© 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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OPHIDIIDAE: LINGS, TUSKS AND CUSK-EELS

© Bernard Yau

Globally, there are around 240 species in the Ophidiidae family (Froese and Pauly, 2007), and very few occur in shallow water. The family is distantly related to the cods in body form, and includes the cusk-eels, brotulas, assfishes and the lings (Gomon, in Gomon et al., 1994; Nielson et al., 1999). During the past decade, new members of the family have regularly been described. For example, more than 25 species of Neobythites were described by Nielsen during the 1990s and early 2000s.
Various members of the family are found in the Atlantic, Indian, and Pacific Oceans. The Ophidiidae contains some very large species (e.g. Lamprogrammus shcherbachevi, which reaches almost 2m in length), and the family also contains the deepest-living fish known to date, the cusk-eel Abyssobrotula galatheae, which has been recorded at 8,370m, in the Puerto Rico Trench (Australian Museum, 2004t).
Members of 3 of the genera (Brotulotaenia, Dannevigia, and Genypterus) are commonly known from southern Australia (Gomon, in Gomon et al., 1994). Examples include the Australian Tusk Dannevigia tusca, found across southern Australia, and caught commercially in small numbers in Commonwealth-managed fisheries, and the Violet Cusk (Cusk-eel), Brotulotaenia crassa, a mid-slope species caught by demersal trawlers that target Orange Roughy (Daley et al., 1998).
There are 6 named species of Genypterus worldwide (Froese and Pauly, 2007), and most are found in deeper waters. Two species are commonly known in southern Australia (G. blacodes and G. tigerinus) and one of these, the Pink Ling G. blacodes, is an important commercial species in Commonwealth fisheries of south-eastern Australia, despite little being known of the species’ biology or population dynamics. The species has been taken off various southern States since at least the 1960s, with annual total catches in the vicinity of 100t - 600t in most years from the late 1970s to late 1980s (BRR, 1991). Pink Ling is managed as a single stock, and genetic work supports this (Ward et al., 2001). It is taken in Commonwealth-managed fisheries by trawl, drop-line and long-line, and by fish trap (DPIWE website, 2002; Australian Government Department for Environment and Heritage, 2003b). Pink Ling is a locally significant bycatch in the Blue-eye Trevalla drop-line fishery (part of the South East Non Trawl Fishery) (Kailola et al., 1993). Off Tasmania, Pink Ling are taken mainly in waters of 300m - 550m depth (DPIWE website, 2002). Traditionally, Pink Ling has also been a bycatch of the trawl fishery that targets Blue Grenadier; however Pink Ling is now becoming more popular due to consumer acceptance, increased demand and higher market prices (FRDC project 97/117, cited in FRDC web site, 2002; SIV, 2004). Increased price has been accompanied by pressures to expand the fishery, particularly in the western sector. In the Commonwealth’s Gillnet, Hook and Trap Fishery (GHATF), which is part of the South East Fisheries, Pink Ling has become a major species. Ling catches are managed in the fishery using a Total Allowable Catch (TAC) and Individual transferable Quotas (ITQs) (AFMA, 2003j). In 2003, the landed catch from automatic long-line vessels in the GHATF fishery was 423t, equivalent to 44% of the entire fish catch in that fishery (AFMA, 2004a). The table below shows the Total Allowable Catch (TAC) of Ling during the early and mid 2000s, in the Commonwealth-managed South East Fisheries (Southern and Eastern Scalefish and Shark Fisheries). The quota in 1999 was 2,400t, which reduced to 2160t in 2003, then to 1800t in 2004, with annual reductions in most years since that time, due to ongoing concern about the sustainability of fishing stocks at the previous high levels (e.g. AFMA, 2004a). The annual TAC is not always met. For example, the total catch from Commonwealth fisheries in 2000/2001 was reported to be 1,386t (McLeay et al., 2002). The majority of the quota is allocated to the SET fishery. Of the 1800t quota in 2004, 1570.8t was allocated to the South East Trawl (SET) Fishery, and 228.7t to the Gillnet, Hook and Trap Fishery (Table 18) (AFMA, 2003j).

Table 18 Annual quota of Pink Ling in the SEF / SESSF
Year		Pink Ling TAC (t)
2003		2,160
2004		1,800
2005		1,400
2006		1,200
2007		1,537
(from AFMA, 2003j, 2004a, 2005b, 2008a)

Pink Ling was considered to be fully fished by the turn of the 21^st century, if not earlier (DPIWE web site, 2002). AFFA (2004a) reported that Pink Ling is probably fully fished east of Bass Strait, but that the status of the stock across the entire fished range is uncertain. Concern for the state of Pink Ling populations has resulted in an annually reducing quote (see above), as well as a number of spatial closures, devised by AFMA and industry, in what are considered to be “key ling habitats”. These voluntary area closures, in Commonwealth waters off Victoria and Tasmania, are monitored by industry, and were initially devised for three years. The area closures include: Everard Horseshoe, Seiners’ Horseshoe, Ling Hole, and Maria Island (AFMA, 2005b).
Pink Ling is also one of the species taken in the NSW Ocean Trawl fishery, and is also one of the 6 major species taken by deepwater line fishing along most of the NSW coast (N.S.W. Fisheries web site, 2004). In W.A., Ling is one of the 3 main bycatch species taken in deeper waters (180m or more) in the South Coast Crustacean Fishery (Australian Government Department of Environment and Heritage, 2004). In New Zealand, Pink Ling is a major commercial species, particularly on the eastern side of the South Island. From 1975 to 1980 there was a substantial long-line fishery on the Chatham Rise (and to a lesser extent in other areas of New Zealand), mainly carried out by Japanese and Korean long-liners, with catches peaking at 34,500t in 1977 (New Zealand Ministry of Fisheries, 2004d). Since 1980, Pink Ling in New Zealand have been caught by large trawlers, both domestic and foreign-owned, and by small domestic long-liners and trawlers. In the early 1990s, when larger long-liners fitted with auto-line equipment were added to the fleet, there was a large increase in the catches of Ling off the east and south of the South Island. The total catch of Pink Ling from all quota management areas in New Zealand has averaged 20,000t per annum between 1991-1992 and 2001-2001 (New Zealand Ministry of Fisheries, 2004d).
Although Pink Ling G. blacodes is a species of conservation concern, it is not discussed in a synopsis below, because it is found mainly in Commonwealth-managed waters (i.e. typically found between 300m and 600m deep; however the full depth range spans 20m to around 1000m).
The site-associated reef fish Rock Ling G. tigerinus, which occurs in shallower habitats, is included below as a species of conservation concern in State waters. The deeper water Australian Tusk Dannevigia tusca is also discussed below, because it is a benthic fish species, possibly of low resilience to fishing, and is taken in outer continental shelf and upper slope waters off South Australia. Very little is known of the biology or population dynamics of Australian Tusk and little assessment has been made of the sustainability of fishing populations of this species.

Associated taxa

Rock Ling	Genypterus tigerinus Klunzinger, 1872
Australian Tusk	Dannevigia tusca Whitley, 1941