Hostname: page-component-76fb5796d-qxdb6 Total loading time: 0 Render date: 2024-04-27T03:39:59.068Z Has data issue: false hasContentIssue false
  • English
  • Français

Assessing the distribution and relative abundance of wobbegong sharks (Orectolobidae) in New South Wales, Australia, using recreational scuba-divers

Published online by Cambridge University Press:  23 October 2009

Charlie Huveneers ,
Kehui Luo ,
Nick M. Otway  and
Robert G. Harcourt
Charlie Huveneers
Affiliation:
Graduate School of the Environment, Macquarie University, Sydney, NSW 2109, Australia School of Biological Sciences, Flinders University, Adelaide, SA 5043, Australia
Kehui Luo
Affiliation:
Department of Statistics, Macquarie University, Sydney, NSW 2109, Australia
Nick M. Otway
Affiliation:
NSW Department of Primary Industries, Port Stephens Fisheries Centre, Taylors Beach Road, Taylors Beach, NSW 2316, Australia
Robert G. Harcourt
Affiliation:
Graduate School of the Environment, Macquarie University, Sydney, NSW 2109, Australia
Get access

Abstract

Wobbegongs are benthic sharks that are commercially targeted in New South Wales (NSW), Australia. Given a dramatic reduction of more than 50% in landed catch in a decade, there is a clear need to ensure that basic ecological data such as distribution and abundance are available for management use. Opportunistic sightings of wobbegongs collected by recreational scuba-divers were used to assess the distribution and relative abundance of wobbegongs in NSW. From July 2003 until January 2005, 304 dives were undertaken by recreational divers and 454 wobbegongs were reported. Larger numbers of wobbegongs were sighted in northern compared to southern NSW. Spotted and ornate wobbegongs were sighted in similar numbers, but species composition was highly variable across locations. Only a few juvenile and newborn spotted wobbegongs were sighted, whereas small ornate wobbegongs were mostly sighted north of central NSW. The latter were possibly the third, cryptic species, the dwarf ornate wobbegong. The paucity of sightings of small wobbegongs suggests that juveniles and newborns are inconspicuous to divers or that small wobbegongs are found in areas not visited by divers. Potential species and size segregation suggest that closing areas to fishing may enable populations to sustain current levels of commercial exploitation. The cost-effectiveness of using recreational scuba-divers to opportunistically collect distribution and relative abundance data was apparent from this study. However, the lack of spatial and temporal homogeneity in diving effort suggests that future studies should consider incorporating organized surveys and a facilitator, rather than using opportunistic records of sightings.

