Title: Kent fisheries department Medway Estuary fisheries survey 2001
Author: T. Munro
Author: J. Cave
Author: A. Saunders
Author: S. Smith
Author: M. Robinson
Author: C. Conroy
Author: T. Erskine
Document Type: Monograph
Abstract:
Fish fauna were surveyed at 5 locations on the tidal Medway as part of a Medway Estuary Project, funded by the Environment Agency's Water Resources function. The 2001 survey was a repeat of the 2000 survey, for comparisons to be drawn between years. Surveys were repeated in summer and autumn of 2001 for each site. Species characteristic of estuarine conditions (e.g. flounder, goby, bass, smelt) were found to be present at all sites in both the summer and autumn. True freshwater species were present at the upper three estuary sites. There was no evidence of shad within the estuary from the surveys carried out as part of this report, although a trawl survey carried out by the Centre for Environment, Fisheries an Aquaculture Science (CEFAS) identified one individual twaite shad in the outer reaches of the estuary. No salmon or sea trout were taken by this survey. An environmental impact assessment carried out in this year included prediction of relative species abundance around the Grain site, an analysis of 20 years of fish presence data up to 1993, compiled by the Fawley Aquatic Research Laboratory. A comparison of their findings to those found in this survey is also included. Bass, herring, sprat and smelt have been identified as suitable indicator species for assessing water quality. This is due to their being relatively common, comparatively sensitive to changes in water quality and occur in the middle reaches of the estuary (defined within the tidal excursion range). It is in this zone that pollutants would concentrate as a consequence of the tidal regime. Bass, sprat and smelt were found in the mid-estuary sites (and further down the estuary), and consequently the estuary has been awarded its environmental quality standard for fish. This was also achieved in the year 2000. Herring were found at one site, having not been recorded in the estuary since the autumn of 1998. A study on smelt spawning recommended in the 2000 survey has been carried out to attempt to find evidence of smelt spawning in the historic smelt shoots between Snodland and Coxton. No smelt ova were recovered in this study, although the relatively large numbers of smelt in the estuary in the summer may indicate spawning.
Publisher: Environment Agency Kent Fisheries Department
Publication Date: 2001
Publication Place: Worthing
Subject Keywords: Tidal rivers; River fisheries; Fishery surveys; Stock assessment; Ova; Spawning migration; Brackishwater environment
Geographic Keywords: Kent (county); Medway (Sussex, Kent); Medway catchment
Extent: 67
Permalink: http://www.environmentdata.org/archive/ealit:971
Total file downloads: 271
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