|Sieve mesh-size and taxonomic resolution needed to describe natural spatial variation of marine macrofauna|
Jameson, R.J.; Smith, M.P.L.; Fairweather, P.G. (1995). Sieve mesh-size and taxonomic resolution needed to describe natural spatial variation of marine macrofauna. Mar. Ecol. Prog. Ser. 118: 187-198
In: Marine Ecology Progress Series. Inter-Research: Oldendorf/Luhe. ISSN 0171-8630, more
|Authors|| || Top |
- Jameson, R.J.
- Smith, M.P.L.
- Fairweather, P.G.
The effects of sieve mesh-size and taxonomic resolution on patterns of natural spatial variation of soft-sediment, marine macrofauna were examined simultaneously over a range of depths and 2 spatial scales. Previous studies have considered the effects of mesh-size and taxonomic resolution separately, mainly for macrofauna exposed to pollution. Mesh-size (0.5 mm or 1 mm) and taxonomic resolution (species or family) made little difference to the spatial patterns detected by non-parametric, multivariate analyses (MDS and ANOSIM) for assemblages of macrofauna but results suggested that slightly more information was lost by using the coarser mesh than by using the coarser level of taxonomic resolution. For about half of the populations of individual taxa examined using parametric, univariate analyses, mesh-size affected the interpretation of spatial patterns to some degree. The absolute abundances of some other populations of macrofauna were underestimated using a 1 mm mesh as compared to a 0.5 mm mesh but patterns of spatial variation of these families did not vary between mesh-sizes. There were often less than 5 species per family and the spatial variation of the single most abundant species in each family probably dominated the spatial patterns detected in family-level analyses. For some speciose families (e.g. Spionidae, Corophiidae), however, the spatial variation of particular, relatively abundant species may differ from that detected at the family level. The best way of incorporating rarer taxa into analyses may be multivariate methods which also seemed more robust to coarser mesh-sizes and levels of taxonomic resolution than univariate methods. Samples of macrofauna sieved through a 0.5 mm mesh took significantly longer to sort to major groups than 1 mm samples. The size of this difference, however, depended on the location from which the samples were taken. Since many more samples can be processed per unit time, coarser mesh-sizes and levels of taxonomic resolution should allow greater replication at both large and small scales for macrofauna with little loss of information.