Native Species Surveys Across Wales (1978 to 2006)

The data comprises primarily of the Welsh abstract of freshwater invertebrates. It comes from BIOSYS, the national ecology database for freshwater species and is related to the aquatic stages of the invertebrates. Most data have been collected from main rivers as part of an extensive routine monitoring network. The data are restricted to a selection of families which contain one species only. The records cover the whole of Wales. Sites are recorded at a minimum precision of 100 m. The distribution of records is biased towards main rivers and areas with historical water quality issues. This is especially true of older records. The sampling methodologies and taxa identified are the same at all sites. Formally known as: Species Surveys Native Species AfA227.