© Baker, J.L. (2009) Marine Species of Conservation Concern in South Australia Full citation Baker, J.L. (2009) Marine Species of Conservation Concern in South Australia: Volume 1 - Bony and Cartilaginous Fishes. Report for the South Australian Working Group for Marine Species of Conservation Concern. J. Baker (consultant); Science and Conservation Division, and Coast and Marine Conservation branches of S.A. Department for Environment and Heritage (DEH); Marine and Coastal Community Network of S.A. (MCCN), and Threatened Species Network (TSN). Web version published by Reef Watch, South Australia.

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Short-headed Lamprey

Family Name:	Petromyzontidae
Scientific Name:	Mordacia mordax (Richardson, 1846)
Recommended Status in S.A:	Vulnerable B2a+b(ii,iii) (possibly also A2)
Rationale:  The species is included here because (i) although Short-headed Lamprey has a wide distribution in south-eastern Australian States, it is not commonly recorded in South Australia, with few recent records, compared with its historic distribution; (ii) the number of permanent creeks and rivers in S.A. that open to the coast is small, and suitable habitat is thus limited in spatial extent; (iii) lampreys rely upon specific habitat of limited distribution, for spawning – i.e. Short-headed Lamprey reportedly requires permanent creek / river headwaters in good ecological health to complete its life cycle, and significant reduction in the quality of estuarine and freshwater habitat has occurred across the central and south eastern coasts of S.A. during the 20th century. Reductions in the quality and extent of the riverine and stream habitat that is used for spawning and other stages of the life cycle, have occurred in areas such as the Adelaide Plains, the River Murray, and the South-East; (iv) many of the waterways in S.A. into which Short-headed Lampreys previously migrated, are subject to barriers such as weirs, dams and diversions, and many such rivers and streams have also suffer reduced flow due to excess water extraction, as well as increased pollution levels from a variety of sources over the past few decades; (v) Lampreys must overcome both natural and human-made obstacles in order to migrate upstream and reach their breeding habitat, and many lampreys can die during this journey; (vi) the longevity of the species, the probable irregularity of spawning, and the specific habitat requirements for completion of the life cycle, all potentially increase the vulnerability of this species; and (vii) there is little information on the current distribution or abundance of this species in South Australia. Based on the evidence that (a) the current distribution in S.A. is limited spatially (historically from the Adelaide Plains / Gulf St Vincent area, to the Lower South East); (b) within that range, much of the available habitat has been severely modified; (c) a number of recent surveys in suitable habitat (including areas of previous occupancy) have not recorded this species, and it is thus inferred that there may be a decline in the area of occupancy; and (d) recognised threats to critical habitat are still occurring, it is recommended that the species be listed as Vulnerable B2a+b(ii,iii), assuming that the current total area of occupancy in South Australia may be less than 2000km2. The species may also qualify for listing as Vulnerable under the criterion A2, if it can be inferred from decline of area of occupancy that population size may have reduced by up to 30% over the last decade, or three generations. Future surveys and assessment may indicate that this species qualifies for listing as Endangered.

Page Contents

Current Conservation Status

The National Parks and Wildlife Council and Department for Environment and Heritage (2003) has recommended that the species be listed as Endangered, under a schedule of the National Parks and Wildlife Act 1972. Criteria for listing in 2003 were B2b(ii,iii)c(i,ii,iv) (National Parks and Wildlife Council and Department for Environment and Heritage, 2003). In 2007, the Action Plan for South Australian Freshwater Fishes (Hammer et al., 2007) recommended a listing of Vulnerable for this species in South Australia. In 2007, criteria for listing were A2, B2a+b(ii,iii).
Mordacia mordax is considered to be a species of conservation concern in South Australia (Hammer, 2002; Hammer et al., 2007).

