Abstract
Demonstrating spatial or temporal gradients of effects on macrobenthic communities can be a useful way of providing strong empirical evidence of natural or anthropogenic disturbance. Gradient designs for environmental assessment are sensitive to change for point source data, enabling the scale of the effects of a disturbance to be readily identified. If the spatial scale that is sampled from the point source is adequate, problems of selecting control sites can be avoided. However, sources of spatial variation in macrobenthic communities, which are not related to the impact, can confound the use of gradient designs. This can occur if the natural spatial structure overlaps that of the gradient and cannot be identified either as a location or environmental covariable. The ability to detect point source impacts using a gradient design against natural spatial variability was tested using benthic macrofaunal data collected from Manukau Harbour, New Zealand. Treated sewage wastewater is discharged into the north-west area of the Manukau Harbour. Sandflats in the vicinity of the outfall are also subject to physical disturbance from wind-waves and strong tides. Ordination techniques and the testing of a priori predictions were used to try and separate the relative effects of organic and physical disturbance on the benthic communities. While the occurrence of other environmental disturbances along a gradient of anthropogenic disturbance makes interpretation of community pattern more difficult, the use of a gradient sampling layout, ordination analysis and the testing of a priori predictions enabled impacts of the anthropogenic and natural environmental disturbances to be interpreted. Gradient designs, therefore, provide a method of assessing complex impacts that operate over broad spatial and temporal scales.
Similar content being viewed by others
References
Auster, P. J. & R. W. Langton, 1999. The effects of fishing on fish habitat. Am. Fisheries Soc. Symp. 22.
Bell, R. G., T. M. Hume, T. J. Dolphin, M. O. Green & R. A. Walters, 1997. Characterisation of physical environmental factors on an intertidal sandflat, Manukau Harbour, New Zealand. J. exp. mar. Biol. Ecol. 216: 11–31.
Bell, R. G., S. V. Dumnov, B. L. Williams & M. J. N. Greig, 1998. Hydrodynamics of Manukau Harbour, New Zealand. New Zealand J. mar. Freshwat. Res. 32(1): 81–100.
Black, K. P., 1997. WGEN3DD, Wave generation model for enclosed water bodies and support software. University of Waikato.
Brown, A. C. & A. McLachlan, 1990. Ecology of sandy shores. Elsevier Amsterdam.
Buhr., K. J. & J. E. Winter, 1977. Distribution and maintenance of a Lanice conchilega association in the Weser Estuary (FRG), with special reference to the suspension-feeding behaviour of Lanice Conchilega. In Keegan, B. F. (ed.), Biology of Benthic Organisms. Pergamon Press, Oxford: 101–113.
Clarke, K. R., 1993. Non-parametric multivariate analyses of changes in community structure. Aust. J. Ecol. 18: 117–143.
Commito, J. A., S. F. Thrush, R. D. Pridmore, J. E. Hewitt & V. J. Cummings, 1995. Dispersal dynamics in wind-driven benthic system. Limnol. Oceanogr. 40(8): 1513–1518.
Dauer, D. M., C. A. Maybury & R. M. Ewing, 1981. Feeding behaviour and general ecology of several spionid polychaetes from the Chesapeake Bay. J. exp. mar. Biol. Ecol. 54: 21–38.
Dayton, P. K., S. F. Thrush, T. M. Agardy & R. J. Horman, 1995. Environmental effects of fishing. Aquatic Conservation: Mar. Freshwat. Ecos. 5: 205–232.
Dayton, P. K., M. J. Tegner, P. B. Edwards & K. L. Riser, 1998. Sliding baselines, ghosts and reduced expectations in kelp forest communities. Ecol. Apps. 8: 309–322.
Dexter, D. M., 1983. Community structure of intertidal sandy beaches in New South Wales, Australia. In McLachlan, A. & Erasmus (eds), Sandy Beaches as Ecosystems. Dr W. Junk Publishers, The Hague: 461–472.
Dexter, D. M., 1984. Temporal and spatial variability in the community structure of the fauna of four sandy beaches in southeastern New South Wales. Aust. J. mar. Freshwat. Res. 35: 663–672.
