers in northern and eastern Australia. Biological Conservation. 100:271-280.
This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.
Citation: Department of the Environment (2014). Aipysurus apraefrontalis in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Tue, 29 Jul 2014 17:50:38 +1000.