Distribution

Southern Australian States

M. mordax is known from N.S.W. (Shoalhaven River and Hawkesbury River are published northern limits), Victoria, Tasmania, and South Australia, with Gulf St Vincent being the published western limit (Glover, in Gomon et al., 1994; Allen, 1989; Paxton et al., 1989, cited by Froese and Pauly, 2008).
The species is reported to be common in Victoria (DPI Victoria, 2003a). There are various records of Short-headed Lamprey from specific locations in coastal drainages across all parts of Victoria (Museum of Victoria records, cited in OZCAM database, 2008; DPI Victoria, 2005b, 2005c, 2005d, 2005e). An incomplete list of examples would include western areas such as the Stokes River in the Glenelg River basin, and the Fitzroy, Moyne and Shaw rivers; central areas such as downstream of Werribee Weir (Werribee River Basin); central eastern areas such as Thomson Reservoir in the Thomson River Basin, and eastern Victorian areas such as B.A. Creek, Brodribb River and Buchan River in the Snowy River Basin (DPI Victoria, 2005b, 2005c, 2005d, 2005e, 2005f).
In Tasmania, the species is considered to be “reasonably common” in many rivers around the State, although the full extent of the distribution in Tasmania is not known (Inland Fisheries Service of Tasmania, 2000).

South Australia - Previous

In general, Mordacia mordax occurs in the central and southern parts of the SA coast and associated drainages, but not on the west coast of S.A., due to lack of suitable habitat.
Historically, the species has been recorded along part of the metropolitan coast (e.g. Glenelg, and Port River / Barker Inlet system); drainages of the Adelaide Hills and plains (e.g. South Para River, Gawler River, Torrens River, Patawalonga catchment, Bremer River, Onkaparinga River, and others); the Coorong and Murray Mouth area (including Lake Alexandrina); various sections of the South Australian portion of the River Murray, from the mouth to the Victorian / N.S.W. / S.A. border; as well as Kangaroo Island, and the South-East (Glover, 1979; Hureau, 1991, cited in Froese and Pauly, 2008; Glover, in Gomon et al., 1994; Hammer, 2002; Catchment Water Management Board, 2004a; S.A. Museum records, cited in OZCAM database, 2008).
Most records of M. mordax that are housed in the S.A. Museum, are from the early and middle decades of the 20^th century, and almost all come from the central coastal part of South Australia (i.e. Mt Lofty Ranges, and Adelaide Hills and Adelaide Plains catchments).
The most westerly extent of Short-headed Lamprey in South Australia is considered to be the catchment area of the Barossa Valley (e.g. including North Para River) (Native Fish Australia – South Australia, 2000).
During a survey of the Gawler River catchment (Hicks and Sheldon, 1999), Mordacia mordax was listed as one of the species that would be expected to have occurred at various sites in the catchment, prior to human disturbance; however no individuals were found during the survey. It is noted that the species was historically recorded in the Gawler River catchment (SA Museum record F 04623, cited in OZCAM database, 2008).
In the past (1870s to 1950s), large numbers of Mordacia mordax (possibly also Geotria australis) have periodically been recorded congregating during the summer months on the seaward side of the River Torrens Outlet (Gulf St Vincent), apparently trying unsuccessfully to migrate into fresh water (Waite 1923; Scott, 1962, cited by Glover, in Gomon et al., 1994). Such records were not prevalent after construction of the weir during the 1950s (Hammer et al., 2007).
There are old museum records of the species from the Coorong area (e.g. Salt Creek, records from 1877) (Hureau, 1991, cited by Froese and Pauly, 2008), and more recent records (see below).

South Australia - Current

Most recent records come from the Murray Mouth region (such as Goolwa Barrage, Hunters Creek and Denver Creek on Hindmarsh Island) , but they are few in number (South Australian Museum records; Higham et al., 2005; Bice et al., 2007; Geddes and Wedderburn, 2007, cited by Hammer et al., 2007). There are also two records from the River Murray channel (SARDI Aquatic Sciences data, cited by Hammer et al., 2007). There is a record from the early 1990s, from a section of the River Murray near the S.A. / Victorian border (S.A. Museum data, cited in OZCAM database, 2004).
During a survey of drainages in the South-East of S.A. in 2000 - 2001, the species was not recorded at any of the sampled sites, but is reported to occur in the South-East region (Hammer, 2002, Table 3.0.1). Divers in Ewens and Piccaninnie Ponds in South Australia evidently occasionally encounter lampreys, and this probably encompasses both the Pouched Lamprey and the Short-headed Lamprey (Hammer, 2002). It is noted that Hammer (2002) also reported the existence of a South Australian Museum specimen of M. mordax, from off the Port MacDonnell coast.
There is a record from the early 1990s, from the Torrens River catchment on the Adelaide Plains (South Australian Museum record, cited in OZCAM database, 2004). The historic large numbers from this area do not now exist (Hammer et al., 2007).

