Abstract
The importance of sampling effort in the statistical exploration of spatial autocorrelation is demonstrated for benthic macroinvertebrate assemblages within the intertidal warm-temperate Knysna estuary, South Africa. While the role of spatial scale in determining autocorrelation patterns in ecological populations has been noted, the effects of changing sampling effort (e.g., sample size) have rarely been explored; neither have the nature of any changes with sample size. Invertebrate assemblages were sampled from a single grid lattice comprised of 48 sampling stations at four sample sizes (0.0015, 0.0026, 0.0054 and 0.01 m2). Four metrics were investigated: assemblage abundance, frequency (species density), and numbers of the two most abundant species in the area Simplisetia erythraeensis and Prionospio sexoculata. Spatial autocorrelation was estimated for each sample size from the global Moran’s I. For a range of distance classes, Moran’s I correlograms were constructed, these plotted autocorrelation estimates as a function of the separation distance between point samples. Spatial autocorrelation was present in three of the metrics (assemblage abundance frequency and Prionospio abundance), but not for Simplisetia abundance. The estimated magnitude of spatial autocorrelation varied across sampling units for all four assemblage and species metrics (global Moran’s I ranged from 0.5 to − 0.07). Correlograms indicated that optimal sampling interval distances fell in the region of 8 m for Simplisetia and 19 m for the remaining three metrics. These distances indicate the dimensions of the processes (both biotic and abiotic) that determine spatial patterning in the microbenthic intertidal invertebrates sampled.
This is a preview of subscription content, access via your institution.




References
Albano, P., B. Sabelli & P. Bouchet, 2011. The challenge of small and rare species in marine biodiversity surveys: microgastropod diversity in a complex tropical coastal environment. Biodiversity and Conservation 20(13): 3223–3237.
Alongi, D. M. & J. H. Tietjen, 1980. Population growth and trophic interactions among freeliving marine nematodes. In Tenore, K. R. & B. C. Coull (eds.), Marine Benthic Dynamics. University of South Carolina Press, Columbia, SC: 151–166.
Anselin, L., 1995. Local indicators of spatial association—LISA. Geographical analysis 27(2): 93–115.
Barnes, R., 2014. The nature and location of spatial change in species assemblages: a new approach illustrated by the seagrass macrofauna of the Knysna estuarine bay, South Africa. Transactions of the Royal Society of South Africa 69(2): 75–80.
Barnes, R., 2016. Spatial homogeneity of benthic macrofaunal biodiversity across small spatial scales. Marine Environmental Research 122: 148–157.
Barnes, R. & M. Barnes, 2014. Biodiversity differentials between the numerically-dominant macrobenthos of seagrass and adjacent unvegetated sediment in the absence of sandflat bioturbation. Marine Environmental Research 99: 34–43.
Barnes, R. & M. Ellwood, 2011. The significance of shore height in intertidal macrobenthic seagrass ecology and conservation. Aquatic Conservation: Marine and Freshwater Ecosystems 21(7): 614–624.
Barnes, R. & M. Ellwood, 2012. Spatial variation in the macrobenthic assemblages of intertidal seagrass along the long axis of an estuary. Estuarine, Coastal and Shelf Science 112: 173–182.
Barnes, R. & S. Hamylton, 2013. Abrupt transitions between macrobenthic faunal assemblages across seagrass bed margins. Estuarine, Coastal and Shelf Science 131: 213–223.
Barnes, R. & S. Hamylton, 2016. On the very edge: faunal and functional responses to the interface between benthic seagrass and unvegetated sand assemblages. Marine Ecology Progress Series 553: 33–48.
Cliff, A. D. & J. K. Ord, 1981. Spatial Processes: Models & Applications, Vol. 44. Pion, London.
Cole, R., T. Healy, M. Wood & D. Foster, 2001. Statistical analysis of spatial pattern: a comparison of grid and hierarchical sampling approaches. Environmental Monitoring and Assessment 69(1): 85–99.
Cooke, B. C., I. D. Goodwin & M. J. Bishop, 2014. Small-scale spatial structuring of interstitial invertebrates on three embayed beaches, Sydney, Australia. Estuarine, Coastal and Shelf Science 150: 92–101.
Cressie, N. A. & N. A. Cassie, 1993. Statistics for spatial data, Vol. 900. Wiley, New York.
Dale, M. R. & M.-J. Fortin, 2014. Spatial Analysis: A Guide for Ecologists. Cambridge University Press, Cambridge.
Dauer, D., 1985. Functional morphology and feeding behavior of Paraprionospio pinnata (Polychaeta: Spionidae). Marine Biology 85(2): 143–151.
Davidson, I. C., A. C. Crook & D. K. Barnes, 2004. Quantifying spatial patterns of intertidal biodiversity: is movement important? Marine Ecology 25(1): 15–34.
Dowd, M., J. Grant & L. Lu, 2014. Predictive modeling of marine benthic macrofauna and its use to inform spatial monitoring design. Ecological Applications 24(4): 862–876.
Dungan, J. L., J. Perry, M. Dale, P. Legendre, S. Citron-Pousty, M. J. Fortin, A. Jakomulska, M. Miriti & M. Rosenberg, 2002. A balanced view of scale in spatial statistical analysis. Ecography 25(5): 626–640.
Fleecer, J., M. Palmer & E. Moser, 1990. On the scale of aggregation of Meio-benthic copepods on a Tidal Mudflat. Marine Ecology 11(3): 227–237.
Fortin, M.-J., 1994. Edge detection algorithms for two-dimensional ecological data. Ecology 75: 956–965.
Fortin, M.-J., 1999. Effects of sampling unit resolution on the estimation of spatial autocorrelation. Ecoscience 6: 636–641.
