© 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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Pouched Lamprey

Family Name:	Petromyzontidae
Scientific Name:	Geotria australis Gray, 1851
Recommended Status in S.A:	Vulnerable B2a+b(ii,iii) (possibly also A2)
Rationale:  The species is included here because (i) although Pouched Lamprey has a wide distribution in southern Australian States, it is not commonly recorded in South Australia, and has not been recorded during a number of recent surveys in areas where it would be expected to occur; therefore, the current area of occupancy in S.A. is thought to be limited; (ii) the number of permanent creeks and rivers in S.A. that open to the coast is small, and thus suitable habitat is limited in spatial extent; (iii) lampreys rely upon specific habitat of limited distribution, for spawning – i.e. Pouched 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 Pouched 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; and (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 (i) the current distribution in S.A. is limited spatially (historically from the Adelaide Plains / Gulf St Vincent area, to the Lower South East); (ii) within that range, much of the available habitat has been severely modified; (iii) 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 (iv) recognised threats to critical habitat are still occurring, it is recommended that the species currently be listed as Vulnerable B2a+b(ii,iii), assuming that 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

In South Australia, the National Parks and Wildlife Council and Department for Environment and Heritage (2003) 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) (see 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).
Geotria australis is considered to be a species of conservation concern in South Australia (Hammer, 2002; Hammer et al., 2007).
Classified as Rare in Victoria (DCNR, 1995, cited by DAFF, 2004).
DPI Victoria (2003a) described the conservation status as Potentially Threatened in Victoria.

Distribution

Global

Pouched Lamprey is known from Australia, New Zealand, South America (e.g. Chile and Argentina), Falkland Islands and South Georgia (McDowall, 1990; Fernholm, 1990; Froese and Pauly, 2008).
In New Zealand, the species is considered to be common in small streams around the country, and it also penetrates considerable distances inland in some major rivers (McDowall, 1990, cited by Jellyman and Glova, 2002). A survey of 34 rivers in New Zealand (Jowett and Richardson, 1995) reported that the species was caught only rarely; however it is noted that sampling was restricted to runs and riffles and did not include silty backwaters that are prime habitats for larval lampreys (McDowall, 1990, cited by Jowett and Richardson, 1995).

Southern Australian States

Geotria australis occurs intermittently around southern Australia, from southern W.A. to Lakes Entrance, Victoria, and around Tasmania (Paxton et al., 1989; Glover, in Gomon et al., 1994; Edgar, 2000).
The species is considered to be reasonably common in many rivers around Tasmania, although the full extent of the distribution in that State is still not known (Inland Fisheries Service of Tasmania, 2000). Rivers such as the Weld, Huon, Picton and the lower Gordon are known to contain G. australis (Davies et al., 2001; Parks and Wildlife Service of Tasmania, undated).
There are records of Pouched Lamprey from specific locations in coastal drainages across all parts of Victoria (Native Fish Australia – East Gippsland, undated; Museum of Victoria records, cited in OZCAM database, 2004; DAFF, 2004); however the species is cryptic and not often recorded within its known range. An incomplete list of examples where the species is known to occur in Victoria, would include western areas such as Hopkins Falls, and the Fitzroy and Shaw rivers; central areas such as downstream of Werribee Weir (Werribee River Basin) and Armstrong Creek (Upper Yarra Dam, where Pouched Lamprey are reported to be abundant); central-eastern areas such as the Thomson Reservoir in the Thomson River Basin, and eastern Victorian areas such as Brodribb River in the Snowy River Basin (DPI Victoria, 2005a, 2005b, 2005c, 2005d, 2005e, 2005f, 2005g).
In W.A., the species occurs in the lower south-west (e.g. mainly between Margaret River and Denmark, including Margaret River, Blackwood Rivers, Donnelly and Warren Rivers) (Water and Rivers Commission of W.A., 2000b; Morgan et al., 1996; CENRM, 2004).

