Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences

Demographic analysis of the Port Jackson shark Heterodontus portusjacksoni in the coastal waters of eastern Australia

David Mark Powter A B and William Gladstone A
+ Author Affiliations
- Author Affiliations

A School of Environmental and Life Sciences, Ourimbah Campus, University of Newcastle, Ourimbah NSW 2258, Australia.

B Corresponding author. Email:

Marine and Freshwater Research 59(5) 444-455
Submitted: 10 May 2007  Accepted: 17 April 2008   Published: 6 June 2008


Demographic analyses are used to assess the status and vulnerability of elasmobranchs but their accuracy is often affected by limited basic biological information. Although the Port Jackson shark Heterodontus portusjacksoni (Meyer) is currently not considered at threat, there is insufficient data for eastern Australia to assess this rigorously. The present study determined vital demographic rates of adult and juvenile H. portusjacksoni at four locations on the central and southern coast of New South Wales, Australia from January 2002 to December 2005 using underwater visual census, tag–recapture and samples obtained from a commercial fishery. Natural mortality was low in adults (0.063–0.074 year–1) and juveniles (0.225 year–1), but substantial at the embryonic stage (0.783–0.896 year–1). Adult growth rates (31.4–32.7 mm year–1) were slightly less than that of juveniles (36.8–37.5 mm year–1). Males at both stages grew slightly faster than females. However, H. portusjacksoni had slower growth rates than many other elasmobranch species. Having a low intrinsic rate of increase (r = 0.069 year–1), long generation times (μ1 = 22.5 year) and a low rebound potential, adults are the stage with the greatest impact on population growth. Hence, their life history strategy makes them susceptible to serious decline under exploitation, and management should strive to maintain the adult reproductive stock as a priority.

Additional keywords: conservation, growth rates, matrix models, mortality.


We wish to thank Australian Geographic and Project AWARE (PADI Asia Pacific) for financial assistance with this research. Special thanks to Brett Bollinger (commercial fisher) for his cooperation and assistance in obtaining sharks. All work was conducted under the University of Newcastle Ethics Approval 804 0602 and NSW Fisheries Scientific Collection Permit P02/0042 and renewals.


Akcakaya, H. R. (2002). Estimating the variance of survival rates and fecundities. Animal Conservation 5, 333–336.

Au, D. W. , and Smith, S. E. (1997). A demographic method with population density compensation for estimating productivity and yield per recruit of the leopard shark (Triakis semifasciata). Canadian Journal of Fisheries and Aquatic Sciences 54, 415–420.
CrossRef |

Avsar, D. (2001). Age, growth, reproduction and feeding of the spurdog (Squalus acanthias Linnaeus, 1758) in the south-eastern Black Sea. Estuarine, Coastal and Shelf Science 52, 269–278.
CrossRef |

Barker, M. J. , Gruber, S. H. , Newman, S. P. , and Schluessel, V. (2005). Spatial and ontogenetic variation in growth of nursery-bound juvenile lemon sharks, Negaprion brevirostris: a comparison of two age-assigning techniques. Environmental Biology of Fishes 72, 343–355.
CrossRef |

Beerkircher, L. , Shivji, M. , and Cortes, E. (2003). A Monte Carlo demographic analysis of the silky shark (Carcharhinus falciformis): implications of gear selectivity. Fishery Bulletin 101, 168–174.

Bishop, S. D. H. , Francis, M. P. , Duffy, C. , and Montgomery, J. C. (2006). Age, growth, maturity, longevity and natural mortality of the shortfin mako shark (Isurus oxyrinchus) in New Zealand waters. Marine and Freshwater Research 57, 143–154.
CrossRef |

Braccini J. M. (2006). Assessment of ecological risks from effects of fishing to piked spurdog (Squalus megalops) in south-eastern Australia. PhD Thesis, University of Adelaide, Australia.

Branstetter, S. (1987). Age and growth validation of newborn sharks held in laboratory aquaria, with comments on the life history of the Atlantic sharpnose shark, Rhizoprionodon terraenovae. Copeia (2), 291–300.
CrossRef |

Branstetter S. (1990). Early life-history implications of selected carcharhinoid and lamnoid sharks of the Northwest Atlantic. In ‘Elasmobranchs as Living Resources: Advances in the Biology, Ecology, Systematics, and the Status of Fisheries’. (Eds H. L. Pratt, S. H. Gruber and T. Taniuchi.) pp. 17–28. (US Department of Commerce: Washington, DC.)

Brewster-Geisz, K. K. , and Miller, T. J. (2000). Management of the sandbar shark, Carcharhinus plumbeus: implications of a stage-based model. Fishery Bulletin 98, 236–249.

Campana S., Marks L., Joyce W., Hurley P., and Showell M. (1999). An analytical assessment of the porbeagle shark (Lamna nasus) population in the Northwest Atlantic. Canadian Stock Assessment Secretariat Research Document 99/158.