Habitat

Short-headed Lamprey has both freshwater and marine stages to the life cycle, and is dependent upon both habitats.
Adults are found in faster flowing water on the sides of rivers with suitable burrowing habitat and shelter, into which they burrow at night. During the day, G. australis can be found beneath sand or loose stones (McDowall, 1996; Inland Fisheries Service of Tasmania, 2000).
Larvae (ammocoetes) prefer slower flowing water, where they can burrow into mud, sand or silt, often in shallow water or near the edges of rivers, where water current is slow (McDowall, 1996; Inland Fisheries Service of Tasmania, 2000).

Notes on Biology and Behaviour

Size and Age

Juveniles are around 11cm long on average (to around 17cm), and the adults commonly grow to 33cm long (Glover, in Gomon et al., 1994; Inland Fisheries Service of Tasmania, 2000). Koehn and O’Connor (2002) reported that the ammocoetes grow to 17cm; the downstream migrants are around 11cm to 17cm, and the older upstream migrants, around 33cm to 48cm. 
Reported maximum size is 50cm TL (Allen, 1989, cited by Froese and Pauly, 2004) or 56cm (Glover, in Gomon et al., 1994).

Behaviour

Lampreys, together with hagfishes, are the sole surviving representatives of jawless vertebrates. The adult lampreys are parasitic, attaching themselves to a host sea fish, and then extracting blood and muscle tissue. The returning migrating adults are capable of climbing wet vertical faces (Inland Fisheries Service of Tasmania, 2000).

Diet and Feeding Behaviour

The larvae are filter feeders, feeding on algae (e.g. diatoms), detritus and micro-organisms.
Adults during their marine stage are parasitic on marine fish, and adults returning to fresh water do not feed when they enter freshwater (Inland Fisheries Service of Tasmania, 2000). Short-headed Lampreys have been found on species such as Australian Salmon (Arripis truttacea) (in W.A.), Black Bream (Acanthopagrus butcheri) and Yellow-eye Mullet (Aldrichetta forsteri)

