Scotland hosts 90% by volume of the UK’s available surface water, in networks of waterbodies that include 125,000km of rivers and 220km of canals. As well as supplying a range of human needs and ecosystem services, these waters are important for biodiversity. In 2009, 56% of Scottish rivers were classified as having good overall status, according to European Water Framework Directive criteria. This demonstrates that a range of issues that detrimentally affect their status remain, including diffuse pollution from both urban and agricultural sources. There have also been widespread changes to river flows over the most recent decades as a result of climatic change, including increased periods of low flow and drought in the east of Scotland. More common across Scotland is an increase in extreme rainfall and flood events involving the majority of rivers. We also know that rivers are in general warming and, for example, Dipper laying dates are getting earlier but how much can the birds adjust before there is a mismatch between their timing of breeding and availability of prey? There are ongoing negative effects of non-native species on river biodiversity, including Mink, non-native Canada Geese and introduced plants, such as Himalayan Balsam and Giant Hogweed.
BTO Scotland has a particular interest in furthering research into river and wetland birds in Scotland. There is some evidence to suggest that some specialist breeding birds of rivers are declining in at least parts of Scotland (e.g. Dipper, Grey Wagtail and perhaps Common Sandpiper and Goosander) and the coverage of current long-term monitoring schemes in Scotland needs to be improved substantially to provide further information on future change. We are also interested in intensive research projects that are able to investigate the links between river characteristics (physical, hydrological, chemical and ecological) and bird populations (e.g. current research related to a river restoration project in Ayrshire).