Abundance and biomass from grab samples

Abundance and biomass of benthic invertebrates from the Smith-McIntyre grab samples per species and per station. Benthic invertebrates were sampled by taking five 0.1 m2 Smith-McIntyre grabs at haphazard locations within the station box. For each grab, a 50ml sediment sample was retained for grain size analysis and the rest of the sample was sorted over a 1 mm sieve and preserved in 4% formalin for identification. All invertebrates were identified to the highest practicable taxonomic resolution (mostly genus or family) and the wet weight of each individual organism was estimated after blotting.