 The invertebrate fauna of the site has been extremely well documented and 1744 species have been recorded in the period 1978-1988 including many nationally scarce species in a wide range of groups.Seventy-six bird species have been recorded on the site.Of these, twenty-eight species are known to breed including sedge warbler ("Acrocephalus schoenobaenus"), reed warbler ("Acrocephalus scirpaceus"), and reed bunting ("Emberiza schoeniclus") which are characteristic inhabitants of tall herb fen and carr vegetation.