Seasonal and between‐year variations of fish populations in the middle Thames estuary: 1980–1989

Abstract

Fish samples collected at the cooling water intake screens of West Thurrock power station located 35.5 km downstream of London Bridge on the Thames estuary during the decade 1980–1989 were analysed. Seasonal and long‐term changes in the abundance of the 15 most numerous fish species and in several fish community parameters were analysed. The majority of species were highly seasonal in their distribution and abundance. Species diversity was lower in the summer (May–August) compared with spring/winter (October–February). Evidence of long‐term changes in species diversity and community structure over the decade is presented. The changes were consistent with a period of relative stability (1980–1984) followed by a period of change (1985–1989) and may reflect a deterioration in water quality in the second quinquennium. It is argued that the monitoring of fish communities in estuaries should be based on a multi‐metric approach as no single indicator alone can describe the complex community structure.

The ways in which fish use estuaries: a refinement and expansion of the guild approach

“…; Araujo et al . ; Hagan and Able ; Maes et al . ) and thus making a major contribution to the pronounced annual cyclical changes that typically occur in the compositions of the fish faunas of estuaries each year (Potter et al .…”

“…1a,b). In the case of marine estuarine-opportunists, the migration into and emigration from estuaries by each of the species belonging to this guild is often seasonal, with the phasing varying among those species Araujo et al 1998;Hagan and Able 2003;Maes et al 2005) and thus making a major contribution to the pronounced annual cyclical changes that typically occur in the compositions of the fish faunas of estuaries each year Thiel and Potter 2001;Maes et al 2005). The importance of increasing our understanding of the relationship between the habitats occupied by marine estuarine-opportunist species in estuaries and ocean environments has been emphasized by Gillanders (2002), Gillanders et al (2003) and Able (2005).…”

Temporal abundance patterns and growth of juvenile herring and sprat from the Thames estuary 1977–1992

“…For example, studies were conducted for 9 years in the Forth estuary (Elliott et al, 1990), 6-8 years in the Severn Potter et al, 1986;Henderson & Holmes, 1989), 3 years is the Medway (Wharfe et al, 1984) and Humber (Marshall & Elliott, 1998), and 2 years in the Clyde and Zeeschelde (Henderson & Hamilton, 1986;Maes et al, 1998). In the Thames, Araujo et al (1998) have presented descriptive fish community data for the 1980-1989 period.…”

Does the Tagus estuary fish community reflect environmental changes?

“…Besides principal components analysis (e.g. Araujo et al 1998), other techniques have been used successfully, namely canonical correspondence analysis (e.g. Attayde & Bozelli 1998) and multidimensional scaling (e.g.…”