Register      Login
Wildlife Research Wildlife Research Society
Ecology, management and conservation in natural and modified habitats
Shopping Cart: ( empty )
You are here: Home > Journals > WR > WR06025
RESEARCH ARTICLE
Contents Vol 33(8)

Dietary analysis of regurgitates and stomach samples from free-living Australian sea lions

Rebecca R. McIntosh A , Brad Page B and Simon D. Goldsworthy B
+ Author Affiliations
- Author Affiliations

A Sea Mammal Ecology Group, Zoology Department, La Trobe University, Bundoora, Vic. 3086, Australia.

B SARDI Aquatic Sciences, 2 Hamra Avenue, West Beach, Adelaide, SA 5024, Australia.

Wildlife Research 33(8) 661-669 https://doi.org/10.1071/WR06025
Submitted: 5 March 2006  Accepted: 30 October 2006   Published: 19 December 2006

Abstract

Dietary remains recovered from Australian sea lion (Neophoca cinerea) digestive tracts and regurgitate samples from Seal Bay (Kangaroo Island, South Australia) were used to identify prey species consumed. Four of eight digestive tracts collected (50%) contained prey items located only in the stomach. On the basis of biomass reconstruction of cephalopod prey remains, octopus contributed 40% of the biomass in the samples, giant cuttlefish (Sepia apama) contributed 30% and ommastrephid squids contributed 14% biomass. The remains of several fish species were found in the samples: leatherjacket (Monocanthidae), flathead (Platycephalus sp.), swallowtail (Centroberyx lineatus), common bullseye (Pempheris multiradiata), southern school whiting (Sillago flindersi) and yellowtail mackerel (Trachurus novaezelandiae). Southern rock lobster (Jasus edwardsii) and swimming crab (Ovalipes australiensis) carapace fragments, little penguin (Eudyptula minor) feathers and bones and shark egg cases (oviparous species and Scyliorhinidae sp.) were also identified.


Acknowledgments

Thanks go to the staff of Seal Bay Conservation Park and the many volunteers for their assistance and support while in the field. P. D. Shaughnessy and S. Gibbs read various drafts for the manuscript and provided valuable comments. Thanks also to S. Gibbs for her assistance in the confirmation of identification of prey hard parts. This study was funded by Sea World Research and Rescue Foundation Inc., Kangaroo Island Sealink and La Trobe University. Research was conducted under permit U24630, provided by the Department for Environment and Heritage, South Australia and La Trobe University Animal Ethics Permit AEC00/42(L).


References

Arnould J. M. (1977). Cephalopoda; Decapoda. In ‘Reproduction of Marine Invertebrates, Vol 4’. (Eds A. C. Giese and J. S. Pearse.) pp. 243–290. (Academic Press: New York.)

Bodley, K. B. , Mercer, J. R. , and Bryden, M. M. (1999). Rate of passage of digesta through the alimentary tract of the New Zealand fur seal (Arctocephalus forsteri) and the Australian sea lion (Neophoca cinerea) (Carnivora: Otariidae). Australian Journal of Zoology 47, 193–198.
| Crossref | GoogleScholarGoogle Scholar | Drexel J. F., and Preiss W. V. (Eds) (1995). The geology of South Australia. Vol. 2: The Phanerozoic. South Australian Geological Survey Bulletin 54.

Dunning, M. C. , and Wormuth, J. H. (1998). The ommastrephid squid genus Todarodes: a review of systematics, distribution, and biology (Cephalopoda: Teuthoidea). Smithsonian Contributions to Zoology 1998, 385–391.586
Edgar G. J. (1997). ‘Australian Marine Life: the Plants and Animals of Temperate Waters.’ (Reed Books: Melbourne.)

Farrell, L. E. , Roman, J. , and Sunquist, M. E. (2000). Dietary separation of sympatric carnivores identified by molecular analysis of scats. Molecular Ecology 9, 1583–1590.
| Crossref | GoogleScholarGoogle Scholar | PubMed | Fea N. I., and Harcourt R. (1997). Assessing the use of faecal and regurgitate analysis as a means of determining fur seal diet. In ‘Marine Mammal Research in the Southern Hemisphere. Vol 1: Status, Ecology and Medicine’. (Eds M. A. Hindell and C. Kemper.) pp. 143–150. (Surrey Beatty: Sydney.)

Gales, N. J. , and Cheal, A. J. (1992). Estimating diet composition of the Australian sea-lion (Neophoca cinerea) from scat analysis: an unreliable technique. Wildlife Research 19, 447–456.
| Crossref | GoogleScholarGoogle Scholar | Gales N. J., and Costa D. P. (1997). The Australian sea lion: a review of an unusual life history. In ‘Marine Mammal Research in the Southern Hemisphere. Vol. 1. Status, Ecology and Medicine’. (Eds M. A. Hindell and C. Kemper.) pp. 78–87. (Surrey Beatty: Sydney.)