Carlson, J. K. , and Parsons, G. R. (1997). Age and growth of the bonnethead shark, Sphyrna tiburo, from northwest Florida, with comments on clinal variation. Environmental Biology of Fishes 50, 331–341.
CrossRef |

Carlson, J. K. , Cortes, E. , and Bethea, D. M. (2003). Life history and population dynamics of the finetooth shark (Carcharhinus isodon) in the northeastern Gulf of Mexico. Fishery Bulletin 101, 281–292.

Carrier, J. C. , and Luer, C. A. (1990). Growth rates in the nurse shark, Ginglymostoma cirratum. Copeia (3), 686–692.
CrossRef |

Castro J. I., Woodley C. M., and Brudek R. L. (1999). A preliminary evaluation of the status of shark species. FAO Fisheries Technical Paper No. 380, Rome.

Caswell H. (2001). ‘Matrix Population Models: Construction, Analysis, and Interpretation.’ 2nd edn. (Sinauer Associates: Sunderland, MA.)

Chen, P. , and Yuan, W. (2006). Demographic analysis based on the growth parameter of sharks. Fisheries Research 78, 374–379.
CrossRef |

Compagno L. J. V. (2002). ‘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).’ (FAO: Rome.)

Cooch E., and White G. (2002). Program MARK. A Gentle Introduction. Available at [Accessed 15 January 2003].

Cortes, E. (1998). Demographic analysis as an aid in shark stock assessment and management. Fisheries Research 39, 199–208.
CrossRef |

Cortes, E. (1999). A stochastic stage-based population model of the sandbar shark in the western North Atlantic. American Fisheries Society Symposium 23, 115–136.

Cortes, E. (2000a). Life history patterns and correlations in sharks. Reviews in Fisheries Science 8, 299–344.

Cortes, E. (2000b). Potential rates of increase and rates of increase per generation for three species of pelagic sharks from the Atlantic Ocean. Collective Volume of Scientific Papers International Commission for the Conservation of Tunas 51, 1822–1828.

Cortes E. (2004). Life history patterns, demography, and population dynamics. In ‘Biology of Sharks and Their Relatives’. (Eds J. C. Carrier, J. A. Musick and M. R. Heithaus.) pp. 449–469. (CRC Press: Boca Raton, FL.)

Duncan, K. M. , and Holland, K. N. (2006). Habitat use, growth rates and dispersal patterns of juvenile scalloped hammerhead sharks Sphyrna lewini in a nursery habitat. Marine Ecology Progress Series 312, 211–221.
CrossRef |

Francis, R. I. C. C. (1988). Maximum likelihood estimation of growth and growth variability from tagging data. New Zealand Journal of Marine and Freshwater Research 22, 42–51.

Frisk, M. G. , Miller, T. J. , and Fogarty, M. J. (2001). Estimation and analysis of biological parameters in elasmobranch fishes: a comparative life history study. Canadian Journal of Fisheries and Aquatic Sciences 58, 969–981.
CrossRef |

Froese, R. , and Binholan, C. (2000). Empirical relationships to estimate asymptotic length, length at first maturity and length at maximum yield per recruit in fishes, with a simple method to evaluate length frequency data. Journal of Fish Biology 56, 758–773.
CrossRef |

Froese, R. , and Palomares, M. L. D. (2000). Growth, natural mortality, length–weight relationship, maximum length and length-at-first-maturity of the coelacanth Latimeria chalumnae. Environmental Biology of Fishes 58, 45–52.
CrossRef |

Gayanilo F. C.Jr, Sparre P., and Pauly D. (2002). FiSAT II User’s Guide. Available at [Accessed 1 May 2005].

Gunderson, D. R. , and Dygert, P. H. (1988). Reproductive effort as a predictor of natural mortality rate. Journal du Conseil: Conseil International pour L’Exploration de la Mer 44, 200–209.

Hall, N. G. , Hesp, S. A. , and Potter, I. C. (2004). A Bayesian approach for overcoming inconsistencies in mortality estimates using, as an example, data for Acanthopagrus latus. Canadian Journal of Fisheries and Aquatic Sciences 61, 1202–1211.
CrossRef |

Heupel, M. R. , and Simpfendorfer, C. A. (2002). Estimation of mortality of juvenile blacktip sharks, Carcharhinus limbatus, within a nursery area using telemetry data. Canadian Journal of Fisheries and Aquatic Sciences 59, 624–632.
CrossRef |

Izzo C. (2005). Aging Port Jackson sharks, Heterodontus portusjacksoni (Meyer 1793), using calcified structures. BSc Honours Thesis, Flinders University, Adelaide, Australia.

Jensen, A. L. (1996). Beverton and Holt life history invariants result from optimal trade-off of reproduction and survival. Canadian Journal of Fisheries and Aquatic Sciences 53, 820–822.
CrossRef |

Krebs C. J. (1985). ‘Ecology: the Experimental Analysis of Distribution and Abundance.’ 3rd edn. (Harper and Row: New York, NY.)

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

Manire C. A., and Gruber S. H. (1993). A preliminary estimate of natural mortality of age-0 lemon sharks, Negaprion brevirostris. NOAA Technical Report NMFS 115, Washington, DC.