Gaudêncio, M. J. & H. Cabral, 2007. Trophic structure of macrobenthos in the Tagus estuary and adjacent coastal shelf. Hydrobiologia 587(1): 241–251.
Gingold, R., S. E. Ibarra-Obando & A. Rocha-Olivares, 2011. Spatial aggregation patterns of free-living marine nematodes in contrasting sandy beach micro-habitats. Journal of the Marine Biological Association of the United Kingdom 91(03): 615–622.
Griffith, D. A., 1987. Spatial Autocorrelation. A Primer. Association of American Geographers, Washington DC.
Hamylton, S., 2013. Five practical uses of spatial autocorrelation for studies of coral reef ecology. Marine Ecology Progress Series 478: 15–25.
Holm, S., 1979. A simple sequentially rejective multiple test procedure. Scandinavian Journal of Statistics 6: 65–70.
Jelinski, D. E. & J. Wu, 1996. The modifiable areal unit problem and implications for landscape ecology. Landscape Ecology 11(3): 129–140.
Klumpp, D. W. & S. N. Kwak, 2005. Composition and abundance of benthic macrofauna of a tropical sea-grass bed in north Queensland, Australia. Pacific Science 59(4): 541–560.
Kraan, C., G. Aarts, J. Van Der Meer & T. Piersma, 2010. The role of environmental variables in structuring landscape-scale species distributions in seafloor habitats. Ecology 91(6): 1583–1590.
Kraan, C., J. van der Meer, A. Dekinga & T. Piersma, 2009. Patchiness of macrobenthic invertebrates in homogenized intertidal habitats: hidden spatial structure at a landscape scale. Marine Ecology Progress Series 383(6): 211–224.
Legendre, P., 1993. Spatial autocorrelation: trouble or new paradigm? Ecology 74(6): 1659–1673.
Legendre, P. & M. J. Fortin, 1989. Spatial pattern and ecological analysis. Vegetatio 80(2): 107–138.
Legendre, P. & L. F. Legendre, 2012. Numerical Ecology, Vol. 24. Elsevier, Amsterdam.
Levin, S. A., 1992. The problem of pattern and scale in ecology: the Robert H. MacArthur award lecture. Ecology 73(6): 1943–1967.
Lewis III, F. G. & A. W. Stoner, 1981. An examination of methods for sampling macrobenthos in seagrass meadows. Bulletin of Marine Science 31(1): 116–124.
McGarvey, R., J. E. Feenstra, S. Mayfield & E. V. Sautter, 2010. A diver survey method to quantify the clustering of sedentary invertebrates by the scale of spatial autocorrelation. Marine and Freshwater Research, 61(2): 153–162.
Pashley, H., 1985. Feeding and Optimization: The Foraging Behaviour of Nereis diversicolor (Polychaeta). University of Cambridge, Cambridge.
Pinckney, J. & R. Sandulli, 1990. Spatial autocorrelation analysis of meiofaunal and microalgal populations on an intertidal sandflat: scale linkage between consumers and resources. Estuarine, Coastal and Shelf Science 30(4): 341–353.
Qi, Y. & J. Wu, 1996. Effects of changing spatial resolution on the results of landscape pattern analysis using spatial autocorrelation indices. Landscape Ecology 11(1): 39–49.
Riisgård, H. U., 1991. Suspension feeding in the polychaete Nereis diversicolor. Marine Ecology Progress Series 70: 29–37.
Rodil, I., T. Compton & M. Lastra, 2014. Geographic variation in sandy beach macrofauna community and functional traits. Estuarine, Coastal and Shelf Science 150: 102–110.
Rossi, R. E., D. J. Mulla, A. G. Journel & E. H. Franz, 1992. Geostatistical tools for modeling and interpreting ecological spatial dependence. Ecological Monographs 62(2): 277–314.
Sandulli, R. & J. Pinckney, 1999. Patch sizes and spatial patterns of meiobenthic copepods and benthic microalgae in sandy sediments: a microscale approach. Journal of Sea Research 41(3): 179–187.
Snelgrove, P., J. Grassle & R. Petrecca, 1994. Macrofaunal response to artificial enrichments and depressions in a deep-sea habitat. Journal of Marine Research 52(2): 345–369.
Tobler, W. R., 1970. A computer movie simulating urban growth in the Detroit region. Economic Geography 46: 234–240.
Yamakita, T. & M. Nakaoka, 2009. Scale dependency in seagrass dynamics: how does the neighboring effect vary with grain of observation? Population Ecology 51(1): 33–40.
Yamakita, T. & M. Nakaoka, 2011. Importance of considering grain and extent for the analysis on spatial dynamics: perspectives from comparison between theory and empirical example on seagrass bed dynamics in Tokyo Bay. Procedia-Social and Behavioral Sciences 21: 177–183.
Acknowledgements
RSKB is grateful to: the Smuts Memorial Fund, managed by the University of Cambridge in memory of Jan Christiaan Smuts, and Rhodes University Research Committee for financial support of the fieldwork; and the Rondevlei Scientific Services Offices of SANParks and the Knysna Area Manager, Johan de Klerk, for permission to undertake research in the Knysna Section of the Garden Route National Park.
Author information
Authors and Affiliations
Corresponding author
Additional information
Handling editor: K. W. Krauss
Rights and permissions
About this article
Cite this article
Hamylton, S.M., Barnes, R.S.K. The effect of sampling effort on spatial autocorrelation in macrobenthic intertidal invertebrates. Hydrobiologia 811, 239–250 (2018). https://doi.org/10.1007/s10750-017-3491-x
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10750-017-3491-x
Keywords
- Sampling effort
- Sample size
- Moran’s I correlogram
- Moran’s I