Spatial variation in soft-sediment benthos

Abstract

V a r~a t~o n (patchiness) In the d~str~bution of organisms and other env~ronmental vanables exists at different spatial scales This patchiness has Important implicat~ons for comparative and d e s c r~p t~v e studies of d~stnbution and abundance because ~t complicates comparisons of abundance at the largest s p a t~a l scales Although the existence of patchiness has been recognised for a long time, it has not been adequately addressed in most studies of manne soft s e d~m e n t s which are often confounded (or pseudoreplicated') because of a lack of appropriate spatlal replicat~on Spatial vanation In the distnbution of soft-sediment macrofauna In Botany Bay, Australia 1s described using a nested hierarchical sampling design Significant vanatlon was detected at spatial scales from 10 m to 3 5 km Implications of patchiness for environmental sampllng and monitoring and the means of overcoming associated problems are discussed The present study concerns the abundance of macrofauna but the conclusions are general and are relevant to s t u d~e s of other vanables such as pollutants

The seaward limit of wave effects on coastal macrobenthos

“…This patchiness has important implications for comparative and descriptive studies of distribution and abundance because it complicates comparisons of abundance at larger spatial scales (Morrisey et al 1992). To overcome the problems associated with strong patchiness, Morrisey et al (1992) proposed pilot studies to identify scales at which variation is significant.…”

“…To overcome the problems associated with strong patchiness, Morrisey et al (1992) proposed pilot studies to identify scales at which variation is significant. However, dealing with an assemblage of several hundred species, it is highly unlikely to find any spatial scale without significant spatial variation in some of the species.…”

An approach for the identification of exemplar sites for scaling up targeted field observations of benthic biogeochemistry in heterogeneous environments

“…Soetaert et al 1996Soetaert et al , 2000Dollar et al 1991;Wijsman et al 1999;Van Cappellen et al 2002;Fulweiler et al 2010;Dale et al 2011). Because the focus of the SSB work is on bed type, these local conditions are considered confounding variables, which can be a particular problem when smaller-scale variables are extrapolated (Morrisey et al 1992). The focus was therefore to minimise any differences in these variables between the sites, so as to simplify analysis, and avoid the risk of masking the signals of interest.…”

“…To allow successful scaling (of both resolution and extent) from these studies to regional scales, interdisciplinary approaches which integrate both local-and macro-scale data are most successful (Queirós et al 2015;Painting et al 2013). However, care must be taken to identify the appropriate temporal and spatial scales whilst designing field programmes or when interpreting collected data (Morrisey et al 1992). Different scales can be important for different variables (e.g.…”

“…Such nested sampling designs have been shown to successfully overcome problems associated with spatial scaling (e.g. Morrisey et al 1992), but are rarely applied at the outset of large multidisciplinary projects.…”