South Australia - Previous

Examples of locations in S.A. where the species has been recorded include parts of the lower South East (including Ewens Ponds, and waters off Port MacDonnell); the Murray Mouth region (e.g. Goolwa, and Lake Alexandrina); Blanchetown (where large numbers were captured and recorded in the 1930s) and Mannum on the River Murray; freshwater drainages of the Adelaide Plains (e.g. Torrens - with records as early as 1886 - and Patawalonga catchments); Onkaparinga River; Adelaide Hills and Mount Lofty Ranges (e.g. Bridgewater - old record, from 1928); and shallow waters off north-eastern Gulf St Vincent (e.g. recorded off Tennyson, 1960); Coorong / Lower Lakes area (including tributaries, such as Bremer, Angas and Finniss rivers), and Kangaroo Island (Kuiter, 1983; SANFA, 2000; Hammer, 2002; Urban Forest Biodiversity Program, undated; Catchment Water Management Board, 2004a; Australian Museum records, SA Museum records, cited in OZCAM database, 2004; Hammer et al., 2007).
The most westerly extent of Pouched 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 surveys of the Wakefield River and Gawler River catchments (Hicks and Sheldon, 1998, 1999), Geotria australis was listed as one of the species that would be expected to have occurred at various sites in these catchments, prior to human disturbance; however no individuals were found during the surveys.

South Australia - Current

There are relatively recent records (1992, 1998 and 2001) of the species from the Torrens Weir, in the metropolitan River Torrens catchment (S.A. Museum records, 1998, cited in OZCAM, 2004; Hammer, 2005; Hammer et al., 2007).
A survey of the marine, estuarine and freshwater fish fauna in the Murray Mouth region during the early 2000s (Ye et al., 2002) did not record this species; however low numbers were recorded in a subsequent related survey (S.A. Museum records; Bice et al., 2007, cited by Hammer et al., 2007).
Kuiter (1983, cited by Hammer, 2002) featured a photo of a Pouched Lamprey from Ewens Ponds. Divers in Ewens and Piccaninnie Ponds evidently occasionally encounter lampreys, and this probably encompasses two species, also including the Short-headed Lamprey (Hammer, 2002) (see synopsis). 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 (Hammer, 2002); however, more recently, two individuals were recorded from the Piccaninnie Ponds (data by M. Hammer, cited by Hammer et al., 2007).
There are old records of the species from the Glenelg River near the S.A. / Victorian border (Museum of Victoria records, 1888 and undated, cited in OZCAM database, 2004). However, a recent inventory of native fish species in the Glenelg River basin did not report this species in the area (e.g. see DPI Victoria, 2005f).

Habitat

Pouched Lamprey has both freshwater and marine stages to the life cycle, and is dependent upon both habitats.
The Pouched Lamprey spends much of its life at sea, re-entering rivers and embarking upon an arduous upstream migration, during winter and spring, to permanent fresh headwater creeks where it spawns and dies (Water and Rivers Commission of W.A., 2000b).
Adults that have re-entered fresh water are found in faster flowing water, on the sides of rivers and streams with suitable burrowing habitat and shelter, into which they burrow at night. Adult Pouched Lampreys commonly exist in small, swiftly flowing rocky streams. During the day, G. australis in freshwater habitats can be found beneath loose stones, and also under rocks and logs, and among fringing vegetation, both native and introduced (e.g. willows) (McDowall, 1996; Water and Rivers Commission of W.A., 2000b; Inland Fisheries Service of Tasmania, 2000; Jellyman et al., 2002).
Spawning sites have been described as “nests of stones” (Koehn and O'Connor, 1990b, cited by DAFF, 2004).
Larval lampreys, which are spawned in fresh water, spend several years filter feeding from burrows in silt and other soft sediments, before metamorphosing into their adult form and moving to the ocean in winter (Water and Rivers Commission of W.A., 2000b; MDBC, 2005). Larvae (ammocoetes) prefer slower flowing water, where they can burrow into mud, sand or silt (Inland Fisheries Service of Tasmania, 2000). In New Zealand, a recent study in a large South Island river showed that larvae of Geotria australis were associated with  runs, overhead shade, and substrate features (such as depth or the proportion of fine sand), and ammocoete abundance was negatively correlated with the amount of particulate organic matter in the water (Jellyman and Glova, 2002).