McLaughlin, R. H. , and O’Gower, A. K. (1971). Life history and underwater studies of a heterodont shark. Ecological Monographs 41, 271–289.
CrossRef |

Mollet, H. F. , and Cailliet, G. M. (2002). Comparative population demography of elasmobranchs using life history tables, Leslie matrices and stage-based matrix models. Marine and Freshwater Research 53, 503–516.
CrossRef |

Musick, J. A. (1999). Ecology and conservation of long-lived marine animals. American Fisheries Society Symposium 23, 1–10.

NSW Department of Primary Industries (2004). Environmental Impact Statement on the Ocean Trawl Fishery in NSW. Public Consultation Document, Cronulla, NSW, Australia.

O’Gower, A. K., and Nash, A. R. (1978). Dispersion of the Port Jackson shark in Australian waters. In ‘Sensory Biology of Sharks, Skates, and Rays’. (Eds E. S. Hodgson and R. F. Mathewson.) pp. 529–544. (Office of Naval Research: Arlington, VA.)

Pauly, D. (1980). On the interrelationships between natural mortality, growth parameters, and mean environmental temperature in 175 fish stocks. Journal du Conseil: Conseil International pour L’Exploration de la Mer 39, 175–192.

Powter D. M. (2006). Conservation biology of the Port Jackson shark, Heterodontus portusjacksoni, in New South Wales. PhD Thesis, University of Newcastle, Australia.

Powter, D. M. , and Gladstone, W. (2008a). Habitat preferences of Port Jackson sharks, Heterodontus portusjacksoni, in the coastal waters of eastern Australia. Proceedings of the Linnean Society of New South Wales 129, 151–165.

Powter, D. M. , and Gladstone, W. (2008b). Embryonic mortality and predation on egg capsules of the Port Jackson shark Heterodontus portusjacksoni (Meyer). Journal of Fish Biology 72, 573–584.
CrossRef |

Powter D. M., and Gladstone W. The reproductive biology and ecology of the Port Jackson shark, Heterodontus portusjacksoni, in the coastal waters of eastern Australia. Journal of Fish Biology, in press.

Rago, P. J. , Sosebee, K. A. , Brodziak, J. K. T. , Murawski, S. A. , and Anderson, E. D. (1998). Implications of recent increases in catches on the dynamics of Northwest Atlantic spiny dogfish (Squalus acanthias). Fisheries Research 39, 165–181.
CrossRef |

Ramos R. O. (2007). Age and growth estimates for the Port Jackson shark, Heterodontus portusjacksoni (Mayer, 1793), from New South Wales, Australia. PhD Thesis, University of Newcastle, Australia.

Rodda K. R. (2000). Development in the Port Jackson shark embryo. PhD Thesis, University of Adelaide, Australia.

Shark Advisory Group (2004). ‘Australian shark assessment report for the Australian national plan of action for the conservation and management of sharks.’ (Department of Agriculture, Fisheries and Forestry: Canberra.)

Simpfendorfer, C. A. (1999). Mortality estimates and demographic analysis for the Australian sharpnose shark, Rhizoprionodon taylori, from northern Australia. Fishery Bulletin 97, 978–986.

Simpfendorfer C. A. (2004a). Demographic models: life tables, matrix models and rebound potential. In ‘Elasmobranch Fisheries Management Techniques’. (Eds J. A. Musick and R. Bonfil.) pp. 187–204. (APEC Secretariat: Singapore.)

Simpfendorfer C. A. (2004b). Mortality estimation. In ‘Elasmobranch Fisheries Management Techniques’. (Eds J. A. Musick and R. Bonfil.) pp. 165–186. (APEC Secretariat: Singapore.)

Smith, S. E. , Au, D. W. , and Show, C. (1998). Intrinsic rebound potentials of 26 species of Pacific sharks. Marine and Freshwater Research 49, 663–678.
CrossRef |

Sparre P., and Venema S. C. (1998). ‘Introduction to Tropical Fish Stock Assessment. Part 1. Manual.’ (FAO: Rome.)

Stevens, J. D. , Bonfil, R. , Dulvy, N. K. , and Walker, P. A. (2000). The effects of fishing on sharks, rays, and chimaeras (chondrichthyans), and the implications for marine ecosystems. ICES Journal of Marine Science 57, 476–494.
CrossRef |

Strong W. R. (1989). Behavioural ecology of horn sharks, Heterodontus francisci, at Santa Catalina Island, California, with emphasis on patterns of space utilization. MSc Thesis, California State University, Long Beach.

Tovar-Avila J. (2006). Reproduction, age validation, growth determination and effects of fishing on the Port Jackson shark (Heterodontus portusjacksoni) in south-eastern Australia. PhD Thesis, University of Melbourne, Australia.

Whitley G. P. (1950). Development of a Port Jackson shark. Proceedings of the Royal Zoological Society of NSW 1950, 28.

Rent Article (via Deepdyve) Export Citation Cited By (9)