Reproduction

Lampreys have several distinct stages in their life cycle. In general, following egg development, newly hatched lampreys complete a larval stage within rivers. Filter-feeding Short-headed Lamprey larvae bury themselves in the substrate of rivers and streams for 3 or 4 years, and feed on microscopic algae. Juveniles migrate as they grow over several years. After a metamorphosis, the juveniles then migrate downstream to the sea in spring, where they become parasitic sub-adults, attaching themselves to a host sea fish, and then extracting blood and muscle tissue. Little is known of the marine stage, except that it lasts for 1-2 years, during which time lampreys grow rapidly. The sub-adult lampreys then return during summer to streams or other fresh water sources, where they complete their development, and then spawn, following an arduous upstream migration lasting months, during which time they do not feed (Glover, in Gomon et al., 1994; Inland Fisheries Service of Tasmania, 2000; Edgar, 2000; Water and Rivers Commission of W.A., 2000b). Specific details of the stages are as follows:
The benthic adults (“upstream migrants”) leave the sea from July to January, with a peak from early September to late November, and ascend into coastal streams and headwaters, particularly in late spring to summer (Potter et al., 1968; Barnharn, 1978; Strahan, 1980a; Sloan, 1984a). During this time, the upstream migrants may burrow deep into the substrate during daylight hours, particularly in fast flowing areas of the stream / river (Potter et al., 1968), and may move upstream during the night, especially during the first and last quarters of the moon (Sloan, 1984a).  One study showed that the main movement occurred with increased water temperature, and an associated reduced river flow (Sloane, 1984a). During this “spawning run”, the upstream migrants can climb rock faces on the side of weirs, and other wet vertical surfaces (Sloane, 1984a; Harris, 1984a; Inland Fisheries Service of Tasmania, 2000).
Spawning occurs in shallow, relatively fast-flowing waters with sand, gravel or pebble substrates, and eggs are usually covered with sand or gravel (Cadwallader and Backhouse, 1983; Beumer, 1979, cited by Koehn and O’Connor, 2002). Egg deposition has also been recorded in U-shaped depressions in the mud (Lake, 1967, cited by Koehn and O’Connor, 2003).
Spawning has variously been recorded between late winter and late spring (Lake, 1967; Hughes and Potter, 1969; Potter, 1970; Sanders, 1973; Hortle, 1979; Allen, 1989, cited by Koehn and O’Connor, 2003, and Froese and Pauly, 2004).
Adult Lamprey probably die after spawning (Cadwallader and Backhouse, 1983, cited by Koehn and O’Connor, 2002; MDBC, 2005). (It is notable that in 1972, R.V. Southcott of the South Australian Museum maintained a captured M. mordax in an aquarium for a period of 2 weeks, during which time it laid 72 eggs, and then died).
The ammocoetes (larvae) are found only in fresh water (usually of gentle flow, such as that along the edge of rivers), and they burrow into sand, silt or mud in such areas, or are found beneath stones (Potter, 1966, 1970; Hughes and Potter, 1969; Hortle, 1979; Strahan, 1980a; Sloane, 1984a, all cited by Koehn and O’Connor, 2002). The ammocoetes may regulate their density, because growth is apparently reduced in high densities (Potter, 1980, cited by Koehn and O’Connor, 2002).
As they grow, the lampreys move downstream, leaving freshwater, and migrating towards the sea (Potter, 1966; Hughes and Potter, 1969, cited by Koehn and O’Connor, 2002). Studies have shown that the migration begins earlier from upstream compared with downstream sites, and migration to sea occurs predominantly at night. During the downstream migration, the lampreys enter coarse substrates in faster flowing regions of rivers, during the day (Potter, 1980, cited by Koehn and O’Connor, 2002). The downstream migration period usually occurs from August to September / October (Hughes and Potter, 1969; Potter, 1966; Potter et al., 1968), with lampreys having completed the migration by November (Hughes and Potter, 1969). Downstream migration has been linked to marked increases in freshwater discharge (Potter, 1980). The metamorphosis into the downstream migrating form is synchronous (Cadwallader and Backhouse, 1983, cited by Koehn and O’Connor, 2002).
By the time the lampreys reach the sea, they have become parasitic young adults (Strahan, 1980a). These young adults feed in the sea by sucking on to fishes with their oral disc, and rasping away flesh with the complex toothed tongue (Strahan, 1980a). In most cases, lampreys of this stage occur at sea; however, young adults have also previously been reported from some estuarine areas, such as the Gippsland Lakes, where they reportedly retain the burrowing habit of ammocoetes, remaining beneath substrate when not feeding, and, after spending 5 months in the area, they migrate to sea for 18 months before the return journey for spawning (Potter et al., 1968).

Fisheries Information

Short-headed Lamprey is one of the species caught in the bycatch of the commercial eel fishery in Victoria (DPI Victoria, 2003a); however data are not available for this report.

Vulnerable Characteristics of the Species

M. mordax may be considered vulnerable, due to a narrow habitat range within South Australia, and specific habitat requirements for breeding and juvenile development.
The species is dependent for part of its life cycle upon a small number of estuaries and permanent creeks and rivers in good ecological health, and impacts upon the quality of critical estuarine and freshwater habitat may affect this species.
In South Australia, the species has previously been known mainly from the catchment areas of the central coast of S.A. (particularly Mt Lofty Ranges, Adelaide Hills and Plains, and the associated nearshore coastal waters of eastern Gulf St Vincent), and also the lower Murray River drainage area. Much of the available riverine and estuarine habitat in these areas has been severely modified during the past century.
Given the significant changes of its riverine habitat, the migratory behaviour of the Short-headed lamprey is considered both an advantage and disadvantage. According to SANFA (2000), the species is not totally dependent upon the river / creek environment throughout its life cycle, and, to a certain extent, Short-headed Lamprey can avoid the vagaries of watercourses drying up due to excessive water extraction. However, even when there is enough water in a stream or riverine habitat, the lamprey is faced with the arduous and perilous task of climbing over weirs and other structures, to reach its spawning ground (SANFA, 2000). (See also synopsis on Pouched Lamprey, for discussion of the vulnerability of lampreys during the upstream migration).

