AbstractsBiology & Animal Science

This study aims to investigate crayfish burrows along tributaries within the northern catchment of Rothay, Windermere situated in the Lake District National Park. The purpose of this research paper is to investigate the spatial relationship and size difference between burrows through an independent river habitat survey. A survey was conducted along three tributaries in the Windermere’s north catchment, Rydal Beck, Stock Ghyll and the river Rothay. Three observation points were randomly selected from each stream, as well as one part of the Rothay catchment. The burrows of both crayfish species were recorded. The data collected suggests that native species are more able to scale riverbanks to dig burrows when compared to the invasive species, this data was realised through the utilisation of ratio analysis. Evidence suggests that native White-Clawed crayfish (WCC) are intolerant of poor water quality, unlike the invasive species such as American Signal Crayfish (ASC) which can thrive in low nutrient conditions. It could be theorised that competition for water with a lower level of nutrients is more significant. This is due to excess nutrients plaguing the watercourses and the low nutrient requirements of WCC. In some steep catchments, WCC have been seen to survive better than the larger ASC, although the smaller ASC may still be capable of carrying the disease vector even if the adult ASC can't sustain a long-term population. White-clawed crayfish (WCC) are more vulnerable to invasion by American species (ASC). The invading species, ASCs have been shown to spread more quickly than WCC, which means they would be able to "overtake" any escaping WCC and then "mechanically" outcompete the WCC.