Notes on Biology and Behaviour

Size and Age

Larval lampreys are around 3cm – 8cm long. Juveniles are 8cm - 10cm long on average, and the marine adults are around 50cm - 70cm long, with shrinkage occurring as sexual maturity is reached (Glover, in Gomon et al., 1994; Inland Fisheries Service (IFS) of Tasmania, 2000; Water and Rivers Commission of Western Australia, 2000b; Koehn and O’Connor, 1990b; Kullander and Fernholm, 2003). It is noted that Fernholm (1990, cited by Froese and Pauly, 2008) reported a maximum size of 62cm, and DPI Victoria (2003a) reported 67cm maximum size.
The maximum age has not been reported, although the species is known to live for about 3 to 4 years during the immature phase in freshwater, with a subsequent marine phase that lasts for at least 1 to 2 years (see below, on Reproduction), followed by an upstream migration for spawning, that may last nearly 1.5 years (Koehn and O’Connor, 1990b, cited by DAFF, 2004; Morgan and Beattie, 2003). Collectively, these phases result in a potential maximum age of about 7 or 8 years.

Behaviour

Lampreys, together with hagfishes, are the sole surviving representatives of jawless vertebrates. The adult lampreys inhabit the sea for 1 or 2 years, attaching themselves to a host sea fish, and then extracting blood and muscle tissue. During the parasitic period at sea, Pouched Lampreys can travel very large distances from their natal streams (Potter et al., 1979, cited by Jellyman et al., 2002). Adults that return from the sea then migrate upstream, which may last for 16 months, and spawn in freshwater. Migration mostly takes place in rainy nights when water levels are rising, with temperatures between 12-14.5°C, and when there is extensive cloud cover, or during the dark phase of the moon. During this nocturnal upstream migration, adults are seldom seen except where their migration is interrupted by barriers such as weirs, waterfalls, and hydro dams (Maskell, 1929; Beattie, 1994; Jellyman and Robinson 1997, cited by Jellyman et al., 2002).
The migrating adults that are returning to freshwater, are capable of climbing wet, vertical faces. They can climb over small obstacles using their mouth as a sucker (MDBC, 2005).
Adults stop feeding while in freshwater and die shortly after spawning (Fernholm, 1990; IFS of Tasmania, 2000).
According to DAFF (2004, citing Koehn and O'Connor, 1990b, and Raadik, 1992a), although the Pouched Lamprey has strong habitat specificity and is therefore not found in many catchments, the species has a “high power of dispersal”, with the potential to disperse and inhabit the entire length of a given catchment.
When moving upstream, Pouched Lampreys must negotiate rapids, and climb waterfalls, dams and/or weirs, in order to reach their breeding habitat. Lampreys are good climbers, using their suctorial mouths to gain a grip on wet surfaces, and whipping their bodies upward to inch their way up and over obstructions. In very wet weather, lampreys will leave the water and snake their way cross-country, to get around the most challenging of obstructions. Most of the lampreys’ migratory movements occur on dark nights when water levels are rising and rain is falling. Occasionally some animals will attempt to climb waterfalls and weirs during daylight. Most lampreys spend their daylight hours hiding under rocks and logs, and among fringing vegetation (Water and Rivers Commission of W.A., 2000b).

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 (IFS of Tasmania, 2000; MDBC, 2005).

Reproduction

Lampreys have several distinct stages in their life cycle. Adult lampreys in the sea leave their parasitic existence, and migrate upstream to spawn in the upper part of catchments (Maskell, 1929; Potter et al., 1986, cited by Jellyman et al., 2002; Koehn and O'Connor 1990b, cited by DAFF, 2004). The adult male of the Pouched Lamprey develops a large pouch below the head during the upstream spawning run (Inland Fisheries Service of Tasmania, 2000). The adult spawners require waters with sand, gravel or pebble substrates for spawning. The upstream migration prior to spawning may last 15 or 16 months, during which time the adults mature, but do not feed (surviving off accumulated fat reserves) (Morgan and Beattie, 2003).
According to Koehn and O’Connor (1990b, cited by DAFF, 2004), the reproductive output may be relatively high, with an average of 58,000 eggs per annual breeding period.
Following egg development, newly hatched lampreys complete a larval stage within rivers. Filter-feeding lamprey larvae bury themselves in soft substrate of rivers and streams for 3 or 4 years, and feed on microscopic algae. Juveniles migrate seawards as they grow over several years. After 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. According to Murray Darling Basin Commission (2005), this migration to the sea occurs in the spring of the fourth year of life.
Little is known of the marine stage; however it is known to last for 1-2 years, during which time lampreys grow rapidly. The adult lampreys then return during spring-summer to streams or other fresh water sources, where they complete their development, and then spawn, following an arduous upstream migration during which they do not feed (Glover, in Gomon et al., 1994; IFS of Tasmania, 2000; Edgar, 2000; Water and Rivers Commission of W.A., 2000b; MDBC, 2005).
Adult Lamprey probably die after spawning (Cadwallader and Backhouse, 1983, cited by Koehn and O’Connor, 2002; MDBC, 2005).