Threatening Processes

Mordacia mordax is dependent for part of its life cycle upon a small number of estuaries, and impacts upon the quality and extent of critical estuarine habitat may affect this species.
In southern Australia, M. mordax is considered to have suffered from the effects of weirs and other barriers, which prevent or inhibit the freshwater migration phase of the life cycle (Inland Rivers Network, Nature Conservation Council of N.S.W. 1999). The lack of effective fishways in the Murray-Darling river system has been implicated in the decline of native fish populations (Stuart et al., 2002).
In the South-East of S.A., periodic dredging of freshwater bodies such as Eight Mile Creek / Ewens Ponds may adversely affect lamprey recruitment (Hammer, 2002), because the ammocoetes spend the first two years of life burrowed in sediments, feeding on algae and detritus (Potter, 1996, cited by Hammer, 2002). The dredging process is undertaken to reduce the resistance to water flow (e.g. by removing benthic vegetation). During dredging operations, bottom vegetation is removed by the dredge, and the water clarity is also much reduced through siltation (Skinner, 2005). When the bottom is dredged, it is possible that the process would remove and kill burrowing larval lampreys, or damage the bottom habitat to the extent that it is not conducive for shelter, feeding and continued survival. It is noted that dredging Eight Mile Creek is now recognised (by management authorities) as a threatening process, and alternatives are being sought (Hammer et al., 2007).
In general, the main issue for freshwater fish species is habitat loss and modification. In South Australia for example, some of the concerns include the construction of dams, weirs, barrages (and drains) along watercourses. These change the rate, volume and direction of water flow; restricts access of native fish species to existing habitat and new areas for colonisation, and also interrupts patterns of migration (e.g. during spawning). Widespread residential and/or agricultural development adversely affects the habitat of native freshwater and estuarine fish, through (i) water extraction and diversion, (ii) point source and diffuse source water pollution (leading to eutrophication and blooms of “nuisance” algae, for example), and (iii) loss or degradation of essential habitat such as riparian vegetation (resulting in reduced habitat for feeding and sheltering; stream and river bank instability; changes to channel morphology; increased siltation; and reduced capacity of streams and channels to filter agricultural and urban pollutants) (Urban Forest Biodiversity Program, undated). The clearing of riparian vegetation and continued stock access to the riparian zone, in addition to the removal of logs and snags from river bottoms, can detrimentally increase erosion and sedimentation, and remove critical habitat, including reproductive sites.
Other changes to riverine and estuarine systems that have a deleterious effect on native fish species in general, include:
interruption of the seasonal pattern of winter/spring high flows and floods, and summer/autumn periods of low flow. Many freshwater fish species rely on this seasonal flow pattern for successful reproduction. Regulation of river systems by numerous dams and weirs can reverse the seasonal flow regime, and restrict migrations upriver, particularly in areas where there are few passageways over or around the barriers. Both growing ammocoetes and returning adult lampreys are adversely affected by increased hydrological developments that result in loss of pools and perennial flow (e.g. Savadamuthu, 2002, 2003, cited by Hammer et al., 2007). The release of cold water from the bottom of dams and weirs can also upset the natural temperature regime, with further deleterious effects on fish reproduction by cold water pollution;
the proliferation of introduced fishes, such as carp, redfin perch, and mosquito fish, which can act as predators, competitors, disease carriers, and/or habitat modifiers;
clearing of floodplain vegetation for agriculture, which increases sedimentation and reduces the carbon inputs that are an important food source for in-stream invertebrates;
some types of agriculture, which can produce threatening processes to native aquatic animals. This includes the reduction of river flow by irrigation, and pollution through insecticide and fertiliser runoff; and
salinisation of inland waters, exacerbated by both forest clearing and irrigation, which is also detrimental to some freshwater species (New South Wales Fisheries Scientific Committee, undated, b).
Periodic closure of the Murray Mouth, in addition to the long term changes to volume and flow rate that have occurred in the area, is likely to directly affect the life cycle of this species (Higham et al., 2002).
As is the case with the Pouched Lamprey, Short-headed Lampreys must overcome both natural and man-made obstacles in order to migrate upstream and reach their breeding habitat. The journey upstream can be hazardous and during this time many lampreys can die (see synopsis on Pouched Lamprey).
In Tasmania, direct threats to populations of Short-headed Lamprey include: in-stream barriers preventing migration; loss of in-stream habitat; and stream channel damage from sand and gravel extraction (Inland Fisheries Service of Tasmania, 2000).

