Proceedings of the Institution of Civil Engineers - Maritime Engineering, 2008
Managed realignment often involves the construction of new sea walls at a location behind existin... more Managed realignment often involves the construction of new sea walls at a location behind existing sea walls to create parcels of land that can be flooded to create new inter-tidal environments. It is employed in the UK to improve flood risk management within the context of flood risk management strategies, but so far most emphasis has focused upon creation of new wildlife habitat because this has been where the opportunities and funding have been found. Initial projects were relatively small in scale, but recent projects have been much larger. Scaling up the size of realignments introduces a variety of additional engineering and social challenges and the realignment of Wallasea Island in 2006 is one of the largest. There were a variety of issues encountered during the development of the Wallasea Island realignment that make it a good platform for exploring the issues and some of the solutions that have been found to date. This account describes the project and some of the measures ...
In recent decades, following the cleanup in the 1960s, the Thames Estuary has become a major nurs... more 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...
One hundred and twenty species of fish have been identified from the River Thames according to su... more One hundred and twenty species of fish have been identified from the River Thames according to surveys of the river by the Environment Agency (tidal Thames survey 1992-2001 and lower freshwater Thames survey 1995-2001). This diversity includes species of conservation importance, notably sea lamprey, lampern, twaite shad and smelt in the tidal Thames. Non-indigenous fish such as grass carp are now found in the lower river. Sea lamprey appears to have made an annual spawning attempt at Barnes in the upper estuary since 1999. This is the first reported spawning of sea lamprey in the Thames catchment this century. Marine and estuarine species of fish displayed marked seasonal migrations and patterns of distribution. Information acquired in the surveys is being used to inform fisheries management policies.
The diets of 0-group bass Dicentrarchus labrax were investigated in SE England in the Blackwater ... more The diets of 0-group bass Dicentrarchus labrax were investigated in SE England in the Blackwater Estuary: three managed realignment sites at Tollesbury, Abbotts Hall and Orplands; and two established saltmarshes at Tollesbury and Abbotts Hall. In Summer, small 0-group (15–30 mm) bass consumed calanoid and harpacticoid copepods predominantly and left the sites significantly fuller than on entering them (Mann–Whitney, W = 5837, P Carcinus
The diets of 0-group bass Dicentrarchus labrax were investigated in SE England in the Blackwater ... more The diets of 0-group bass Dicentrarchus labrax were investigated in SE England in the Blackwater Estuary: three managed realignment sites at Tollesbury, Abbotts Hall and Orplands; and two established saltmarshes at Tollesbury and Abbotts Hall. In Summer, small 0-group (15–30mm) bass consumed calanoid and harpacticoid copepods predominantly and left the sites significantly fuller than on entering them (Mann–Whitney, W=5837, P<0.001). In Summer, large 0-group (30–59mm) bass consumed benthic prey, predominantly Carcinus maenas, Nereis spp. and amphipods. These larger bass left Tollesbury managed realignment site, and the established saltmarshes at Tollesbury and Abbotts Hall, significantly fuller than on entry (Mann–Whitney, W=1116, 372 and 229, respectively, all P<0.05), unlike at the Abbotts Hall and Orplands managed realignment sites where they had less time to feed. Early site access and soft sediments for macroinvertebrates improved bass feeding opportunities. A wider range ...
The construction of a new generation of coastal power stations in the UK and other western Europe... more The construction of a new generation of coastal power stations in the UK and other western European countries has highlighted the absence of robust standards for thermal discharges to transitional and coastal waters. The proposed discharge volumes are greater than hitherto, yet there has been little independent critical examination of their potential impact, whilst much of the existing guidance has been adapted from freshwater practice. This review considers the available knowledge on the tolerance and behaviour of fish and other marine biota to heated effluents. Appropriate ways are suggested of grouping fish species to reflect their sensitivity to thermal effects. The plethora of existing standards are considered and their validity assessed in a framework of predicted seawater temperature rise. Those species or groups of organisms most likely to be affected are identified and finally specific recommendations for thermal standards consistent with long term sustainability are proposed.
