ISSN:
1365-2427
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
This paper forms a sequel to that describing the physical and chemical aspects of Chew Valley and Blagdon Lakes (Wilson et al., 1975).General accounts of the phytoplankton, zooplankton, macrophytes, littoral and benthic faunas, and fish are presented, based on surveys undertaken between 1966 and 1973.The spring diatom blooms (principally Asterionella) are correlated with silica and phosphate depletion in both lakes, while growths of blue-green (principally Microcystis) in the summer and autumn are correlated with low values of nitrate and saline ammonia.The principal zooplankter in both lakes is Daphnia hyalina. Daphnia pulex was found very commonly in Blagdon in 1970/71, but has not been recorded since. The Daphnia in Chew are smaller in size than those in Blagdon.Blagdon is richer in abundance and number of species of littoral animals, and in macrophyte development, than is Chew. The benthos of both lakes is very similar, except that Blagdon has a well-established population of Anodonta cygnaea, while in Chew the species has apparently only recently become established.Both lakes are maintained artificially as trout fisheries. Other fish present include eels, sticklebacks, and gudgeon. Roach and Perch are found in Chew only. An outline account of their food is given based on stomach content analysis, and shows that trout feed principally on chironomid pupae in spring, and on small fish in autumn.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2427.1975.tb01761.x
