The macrofaunal communities are described for the four transect stations of the April 1995 LISP-UK (Littoral Investigation of Sediment Properties) project. Cores of different sizes were taken to sample major bioturbating macrofauna (500#m sieve) and smaller annelids (125/~m sieve). Three species, the small clam Macoma balthica and the polychaetes Nereis diversicolor and Nephtys hombergii, are discussed in detail because they have the greatest impact on sediment properties through disturbance by feeding, the construction and irrigation of burrow structures and sediment movement. Macoma was the only species present at all four stations, but whilst their population densities were similar, their calculated potential feeding areas varied by a factor of between 2 and 5. This affects the rate at which they disturb and re-cycle sediment by feeding. Nereis burrow walls at the two most shoreward stations were estimated to provide an additional sediment/water interface equivalent to 0.2-0.3 of the unburrowed area. Nephtys at the two most seaward stations may MethodsThe Transect stations A, B, C and D ran in a downshore direction from below the saltmarsh zone at the NRA Pumping Station on the dyke at Skeffling. Station A was immediately beyond the limit of the saltmarsh, station B c. 0.5km further out and stations C and D were at c. 2 and 3 km from A. They are all more precisely described by Black & Paterson (this volume). Our samples were taken on April 4th (A), 6th (C), 9th (B) and 19th (D).Macrofauna were sampled with a 10cm diameter corer. Four replicate cores (only three at station D) were taken at three 'sites', designated I, II and III, at each station, each separated by a distance of c. 2 m. Within these sites the replicates were taken within an area of a square metre or DAVEY, J. T. & PARTRIDGE, V. A. 1998. The macrofaunal communities of the Skeffling muds (Humber estuary), with special reference to bioturbation.

The Washington State Department of Ecology annually conducts sediment quality monitoring in Puget Sound as a component of the Puget Sound Ecosystem Monitoring Program. Sediment samples are analyzed to determine the concentrations of about 170 chemical and physical variables. A Sediment Chemistry Index (SCI) was derived using the State of Washington Sediment Management Standards to account for the presence and concentrations of mixtures of toxicants. Mean Sediment Quality Standard quotients (mSQSq) were calculated as the basis for the SCI and compared to the incidence and degree of toxicity in laboratory tests and to metrics of the diversity and abundance of resident benthic assemblages in a database consisting of as many as 664 samples. These data were evaluated with co-occurrence analyses to identify ''cut points'' (i.e., thresholds) in the index below which the frequency and magnitude of biological effects were relatively low and above which they occurred with increasing frequency or magnitude. Iterative trials of different sets of cut points established the final cut points in mSQSq of 0.1, 0.3, and 0.5. They defined 4 ranges in chemical exposure: Minimum (<0

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To integrate paleoecological data with the “whole fauna” data used in biological monitoring, analyses usually must focus on the subset of taxa that are inherently preservable, for example by virtue of biomineralized hardparts, and those skeletal remains must also be identifiable in fragmentary or otherwise imperfect condition, thus perhaps coarsening analytical resolution to the genus or family level. Here we evaluate the ability of readily preserved bivalves to reflect patterns of compositional variation from the entire infaunal macroinvertebrate fauna as typically sampled by agencies in ocean monitoring, using data from ten long-established subtidal stations in Puget Sound, Washington State. Similarity in compositional variation among these stations was assessed for five taxonomic subsets (the whole fauna, polychaetes, malacostracans, living bivalves, dead bivalves) at four levels of taxonomic resolution (species, genera, families, orders) evaluated under four numerical transformations of the original count data (proportional abundance, square root- and fourth root-transformation, presence-absence). Using the original matrix of species-level proportional abundances of the whole fauna as a benchmark of “compositional variation,” we find that living and dead bivalves had nearly identical potential to serve as surrogates of the whole fauna; they were further offset from the whole fauna than was the polychaete subset (which dominates the whole fauna), but were far superior as surrogates than malacostracans. Genus- and family-level data were consistently strong surrogates of species-level data for most taxonomic subsets, and correlations declined for all subsets with increasing severity of data transformation, although this effect lessened for subsets with high community evenness. The strong congruence of death assemblages with living bivalves, which are themselves effective surrogates of compositional variation in the whole fauna, is encouraging for using bivalve dead-shell assemblages to complement conventional monitoring data, notwithstanding strong natural environmental gradients with potential to bias shell preservation.