Management Notes

South-Eastern Australia

In recognition of the 5000 different barriers (including barrages, locks and weirs) to fish migration along the length of the Murray-Darling Basin, the Murray Darling Basin Commission’s recent Sea to Hume Dam project aims to provide fish passage for 2275km upstream from the Murray Mouth. Part of this program includes construction and monitoring of barrage fishways (MDBC, 2005), as discussed below.
During the early 2000s, the Murray-Darling Basin Commission undertook a fishway construction program, to restore fish passage at locks and weirs along the Murray River between Lake Hume and the Goolwa barrages (Stuart et al., 2002). State agencies from Victoria, New South Wales and South Australia are collaborating, to assess up to 11 new fishways. The key research objectives include quantifying the contribution of the fishways toward improved fish passage and identifying changes to whole native fish communities.  Pilot sampling to address these objectives commenced in September 2001 and initially involved field-testing a range of methods to develop a long-term experimental design.  Data collected will be incorporated into the design of the new fishways, while also providing a baseline sample of current fish populations. Following construction, the performance of new fishways will be assessed, to ensure that future fishways work efficiently (Stuart et al., 2002).

Victoria

Since 1999, more than 20 “fishways” that permit upstream passage of migrating fish species (including lampreys), have been constructed in various rivers around Victoria (e.g. Maribyrnong River, which feeds into the Yarra). The devices look like curved, rocky ramps, or in some cases, gentle cascades, with water tumbling down. The fishways are designed to enable fish to “climb” past barriers such as dams, weirs and road culverts (Melbourne Water, 2002).

South Australia

In South Australia, there is not yet a formal recovery plan for this species; however an Action Plan with recommendations for population recovery of all native freshwater fish species has been produced (Hammer et al., 2007).
In 2004, Native Fish Australia prepared a report for the South Eastern Water Conservation and Drainage Board, discussing the potential impacts (including impacts on native fish) of the periodic dredging of Eight Mile Creek (Hammer et al., 2004, cited by Skinner, 2005), a location where lampreys are thought to still exist (see Hammer, 2002).
In 2003, fish ladders were designed by Adelaide University students, for use in the Torrens River catchment, to enable native fish species to swim upstream past weirs (such as the Breakout Creek outlet at Henley Beach South) (Catchment Water Management Board, 2004b). A fishway has now been installed (with support of the AMLR Natural Resources Management Board) at the mouth of the Torrens (Hammer et al., 2007).
A report on the status of native fish in the River Torrens, has been undertaken by the Australian Water Quality Centre, the University of Adelaide and the South Australian Research and Development Institute (SARDI) (Catchment Water Management Board, 2004b). Since 2003, there have been at least two projects examining the present distribution of fish within the Torrens, and the possible benefits of fishways to natural recruitment of native fish populations.
The Sea to Hume Dam program (see above) may benefit lampreys that utilise the lower Murray drainage area in South Australia. As part of this program, various types of fishways (vertical-slot, rock-ramp and Denil) have been trialled at Goolwa and Tauwitchere barrages. SARDI has undertaken an assessment and monitoring program, to collect baseline data on the potential migratory fish species that could use the fishways, compare the relative efficiency of the fishway options, conduct specific fishway experiments to optimise final fishway design, placement and operation, and gauge the success of the fish passage at the Murray mouth barrages. A report was submitted to the MDBC in 2002, which summarised the findings of the baseline studies (Ye et al., 2002). Stage II assessments of vertical-slot and rock-ramp fishways commenced at Tauwitchere Barrage in 2004/05. Bice et al. (2007) provided more information about this program and the utility of the fishways to date. According to the Murray Darling Basin Commission (2005), the vertical slot fishways installed at Goolwa and Tauwitchere barrages are used by lampreys, and recent survey results (e.g. Bice et al., 2007) support this.

