Offshore Nutrient Dynamic Change with Profunda Quagga Mussels

Session: 48. - Physical Ecology in Large Lakes and their Watersheds

Rae-Ann MacLellan-Hurd, University of Wisconsin-Milwaukee, [email protected]
David Cannon, Purdue University, [email protected]
Qian Liao, University of Wisconsin-Milwaukee, [email protected]
Cary Troy, Purdue University, [email protected]
Harvey Bootsma, University of Wisconsin-Milwaukee, [email protected]

Abstract

Quagga mussels grazing has been a major focus for nutrient dynamics nearshore in Lake Michigan due to the conventional thought that benthic areal grazing rates are only comparable to phytoplankton production rates in shallow systems. However recent studies have indicated that quagga mussels have fundamentally altered nutrient dynamics in the deeper waters of Lake Michigan through indirect processes. Indirect means of altering nutrient dynamics include possible changes to turbulent mixing and changes to nutrient flux through the water column. This talk will focus on quagga mussel influence on nutrient profiles offshore of Lake Michigan using a mass balance approach for phosphorous and carbon. The mass balance includes data from isothermal to a stratified period that is coupled with mixing profiles. Chemical profiles were created with discrete samples of soluble reactive phosphorous, particulate phosphorus, total dissolved phosphorous, dissolve inorganic carbon, dissolved organic carbon, and carbon dioxide. Mixing coefficients were measured using particles image velocimetry and temperature differences. The profiles give an indication of quagga mussel affect on whole water column nutrient flux in deep water systems.

1. Keyword
benthos

2. Keyword
nutrients