These data include mysid counts, water quality and sampling metadata from 24hr sampling events that occurred between May 2024 and October 2024 in the Patuxent River in MD, USA. Observations were collected with a zooplankton net (500 µm net mesh) and epi-benthic sled (500 µm net mesh) and water quality sonde. These measurements were taken to understand mysid (opossum shrimp) spatial and temporal dynamics in shallow-water estuarine habitats to inform models and were collected by Dr. Ryan Woodland and team at the University of Maryland Center for Environmental Science Chesapeake Biological Laboratory in Solomons, MD. 

Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • BCO-DMO Processing Description
  • Problem Description
• Parameters
• Instruments
• Project Information
• Funding

Zooplankton net samples (500 μm mesh) were collected from a small vessel at surface and mid-water column depths for 2 minutes. Epi-benthic sled samples (500 μm mesh) were collected from a small vessel and from the Chesapeake Biological Laboratory pier at recorded depth per sample. Water quality samples were collected via sonde before each sampling. 

After collection, samples were placed into sample jars with either 75% buffered ethanol OR 10% formalin solution. Samples were then transported back to the Chesapeake Biological Laboratory. Upon analysis, individual mysids were separated from the rest of the sample, counted and speciated by hand. 

- Loaded sheet 1 from "24hr_Mysid_Sampling_BCODMO.xlsx" treating "nd" and "N/A" as missing values
- Combined Date and Time fields into a new string field datetime_raw
- Applied find/replace patterns on datetime_raw to normalize datetime strings: padded times missing seconds with ":00" and standardized spacing
- Converted datetime_raw from format "%m-%d-%y %H:%M:%S" to ISO 8601 datetime field datetime with output format "%Y-%m-%dT%H:%M:%S"
- Deleted fields Date, Time, and datetime_raw
- Reordered fields placing datetime first, followed by Site, Lat, Long, Gear, Type, count fields, proportion fields, Mysids/m^2, volume/area fields, water quality fields, and Notes
- Applied find/replace on Notes field to replace a raw annotation ("****October depth data from pier all says zero?") with a cleaner description ("October depth data from pier all says zero: Depth meter failure")
- Renamed fields: Mysids/m^2 to Mysids_per_m2, "Volume filtered (zoop nets only)" to Volume_filtered, "Swept area (sled only)" to Swept_area, "Sonde_depth (m)" to Sonde_depth, "Temperature (C)" to Temperature, "Conductivity (mS/cm)" to Conductivity, "Salinity (PSU)" to Salinity
- Exported file as "996519_v1_24hr_mysid_sampling.csv"

World Register of Marine Species (WoRMS) Taxon Match. All scientific names referenced in the parameter descriptions are valid and accepted names as of 2026-04-22.

Americamysis Price, Heard & Stuck, 1994 (urn:lsid:marinespecies.org:taxname:161519)
Neomysis americana (S.I. Smith, 1873) (urn:lsid:marinespecies.org:taxname:157807)

Depth meter failure: there was a failure of unknown origin from pier data sonde. No other sensors from those observations are known to be affected. 

Coverage: Chesapeake Bay

NSF Award Abstract:

Diagrams of food webs are typically drawn as boxes that show linkages between predators and prey. While these are useful models of how energy is transferred along a food chain, real food webs are more complex. Predator diets are often variable making it difficult to establish predator-prey links in marine communities. This project is investigating prey switching in a key member of coastal food webs, the shrimp-like mysid, Neomysis americana. Prey switching affects community structure and an organism’s resilience to environmental perturbation, but it is not easy to quantify. This project is using a combination of laboratory experiments and field sampling to develop a food web model that predicts mysid feeding patterns in the environment. This realistic and predictive food web model uses traditional gut analysis and analytical techniques that follow carbon and nitrogen as it is incorporated into the bodies of the mysids. In addition, mysid food preferences are being determined in the laboratory across a full range of diet possibilities. The calibrated gut analysis and chemical marker data in combination with feeding experiments are incorporated into the model, which then predicts mysid feeding on mixed diets under different environmental conditions. These predictions are validated against field data. Broader impacts include benefits to society for a better understanding of how coastal food webs work. Doctoral students and undergraduate students are being trained in experimental and field research. Increasing diversity in STEM fields is occurring through a partnership with two community colleges (College of Southern Maryland, Chesapeake College) to recruit summer interns for research experiences. Outreach activities include the development of educational materials for grade-appropriate hands-on laboratory experiments and training opportunities for middle and high school teacher groups in the use of these materials in their classrooms.

This project is developing and field-testing a generalizable approach to understand and predict complex predator-prey relationships in marine food webs. The research plan involves building and validating a multispecies functional response (MSFR) model for an omnivorous consumer, the mysid Neomysis americana. These models predict diet for consumers that feed on multiple types of prey under differing prey concentrations and identify conditions under which prey switching occurs in the environment. Recent and time-integrated diet tracking with gut contents, bulk stable isotope (SI) and compound-specific amino acid stable isotope (AA-CSI) analysis are validated in the lab and used to reconstruct diet of Neomysis in the field. The proposed research is testing specific hypotheses about Neomysis’ consumption rates and prey preferences and the effectiveness of integrating SI and AA-CSI into MSFR models. Laboratory experiments are determining prey-specific functional response curves by Neomysis under varying prey concentrations and environmental (temperature) conditions using grazing experiments. Experimental results are incorporated into a temperature-dependent MSFR model for a 5-compartment simplified food web (Neomysis, adult copepod, copepod nauplii, phytoplankton, detritus). A complementary element of the project is the experimental determination of bulk SI (𝛿13C and 𝛿15N) and AA-CSI (𝛿15N) equilibration rates and trophic enrichment factors for Neomysis and each prey type. The predator-prey dynamics of Neomysis in the environment are being modeled using the lab-validated MSFR approach and field data, including prey concentrations, gut contents, and prey and Neomysis SI and AA-CSI data.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.