Seasonal oxygen, temperature, chlorophyll, and zooplankton data – Portage Lake, MN

This dataset includes seasonal water quality and zooplankton data from Portage Lake in Hubbard County, Minnesota, USA, during 2023–2024. The dataset contains three components: (1) vertical profiles of temperature, dissolved oxygen, and chlorophyll a; (2) discrete chlorophyll a samples from 2 depths at lake center; and (3) zooplankton community data containing species-level counts. Water profiles were taken at the lake center using a YSI EXO2 sonde, and discrete water samples were collected from 0.5 m and 3–4 m depths at lake center. Chlorophyll a samples were filtered, frozen, extracted in the dark for 18 hours, and analyzed with a Turner Designs 10-AU fluorometer. Zooplankton were sampled at lake center by pooling three net tows per replicate. Zooplankton were preserved in ethanol and identified under a stereoscopic microscope at 7x-70x magnification using standard identification keys. At least 300 individuals were counted per sample. Abundance is reported as individuals per liter..., , # Seasonal oxygen, temperature, chlorophyll, and zooplankton data – Portage Lake, MN Dataset DOI: [10.5061/dryad.m63xsj4fs](10.5061/dryad.m63xsj4fs) ## Description of the data and file structure **Seasonal water quality and zooplankton data for Portage Lake, Hubbard County, MN, USA (2023-2024)** ### Files and variables #### File: #### **Portage_CTD.csv** **Description:** Complete water column measurements of dissolved oxygen, chlorophyll *a*, and temperature in Portage Lake, Hubbard County, MN, USA (2023-2024) ##### Variables: * \"*Oxygen_perc_sat*\" : dissolved oxygen in percent saturation * \"*Chlorophyll_a_ug_L*\" : chlorophyll *a* in micrograms per liter, μg/L * \"Temperature_C \" : temperature in degrees Celcius, °C #### **Portage_discrete_chlorophyll.csv** **Description:** Discrete chlorophyll a measurements from 2 depths at lake center (surface: 0.5 m below surface; bottom: 3-4 m below surface). **Methodology:** Whole water, not sieved, filtered through 0.22 cellulose nitra...,