Gales, N. J. , Shaughnessy, P. D. , and Dennis, T. E. (1994). Distribution, abundance and breeding cycle of the Australian sea lion Neophoca cinerea (Mammalia: Pinnipedia). Journal of Zoology 234, 353–370..
Gentry R. L., Costa D. P., Croxall J. P., David J. H. M., Davis R. W., Kooyman G. L., Majluf P., McCann T. S., and Trillmich F. (1986). Synthesis and conclusions. In ‘Fur Seals. Maternal Strategies on Land and at Sea’. (Eds R. L. Gentry and G. L. Kooyman.) pp. 220–264. (Princeton University Press: Princeton, NJ.)

Goldsworthy S. D., Bulman C., He X., Larcombe J., and Littan C. (2003). Trophic interactions between marine mammals and Australian fisheries: an ecosystem approach. In ‘Marine Mammals and Humans: Towards a Sustainable Balance’. (Eds N. Gales, M. Hindell and R. Kirkwood.) pp. 62–99. (CSIRO Publishing: Melbourne.)

Harwood, J. , and Croxall, J. P. (1988). The assessment of competition between seals and commercial fisheries in the North Sea and the Antarctic. Marine Mammal Science 4, 13–33.
| Crossref | GoogleScholarGoogle Scholar | Jackson G. D. and McGrath-Steer B. L. (2005). Arrow squid in Southern Australian waters – Supplying management needs through biological investigations. FRDC Final Report 1999/112. Fisheries Research and Development Corporation and South Australian Research and Development Institute, Adelaide.

Jackson, G. D. , Wotherspoon, S. , and McGrath-Steer, B. L. (2005). Temporal population dynamics in arrow squid Nototodarus gouldi in southern Australian waters. Marine Biology (Berlin) 146, 975–983.
| Crossref | GoogleScholarGoogle Scholar | Jones D., and Morgan G. (1994). ‘A Field Guide to Crustaceans of Australian Waters.’ (Reed: Sydney.)

Jordan, A. R. (2001). Reproductive biology, early life-history and settlement distribution of sand flathead (Platycephalus bassensis) in Tasmania. Marine and Freshwater Research 52, 589–601.
| Crossref | GoogleScholarGoogle Scholar | Kemper C. M., and Gibbs S. E. (1997). study of life history parameters of dolphins and seals entangled in tuna farms near Port Lincoln, and comparisons with information from other South Australian dolphin carcasses. Report to Environment Australia (Australian Nature Conservation Agency), South Australian Museum.

Koen Alonso, M. , Crespo, E. A. , Pedraza, S. N. , Garcia, N. A. , and Coscarella, M. A. (2000). Food habits of the South American sea lion, Otaria flavescens, off Patagonia, Argentina. Fishery Bulletin 98, 250–263.
Lake S. (1997). Analysis of the diet of New Zealand fur seals, Arctocephalus forsteri, in Tasmania. In ‘Marine Mammal Research in the Southern Hemisphere. Vol 1: Status, Ecology and Medicine’. (Eds M. A. Hindell and C. Kemper.) pp. 125–129. (Surrey Beatty: Sydney.)

Lalas C. (1997). Prey of Hooker’s sea lions Phocarctos hookeri based at Otago Peninsula New Zealand. In ‘Marine Mammal Research in the Southern Hemisphere. Vol. 1: Status, Ecology and Medicine’. (Eds M. A. Hindell and C. Kemper.) pp. 130–136. (Surrey Beatty: Sydney.)

Last P. R., and Stevens J. D. (1994). ‘Sharks and Rays of Australia.’ (CSIRO: Melbourne.)

Ling, J. K. (1992). Neophoca cinerea. Mammalian Species 392, 1–7.
Lu C. C., and Ickeringill R. (2002). Cephalopod beak identification and biomass estimation techniques: tools for dietary studies of southern Australian finfishes. Museum Victoria Science Report No. 5. Museum Victoria, Melbourne.

Marlow, B. J. (1975). The comparative behaviour of the Australasian sea lions Neophoca cinerea and Phocarctos hookeri (Pinnipedia: Otariidae). Mammalia 39, 159–230.
May J. L., and Maxwell J. G. H. (1986). Trawl fish from temperate waters of Australia. CSIRO Division of Fisheries Research, Tasmania.

McGarvey R. (2003). Assessing the impact of proposed marine protected areas on South Australian rock lobster catches. South Australia Research and Development Institute, FRDC Final Report. Project No. 2000/195. Fisheries Research and Development Corporation and South Australian Research and Development Institute, Adelaide.

McIntosh R. R., Shaughnessy P. D., and Goldsworthy S. D. (2006). Mark–recapture estimates of pup production for the Australian sea lion, Neophoca cinerea, at Seal Bay Conservation Park, South Australia. In ‘Sea Lions of the World’. (Eds A. W. Trites, S. K. Atkinson, D. P. DeMaster, L. W. Fritz, T. S. Gelatt, L. D. Rea and K. M. Wynne.) pp. 353–367. (Alaska Sea Grant College Program: University of Alaska, Fairbanks, AK.)

