Photograph 4: Manor Farm outflow.
Results
The full species lists are presented as an appendix. Note that the significance of blank counts against species in each site means that that species has been recorded in previous seasons but not this one. The results summarised here consist of number of species, abundance and WHPT, N-taxa and ASPT for current and previous years. These are presented by site as well as by index for comparative purposes. The significant measure of water quality is the ASPT score. This is because gross scores such as abundance or WHPT are heavily influenced by sampling bias and would be expected to vary on every occasion to some extent. To overcome such bias the Average Score Per Taxon (ASPT) is calculated which reflects more accurately the water quality with higher scores representing less impact.
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