John D. Stevens
by Colin Simpfendorfer
John Stevens is a true pioneer of shark research in Australia. For more than 30 years he has worked tirelessly to understand the sharks that inhabit our waters. Along the way he has touched the careers of just about every shark researcher that has been active in the country. His humility and collaborative nature enabled him to share his knowledge and experience with many young researchers who have started working on Australia’s diverse and abundant shark fauna.
John grew up on the Devon coast of SW England and attended London University for both his undergraduate and doctoral degrees. During his PhD research he worked out of the Marine Biological Association Laboratories in Plymouth where he had good access to blue sharks – the main focus of his research.
John’s PhD work on using vertebrae to age blue sharks paved the way for a revolution in our understanding of shark life history. While growth bands had been observed in vertebrae previously, he was able to demonstrate that they were produced regularly and could be used to estimate age and so enable the fitting of growth models. The following decades have seen vertebral age and growth studies of many species of sharks, especially those taken in fisheries. The information produced from this type of work has led to improved understanding of the dynamics of shark populations and improved management.
Following his PhD John did post-doctoral research at Aldabra Atoll in the Indian Ocean. Here he studied the sharks of coral reefs and produced a seminal work on their ecology that is still often cited. The long-term prospects were poor at Aldabra and John accepted a position at CSIRO in 1979 where he continued his work with sharks, first in Cronulla and then in Hobart.
Much of the early focus of John’s work at CSIRO was in the north of Australia during a period when foreign vessels caught large quantities of sharks in this region. This work included life history studies on a diverse range of coastal species, tagging studies, fisheries biology and much more. In collaboration with a team from NT Fisheries led by Jeremy Lyle he produced a collection of scientific papers and reports that led to fundamental changes the way sharks were managed in the region.
John’s passion for sharks led him all over the country to collect samples and data that would start to lift the lid on the mysteries of the life of sharks. This wealth of knowledge was integral in the production of “Sharks and Rays of Australia” with colleague and good friend Peter Last in 1994. This book, and the revised 2nd edition published in 2009, is the quintessential guide to sharks and rays and has served as the encyclopedia of Australian sharks and rays since it first appeared.
John’s passion for sharks has seen him research a wide range of species, from the massive sleeper sharks that live in the deep sea, to the mako sharks that swim in the open ocean, the very rare speartooth sharks that inhabit the rivers of northern Australia, and all those in between. His breadth of knowledge and experience made him a common choice as an expert on committees and review panels. He was the Regional Vice-Chair (Australia and Oceania) of the IUCN’s Shark Specialist Group for nearly two decades, and helped assess many shark species for listing on the Red List of Threatened Species. He has contributed his scientific knowledge to fisheries management committees such as AFMA’s Shark Resource Assessment Group, Southern Shark MAC, and many others.
John has been a regular at ASFB meetings throughout his career and he well known to many members. Despite his quiet and humble nature, he has still managed to be a winner of the Donald Francois Award for his contributions at an Annual Conference. He truly deserves his place in the ASFB Hall of Fame for all that he has contributed to the Society and the country as a whole.
As a result of John’s work Australia’s sharks are better understood and better managed. He has been a role-model for many aspiring shark scientists, and helped formally and informally supervise many post-graduate students. These students have benefited from his experience and have ensured that the work that John started back in 1979 will continue for many decades into the future. While he has now retired and enjoying the eternal summers of Hobart and Devon, his influence on all things shark in Australia shows no sign of fading.
Selected publications
Stevens, J.D. 1973. Stomach contents of the blue shark (Prionace glauca L.) off southwest England. Journal of the Marine Biological Association of the UK 53, 357-361.
Clarke, M.R. and Stevens, J.D. 1974. Cephalopods, blue sharks and migration. Journal of the Marine Biological Association of the UK 54, 949-293
Stevens, J. D., and Brown, B. E. 1974. Occurrence of Heavy Metals in the Blue Shark Prionace glauca and Selected Pelagic in the N. E. Atlantic Ocean. Marine Biology, 26: 287–293.
Stevens, J.D. 1975. Vertebral rings as a means of age determination in the blue shark (Prionace glauca L.). Journal of the Marine Biological Association of the UK 55, 657-665.