McKay R. J. (1992). ‘FAO Species Catalogue, Vol. 14. Sillaginid fishes of the world (family Sillaginidae). An annotated and illustrated catalogue of the sillago, smelt or Indo-Pacific whiting species known to date.’ FAO Fisheries Synopsis 125. (FAO: Rome.)

McKenzie J., Goldsworthy S. D., Shaughnessy P. D., and McIntosh R. (2005). Understanding the impediments to the growth of Australian sea lion populations. South Australian Research and Development Institute (Aquatic Sciences), SARDI Publication Number RD04/0171. SARDI, Adelaide.

Needham D. J. (1997). The role of stones in the sea lion stomach: investigations using contrast radiography and fluoroscopy. In ‘Marine Mammal Research in the Southern Hemisphere. Vol. 1: Status, Ecology and Medicine.’ (Eds M. A. Hindell and C. Kemper.) pp 164–169. (Surrey Beatty: Sydney.)

O’Dor, R. K. , Adamo, S. , Aitken, J. P. , Andrade, Y. , Finn, J. , Hanlon, R. T. , and Jackson, G. D. (2002). Currents as environmental constraints on the behavior, energetics and distribution of squid and cuttlefish. Bulletin of Marine Science 71, 601–617.
Paxton J. R., Hoese D. F., Allen G. R., and Hanley J. E. (1989). ‘Pisces. Petromyzontidae to Carangidae.’ (Australian Government Publishing Service: Canberra).

Pecl, G. (2001). Flexible reproductive strategies in tropical and temperate Sepioteuthis squids. Marine Biology 138, 93–101.
| Crossref | GoogleScholarGoogle Scholar | Robinson A. C., and Dennis T. E. (1988). The status and management of seal populations in South Australia. In ‘Marine Mammals of Australasia – Field Biology and Captive Management’. (Ed. M. L. Augee.) pp. 87–104. (Royal Zoological Society of NSW: Sydney.)

Shaughnessy P. D. (1999). ‘The Action Plan for Australian Seals.’ (Environment Australia: Canberra.)

Shaughnessy P. D., and Dennis T. E. (2001). Research on New Zealand fur seals and Australian sea lions in South Australia, 2000–2001. Report to National Parks and Wildlife South Australia, Department for Environment and Heritage. CSIRO, Canberra.

Shaughnessy, P. D. , Dennis, T. E. , and Seager, P. G. (2005). Status of Australian sea lions, Neophoca cinerea, and New Zealand fur seals, Arctocephalus forsteri, on Eyre Peninsula and the far west coast of South Australia. Wildlife Research 32, 85–101.
| Crossref | GoogleScholarGoogle Scholar | Smale M. J., Watson G., and Hecht T. (1995). ‘Otolith Atlas of Southern African Marine Fishes.’ (JLB Smith Institute of Ichthyology: Grahamstown, South Africa).

Stranks, T. N. (1996). Biogeography of Octopus species (Cephalopoda: Octopodidae) from southeastern Australia. American Malacological Bulletin 12, 145–151.
Tate M. L. (1981). The autumn–winter diet of the New Zealand fur seal Arctocephalus forsteri (Lesson) with special reference to its cephalopod prey. Dip.Sci. Thesis, University of Otago, Dunedin.

Taylor, M. A. (1993). Stomach stones for feeding or buoyancy – the occurrence and function of gastroliths in marine tetrapods. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 341, 163–175.
| Crossref | GoogleScholarGoogle Scholar | Triantifillos L., Jackson G. D., Adams M., and McGrath-Steer B. L. (2004). An allozome investigation of species boundaries and stock structure in Australian populations of the arrow squid Nototodarus gouldi (Cephalopoda: Ommastrephidae). In ‘FRDC Final Report. Arrow squid in Southern Australian Waters – Supplying Management Needs Through Biological Investigations’. (Eds G. D. Jackson and B. McGrath-Steer.) pp. 18–24. (Fisheries Research and Development Corporation & South Australian Research and Development Institute: Adelaide.)

Uozumi, Y. (1998). Fishery biology of arrow squids, Nototodarus gouldi and N. sloanii, in New Zealand waters. Bulletin of the National Research Institute of Far Seas Fisheries. Shimizu 35, 1–111.
Ward T. M., McLeay L. J., Dimmlich W. F., Rogers P. J., McClatchie S., Matthews R., Kampf J., and van Ruth P. (2004). Pelagic ecology of a northern boundary current system. In ‘Trophodynamics of the GAB: Assessing the Need for an Ecological Allocation in the SA Pilchard Fishery’. (Eds T. M. Ward, S. D. Goldsworthy and B. Page.) pp. 28–47. (Fisheries Research and Development Corporation & South Australian Research and Development Institute: Adelaide.)

Wells M. J. (1977). ‘Octopus: Physiology and Behaviour of a Marine Invertebrate.’ (Chapman and Hall: London.)