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

Abstract

In recent decades, following the cleanup in the 1960s, the Thames Estuary has become a major nursery ground for economic and conservation species, and has seen the development of substantial commercial and recreational fisheries. The Environment Agency has both sea fisheries and freshwater fisheries statutory powers in the estuary. A unique and focussed survey programme has been developed to inform management policies. A Fisheries Management Action Plan has been developed to promote integrated salmonid, eel Anguilla anguilla and sea fisheries management, promote nurseries, sustainable exploitation and habitat protection and enhancement. Data are used to influence water quality, water resources and flood defence management regimes and in the planning field to influence development proposals. Consensus and collaboration have been built through the Thames Estuary Partnership. Research aims identified through the Thames Estuary Research Forum are described together with future pressures on key species. The survey rationales being developed will contribute to new standard sampling strategies and classification scheme to meet the requirements of the E.U. Water Framework Directive.

Aspects of anadromous Allis shad (Alosa alosa Linnaeus) and Twaite shad (Alosa fallax Lacépède) biology in four Irish Special Areas of Conservation (SACs): status, spawning indications and implications for conservation designation

“…Implementation of the EU Water Framework Directive, the Nitrates Directive and the Urban Wastewater Directives should be conducive to the improvement of water quality in Irish rivers and estuaries, which could, in turn, be conducive to shad conservation in the four Irish SACs. Improved water quality has led to the upstream displacement of the major shad spawning areas in the R. Elbe (Thiel et al, 1996) and contributed to the re-appearance of shad in the Thames (Colclough et al, 2002) and the Clyde (Maitland & Lyle, 2001). While none of the four current Irish SACs is designated for Allis shad, it is likely that, if Twaite shad reach a satisfactory conservation status within these waters then the water quality and habitat conditions would be conducive for Allis shad to attain a similar status.…”

The commercial exploitation of a protected anadromous species, the river lamprey (Lampetra fluviatilis (L.)), in the tidal River Ouse, north-east England

“…Witkowski, 1992;Birstein, 1993;Thiel et al, 1995;Peter, 1998;Boyer et al, 2000;Bianco and Ketmaier, 2001;Raat, 2001;Colclough et al, 2002;de Groot, 2002;Vasil'eva,In addition to fishing pressure, river lampreys within the Humber basin are subject to other potentially detrimental influences, including periods of poor water quality during low flows in the tidal Ouse and the presence of numerous barriers, which may reduce longitudinal connectivity within the system (Lucas and Baras, 2001). The aim of this study, therefore, was to investigate the pattern of relative abundance and exploitation of adult river lampreys in the tidal Ouse to help meet the conservation objectives for river lampreys in this river and more generally.…”

Densities and biomass of larval sea lamprey populations (Petromyzon marinus Linnaeus, 1758) in north-western Spain and data comparisons with other European regions

“…Thus, on the basis of P. marinus catches from fisheries, Beaulaton et al (2008) suggested a progressive population increase of P. marinus in the rivers Adour, Garonne, Vilaine and Rhine, between 1990 and 2005. Signs of a possible improvement of P. marinus populations in the UK have been observed; one of the factors responsible for this recovery is considered to be the restoration of water quality (Colclough et al 2002;Joint Nature Conservation Committee 2007). Also, Pereira et al (2012) mentioned a recent rise in the occurrence of this species in coastal areas and rivers of Iceland.…”