Disused docks as habitats for estuarine fish: a case study of Preston dock

Abstract

A netting and hydrographic study of Preston dock was undertaken between May 1987 and April 1988. Fish populations were assessed using Lundgren monofilament multimesh gillnets. The dock was a low-salinity environment regularly replenished with estuarine water on spring tides. Influxes of higher-salinity water caused intennittent saline wedges in the deeper regions. The dock water was poorly mixed in the summer, resulting in bottom water anoxia. The water was eutrophic, and blue-green algal blooms were common for much of the year.Fourteen freshwater, marine-estuarine, anadromous and catadromous species were present in the dock. No seasonal patterns in diversity were apparent, due to the dominance of the herring population. Changes in species composition and abundance seem to relate to seasonal migratory patterns and, in the case of the freshwater fish, estuarine salinity, rather than to water quality. The suitablity of docks for sampling estuarine fish assemblages is discussed.

Fish and fisheries of the tidal Thames: management of the modern resource, research aims and future pressures

“…Docks and tidal creeks provide specialized refuge habitats (Conlan et al, 1988;Tyner, 1993;G. Rayner, pers.…”