Dexter, D. M., 1992. Sandy beach community structure: the role of exposure and latitude. J. Biogeog. 19: 59–66.
Dolphin, T. J. & M. O. Green, 1997. Sediment dynamics of an estuarine ‘turbid fringe’. Pacific Coasts and Ports, 1997. Proceedings Vol 1. Centre for advanced engineering, University of Canterbury: 113–118.
Draper, N. R. & H. Smith, 1981. Applied Regression Analysis. 2nd edn. Wiley, New York.
Eleftheriou, A. & M. D. Nicholson, 1975. The effects of exposure on beach fauna. Cah. Biol. mar. 16: 695–710.
Ellis, J. I. & D. C. Schneider, 1997. Evaluation of a gradient sampling design for environmental impact assessment. Envir. Mon. and Assess. 48(2): 157–172.
Ellis, J. I., A. Norkko & S. F. Thrush, 2000. Broad scale disturbance of intertidal and shallow sublittoral soft sediment habitats: effects on benthic macrofauna. J. Aquat. Ecos. Health 7(1): 57–74.
Essink, K., 1984. The discharge of organic waste into the Wadden sea-Local effects. Netherlands Inst. Sea Res. Pub. Ser. 10: 165–177.
Fauchald, K. & P. A. Jumars, 1979. The diet of worms: A study of polychaete feeding guilds. Oceangr. mar. Biol. ann. Rev. 17: 193–284.
Grant, J., 1983. The relative magnitude of biological and physical sediment reworking in an intertidal community. J. mar. Res. 41: 673–689.
Hall, S. J., 1994. Physical disturbance and marine benthic communities: life in unconsolidated sediments. Oceanogr. mar. Biol. ann. Rev. 32: 179–239.
Hewitt. J. E., S. F. Thrush, V. J. Cummings & R. D. Pridmore, 1996. Matching patterns with processes: predicting the effect of size and mobility on the spatial distributions of the bivalves Macomona liliana and Austrovenus stutchburyi. Mar. Ecol. Prog. Ser. 135: 57–67.
Hughes, R. N., 1969. A study of feeding in Scrobicularia plana. J. mar. biol. Ass. U.K. 49: 805–823.
Legendre, P. & L. Legendre, 1998. Numerical Ecology. 2nd edn. Elsevier, The Netherlands.
Levinton, J. S., 1991. Variable feeding behavior in three species of Macoma (Bivalvia: Tellinacea) as a response to water flow and sediment transport. Mar. Biol. 110: 375–383.
Jennings, S. & M. J. Kaiser, 1998. The effects of fishing on marine ecosystems. Adv. mar. Biol. 34: 203–314.
McLachlan, A., T. Wooldridge & A. H. Dye, 1981. The ecology of sandy beaches in southern Africa. Sth. african J. Zool. 16: 219–231.
Mirza, F. B. & J. S. Gray, 1981. The fauna of benthic sediments from the organically enriched Oslofjord, Norway. J. exp. mar. Biol. Ecol. 54: 181–207.
Pearson, T. H. & R. Rosenberg, 1978. Macrobenthic succession in relation to organic enrichment and pollution of the marine environment. Oceanogr. mar. Biol. ann. Rev. 16: 229–311.
Pearson, T. H., A. D. Ansell & L. Robb, 1986. The benthos of the deeper sediments of the Firth of Clyde, with particular reference to organic enrichment. Proc. r. Soc. Edinburgh 90B: 329–350.
Pridmore, R. D., S. F. Thrush, J. E. Hewitt & D. S. Roper, 1990. Macrobenthic community composition of six intertidal sand-flats in Manukau Harbour, New Zealand. New Zealand J. mar. Freshwat. Res. 24: 81–96.
Raffaelli, D. G., A. G. Hildrew & P. S. Giller, 1994. Scale, pattern and process in aquatic systems: concluding remarks. In Giller, P. S., A. G. Hildrew & D. G. Raffaelli (eds), Aquatic Ecology: Scale, Pattern and Process. Blackwell Scientific Publications, London: 601–606.
Sanders, H. L., 1958. Benthic studies in Buzzards Bay. I. Animal-Sediment relationships. Limnol. Oceanogr. 3: 245–258.
