Species composition and biodiversity

Littoral mud communities tend to be relatively poor in species but have very high abundances of those species which are present. Sheltered shores are found in areas of low energy and have poorly-sorted sediments with high levels of organic matter and an increased silt content (Dyer 1979). Extreme shelter favours the establishment of a predominantly sessile tube-dwelling community of polychaetes which are often numerically dominant, with bivalves also well represented (Atkins 1983). Some species characteristic of subtidal areas may also occur. Many infaunal species e.g. Nephtys scavenge on littoral mud and the quantity of food determines the density of scavengers (Ansell et al. 1972; Hayward 1994). There are few macrophytes on intertidal mud unless there are some stones or shells for attachment of species. Those may include mats of Enteromorpha and Ulva, possibly in large aggregations to form so-called ‘green tides’ (Piriou, Menesguen & Salomon 1991).

Characterising species

For LMU in the UK % Frequency Faithfulness Typical abundance
Nematoda indet. Common
Eteone longa Abundant
Hediste diversicolor Abundant
Nephtys hombergii Common
Pygospio elegans Common
Streblospio shrubsolii Common
Capitella capitata Common
Arenicola marina Frequent
Manayunkia aestuarina Common
Oligochaeta indet. Abundant
Tubificoides benedii Common
Corophium volutator Common
Hydrobia ulvae Common
Cerastoderma edule Common
Macoma balthica Common
Scrobicularia plana Abundant

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