Summary

Summary

Macroinvertebrate surveys of outflows from Bishop’s Sutton, above and below Drayton Farm and Manor Farm watercress farms at Alresford, Hampshire were carried out using standard sampling techniques. The purpose was to repeat surveys a year on to investigate any changes and identify any potential water quality issues.

The species present were typical of a chalk stream, with good diversity and high water quality scores. A complete list of species is presented together with abundance and diversity (WHPT) scores. The indices indicate very similar biodiversity and water quality to 2020 for two sites with slight reduction in scores at the other two sites although these are still higher than the scores from 2019. The differences are accounted for by variation in sampling efficacy and natural environmental variation due to weather.

A nationally scarce moss beetle, Ochthebius exsculptus, was found at two sites. This is the first record in southern England in some decades and the first for Hampshire. It is more frequent in the north of England and Scotland.