Response of the ®sh populations of the River Don in South Yorkshire to water quality and habitat improvements S. Amisah, I.G. Cowx* University of Hull International Fisheries Institute, Hull HU6 7RX, UK Received 23 March 1999; accepted 8 July 1999 ``Capsule'': Despite some improvements in water quality, ®sh stocking programs have been ineective. Abstract The River Don in Yorkshire, UK, has suered a legacy of pollution and land contamination that dates back to the Industrial Revolution. The river continues to be impacted by discharges from industry, mining and sewage sources, resulting in poor water quality and considerable damage to the ®sh stocks. Some modest reductions in ammonia, biochemical oxygen demand (BOD) and metal levels have been achieved through improvements to sewage treatment works and the shutting down of some industries. The decline in the steel industry has generally led to sustained low and acceptable levels of iron and nickel in the river, although some locations are impacted by ochre from abandoned mines. As a consequence, recreational ®shing in the catchment remains restricted at many locations. Fish stocking and enhancement programmes have so far been ineective due to setbacks from ad hoc pollution incidents and degraded habitats. It is suggested that the water quality and habitat degradation problems be addressed prior to embarking on any large-scale ®sh stock enhancement programmes. This would require substantial ®nancial investment and it is recommended that funding be actively sought from both internal and external agencies to achieve this objective. # 2000 Elsevier Science Ltd. All rights reserved. Keywords: River Don; Yorkshire; Pollution; Land contamination; Fish stocking; Water quality; BOD 1. Introduction Human uses and abuses of rivers have grown and diversi®ed over the last few centuries. Population growth has resulted in increasing demand for the use of rivers to satisfy a diverse range of human needs, including solid waste disposal and the discharge of industrial, sewage and mining euents. Water has been abstracted for agricultural and potable water supply, and river channels have been modi®ed for navigation (Murphy and Eaton, 1983), ¯ood defences and hydro- electric power generation (Petts, 1980, 1984; Liu and Yu, 1992). These modi®cations to rivers disrupt the fabric of the aquatic ecosystem and diminish its integ- rity (Bretschko and Moog, 1990; Morgan et al., 1991; Moog, 1993), aecting the capacity of ®sh and other organisms to survive. One region of the UK, which has suered heavily through industrial development and population growth, is in South Yorkshire and North East Derbyshire. This region is drained by three major rivers: the Don, Rother and Dearne (Fig. 1). This catchment suers from a legacy of pollution and land contamination that dates back to the Industrial Revolution (Firth, 1996, 1997). These rivers have been grossly polluted by industrial, sewage, and mining euents and the disposal of solid wastes. This has caused considerable damage to the ®sh stocks of the catchment over the years, thus reducing angling activities substantially (Firth, 1996). A high proportion of the length of the rivers was ®shless into the mid-1980s (Firth, 1997). However, in the past 10 years these rivers have been the subject of considerable attention to improve the water quality and general habitat with the ultimate objective of improving the status of the ®sheries (Firth, 1997). This study investigates the impact of pollution and habitat degradation caused by the various anthro- pogenic activities on the ®sheries of the River Don and how the ®sheries have responded to water quality and habitat improvements in recent years. 0269-7491/00/$ - see front matter # 2000 Elsevier Science Ltd. All rights reserved. PII: S0269-7491(99)00190-6 Environmental Pollution 108 (2000) 191±199 www.elsevier.com/locate/envpol * Corresponding author. Tel.: +44-1482-466427; fax: +44-1482- 470129 E-mail address: i.g.cowx@biosci.hull.ac.uk (I.G. Cowx).