Other Notes on the Biology

Geotria australis marine sub-adults are brilliant cobalt blue in colour with bright greenish lateral stripes. On entering fresh water, these fish become drab brown adults, with males developing a large sac or pouch, which hangs down just behind the mouth. Young larval lampreys have no eyes and are dull brown or black in colour, while recently metamorphosed sub-adults, known as ‘downstream migrants’, are miniature versions of their parents (Potter et al., 1986, cited by Water and Rivers Commission of Western Australia, 2000b).
In South Georgia, Antarctica, albatrosses have been recorded feeding on Geotria australis (Croxall et al., 1999, cited by Froese and Pauly, 2004). Lampreys are recorded as part of the diet of the Grey-headed Albatross Thalassarche chrysostoma (National Oceans Office, 2002).

Fisheries Information

Southern Australia

The species is not targeted, and generally is of no interest in commercial or recreational fisheries in southern Australia.
Pouched Lamprey is one of the species caught in the bycatch of the commercial eel fishery in Victoria (DPI Victoria, 2003), but data are not available for this report.

New Zealand

In New Zealand, Lampreys were historically an important food resource for Maori, and elaborate weirs, rock groynes and concealing mats of vegetation were constructed to catch them. Lampreys were also hand-picked at rapids and waterfalls (Downes, 1918, and Best, 1929, cited by Jellyman et al., 2002).  The traditional fishery still occurs on a small scale in the Whanganui River near Pipiriki, Mataura and Niagara Rivers (hand-picking), and various Taranaki Rivers (rock groynes) (Todd, 1979, cited by Jellyman et al., 2002; NIWA, 2004).

Vulnerable Characteristics of the Species

Geotria australis may be considered vulnerable, due to a narrow habitat range within South Australia, and specific habitat requirements for breeding and juvenile development. The situation is similar in Victoria, where Geotria australis is described as having a “narrow habitat specificity”, thus occupying only a small proportion of available river and stream habitat (Koehn and O'Connor, 1990b, Raadik, 1992a, cited by DAFF, 2004).
The species reportedly requires permanent creek / river headwaters in good ecological health to complete its life cycle (Water and Rivers Commission of W.A., 2000a), and such waters can be considered critical habitat. Much of the available critical habitat in South Australia (and other States) has been severely modified during the past century.
Lampreys must overcome both natural and human-made obstacles in order to migrate upstream and reach their breeding habitat. The journey upstream can be hazardous and during the early stages of the migration, lampreys are susceptible to blood poisoning and internal bleeding. During the migration, many lampreys can die from injury or exhaustion incurred from attempting to climb over or get around obstacles. Some lampreys get lost during the journey (which normally occurs on rainy nights) if they follow flowing water paths onto roads or fields etc, and die in sunlight the following day, when they become stranded (Pen et al., 1991, cited by Water and Rivers Commission of W.A., 2000b).
In Victoria, there is no information on current abundance of the species; however populations are considered to have declined since European settlement (T. Raadik, pers. comm., cited by DAFF, 2004). Similarly, lack of recent records after intensive opportunistic sampling across South Australia indicate a decline in lamprey populations in this State (Hammer et al., 2007).