Proceedings of the Institution of Civil Engineers - Maritime Engineering, 2008
Managed realignment often involves the construction of new sea walls at a location behind existin... more Managed realignment often involves the construction of new sea walls at a location behind existing sea walls to create parcels of land that can be flooded to create new inter-tidal environments. It is employed in the UK to improve flood risk management within the context of flood risk management strategies, but so far most emphasis has focused upon creation of new wildlife habitat because this has been where the opportunities and funding have been found. Initial projects were relatively small in scale, but recent projects have been much larger. Scaling up the size of realignments introduces a variety of additional engineering and social challenges and the realignment of Wallasea Island in 2006 is one of the largest. There were a variety of issues encountered during the development of the Wallasea Island realignment that make it a good platform for exploring the issues and some of the solutions that have been found to date. This account describes the project and some of the measures ...
In recent decades, following the cleanup in the 1960s, the Thames Estuary has become a major nurs... more 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...
One hundred and twenty species of fish have been identified from the River Thames according to su... more One hundred and twenty species of fish have been identified from the River Thames according to surveys of the river by the Environment Agency (tidal Thames survey 1992-2001 and lower freshwater Thames survey 1995-2001). This diversity includes species of conservation importance, notably sea lamprey, lampern, twaite shad and smelt in the tidal Thames. Non-indigenous fish such as grass carp are now found in the lower river. Sea lamprey appears to have made an annual spawning attempt at Barnes in the upper estuary since 1999. This is the first reported spawning of sea lamprey in the Thames catchment this century. Marine and estuarine species of fish displayed marked seasonal migrations and patterns of distribution. Information acquired in the surveys is being used to inform fisheries management policies.
The diets of 0-group bass Dicentrarchus labrax were investigated in SE England in the Blackwater ... more The diets of 0-group bass Dicentrarchus labrax were investigated in SE England in the Blackwater Estuary: three managed realignment sites at Tollesbury, Abbotts Hall and Orplands; and two established saltmarshes at Tollesbury and Abbotts Hall. In Summer, small 0-group (15–30 mm) bass consumed calanoid and harpacticoid copepods predominantly and left the sites significantly fuller than on entering them (Mann–Whitney, W = 5837, P Carcinus
The diets of 0-group bass Dicentrarchus labrax were investigated in SE England in the Blackwater ... more The diets of 0-group bass Dicentrarchus labrax were investigated in SE England in the Blackwater Estuary: three managed realignment sites at Tollesbury, Abbotts Hall and Orplands; and two established saltmarshes at Tollesbury and Abbotts Hall. In Summer, small 0-group (15–30mm) bass consumed calanoid and harpacticoid copepods predominantly and left the sites significantly fuller than on entering them (Mann–Whitney, W=5837, P<0.001). In Summer, large 0-group (30–59mm) bass consumed benthic prey, predominantly Carcinus maenas, Nereis spp. and amphipods. These larger bass left Tollesbury managed realignment site, and the established saltmarshes at Tollesbury and Abbotts Hall, significantly fuller than on entry (Mann–Whitney, W=1116, 372 and 229, respectively, all P<0.05), unlike at the Abbotts Hall and Orplands managed realignment sites where they had less time to feed. Early site access and soft sediments for macroinvertebrates improved bass feeding opportunities. A wider range ...
The construction of a new generation of coastal power stations in the UK and other western Europe... more The construction of a new generation of coastal power stations in the UK and other western European countries has highlighted the absence of robust standards for thermal discharges to transitional and coastal waters. The proposed discharge volumes are greater than hitherto, yet there has been little independent critical examination of their potential impact, whilst much of the existing guidance has been adapted from freshwater practice. This review considers the available knowledge on the tolerance and behaviour of fish and other marine biota to heated effluents. Appropriate ways are suggested of grouping fish species to reflect their sensitivity to thermal effects. The plethora of existing standards are considered and their validity assessed in a framework of predicted seawater temperature rise. Those species or groups of organisms most likely to be affected are identified and finally specific recommendations for thermal standards consistent with long term sustainability are proposed.
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