SECONDARY PRODUCTION OF CHIRONOMIDAE IN A LARGE EUTROPHIC LAKE
File(s)
Date
2010-12Author
Anderson, Timothy J.
Advisor(s)
Stelzer, Robert S.
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Show full item recordAbstract
To date the majority of food web research in lentic systems has focused on pelagic
primary (phytoplankton) and secondary (zooplankton) production as the primary energy sources
for higher trophic level production. Recently research has provided evidence that benthic
secondary production of primary consumers can impact pelagic fish production and food web
structure in lakes. I calculated secondary production of chironomids in Lake Winnebago
Wisconsin where previous research has shown that lake sturgeon (Acipenser fulvescens) rely
heavily on the benthos (chironomids) as a food source. I also calculated lake sturgeon annual
production from literature-derived data using the instantaneous growth method in order to
determine if there is sufficient chironomid production to support the current lake sturgeon
population in Lake Winnebago. Benthic samples were collected with an Ekman dredge at four
profundal sites on eleven dates from spring 2008 through spring 2009. Instantaneous growth
rates for seven chironomid length-classes at five thermal regimes were measured in the
laboratory. Mean annual production of Chironomidae using the instantaneous growth rate
method was 7.59 g dry mass (DM) m-2 yr-1. The subfamily Chironominae accounted for 5.56 g
DM m-2 yr-1 and Tanypodinae production was 2.04 g DM m-2 yr-1. Lake sturgeon annual
production was estimated at 0.044 g dry mass (DM) m-2 yr-1. Mean annual density of
Chironomidae was 2714 m-2 and mean biomass was 2.75 g DM m-2. In 2008-2009 there was
sufficient chironomid secondary production to support the lake sturgeon population in Lake
Winnebago. The annual production estimates for chironomids are higher than many other
chironomid production rates from lakes in North America, presumably due the eutrophic
conditions of Lake Winnebago.
Subject
Lake sturgeon Lake Winnebago, Wisconsin
Chironomidae Lake Winnebago, Wisconsin
Permanent Link
http://digital.library.wisc.edu/1793/49181Description
A Thesis submitted in partial fulfillment of the requirements for the degree of Master of Science-Biology