Bathyraja irrasa

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

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Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	CHONDRICHTHYES	RAJIFORMES	ARHYNCHOBATIDAE

Scientific Name:

Bathyraja irrasa

Species Authority:

Hureau & Ozouf-Costaz, 1980

Common Name/s:

English

–

Kerguelen Sandpaper Skate

Assessment Information [top]

Red List Category & Criteria:	Near Threatened ver 3.1
Year Published:	2009
Assessor/s:	Smale, M.J.
Reviewer/s:	Valenti, S.V. & Pollard, D. (Shark Red List Authority)
Contributor/s:
Justification: This large, Southern Ocean skate has an apparently limited distribution, known only from the Kerguelen Islands, at depths of 300–1,200 m. It probably exhibits extremely slow growth, late maturity and attains more than 120 cm TL maximum size (generation period possibly >10 years, based on similar species). This combination of apparently limited habitat and life history characteristics makes it highly vulnerable to fishing pressure, and tooth fish fisheries (of which this skate is a bycatch), are undoubtedly having a negative impact on stocks of this skate, although mitigating measures (surface release) are being practiced by at least some vessels. Illegal, unreported and unregulated fishing effort for Patagonian Toothfish (Dissostichus eleginoides) has rapidly increased in recent years, particularly around the Kerguelen Islands, where the Kerguelen Sandpiper Skate (Bathyraja irrasa) is endemic. High levels bycatch have led to rapid declines in other large species of skate, where they are heavily fished. This species is given a precautionary assessment of Near Threatened on the basis of a suspected continuing decline as a result of high levels of exploitation throughout much of its distribution, coupled with probable limiting life history characteristics (close to meeting the criteria for Vulnerable A4d). Efforts should be made to monitor population trends as more serious depletion has been observed in similar species that are heavily fished.

Geographic Range [top]

Range Description:	Antarctic and southern Indian Ocean: known only from slopes around Kerguelen Islands at present.
Countries:	Native: French Southern Territories (the) (Kerguelen)
FAO Marine Fishing Areas:	Native: Indian Ocean – Antarctic
Range Map:	Click here to open the map viewer and explore range.

Population [top]

Population:	Unknown.
Population Trend:	Unknown

Habitat and Ecology [top]

Habitat and Ecology:	This skate is found at depths of 300–1,200 m (Stehmann and Burkel 1990). Reaches a maximum size of at least 120 cm total length (TL) (Stehmann and Burkel 1990), possibly larger. Reproduction is presumably oviparous, like other skates, but nothing else is known of this species’ biology.
Systems:	Marine

Threats [top]

Major Threat(s):	This species is threatened by increased longlining and trawling for fishes in the region, particularly the legal and pirate fishery for toothfish. This species is taken as bycatch of toothfish fisheries operating in this area and probably discarded. Fishing effort in the Patagonian Toothfish (Dissostichus eleginoides) fishery concentrated in the Southern Ocean, has increased in recent years, largely due to illegal, unreported and unregulated (IUU) fishing in this region (Lack and Sant 2001). Lack and Sant (2001) identified the Kerguelen Islands, where this species is possibly endemic, as a hotspot for IUU fishing activity. High levels of unregulated fishing pressure throughout this species’ range are unlikely to be sustainable, particularly as this species is likely to have limiting life-history characteristics, similar to other deepwater skates.

Major Threat(s):

This species is threatened by increased longlining and trawling for fishes in the region, particularly the legal and pirate fishery for toothfish. This species is taken as bycatch of toothfish fisheries operating in this area and probably discarded. Fishing effort in the Patagonian Toothfish (Dissostichus eleginoides) fishery concentrated in the Southern Ocean, has increased in recent years, largely due to illegal, unreported and unregulated (IUU) fishing in this region (Lack and Sant 2001). Lack and Sant (2001) identified the Kerguelen Islands, where this species is possibly endemic, as a hotspot for IUU fishing activity. High levels of unregulated fishing pressure throughout this species’ range are unlikely to be sustainable, particularly as this species is likely to have limiting life-history characteristics, similar to other deepwater skates.

Conservation Actions [top]

Conservation Actions:	No specific measures in place. Despite this skate occurring in areas protected by CCAMLR, pirate fisheries and accidental captures of this bycatch are a problem that may be mitigated by surface release of this skate.

Conservation Actions:

No specific measures in place. Despite this skate occurring in areas protected by CCAMLR, pirate fisheries and accidental captures of this bycatch are a problem that may be mitigated by surface release of this skate.

Citation:	Smale, M.J. 2009. Bathyraja irrasa. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 20 May 2013.
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