Stevens, J.D. 1976. Preliminary results of shark tagging in the north-east Atlantic, 1972-1975. Journal of the Marine Biological Association of the UK 56, 929-937.
Stevens, J.D. 1976. The ecology of the blue shark (Prionaceglauca L.) in British waters. Ph.D. thesis London University, 255 pp.
Stevens, J.D., Dunning, M.C. and Machida, S. 1983. Occurrence of the porbeagle shark, Lamna nasus in the Tasman Sea. Japanese Journal of Ichthyology 30 (3), 301-307.
Stevens, J.D. 1984. Biological observations on sharks caught by sport fishermen off New South Wales. Australian Journal of Marine and Freshwater Research 35 573-590.
Stevens, J.D. 1984. Life-history and ecology of sharks at Aldabra Atoll, Indian Ocean. Proceedings of the Royal Society of London Series B 222, 79-106.
Stevens, J.D. and Wiley, P.D. 1986. Biology of two commercially important carcharhinid sharks from Northern Australia. Australian Journal of Marine and Freshwater Research. 37, 671-88.
Stevens, J.D. and Lyle, J.M. 1989. The biology of three hammerhead sharks (Eusphyra blochii , Sphyrna mokarran and S. lewini) from northern Australia. Australian Journal of Marine and Freshwater Research 40, 129-46.
Vas, P., Stevens, J.D., Bonwick, G.A. and Tizini, O.A. 1990. Cd, Mn, and Zn concentrations in vertebrae of blue shark and shortfin mako in Australian waters. Marine Pollution Bulletin 21(4), 203-206.
Stevens, J.D.1990. Further results from a tagging study of pelagic sharks in the north-east Atlantic. Journal of the Marine Biological Association of the UK. 70, 707-720.
Stevens, J.D. 1992. Blue and mako shark by-catch in the Japanese longline fishery off south-eastern Australia. Australian Journal of Marine and Freshwater Research 43, 227-236.
McLoughlin, K.J., and Stevens, J.D. 1994. Gill-net mesh selectivities for two species of commercial carcharhinid shark taken in northern Australia. Australian Journal of Marine and Freshwater Research 45: 521-534.
Last, P.R. and Stevens, J.D. 1994. Sharks and rays of Australia. First edition. C.S.I.R.O. Australia.
Francis, M.P., and Stevens J.D. 1999 Reproduction, embryonic development, and growth of the porbeagle shark, Lamna nasus, in the southwest Pacific Ocean. Fisheries Bulletin. 98:41-63.
Gunn, J.S., Stevens, J.D., Davis, T.L.O., and Norman, B.M.1999. Observations on the short-term movements and behaviour of whale sharks (Rhincodon typus) at Ningaloo Reef, Western Australia. Marine Biology. 135: 553-559.
Xiao, Y., Stevens, J.D., and West G.J. 1999. Estimation of fishing and natural mortalities from tag experiments with exact or grouped time at liberty. Canadian Journal of Fisheries and Aquaculture 56: 868-874.
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 J. Mar. Sci.57(3): 476–494
Francis, M. P., and Stevens, J. D. 2000. Reproduction, embryonic development, and growth of the porbeagle shark, Lamna nasus, in the southwest Pacific Ocean. Fishery Bulletin, 98: 41–63.
Stevens, J. D., Walker, T. I., Cook, S. F., and Fordham, S. V. 2005. Threats faced by chondrichthyan fish. In Sharks, Rays and Chimeras: The Status of Chondrichthyan Fishes. IUCN/SSC Shark Specialist Group, pp. 48–57. Ed. S. L. Fowler, R. D. Cavanagh, M. Camhi, G. H. Burgess, G. M. Cailliet, S. V. Fordham, C. A. Simpfendorfer, et al.
Irvine, S. B., Stevens, J. D., and Laurenson, L. J. B. 2006. Comparing external and internal dorsal-spine bands to interpret the age and growth of the giant lantern shark, Etmopterus baxteri (Squaliformes: Etmopteridae). Environmental Biology of Fishes, 77: 253–264.
