Dipteran standing stock biomass and effects of aquatic bird predation at a constructed wetland

Abstract

Abstract We studied the relationship between benthic invertebrates and aquatic birds at a newly constructed wetland using an avian exclosure experiment combined with counts of aquatic bird use. We measured the standing stock biomass of benthic dipterans both inside and outside exclosures. Chironomidae was the most abundant dipteran family present. Maximum chironomid standing stock biomass per pond ranged from 3.62 to 27.82 g/m2 and was comparable to that found in a number of natural systems. We monitored the abundance of ten aquatic birds species. Abundances of three aquatic bird species [American avocet (Recurvirostra americana), Wilson's phalarope (Phalaropus tricolor), and cinnamon teal (Anas cyanoptera)] were significantly correlated with chironomid and total dipteran densities. Our experiment, however, found no significant effect of predation on invertebrate densities.