Individual study: Water level manipulations aimed at enhancing foraging habitat for Latham's snipe Gallinago hardwickii reduces benthic invertebrate abundance, Sydney, New South Wales, Australia
Lindegarth M. & Chapman M.G. (2001) Testing hypotheses about management to enhance habitat for feeding birds in a freshwater wetland. Journal of Environmental Management, 62, 375-388
Water levels were manipulated in a freshwater wetland aiming to enhance benthic invertebrate abundance and to create areas of wet sediment along pond margins thus improving foraging habitat for Latham's (Japanese) snipe Gallinago hardwickii in a previously developed site in Sydney, New South Wales, south-east Australia.
Water levels were manipulated at Wharf Marsh East and Wharf Marsh West, with one control location (Bennelong Pond; sample sites always covered by 20-30 cm water). Benthic invertebrates were sampled in two 15m² plots (1-2 m from shore) per location. Each was sampled before and after the marsh was fully drained in August-September 1997 and January-February 1998. Wharf Marsh was refilled in April, drained again in August 1998, and resampled in early and late September 1998, and January-February 1999.
The average number of taxa and chironomid abundance decreased significantly in both Wharf Marsh sites as compared to the control. Average oligochaete abundance was not significantly affected by draining but there were greater abundances at Bennelong Pond compared to Wharf Marsh at all times after drainage. Thus in contrast to what was predicted, management reduced benthic invertebrate abundance.
Note: If using or referring to this published study please read and quote the original paper, the abstract can be viewed at: http://www.ncbi.nlm.nih.gov/pubmed/11505764