Abstract
Changes in the Hawkesbury zoobenthos associated with a major flood and drought are described and comparisons made in the patterns of change among estuarine reaches and among sites within reaches. The consequences for environmental monitoring and management are discussed. Replicate grab samples were taken from four sites in each of the lower, middle and upper reaches. Reductions in the mean number of species per grab (S) following the flood were significant only in the lower reaches and at one site in the middle reaches. Increases in S accompanied the drought in all reaches but intra-reach variation in temporal patterns occurred in both S and in the most abundant species found. Thus, major weather events are associated with temporal changes whose patterns differ on both small and large spatial scales. Consequently, the results from fixed-factor sampling designs, which are widely used, may be unrepresentative of other areas. Unfortunately, the alternative approach of stratified random sampling will probably be both prohibitively expensive and difficult to implement in the complex estuarine benthic habitat. Further, short-term studies will probably be grossly unrepresentative of natural temporal variation. Attempts to reduce expenses by using only one or two abundant species as characterising communities or as indicators of physicochemical conditions may be unreliable because of variation in both time and space in dominant species and the lack of pollution-response knowledge for local species.
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References
Andrew, N. L. and Mapstone, B. D.: 1987, ‘Sampling and the Description of Spatial Pattern in Marine Ecology’,Oceanog. Mar. Biol. Ann. Rev. 25, 39–90.
Armstrong, N.: 1982, ‘Responses of Texas Estuaries to Freshwater Inflows’, in V. S. Kennedy (ed.),Estuarine Comparisons, Academic Press, New York, pp. 103–120.
Bilyard, G. R.: 1987, ‘The Value of Benthic Infauna in Marine Pollution Monitoring Studies’,Mar. Pollut. Bull. 18, 581–585.
Boesch, D. F., Diaz, R. J., and Virnstein, R. W.: 1976, ‘Effects of Tropical Storm Agnes on Soft-Bottom Macrobenthic Communities of the James and York Estuaries and the Lower Chesapeake Bay’,Ches. Sci. 17, 246–259.
Botton, L. L.: 1979, ‘Effects of Sewage Sludge on the Benthic Invertebrate Community of the Inshore New York Bight’,Estuarine Coastal Mar. Sci. 8, 169–180.
Connell, J. H. and Sousa, W. P.: 1983, ‘On the Evidence Needed to Judge Ecological Stability or Persistence’,Amer. Nat. 121, 789–824.
Cox, D. R.: 1958,Planning of Experiments, Wiley, New York.
Dayton, P. K. and Tegner, M. J.: 1984, ‘The Importance of Scale in Community Ecology: A Kelp Forest Example with Terrestrial Analogs’, in P. W. Price, C. N. Slobodchikoff and W. S. Gaud (eds.),A New Ecology, Wiley, New York, pp. 457–482.
Green, R. H.: 1979,Sampling Design and Statistical Methods for Environmental Biologists, Wiley, New York.
Glasby, C. J.: 1984, ‘The Population Structure and Reproductive Biology ofCeratonereis limnetica (Polychaeta: Nereididae) at Lower Portland, Hawkesbury River’, M.Sc. Thesis, University of Sydney.
Harris, J. H.: 1984, ‘Impoundment of Coastal Drainages of Southeastern Australia, and a Review of its Relevance to Fish Migrations’,Aust. Zool. 21, 235–50.
Hirsch, A.: 1980, ‘Monitoring cause and effects—ecosystem changes’, in D. L. Worf (ed.),Biological Monitoring for Environmental Effects, Lexington Books, Lexington, pp. 137–142.
Hodgkin, E. P.: 1978, ‘An Environmental Study of the Blackwood River Estuary, Western Australia, 1974–1975’,W. A. Dept Cons. and Envir., Report No. 1, p. 78.
Jones, A. R., Watson-Russell, C. J., and Murray, A.: 1986, ‘Spatial Patterns in the Macrobenthic Communities of the Hawkesbury Estuary, N.S.W.’,Aust. J. Mar. Freshw. Res. 37, 521–43.
Jones, A. R.: 1987, ‘Temporal Patterns in the Macrobenthic Communities of the Hawkesbury Estuary, N.S.W.’,Aust. J. Mar. Freshw. Res. 38, 607–624.
Jones, A. R., Murray, A., and Skilleter, G. A.: 1988, ‘Aspects of the Life History and Population Biology ofNotospisula trigonella (Bivalvia: Mactridae) from the Hawkesbury Estuary, Southeastern Australia’,The Veliger 30, 267–277.
Kennedy, V. S. (ed.): 1982,Estuarine Comparisons, Academic Press, New York.
Lewis, M. R. and Platt, T.: 1982, ‘Scales of Variability in Estuarine Ecosystems’, in V. S. Kennedy (ed.),Estuarine Comparisons, Academic Press, New York, pp. 3–20.
McLachlan, A. and Grindley, J. R.: 1974, ‘Distribution of Macrobenthic Fauna on Soft Substrata in the Swartkops Estuary, with Observations on the Effects of Floods’,Zool. Afr. 9, 211–233.
Rochford, D. J.: 1959, ‘Classification of Australian Estuarine Systems’,Arch. Oceanografia Limnolgica 11, 171–177.
Saenger, P., Stephenson, W., and Moverley, J.: 1980, ‘The Estuarine Macrobenthos of the Calliope River and Auckland Creek, Queensland’,Mem. Queensl. Mus. 20, 143–161.
Sousa, W. P.: 1984, ‘The Role of Disturbance in Natural Communities’,Ann. Rev. Ecol. Syst. 15, 353–91.
Sokal, R. R. and Rohlf, F. J.: 1981,Biometry: The Principles and Practice of Statistics and Biological Research, 2nd ed., W. H. Freeman and Co: San Francisco.
Stephenson, W., Cook, S. D., and Raphael, Y. I.: 1977, ‘The Effect of a Major Flood on the Macrobenthos of Bramble Bay, Queensland’,Mem. Queensl. Mus. 18, 95–119.
Tenore, K. R.: 1972, ‘Macrobenthos of the Pamlico River Estuary, North Carolina’,Ecol. Monogr. 42, 51–69.
Underwood, A J., Denley, E. J. and Moran, M. J.: 1983, ‘Experimental Analyses of the Structure and Dynamics of Mid-shore Rocky Intertidal Communities in New South Wales’,Oecologia 56, 202–219.
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Jones, A.R. Zoobenthic variability associated with a flood and drought in the Hawkesbury estuary, New South Wales: Some consequences for environmental monitoring. Environ Monit Assess 14, 185–195 (1990). https://doi.org/10.1007/BF00677915
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DOI: https://doi.org/10.1007/BF00677915