Bruce, B. D., Stevens, J. D., and Malcolm, H. 2006. Movements and swimming behaviour of white sharks (Carcharodon carcharias) in Australian waters. Marine Biology, 150: 161–172.
Stevens, J. D. 2007. Whale shark (Rhincodon typus) biology and ecology: A review of the primary literature. Fisheries Research, 84: 4–9.
Norman, B. M., and Stevens, J. D. 2007. Size and maturity status of the whale shark (Rhincodon typus) at Ningaloo Reef in Western Australia. Fisheries Research, 84: 81–86.
Yano, K., Stevens, J. D., and Compagno, L. J. V. 2007. Distribution, reproduction and feeding of the Greenland shark Somniosus (Somniosus) microcephalus, with notes on two other sleeper sharks, Somniosus (Somniosus) pacificus and Somniosus (Somniosus) antarcticus. Journal of Fish Biology, 70: 374–390.
Wilson, S. G., Stewart, B. S., Polovina, J. J., Meekan, M. G., Stevens, J. D., and Galuardi, B. 2007. Accuracy and precision of archival tag data: A multiple-tagging study conducted on a whale shark (Rhincodon typus) in the Indian Ocean. Fisheries Oceanography, 16: 547–554.
Awruch, C. a., Frusher, S. D., Pankhurst, N. W., and Stevens, J. D. 2008. Non-lethal assessment of reproductive characteristics for management and conservation of sharks. Marine Ecology Progress Series, 355: 277–285.
Last, P. R. and Stevens, J. D. 2009. Sharks and Rays of Australia. Second edition. CSIRO Publishing, Collingwood, Victoria.
Stevens, J. D., Bradford, R. W., and West, G. J. 2010. Satellite tagging of blue sharks (Prionace glauca) and other pelagic sharks off eastern Australia: Depth behaviour, temperature experience and movements. Marine Biology, 157: 575–591.
Barnett, A., Stevens, J. D., Frusher, S. D., and Semmens, J. M. 2010. Seasonal occurrence and population structure of the broadnose sevengill shark Notorynchus cepedianus in coastal habitats of south-east Tasmania. Journal of Fish Biology, 77: 1688–1701.
Barnett, A., Abrantes, K. G., Stevens, J. D., Bruce, B. D., and Semmens, J. M. 2010. Fine-Scale Movements of the Broadnose Sevengill Shark and Its Main Prey, the Gummy Shark. PLoS ONE, 5: e15464. Public Library of Science. http://dx.doi.org/10.1371%2Fjournal.pone.0015464.
Barnett, A., Abrantes, K. G., Stevens, J. D., and Semmens, J. M. 2011. Site fidelity and sex-specific migration in a mobile apex predator: Implications for conservation and ecosystem dynamics. Animal Behaviour, 81: 1039–1048.
Speed, C. W., Meekan, M. G., Field, I. C., McMahon, C. R., Stevens, J. D., McGregor, F., Huveneers, C., et al. 2011. Spatial and temporal movement patterns of a multi-species coastal reef shark aggregation. Marine Ecology Progress Series, 429: 261–275.
Fitzpatrick, R., Thums, M., Bell, I., Meekan, M. G., Stevens, J. D., and Barnett, A. 2012. A Comparison of the Seasonal Movements of Tiger Sharks and Green Turtles Provides Insight into Their Predator-Prey Relationship. PLoS ONE, 7: e51927. Public Library of Science. http://dx.doi.org/10.1371%2Fjournal.pone.0051927.
Awruch, C. A., Frusher, S. D., Stevens, J. D., and Barnett, a. 2012. Movement patterns of the draughtboard shark Cephaloscyllium laticeps (Scyliorhinidae) determined by passive tracking and conventional tagging. Journal of Fish Biology, 80: 1417–1435.
Ferreira, L. C., Thums, M., Meeuwig, J. J., Vianna, G. M. S., Stevens, J., McAuley, R., and Meekan, M. G. 2015. Crossing Latitudes—Long-Distance Tracking of an Apex Predator. PLoS ONE, 10: e0116916. Public Library of Science. http://dx.doi.org/10.1371%2Fjournal.pone.0116916.