Distribution, population structure and biological aspects of Squalus spp. (Chondrichthyes : Squaliformes) from New South Wales and adjacent Australian waters
Ken J. GrahamNSW Department of Primary Industries, Cronulla Fisheries Research Centre, PO Box 21, Cronulla, NSW 2230, Australia. Email: grahamk@fisheries.nsw.gov.au
Marine and Freshwater Research 56(4) 405-416 https://doi.org/10.1071/MF04275
Submitted: 19 November 2004 Accepted: 31 March 2005 Published: 27 June 2005
Abstract
Four species of Squalus dogsharks, S. megalops, S. cf. mitsukurii, Squalus sp. B and Squalus sp. F inhabit shelf and upper-slope depths off New South Wales and adjacent Australian states. During fishery surveys between 1976 and 2001, distributional, size composition and reproductive data were collected for these species. Adult size classes dominated catches and, for S. megalops, heavily biased sex ratios were observed. Although no female data were available for the rarely caught Squalus sp. B, reproduction in the other three species was found to be continuous with no evidence of seasonality. Fecundity was 1–3 embryos for S. megalops, 1–5 for Squalus sp. F and 4–10 for S. cf. mitsukurii. All species are commercially exploited, contributing to the mixed species demersal trawl fishery off New South Wales. Stocks of some species are greatly depleted on the main trawling grounds, but the overall distributions of all species include large areas of lightly exploited habitat.
Extra keywords: dogfish, fishery management, length–frequency, reproduction, Squalidae.
Acknowledgments
All associated with FRV Kapala are thanked for their cooperation and assistance over many years. John Stevens and Ross Daley are also thanked for their contributions to this and associated studies. Michael Lowry and Dennis Reid gave helpful advice with data analyses. Sarah Irvine, Kevin Rowling, Steve Kennelly and two anonymous referees made many constructive suggestions to improve the manuscript. Data from Bermagui and Portland were recorded during the FRDC funded project 98/204.
Clarke, M. W. , Connolly, P. L. , and Bracken, J. J. (2002). Catch, discarding, age estimation, growth and maturity of the squalid shark Deania calceus west and north of Ireland. Fisheries Research 56, 139–153.
| Crossref | GoogleScholarGoogle Scholar |
Compagno, L. J. V. , Ebert, D. A. , and Cowley, P. D. (1991). Distribution of offshore demersal cartilaginous fish (Class Chondrichthyes) off the west coast of southern Africa, with notes on their systematics. South African Journal of Marine Science 11, 43–139.
Gell, F. R. , and Roberts, C. M. (2003). Benefits beyond boundaries: the fishery effects of marine reserves. Trends in Ecology & Evolution 18, 448–455.
| Crossref | GoogleScholarGoogle Scholar |
Graham, K. J. , Andrew, N. J. , and Hodgson, K. E. (2001). Changes in relative abundance of sharks and rays on Australian South East Fishery trawl grounds after twenty years of fishing. Marine and Freshwater Research 52, 549–561.
| Crossref | GoogleScholarGoogle Scholar |
Irvine, S. B. , Graham, K. J. , Daley, R. K. , and Stevens, J. D. (In press). Size composition, reproductive biology and diet of deepwater dogfishes (Chondrichthyes, Squaliformes) from southeastern Australia. Environmental Biology of Fishes. ,
Litvinov, F. F. (1990). Ecological characteristics of the dogfish, Squalus mitsukurii, from the Sala-Y-Gomez Seamounts. Journal of Ichthyology 30, 104–115.
Nammack, M. F. , Musick, J. A. , and Colvocoresses, J. A. (1985). Life history of spiny dogfish off the northeastern United States. Transactions of the American Fisheries Society 114, 367–376.
| Crossref | GoogleScholarGoogle Scholar |
Walker, T. I. (1998). Can shark resources be harvested sustainably? A question revisited with a review of shark fisheries. Marine and Freshwater Research 49, 553–572.
| Crossref | GoogleScholarGoogle Scholar |
Watson, G. , and Smale, M. J. (1998). Reproductive biology of the shortnose spiny dogfish, Squalus megalops, from the Agulhas Bank, South Africa. Marine and Freshwater Research 49, 695–703.
| Crossref | GoogleScholarGoogle Scholar |
Watson, G. , and Smale, M. J. (1999). Age and growth of the shortnose spiny dogfish, Squalus megalops, from the Agulhas Bank, South Africa. South African Journal of Marine Science 21, 9–18.
Wilson, C. D. , and Seki, M. P. (1994). Biology and population characteristics of Squalus mitsukurii from a seamount in the central North Pacific Ocean. Fishery Bulletin 92, 851–864.