JAMP Eutrophication Monitoring Guidelines: Benthos

Abstract

Benthic communities (including hard-bottom and soft-bottom macrophytobenthos and hard-bottom and soft-bottom macrozoobenthos) generally occur in recognisable states, depending on the substrate, depth, wave exposure and salinity etc. Macrobenthic communities are an appropriate target for monitoring since: a) an important component of benthic communities is that formed by species which are long-lived and which therefore integrate environmental change over long periods of time; b) they are relatively easy to sample quantitatively; c) they are well-studied scientifically, compared with other sediment-dwelling components (e.g. meiofauna and microfauna) and taxonomic keys are available for most groups; d) community structure responds in a predictable manner to a number of anthropogenic influences (thus, the results of change can be interpreted with a degree of confidence); e) there may be direct links with commercially valued resources, e.g. fish (via feeding) and edible molluscs; f) the floral part integrates long-term change of water quality (turbidity). Nutrient enrichment/eutrophication may increase the food supply to the benthos and therefore may give rise to changes in species composition and numbers, increased biomass, a shift from k-selected to r-selected species, shifts in functional groups, changes in community structure and an impoverishment of benthic communities due to anoxia. These guidelines are intended to support the minimum monitoring requirements of the Monitoring Programme. Much information exists on methodology for benthos investigations. The most relevant reports are those by Rumohr (2009) which deals largely with methodology for the collection and treatment of the soft-bottom macrofauna, and by Rees et al. (1991) and Rees (2009) which focus on the monitoring of benthic communities around point-source discharges and epibenthic studies, respectively. These accounts also deal more generally with the role of benthos studies in investigations of human impact, including guidance on the sampling of different substrate types. The HELCOM ‘COMBINE’ manual for monitoring in the Baltic Sea is another important reference source (see www.helcom.fi). A range of other documents are of value in the planning and carrying out of marine benthos sampling programmes. The most useful is that by Eleftheriou and McIntyre (2005) which is a standard reference for work of this type. Gray et al. (1992) report on approaches to marine pollution assessment and provide practical examples of applying the PRIMER (‘Plymouth Routines in Multivariate Ecological Research’) package for univariate, graphical and multivariate data analyses (see Clarke and Gorley, 2001 for further details). Kramer et al. (1994) have produced a manual for the sampling of tidal estuaries. An account of survey methods employed by a team of scientists undertaking a review of marine nature conservation in UK inshore waters together with a rationale for such work is given by Hiscock (1996), Davies et al. (2001) and Connor et al. (2004). A monitoring programme and monitoring guidelines have been prepared for the Wadden Sea ‘Trilateral Monitoring and Assessment Programme’ (TMAP, 2000). The last update of this document was mainly to harmonize it with the EN ISO 16665 (2005) a European and International Standard on quantitative sampling and sample processing of marine soft-bottom macrofauna. For marine biological surveys of hard-substrate communities the EN ISO 19493 (2007) gives advice. These EN ISO guidelines are mandatory regulations which have to take over in national regulations and should be consulted when detailed questions on sampling and sample processing are to be cleared.