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The fauna of the muddy sediments of Lough Neagh, with particular reference to eutrophication
Author(s) -
CARTER C. E.
Publication year - 1978
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.1365-2427.1978.tb01477.x
Subject(s) - chironomidae , oligochaeta (plant) , bay , eutrophication , chironomus , biology , fauna , biomass (ecology) , ecology , oceanography , nutrient , larva , geology
SUMMARY. The main groups of animals found in the muddy sediments of Lough Neagh were Chironomidae (Diptera) and Oligochaeta (mainly Tubificidae). At 8 m depth, the average biomass of the main species in these groups was: Chironomus anthracinus , 2.64gm −2 ; Procladius , 342.8 mgm −2 ; tubificids ( Tubifex, Potamothrix, Aulodrilus, Limnodrilus ), 418.7mgm −2 . At 25m depth C. anthracinus and Procladius were less abundant, C. plumosus was present and among the tubificids Limnodrilus had a higher density (up to 50000m −2 ) often an order of magnitude greater than at 8m. Kinnego Bay, a semi‐enclosed, polluted area of the lough, had fewer chironomids than the open lough, with chiefly C. plumosus and Procladius. Limnodrilus was more abundant than at 8m. Dero obtusa (Naididae) was also present, sometimes in large numbers (31000m −2 ). The response of this fauna to eutrophication in L. Neagh appears to be a diminution in the number of species present, with C. plumosus gradually replacing C. anthracinus as the dominant Chironomus , and tubificids, particularly Limnodrilus , becoming more abundant, A further stage, shown in Kinnego Bay, has Procladius as the most numerous' chironomid. Average total biomass at the three sites was 3.9gm −2 at 8m, 13.2gm −2 at 25 m in the main lake, 2.8gm −2 in Kinnego Bay. At 8m depth, C. anthracinus contributed 76% of the total biomass, at 25m Limnodrilus contributed 74% and C. anthracinus 15%, and in Kinnego Bay, Limnodrilus contributed 40%, C. plumosus 28% and Procladius 20%.