Environmental Biology of Fishes

, Volume 58, Issue 4, pp 371–377 | Cite as

Predicting Population Recovery Rates for Endangered Western Atlantic Sawfishes Using Demographic Analysis

  • Colin A. Simpfendorfer


Sawfish are a group of endangered elasmobranchs that were common in tropical inshore, estuarine and freshwaters. The demography of two species of sawfish that occur in the western Atlantic – Pristis pectinata and P. perotteti – was investigated using age-structured life tables. Life history parameters for use in the life tables were obtained from published data. Five scenarios were tested for P. pectinata to incorporate uncertainties about life history data. Values of intrinsic rate of increase ranged from 0.08 to 0.13 yr−1, and population doubling times from 5.4 to 8.5 yrs. Eight scenarios were tested for P. perotteti. The most likely range for the intrinsic rate of increase was 0.05–0.07 yr−1, with population doubling times of 10.3–13.5 yrs. Four scenarios investigating the sensitivity to methods of estimating natural mortality produced similar results. The demographic results were sensitive to changes in reproductive periodicity and natural mortality. The results indicate that if effective conservation plans can be implemented for sawfish and sawfish habitats, recovery to levels where there is little risk of extinction will take at least several decades.

largetooth sawfish Pristis perotteti smalltooth sawfish Pristis pectinata life tables conservation 