Research Requirements / Notes

Initial assessments of Short-headed Lamprey distribution have been undertaken as part of opportunistic surveys along much of the known range of this species in South Australia (Hammer, 2002; and records in Hammer et al., 2007).
It would be difficult to determine range and relative abundance of the Short-headed Lamprey’s marine phase; hence surveys should be conducted in the riverine habitat of spawning populations, by expert surveyors. Lampreys are cryptic species that are difficult to survey (e.g. due to their use of burrows, and also, living under stones or riparian vegetation etc). Systematic fish surveys of all suitable catchments in South Australia are required over space and time, to determine the current range and relative abundance of this species during the estuarine / freshwater phase. As part of this, an updated assessment of the quality and extent of breeding habitat in South Australia is required.
In conjunction with research to improve knowledge of the distribution and abundance, work is needed to determine specific habitat requirements and tolerances (particularly for ammocoetes), behaviour, and migration and dispersal ability (Hammer et al., 2007).
In the lower South East of S.A., recreational divers (including those using Piccaninnie Ponds and Ewens Ponds) could potentially provide useful information about the distribution of lampreys in the area (Hammer, 2002). It is important that the general public be encouraged to record and photograph sightings, and send to either the South Australian Museum, or Native Fish Australia.

Management Requirements

Maintenance of the quality of the spawning habitat and ammocoete burrowing habitat is important for this species (see section above, on Threatening Processes). Some specific examples of measures that might improve conditions for lampreys, include: preventing dredging operations from the major creeks of the Lower South East; reducing urban and agricultural run-off into creeks and rivers that form key habitat for this species; removing feral fish species; and, where possible, investigating methods of re-establishing historic flow regimes and in-stream habitat in the coastal-draining rivers and creeks in the central and south-eastern part of South Australia.
With an increasing number of obstructions to river flow, and diminishing habitat due to the clearing of natural bushland, it is important to reduce lamprey mortality rates associated with obstructions to upstream movement. This is especially necessary where dams and weirs are located below prime lamprey habitat, and, to a lesser extent, in rural areas where road and paddock runoff threatens to lure lampreys into danger (Water and Rivers Commission of W.A., 2000b). “Lamprey guides”, similar to those being used in W.A., may assist the upstream passage of this species in spawning locations in South Australia. It is noted that a major project in the Murray Darling Basin is addressing the need to ensure fish passage upstream (Stuart et al., 2002; MBDC, 2005), and this may improve conditions for lampreys in the Lower Murray and Murray Mouth portion of the basin, in South Australia, where fishways have now been installed (e.g. SARDI Aquatic Sciences, 2004).
Specific requirements include maintaining or restoring natural flow regimes; re-establishing natural pathways for migration (water flows and fishways), and restoring critical freshwater habitats to enable growth and survival of ammocoetes, particularly along the River Murray, and near the Murray Mouth (Hammer et al., 2007).
Assessment of barriers to migration over the range is needed, and further investigation into (and monitoring of the effectiveness of) fishways is required (Hammer et al., 2007).
Improved awareness of the biological requirements and uniqueness of Short-headed Lamprey (Hammer et al., 2007), and its vulnerability. An education program is recommended, with Short-headed Lamprey being a suitable “icon species” to promote catchment awareness, waterway improvement programs, and natural resource management, especially in the River Murray (Hammer et al., 2007).

Other Information
The Short-headed Lamprey is a member of the ancient jawless vertebrates group (Class Cephalaspidomorphi), that contains few living species, but was dominant in seas around 300 million years ago (Glover, in Gomon et al., 1994; Edgar, 2000).
M. mordax is very rarely collected in coastal seas (Glover, in Gomon et al., 1994).
The N.S.W. Fisheries Scientific Committee nominated the aquatic community of the Lower Murray River Drainage, including the regulated portions of the Murray River below the Hume Weir, the Murrumbidgee River below Burrinjuck Dam, and the Tumut River below Blowering Dam, as an Endangered Ecological Community in Part 3 of Schedule 4 of the Environment and Biodiversity Conservation Act, 1999. The Short-headed Lamprey was one of the fish species included by the Independent Scientific Committee, in the list of species that occur in the habitat. However, the Commonwealth rejected the nomination, because the ecological community could not be accurately defined, with regard to the species composition and geographic extent.