Can nitrogen pollution from aquaculture be reduced?

Nitrogen is essential for the normal growth of fish. It is an important ingredient in fish feed but is very expensive. There is evidence that nitrogen loading from feeding and metabolic activities of fish can cause pollution of the receiving waters. This paper reviews nitrogen losses and nitrogen retention in fish and suggests ways of reducing nitrogen loading to the environment for a sustainable aquaculture program.

Aspects of phosphorus pollution from aquaculture

Phosphorus is an essential element for living organisms and exists in waterbodies as dissolved and particulate forms. Phosphorus is required for optimum growth, feed efficiency, bone development and maintenance of acid-base regulation in fish. The presence of high concentration of phosphates in water may indicate presence of pollution as it may accelerate plant growth and disrupt the aquatic ecosystem thereby benefiting certain species and altering species diversity in affected areas. Eutrophication of waterbodies is often correlated with the phosphorus loading into the environment and aquaculture has been identified as one of the sources of phosphorus pollution. Details of the impacts of eutrophication is given in Bernhardt (1981). Phosphorus must be provided in fish feed because of its low concentration in water. Studies made in Europe and Northern America have revealed a phosphorus surplus in most commercial feeds which is above actual requirements; or is supplied in a form which is unavailable to the fish. Surplus phosphorus is excreted, while unavailable phosphorus is passed out in the feces. Discharge of phosphorus from fish farms and hatchery effluents have caused phosphorus pollution in Nordic countries, North America and Europe. This article examines the path of phosphorus pollution, quantification/prediction of phosphorus load from aquaculture and remedial measures.

South Lancashire Fisheries Advisory Committee 30th March, 1977.

This is the report from the South Lancashire Fisheries Advisory Committee meeting, which was held on the 30th March, 1977. The report contains sections on radioactivity discharges and fisheries interests, fish mortality at Henthorn on the River Ribble, and fisheries activities. The section on radioactivity discharges looks at pollution caused by radioactive discharges from Windscale to the Irish Sea and possible effects on fish. The section on fisheries activities includes information on artificial propagation of salmonids; fish mortalities; silting in River Hodder; and the fish counter Winckley Hall. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South Lancashire Fisheries Advisory Committee 11th January, 1978

This is the report from the South Lancashire Fisheries Advisory Committee meeting, which was held on the 11th January, 1978. It covers information of fisheries income and expenditure, licence duties, regional water resources study, Worthington reservoirs regarding fishery regulations and radioactive discharge in relation to fishery interests. It also includes the report by the area fisheries officer on river conditions and fishing for salmon, sea trout, brown trout and coarse fish, numbers of migratory fish movements at Waddow Weir, Winckley Hall and Locks Weir, and Langcliffe Hatchery. Included in this report is also a brief note on fish disease in salmon in the Ribble and Hodder, and the improvement of Stock Beck after the pollution incident. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

Habitats regulations for stage 3 assessments radioactive substance authorisations

This is the Habitats regulations for stage 3 assessments: radioactive substances authorisations report from the Environment Agency, published on October 2003. The report focuses on the stage 3 assessments of radioactive substances authorisations in UK (to take place over the next five years, starting in 2003), which may have a potential impact on European designated Natura 2000 sites such Special Protection Areas (SPA), Special Areas of Conservation (SAC); and thus require further detailed assessment. This Environment Agency R&D project was commissioned to ERC, University o f Liverpool, in conjunction with Westlakes Scientific Consulting and the Centre for Ecology and Hydrology, as part o f the agency's preparation for the Stage 3 Assessments o f radioactive substances authorisations. The aim was to prepare site information sheets containing all data relevant for individual Natura 2000 sites needing Stage 3 Assessment and to stylise and represent species that require protection under the Habitats Regulations by the reference organism geometries listed in R&D Publication 128 (Copplestone et al., 2001).

The effect of water quality on coarse fish productivity and movement in the Lower River Irwell and Upper Manchester Ship Canal a watercourse recovering from historical pollution

This is the Effect of water quality on coarse fish productivity and movement in the Lower River Irwell and Upper Manchester Ship Canal: a watercourse recovering from historical pollution report produced by the Environment Agency in 2003. The aim of this study was to investigate the impact of water quality upon coarse fish population dynamics in a lowland, urban watercourse. All of the research carried was undertaken in the lower River Irwell and upper Manchester Ship Canal, between February 1998 and December 2001. Of particular interest was the natural sustainability of the urban fishery given recent concern raised in the angling community over an apparent decline in coarse fish populations in lowland rivers. The research described in this report has concentrated upon the role of water quality in determining coarse fish population dynamics, and in particular: The impact of water quality upon fish growth and productivity; The impact of poor water quality and low dissolved oxygen concentrations upon fish distribution and movement; The impact of water quality upon the sexual development of fish.

River Lune Pollution at Lancaster in July 1949

Houses close to River Lune at Lancaster, North West England, UK. This photo shows the polluted River Lune in July 1949. This photo is part of a Photo Album that includes pictures from 1935 to 1954.