This data release includes zooplankton data collected from a collaborative effort for Environmental Protection Agency’s Cooperative Science and Monitoring Initiative (CSMI). Zooplankton surveys were conducted during the growing season, from late April to early November, in two Lake Michigan transects in 2010, two Lake Huron transects in 2012, eight Lake Michigan transects in 2015, and nine Lake Huron transects in 2017. Zooplankton samples were collected by whole water-column tows at two or three stations in different bottom-depth categories (i.e., shallow, middle, and deep) in each of the transects. Due to the difference in bathymetry, some transects did not have a deep station. The shallow and middle stations have bottom depths of 11-27 m and 40-51 m, respectively, in both Lakes Michigan and Huron. As Lake Michigan is generally deeper than Lake Huron, the deep stations have bottom depths of 85-112 m in Lake Michigan and 64-90 m in Lake Huron. The dataset includes tables for sampling operation, zooplankton count, and zooplankton individual size, which may be used to derive zooplankton count or biomass per volume.

Crustacean zooplankton were collected, enumerated, identified, and measured within the St. Clair-Detroit River System (SCDRS). Collections were made using a 0.5 m diameter 153 um zooplankton net. Nets were lowered to ~0.5 m from bottom depth and retrieved. Nets were utilized with a General Oceanics flowmeter to calculate the distance the net traveled. At sites of collection, both temperature (degrees C) and Secchi depth (m) were collected for abiotic influencing factors of the zooplankton community. Collected specimens were narcotized in sugar formalin. Specimens were enumerated, identified, and measured under a dissection microscope. Volumetric estimates (m^-3) were obtained by applying the distance traveled and the area of the net. Abundances and biomasses were estimated based on the average length of a group of organisms and the samples estimated to be within a collected sample, and then the average estimated weight of an individual from length-weight regressions. This is a revised version of a data release. For details on changes, please see the “version-history.txt” document in the attached files. All previous versions are available from the author. First posted - March 23, 2018 (available from author) Revised - April 24, 2018 (version 1.1) Revised - November 18, 2020 (version 1.2)

Zooplankton data were collected using zooplankton net casts in Coastal Waters of Washington / Oregon. Data were collected from 01 January 1969 to 31 December 1972 by Oregon State University. Report from OSU Sea Grant College Program (OSU, School of Oceanography), titled "Zooplankton Along the Continental Shelf off Newport, Oregon 1969-72: distribution, abundance, seasonal cycle and year-to-year variations". Lead author is Dr. William Peterson and is dated June 1976.

Zooplankton data were collected using zooplankton net casts and other instruments in the Delaware Bay and North Atlantic Ocean from November 3, 1976 to November 18, 1977. Data were submitted by Virginia Institute of Marine Science - Gloucester Point as part of the Ocean Continental Shelf (OCS - Mid Atlantic) project. Data were processed by NODC to the NODC standard Zooplankton (F004) format. The F124 format is used for data from sampling and analysis of marine zooplankton. Information on zooplankton abundance, distribution, and productivity derived from these data support studies of marine populations and ecosystems. Data reported may include: cruise information, position, date, and time of sampling; bottom depth, sampling depths, temperature, and salinity; gear type, volume of water filtered, total dry and wet weight, and other data for total haul; and data for subsamples by species. Data on zooplankton catch by species may include subsample size, zooplankton concentration, life history code, and numbers of adults, juveniles, eggs, and larvae. Estimated density of holoplankton and meroplankton and data on ichthyoplankton may also be reported. A text record is available for comments. Note: there are two options for reporting subsample counts of individuals at different life history stages. If life history codes are used, only number of adults should be reported on that record. Additional separate records should then be used to report number of juveniles and so on. Alternatively, life history codes may not be used and number of adults, juveniles, and so entered in the proper fields of a single record.

This data set contains information on zooplankton and associated environmental parameters for sampling conducted in California's northern Sacramento-San Joaquin Delta between May 2016 and April 2018. Macrozooplankton were sampled with horizontal tows (water surface) of a 50 cm-diameter conical plankton net that was 150cm long with 102µm mesh. Samples were preserved in the field in 10% formalin for laboratory processing that was conducted by a contractor (EcoAnalysts, Inc). Due to processing limitations, taxonomic data is not available for every sample and are thus not reflected in every data table (samples 1-28, 318-328, 531-620 have no data in the Zooplankton Taxa Table)

This data set contains information on zooplankton and associated environmental parameters for sampling conducted in the San Joaquin River and False River near their confluence at Jersey Point (Contra Costa County, California), during February-March, 2016. Macrozooplankton were sampled with vertical tows (bottom to surface) of a 50 cm-diameter conical plankton net that was 150cm long with 102µm mesh. Samples were preserved in the field in 10% formalin for laboratory processing that was conducted by a contractor (EcoAnalysts, Inc).

These data consist of a multi-trophic, day vs. night, nearshore to offshore transect approach for data collection for this Cooperative Science and Monitoring Initiative effort at two northwestern Lake Huron sites near Hammond Bay and Thunder Bay, Michigan. Zooplankton and Mysis samples were collected monthly from April-October while benthos and prey fish samples were collected seasonally during Spring, Summer, and Fall. Invertebrate taxa (zooplankton, Mysis, benthic macroinvertebrates) were identified, enumerated, and measured using a dissecting microscope. Diet items of the prey fish were processed similarly to the other samples in terms of taxonomy. These data were used to calculate densities of fish prey items and compare that to what the fishes ate for selectivity analysis. The data are in raw form.

Zooplankton, chemical, and other data were collected using net, sediment sampler, and other instruments in the Great Lakes. Data were collected from 01 July 1970 to 01 March 1972 by University of Michigan with support from the Great Lakes Project and Seagrant project.

NOAA Great Lakes Environmental Research Laboratory (GLERL) samples and studies the ecosystem of the lower food web of the Laurentian Great Lakes. This collection contains zooplankton biomass and density data at 15 stations during the open water season in Lake Michigan from 2010-2019. Note, no samples were collected in Lake Michigan in 2012, efforts were instead put towards Lake Huron for the Cooperative Science and Monitoring Initiative (CSMI) that year. Zooplankton density is given in the number of organisms per cubic meter and biomass is given in milligrams per cubic meter. File formats included in this data package are .csv and jpg.