Threatening Processes

The species is dependent for part of its life cycle upon a small number of estuaries and permanent creeks and rivers, and impacts upon the quality of critical estuarine and freshwater habitat may affect this species.
In southern Australia, G. australis 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); however there is a major program underway to restore upstream passage (MDBC, 2005).
Apart from barriers, restrictions to flow volume and velocity can interfere with the migration cycle of lampreys. For example, in areas such as the Murray Mouth, freshwater flows and fish passage between the sea, the Coorong and Lower Lakes are considered to be critical for the migration needs of diadromous species such as lamprey, to complete their life cycle (AWE 2003). Increased flow is known to stimulate upstream migration of G. australis (e.g. Maskell, 1929; Todd, 1979; Potter et al., 1983; Tweed, 1987, cited by Jellyman 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 flow. 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 habitat to the extent that it is not conducive for 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, which changes 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 water extraction and diversion, point source and diffuse source water pollution (leading to eutrophication and blooms of “nuisance” algae, for example), and 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: (i) 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; (ii) 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; (iii) clearing of floodplain vegetation for agriculture, which increases sedimentation and reduces the carbon inputs that are an important food source for in-stream invertebrates; (iv) 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 (vi) 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 in South Australia (Higham et al., 2002).
In many of the rivers in south-western Australia, threats to lamprey populations include (i) salinisation, and (ii) dams and other artificial barriers (which are obstacles to lamprey migration and breeding) (Water and Rivers Commission of W.A., undated). In the Margaret River, weirs are considered to (i) obstruct the upstream movement Pouched Lamprey, (ii) modify the habitat to the extent that sites immediately upstream and downstream of the weirs are not utilised by lamprey larvae; and (iii) increase the possibility of predation (by birds) during the upstream migration (Morgan and Beattie, 2003). There are examples of rivers in which the species was previously known, but now not recorded. For example, the last recorded observation of Pouched Lampreys in the Collie River, was in 1936 (Morgan et al., 1998), and the species’ absence from that system during more recent surveys is considered to be due to loss of suitable in-stream habitat and/or salinisation (CENRM, 2004).
In Tasmania, direct threats to populations of Pouched Lamprey include (i) in-stream barriers preventing migration; (ii) loss of in-stream habitat; and (iii) stream channel damage from sand and gravel extraction (Inland Fisheries Service of Tasmania, 2000).
Processes that threaten Pouched Lamprey populations in Victoria may include (i) altered hydrology, such as siltation / sedimentation of spawning areas and other freshwater habit, due to vegetation clearance and other factors; (ii) predation by introduced species on juvenile lampreys, although there are no firm data; and (iii) possible reduction of food sources (Campbell and Doeg, 1989; Koehn and O'Connor, 1990a; T. Raadik, pers. comm., cited by DAFF, 2004).

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 2275 km 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, N.S.W. and S.A. 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.  The 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).
In Victoria, it is noted that the Department of Primary Industries (2003a) considered that Pouched Lamprey should be added to the list of threatened “indicator species”, for purposes of managing bycatch in the commercial eel fishery. Commercial eel fishing is not permitted in waters in which populations of indicator species (including platypuses, Estuary Perch, Australian Grayling and Australian Bass) are perceived to be threatened by the practice of commercial eel fishing.
In parts of Victoria (e.g. East Gippsland), there are various conservation measures, such as classified Heritage Rivers, and linear reserves with Special Protection Zones and Special Management Zones, which include protection of species such as Pouched Lamprey as a conservation objective (DAFF, 2004).

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.

Western Australia

In W.A., “lamprey guides” have been constructed around obstructions such as weirs, to assist the upstream passage of populations of this species. Lamprey guides are low, horseshoe-shaped fences, around 50cm in height, made of heavy-gauge, non-abrasive wire mesh, supported with permanent-set poles. The ends of the fence are located on either side of the obstruction, so as to guide the lampreys around the obstruction when they leave the water on dark wet nights. W.A.’s Water and Rivers Commission (2000b) provided specifications and advice for construction of lamprey guides.
In 2003-2004, Murdoch University received a grant to develop a recovery plan for the Pouched Lamprey in south-western Australia (Department of Fisheries, Western Australia, 2004e).

Research Requirements / Notes

Initial assessments of Pouched 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 Pouched 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 S.A.. 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 (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 Pouched Lamprey (Hammer et al., 2007), and its vulnerability. An education program is recommended, with Pouched Lamprey being a suitable “icon species” to promote catchment awareness, waterway improvement programs, and natural resource management (Hammer et al., 2007).

Other Information

The Pouched Lamprey is a member of the ancient jawless, parasitic vertebrate 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).

Support for S.A. Listing:

Graham Edgar (University of Tasmania), who considered that the species probably should be listed as threatened, depending upon distribution data in South Australia; Barry Hutchins (ex-WA Museum) who recommended Data Deficient category, and Scoresby Shepherd (Senior Research Fellow, SA).