Snelgrove, P. V. R. & C. A. Butman, 1994. Animal-Sediment relationships revisited: cause versus effect. Oceangr. mar. Biol. ann. Rev. 32: 111–177.
Suter, G. W., 1996. Abuse of hypothesis testing statistics in ecological risk assessment. Human Ecol. Risk Assess. 2(2): 331–347.
Taghon, G. L. & R. B. Greene, 1992. Utilization of deposited and suspended particulate matter by benthic ‘interface’ feeders. Limnol. Oceanogr. 37: 1370–1391.
Ter Braak, C. J. F., 1986. Canonical correspondence analysis: A new eigenvector technique for multivariate direct gradient analysis. Ecology 67(5): 1167–1179.
Ter Braak, C. J. F., 1987. The analysis of vegetation-environment relationship by canonical correspondence analysis. Vegetatio 69: 69–77.
Thrush, S. F, R. D. Pridmore & J. E. Hewitt, 1994. Impacts on softsediment macrofauna: the effects of spatial variation on temporal trends. Ecol. Apps. 4(1): 31–41.
Thrush, S. F., R. B. Whitlatch, R. D. Pridmore & J. E. Hewitt, 1996. Scale-dependent recolonization: the role of sediment stability in a dynamic sandflat habitat. Ecology 77(8): 2472–2487.
Thrush, S. F., S. M. Lawrie, J. E. Hewitt & V. J. Cummings, 1999. The problem of scale: uncertainties and implications for soft-bottom marine communities and the assessment of human impacts. In Gray, J. S. (ed.), Biogeochemical Cycling and Sediment Ecology. Kluwer Academic Publishers, Dordrecht, The Netherlands: 195–210.
Turner, S. J., S. F. Thrush, R. D. Pridmore, J. E. Hewitt, V. J. Cummings & M. Maskery, 1995. Are soft-sediment communities stable? An example from a windy harbour. Mar. Ecol. Prog. Ser. 120: 219–230.
Underwood, A. J., 1992. Beyond BACI. The detection of environmental impacts on populations in the real, but variable, world. J. exp. mar. Biol. Ecol. 161: 145–178.
Underwood, A. J., 1993. The mechanics of spatially replicated sampling programmes to detect environmental impacts in a variable world. Aust. J. Ecol. 18: 99–116.
Vant, W. N. & B. L. Williams, 1992. Residence times of Manukau Harbour, New Zealand. New Zealand J. mar. Freshwat. Res. 26: 393–404.
Warwick, R. M. & R. J. Uncles, 1980. Distribution of benthic macrofauna associations in the Bristol channel in relation to tidal stress. Mar. Ecol. Prog. Ser. 3: 97–103.
Warwick, R. M., J. D. Goss-Custard, R. Kirby, C. L. George, N. D. Pope & A. A. Rowden, 1991. Static and dynamic environmental factors determining the community structure of estuarine macrobenthos in SW Britain: Why is the Severn Estuary different. J. appl. Ecol. 28: 329–345.
Watling, L. & E. A. Norse, 1998. Disturbance of the seabed by mobile fishing gear: a comparison to forest clearcutting. Conserv. Biol. 12: 1180–1197.
Weston, D. P., 1990. Quantitative examination of macrobenthic community changes along an organic enrichment gradient. Mar. Ecol. Prog. Ser. 61: 233–244.
Wiens, J. A. & K. R. Parker, 1995. Analyzing the effects of accidental environmental impacts: approaches and assumptions. Ecol. App. 5(4): 1069–1083.
Whitlatch, R. B. & R. N. Zajac, 1985. Biotic interactions among estuarine infaunal opportunistic species. Mar. Ecol. Prog. Ser. 21: 299–311.
Rights and permissions
About this article
Cite this article
Ellis, J., Schneider, D. & Thrush, S. Detecting anthropogenic disturbance in an environment with multiple gradients of physical disturbance, Manukau Harbour, New Zealand. Hydrobiologia 440, 379–391 (2000). https://doi.org/10.1023/A:1004172622751
Issue Date:
DOI: https://doi.org/10.1023/A:1004172622751