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.

Fish utilisation of managed realignments

“…Encroachment onto the intertidal foreshore is an extreme pressure on estuaries. In the Thames estuary in the UK, <1% of the original bank form remains (Colclough, Gray, Bark & Knights 2002). Encroachment can reduce flood storage capacity, increase scour and flow, and remove important intertidal foreshore habitat.…”

“…Encroachment can reduce flood storage capacity, increase scour and flow, and remove important intertidal foreshore habitat. The aggregate impacts of encroachment can impede the migration of fish fry, which use selective tidal stream transport (Colclough et al. 2002).…”

Catching invasive Chinese mitten crabs while releasing the endangered European eel and other fish by‐catch: The implications of fyke net design

“…Wheeler () and Colclough, Gray, Bark, and Knights () summarize the history of tidal Thames River Surveys. These accounts indicate that current information by regarding the fish life of the Thames has been obtained piecemeal and has come from such diverse sources as angling club records, examination of power station intake screens, fishing competition results, seine and small trawl netting experiments, trap surveys, commercial fishing returns and individual fieldwork initiatives.…”

Meeting the challenges of urban river habitat restoration: developing a methodology for the River Thames through central London

“…Tittley 2001; TEP nd; and see e.g. Colclough et al 2002). Consequently the data are generally incomplete, unpublished and often held in relative isolation by varying organisations.…”

“…Birkhead and Perrins 1985; Power et al 2000; Aldridge et al 2004; Herborg et al 2005). Thus, long‐term monitoring of many species has not taken place or is sporadic, other than for populations of several fish species (Environment Agency 1997; Colclough et al 2002). A scientific methodology for biodiversity restoration along the upper tidal Thames must focus on the appropriate degraded habitats rather than species, as ensuring that suitable riverine landforms exist is the first step in maintaining and promoting populations and communities of species in general (Bond and Lake 2003).…”