SECONDARY PRODUCTION OF CHIRONOMIDAE IN A LARGE EUTROPHIC LAKE

Lake sturgeon Lake Winnebago;Wisconsin;Chironomidae Lake Winnebago;Wisconsin

Anderson, Timothy J.Stelzer, Robert S. ;

University of Wisconsin

关键词: Lake sturgeon Lake Winnebago;    Wisconsin;    Chironomidae Lake Winnebago;    Wisconsin;   

Others  :  https://minds.wisconsin.edu/bitstream/handle/1793/49181/Anderson%2c_Timothy_%28With_TP%29.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: University of Wisconsin

【 摘 要 】

To date the majority of food web research in lentic systems has focused on pelagicprimary (phytoplankton) and secondary (zooplankton) production as the primary energy sourcesfor higher trophic level production. Recently research has provided evidence that benthicsecondary production of primary consumers can impact pelagic fish production and food webstructure in lakes. I calculated secondary production of chironomids in Lake WinnebagoWisconsin where previous research has shown that lake sturgeon (Acipenser fulvescens) relyheavily on the benthos (chironomids) as a food source. I also calculated lake sturgeon annualproduction from literature-derived data using the instantaneous growth method in order todetermine if there is sufficient chironomid production to support the current lake sturgeonpopulation in Lake Winnebago. Benthic samples were collected with an Ekman dredge at fourprofundal sites on eleven dates from spring 2008 through spring 2009. Instantaneous growthrates for seven chironomid length-classes at five thermal regimes were measured in thelaboratory. Mean annual production of Chironomidae using the instantaneous growth ratemethod was 7.59 g dry mass (DM) m-2 yr-1. The subfamily Chironominae accounted for 5.56 gDM m-2 yr-1 and Tanypodinae production was 2.04 g DM m-2 yr-1. Lake sturgeon annualproduction was estimated at 0.044 g dry mass (DM) m-2 yr-1. Mean annual density ofChironomidae was 2714 m-2 and mean biomass was 2.75 g DM m-2. In 2008-2009 there wassufficient chironomid secondary production to support the lake sturgeon population in LakeWinnebago. The annual production estimates for chironomids are higher than many otherchironomid production rates from lakes in North America, presumably due the eutrophicconditions of Lake Winnebago.