Salford Quays is a redeveloped freshwater dockland, which initially constituted part of the grossly polluted Manchester Docks, Manchester, UK. Such water bodies are characterized by a lack of suitable spawning sites and littoral refuges, and this will act to reduce fish recruitment. To redress this, a variety of artificial spawning substrates were introduced to these waters. Spawning structures were made from bundles of different types of thin brushwood suspended from the dock walls. Roach, Rutilus rutilus (L.), spawned on bundles of willow, Salix alba (L.), and spruce, Pilea abies (L.), branches, whilst perch, Perca fluviatilis L., spawned on bundles of willow, sycamore, Acer pseudoplatanus (L.), spruce and plastic netting. Unused bundles were made up of lime, Tilia platyphyloss (Scop.), pear willow, Pyrus salicitolia (Pall.), and laurel, Laurus nobilis (L.). Perch spawning began around 20 May and showed a preference for open structures (between one and three ribbons per bundle). Roach spawning began about 10 days after perch and showed a preference for dense bundles of spruce (geometric mean egg density 1.5 cm− 2 spruce). The use of such structures in fisheries management is discussed.
Over recent years the rod and net catch of Atlantic salmon, Salmo salar L., on the River Tamar in south-west England has decreased markedly, resulting in a consistent failure to meet the minimum egg deposition target (conservation limit). Compliance with the target is by annual assessment using rod catch as the major input variable. Further analysis suggested a disproportionate deterioration in the rod fishery performance of the Tamar compared with rivers locally, regionally and nationally. A concomitant decrease in rod licence sales and fishing effort, above both national and regional trends was also evident. However, examination of juvenile electric fishing and adult fish counter data revealed a different trend for the past 10 years, indicating a stable fish population, albeit at a lower level of abundance than previously. The analyses suggested that without consideration of changes in effort and rod exploitation rate, rod catch alone is not a reliable indicator of stock abundance and hence should not be used as such in stock assessment.
Tamar Lakes is comprised of two reservoirs, which are located in South West England and in the headwaters of River Tamar at approximately 135 m above ordnance datum. Upper Tamar Lake (UTL) is a direct feed source reservoir of potable water in North Cornwall. Immediately following completion in 1975, UTL was subject to intense blue‐green algal blooms that continue to the present. These blooms create operational problems for water treatment, especially in hot‐dry years. Lower Tamar Lake (LTL) was constructed as a water supply reservoir in 1819 and became obsolete following UTL coming on‐line. Detailed water quality investigations over a period of some 28 years have confirmed the source of nutrient enrichment that fuels the algal blooms to be agriculturally derived, corresponding with a substantial increase in livestock farming. Associated poor land management practices, such as extensive field drainage and inappropriate slurry disposal to land, are linked with substantial elevations in organic contaminants such as ammonia, biochemical oxygen demand (BOD) and suspended solids (SS) during rainfall events. Evidence demonstrates that both reservoirs act as primary treatment lagoons, substantially reducing the worst of these pollutants and providing significant environmental gain. The implications of the Common Agricultural Policy (CAP), the Water Framework Directive (WFD) and regulatory monitoring are discussed in relation to resource management.
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