Keywords

Orectolobus ornatusOrectolobus maculatusOrectolobus haleiSurveyTasman sea
Type
Research Article
Information
Aquatic Living Resources , Volume 22 , Issue 3 , July 2009 , pp. 255 - 264
Copyright
© EDP Sciences, IFREMER, IRD, 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Baker M.A., 1998, The population structure of Orectolobidae sharks, Orectolobus ornatus and O. maculatus in Byron Bay, NSW. Lismore, Australia, School of Resource Science and Management, Southern Cross University.
Barrett N., Edgar G., Morton A., 2002, Monitoring of Tasmanian inshore reef ecosystems. An assessment of the potential for volunteer monitoring programs and summary of changes within the Maria Island Marine Reserve from 1992–2001. Technical Report Series. Hobart, Tasmania, Australia, Tasmanian Aquaculture & Fisheries Institute, University of Tasmania.
Brandon, A., Spyreas, G., Molano-Flores, B., Carroll, C., Ellis, J., 2003, Can volunteers provide reliable data for forest vegetation surveys? Nature Areas J. 23, 254–262.
Carraro, R., Gladstone, W., 2006, Habitat preference and site fidelity of the ornate wobbegong shark (Orectolobus ornatus) on rocky reefs of New South Wales. Pac. Sci. 60, 207–224. CrossRef
Casey, J.G., Kohler, N.E., 1992, Tagging studies on the shortfin mako shark (Isurus oxyrinchus) in the Western North Atlantic. Aust. J. Mar. Freshw. Res. 43, 45–60. CrossRef
Cavanagh R., Kyne P., Fowler S.L., Musick J.A., Bennett M.B., 2003, The conservation status of Australasian chondrichthyans. Report of the IUCN Shark Specialist Group Australia and Oceania regional red list workshop. Queensland, Australia, 7–9 March 2003. Brisbane, The University of Queensland.
Compagno L.J.V., 2001, Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Volume 2. Bullhead, mackerel and carpet sharks (Heterodontiformes, Lamniformes and Orectolobiformes). Rome, FAO.
Corrigan, S., Huveneers, C., Schwartz, T., Harcourt, R., Beheregaray, L., 2008, Genetic and reproductive evidence for two species of ornate wobbegong shark Orectolobus spp. on the Australian East Coast. J. Fish Biol. 73, 1662–1675. CrossRef
Darwell, W.R.T., Dulvy, N.K., 1996, An evaluation of the suitability of non-specialist volunteer researchers for coral reef fish surveys. Mafia Island, Tanzania - A case study. Biol. Conserv. 18, 259–271.
Economakis, A.E., Lobel, P.S., 1998, Aggregation behavior of the grey reef shark, Carcharhinus amblyrhynchos, at Johnston Atoll, Central Pacific Ocean. Environ. Biol. Fishes 51, 129–139. CrossRef
Evans, S.M., Birchenough, A.C., Fletcher, H., 2000, The value and validity of communitybased research: TBT contamination of the North Sea. Mar. Pollut. Bull. 40, 220–225. CrossRef
Fore, L.S., Paulsen, K., O'Laughlin, K., 2001, Assessing the performance of volunteers in monitoring streams. Freshw. Biol. 46, 109–123. CrossRef
Forster-Smith, J., Evans, S.M., 2003, The value of marine ecological data collected by volunteers. Biol. Conserv. 113, 119-213.
Goffredo, S., Piccinetti, C., Zaccanti, F., 2005, Volunteers in marine conservation monitoring: a study of the distribution of seahorse carried out in collaboration with recreational scuba divers. Conserv. Biol. 18, 1492–1503. CrossRef
Halusky, J.G., Seaman, W.J., Strawbridge, E.W., 1994, Effectiveness of trained volunteer divers in scientific documentation of artificial aquatic habitats. Bull. Mar. Sci. 55, 939–959.
Heupel, M.R., Carlson, J.K., Simpfendorfer, C.A., 2007, Shark nursery areas: concepts, definition, characterization and assumptions. Mar. Ecol. Prog. Ser. 337, 287–297. CrossRef
Huveneers, C., 2006, Redescription of two species of wobbegongs (Chondrichthyes: Orectolobidae) with elevation of Orectolobus halei Whitley 1940 to species level. Zootaxa 1284, 29–51.
Huveneers, C., Harcourt, R.G., Otway, N.M., 2006, Observations of localised movements and residence times of wobbegong sharks (Orectolobus halei) at Fish Rock, NSW, Australia. Cybium 30, 103–111.
Huveneers, C., Otway, N.M., Harcourt, R.G., 2007, Morphometric relationships and catch composition of wobbegong sharks (Chondrichthyes: Orectolobus) commercially fished in New South Wales, Australia. Proc. Linn. Soc. NSW 128, 243–250.
Huveneers, C., Walker, T.I., Otway, N.M., Harcourt, R., 2007, Reproductive synchrony of three sympatric species of wobbegong shark (genus Orectolobus) in New South Wales, Australia. Mar. Freshw. Res. 58, 765–777. CrossRef
Johnson, J., 2001, The BDS deer distribution survey 2000. Deer 12, 265–274.
Last P.R., Stevens J.D., 2009, Sharks and Rays of Australia. Australia, CSIRO Australia.
Mims, F.M., 1999, Amateur Science - strong tradition, bright future. Science 184, 55–56. CrossRef
Morrissey, J.F., Gruber, S.H., 1993, Habitat selection by the juvenile lemon shark, Negaprion brevirostris. Environ. Biol. Fishes 38, 311–319. CrossRef
Otway N.M., Burke A.L., Morrison N.S., Parker P.C., 2003, Monitoring and identification of NSW critical habitat sites for conservation of Grey Nurse Sharks. Sydney, NSW, Australia, NSW Fisheries.
Parker, P., Bucher, D.J., 2000, Seasonal variation in abundance and sex ratio of grey nurse (sand tigers) sharks Carcharias taurus in northern New South Wales, Australia: a survey based on observations of recreational scuba divers. Pac. Conserv. Biol. 5, 336–346. CrossRef
Scandol J., Rowling K., Graham K., Eds., 2008, Wobbegong Sharks (Orectolobus spp.), Status of Fisheries Resources in NSW 2006/07. Cronulla, NSW, NSW Department of Primary Industries, pp. 313-315.
US environmental Protection Agency, 1998, Introduction to the national directory of volunteer environmental monitoring programs EPA 841-B-98-009. Washington, DC, US Environmental Protection Agency.