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Numerical indices applied to the results of a survey of the macro‐invertebrate fauna ofthe Tamar catchment (southwest England)
Author(s) -
NUTTALL P.M.,
PURVES J.B.
Publication year - 1974
Publication title -
freshwater biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 156
eISSN - 1365-2427
pISSN - 0046-5070
DOI - 10.1111/j.1365-2427.1974.tb00091.x
Subject(s) - fauna , invertebrate , tributary , drainage basin , ecology , pollution , environmental science , outfall , hydrology (agriculture) , water quality , effluent , sewage , main river , sewerage , geography , biology , geology , environmental engineering , cartography , geotechnical engineering
Summary A survey ofthe macro‐invertebrate fauna in the River Tamar revealed that a division ofthe catchment can be made which separates an organically enriched upper region from a more stable environment in the lower tributaries and reaches. Invertebrate species normally associated with organic pollution were found immediately downstream from farm waste and sewage effluent outfalls. Invertebrate species normally associated with an unpolluted condition were widely distributed throughout the catchment, and revealed that the Tamar is essentially free from gross pollution causing the continuous elimination of stream fauna. Systems used by pollution control organizations to codify biological results are reviewed and applied comparatively to the results. The Diversity index was found to be the most consistent method in assessing the biological state of the river. The Trent, Lothian, Chandler and Carpenter indices were found to give either anomalous figures or proved insensitive to conditions beyond a certain quality.