Depth profiles of temperature, conductivity, dissolved oxygen, pH, chlorophyll fluorescence, etc., collected with a SeaBird SBE 25plus CTD in Lake Michigan during 2017, 2018, and 2019

Abstract

This dataset provides conductivity-temperature-depth (CTD) data from Lake Michigan collected over several cruises conducted during 2017, 2018, and 2019. Data were obtained using a SeaBird SBE 25plus CTD.

Water chemistry and CTD profiles were measured at several stations in Lake Michigan, ranging in depth from 10 to 55 m, in a region northeast of Milwaukee Harbor. Measurements included soluble reactive phosphorus, total dissolved phosphorus, particulate phosphorus, chlorophyll a, the concentrations and stable isotope ratios of particulate carbon and particulate nitrogen, dissolved carbon dioxide, dissolved total inorganic carbon, and dissolved organic carbon. In addition, continuous lake surface and atmospheric CO2 data collected in 2019 and 2021 on a Lake Michigan transect between Milwaukee, WI and Muskegon MI. The chemistry and CO2 data are provided in separate datasets.

These data have several applications, including: 1) Constructing an annual carbon and nutrient budget for the water column, which is used along with direct measurements of quagga mussel nutrient recycling to assess the role of invasive quagga mussels in the lake's carbon and nutrient cycles; 2) When combined with separate measurements of the vertical structure of water density and currents, to quantify vertical fluxes of dissolved nutrients and inorganic carbon, to determine how carbon and nutrient recycling by profundal quagga mussels may affect plankton production in the euphotic zone; 3) The calibration and validation of physical / biogeochemical models used to better understand how invasive quagga mussel have altered energy flow and nutrient dynamics in the Great Lakes, and guide management decisions with regard to nutrients and fish stocking.

For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/737534