|Scientific Name:||Brachaelurus colcloughi Ogilby, 1908|
Heteroscyllium colcloughi (Ogilby, 1908)
|Taxonomic Source(s):||Eschmeyer, W.N. and Fricke, R. (eds). 2015. Catalog of Fishes: genera, species, references. Updated 1 October 2015. Available at: http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp. (Accessed: 1 October 2015).|
|Red List Category & Criteria:||Vulnerable C2a(ii) ver 3.1|
|Assessor(s):||Kyne, P.M., Compagno, L.J.V., Last, P.R. & Stevens, J.D.|
|Reviewer(s):||Dulvy, N.K. & Walls, R.H.L.|
|Facilitator/Compiler(s):||Kyne, P.M. & Walls, R.H.L.|
Colclough's Shark (Brachaelurus colcloughi) has a restricted distribution off southern Queensland and northern New South Wales, eastern Australia, a heavily populated region. This rare species is presently known from only 50 records, with the bulk of these from a core narrow area of <2° latitude. It occurs from shallow inshore waters of <4 m depth out to a maximum of 217 m depth (mostly <100 m). Despite a long history of surveys and research within its distribution, the species is rarely encountered.
Most of its distribution has long been subject to trawling and other fishing pressure, and it is a bycatch species in trawl, gillnet, and tunnel net fisheries. Habitat degradation and loss due to urban development pressure (including large-scale port and airport reclamation projects) in Moreton Bay, the core part of the species' distribution, has affected inshore habitat.
Colclough's Shark is assessed as Vulnerable on account of a suspected continuing decline and a small population size (estimated to be <10,000 mature individuals) that is subject to a number of threatening processes. Fully protected zones within Moreton Bay Marine Park (15% of Moreton Bay) are likely to be critical for the conservation of the species.
|Previously published Red List assessments:|
|Range Description:||Colclough's Shark is endemic to a small area of the east coast of Australia from Bryon Bay, New South Wales, to the Hardline Reefs, Queensland, with over half the known records from Moreton Bay, southern Queensland (Kyne et al. 2011). All but four records are from a <2° latitude core distribution within southern Queensland and northern New South Wales (Kyne et al. 2011). Reports from the tip of Cape York Peninsula and south of Princess Charlotte Bay, north Queensland (Last and Stevens 2009) are unsupported (Kyne et al. 2011).|
Native:Australia (New South Wales, Queensland)
|FAO Marine Fishing Areas:|
Pacific – western central; Pacific – southwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This is a rare species. Given its restricted distribution, it is assumed that all individuals belong to the one continuous population. Currently it is known from only 50 records in one location, despite its distribution being well surveyed and researched (Kyne et al. 2011). Under these circumstances, it is likely that the population size is very small. We estimate that there are <10,000 mature individuals in the population; more data will be required to be able to refine this estimation to a more accurate figure.|
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Colclough's Shark occurs in inshore waters of <4 m depth out to 217 m (mostly <100 m) (Compagno 2001, Kyne et al. 2011). It is a nocturnal species, which shelters on rocky reefs during the day and forages around reefs and surrounding substrates, including seagrass beds, during the night (Compagno 2001, Kyne et al. 2011). This species reaches a maximum size of 85 cm total length (TL) with females mature from 54.5 cm TL and males from 61 cm TL; size at birth possibly ~17-19 cm TL (Kyne et al. 2011). Lecithotrophic viviparous with litter sizes of 6-7 (Kyne et al. 2011). Recent research on the congeneric Blind Shark (B. waddi) suggests a biennial or triennial reproductive cycle (Norén 2013), which is therefore also possible for Colclough's Shark.|
Age and growth data are not available, but data from the Blind Shark can be used to provide an estimate of generation length. In the Blind Shark, males reach maturity at 7.3 years (age at maturity data not available for females) and the species reaches a maximum age of 19 years (assuming annual vertebral band deposition) (Norén 2013). Generation length is therefore estimated as 15.5 years.
|Generation Length (years):||15.5|
|Use and Trade:||This species is apparently exploited at low levels for the marine aquarium trade (Pogonoski et al. 2002).|
The restricted geographic distribution of Colclough's Shark is under considerable human pressure from commercial and recreational fisheries as well as habitat modification. The Queensland East Coast Trawl Fishery operates over much of the Queensland range, with both beam trawl vessels fishing in shallow nearshore waters and otter trawl vessels operating in Moreton Bay and on the continental shelf; the species is caught irregularly by this fishery (Kyne et al. 2011). Furthermore, this shark is caught in the Queensland East Coast Inshore Fin Fish Fishery as bycatch by gillnet and tunnel net (Kyne et al. 2011).
Moreton Bay and other parts of the southern Queensland/northern New South Wales coast are popular recreational fishing areas, although the nocturnal behaviour of Colclough's Shark may limit its catch by recreational fisheries. Large-scale developments in Moreton Bay have affected inshore shallow water habitats. These include reclamation projects for the Brisbane Airport and the Port of Brisbane.
Colclough's Shark receives refuge in marine national park or sanctuary zones (where no extractive activities are permitted) of marine protected areas that overlap with its distribution. In particular, Moreton Bay Marine Park is of critical importance to the conservation of this species; 15% of that park is protected as marine national park zones, with significant other areas where trawling is not permitted. In New South Wales the species occurs in the Cape Byron Marine Park.
While turtle exclusion devices are compulsory in Queensland otter trawlers, the small size of Colclough's Shark still means that it is susceptible to capture (Kyne et al. 2011).
|Citation:||Kyne, P.M., Compagno, L.J.V., Last, P.R. & Stevens, J.D. 2015. Brachaelurus colcloughi. The IUCN Red List of Threatened Species 2015: e.T39335A68610594.Downloaded on 22 September 2017.|
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