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References cited

  1. Au, D.W. & S.E. Smith. 1997. A demographic method with population density compensation for estimating productivity and yield per recruit of the leopard shark (Triakis semifasciata). Can. J. Fish. Aquat. Sci. 54: 415–420.Google Scholar
  2. Baillie, J & B. Groombridge. 1996. IUCN Red List of threatened animals. IUCN, Cambridge. 448 pp.Google Scholar
  3. Baughman, J.L. 1943. Notes on sawfish, Pristis perotteti Muller and Henle, not previously reported from the waters of the United States. Copeia 1943: 43–48.Google Scholar
  4. Bigelow, H.B. & W.C. Schroeder. 1953. Sawfishes, guitarfishes, skates and rays. Fisheries of the Western North Atlantic. Memoirs of the Sears Memorial Foundation for Marine Research 1: 1–514.Google Scholar
  5. Cailliet, G.M. 1992. Demography of the central California population of the leopard shark (Triakis semifaciata). Aust. J. Mar. Freshw. Res. 43: 183–193.Google Scholar
  6. Cailliet, G.M., R.L. Radtke & B.A. Welden. 1986. Elasmobranch age determination and verification: a review. pp. 344–360. In: T. Uyeno, R. Arai, T. Taniuchi & K. Matsuura (ed.) Indo-Pacific Fish Biology: Proceedings of the Second International Conference on Indo-Pacific Fishes. Ichthyological Society of Japan, Tokyo.Google Scholar
  7. Camhi, M. 1998. Sharks on the line. A state-by-state analysis of sharks and their fisheries. National Audubon Society, New York. 156 pp.Google Scholar
  8. Cole, G.A. 1976. Limnology of the great lakes of Nicaragua. pp. 9–15. In: T.B. Thorson (ed.) Investigations of the Ichthyofauna of Nicaraguan Lakes. School of Life Sciences, University of Nebraska-Lincoln, Lincoln.Google Scholar
  9. Cortes, E. 1995. Demographic analysis of the Atlantic sharpnose shark, Rhizoprionodon terraenovae, in the Gulf of Mexico. U.S. Fish. Bull. 93: 57–66.Google Scholar
  10. Cortes, E. 1998. Demographic analysis as an aid in shark stock assessment and management. Fish. Res. 39: 199–208.Google Scholar
  11. Crooks, K.R., M.A. Sanjayan & D.F. Doak. 1998. New insights on cheetah conservation through demographic modeling. Conserv. Biol. 12: 889–895.Google Scholar
  12. Crouse, D.T., L.B. Crowder & H. Caswell. 1987. A stage-based population model for loggerhead sea turtles and implications for conservation. Ecology 68: 1412–1423.Google Scholar
  13. Henshall, J.A. 1895. Notes on fishes collected in Florida in 1892. Bulletin of the U.S. Fish Commission 14(1894): 209–221.Google Scholar
  14. Hoenig, J.M. 1983. Empirical use of longevity data to estimate mortality rates. U.S. Fish. Bull. 82: 898–903.Google Scholar
  15. Hoenig, J.M. & S.H. Gruber. 1990. Life-history patterns in the elasmobranchs: implications for fisheries management. pp. 1–16. In: H.L. Pratt Jr., S.H. Gruber & T. Taniuchi (ed.) Elasmobranchs as Living Resources: Advances in the Biology, Ecology, Systematics and the Status of the Fisheries, NOAA Tech. Rep. NMFS 90.Google Scholar
  16. Jensen, A.L. 1996. Beverton and Holt life history invariants result from optimal trade-off of reproduction and survival. Can. J. Fish. Aquat. Sci. 53: 820–822.Google Scholar
  17. Jordan, D.S. & B.W. Evermann. 1896. The fishes of North and Middle America. Bull. U.S. Nat. Mus. Number 47, Part 1, Volume 1: 1–954.Google Scholar
  18. Krebs, C.J. 1985. Ecology: the experimental analysis of distributions and abundance. Harper and Row, New York. 694 pp.Google Scholar
  19. Last, P.R. & J.D. Stevens. 1994. Sharks and rays of Australia. CSIRO, Melbourne. 513 pp.Google Scholar
  20. Pauly, D. 1980. On the interrelationship between natural mortality, growth parameters, and mean environmental temperatures in 175 fish stocks. Journal du Conseil International pour l'Exploration de la Mer 39: 175–192.Google Scholar
  21. Peterson, I. & J.S. Wroblewski. 1984. Mortality rates of fishes in the pelagic ecosystem. Can. J. Fish. Aquat. Sci. 41: 1117–1120.Google Scholar
  22. Simpfendorfer, C.A. 1999a. Demographic analysis of the dusky shark fishery in south-western Australia. pp. 149–160. In: J.A. Musick (ed.) Life in the Slow Lane: Ecology and Conservation of Long-lived Marine Animals, American Fisheries Society Symposium 23, Bethesda.Google Scholar
  23. Simpfendorfer, C.A. 1999b. Mortality estimates and demographic analysis for the Australian sharpnose shark, Rhizoprionodon taylori from Northern Australia. U.S. Fish. Bull. 97 (in press).Google Scholar
  24. Sminkey, T.R & J.A. Musick. 1996. Demographic analysis of the sandbar shark, Carcharhinus plumbeus, in the western North Atlantic. U.S. Fish. Bull. 94: 341–347.Google Scholar
  25. Tanaka, T. 1991. Age estimation of freshwater sawfish and sharks in northern Australia and Papua New Guinea. University Museum, University of Tokyo, Nature and Culture (3): 71–82.Google Scholar
  26. Thorson, T.B. 1976. Observations on the reproduction of the sawfish, Pristis perotteti, in Lake Nicaragua, with recommendations for its conservation. pp. 641–650. In: T.B. Thorson (ed.) Investigations of the Ichthyofauna of Nicaraguan Lakes, School of Life Sciences, University of Nebraska-Lincoln, Lincoln.Google Scholar
  27. Thorson, T.B. 1982a. Life history implications of a tagging study of the largetooth sawfish, Pristis perotteti, in the Lake Nicaragua-Rio San Juan system. Env. Biol. Fish. 7: 207–228.Google Scholar
  28. Thorson, T.B. 1982b. The impact of commercial exploitation on sawfish and shark populations in Lake Nicaragua. Fisheries 7: 2–10.Google Scholar
  29. Thorson, T.B., C.M. Cowan & D.E. Watson. 1966. Sharks and sawfish in the Lake Izabal-Rio Dulce system, Guatemala. Copeia 1966: 620–622.Google Scholar

Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • Colin A. Simpfendorfer
    • 1
  1. 1.Center for Shark ResearchMote Marine LaboratorySarasotaU.S.A.

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