Abstract:

In a 2019 field study, the effect of freshwater intrusion on oyster reefs in the Mississippi Sound was observed through sampling. A handheld water meter was used in six locations 23 April, 6 May, 24 May, and 27 September 2019 to measure salinity (ppt), temperature (°C), dissolved oxygen (mg/L), conductivity (µS/cm), and pH. Dredging of five of these reef sites showed numbers of living and dead adult oysters, living and dead spat, clutch shells and whether or not mussels were present. A seafloor platform observed temperature (°C) and salinity (ppt) at The Nature Conservancy (TNC) Bay St. Louis reef site every five minutes from 23 April to 27 September 2019.

Suggested Citation:

Deborah Gochfeld, Marc Slattery, Kristie Willett, Greg Easson, Ann Fairly Barnett, James Gledhill. 2020. Effect of Freshwater Intrusion on Oyster Reefs in the Mississippi Sound from 2019-04-23 to 2019-09-27. Distributed by: Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC), Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/J420QN15

Publications:

Gledhill, J. H., Barnett, A. F., Slattery, M., Willett, K. L., Easson, G. L., Otts, S. S., & Gochfeld, D. J. (2020). Mass Mortality of the Eastern Oyster Crassostrea virginica in the Western Mississippi Sound Following Unprecedented Mississippi River Flooding in 2019. Journal of Shellfish Research, 39(2), 235. doi:10.2983/035.039.0205

Purpose:

Heavy rains in early 2019 produced a large influx of freshwater into the Mississippi Sound. The effect of freshwater intrusion on oyster reefs in the Mississippi Sound was observed through sampling water parameters and dredging reefs.

Data Parameters and Units:

Main parameters: Site (Back Bay St. Louis, The Nature Conservancy (TNC) Bay St. Louis Reef, St. Stanislaus Reef, Waveland Reef, Henderson Point Reef, Kittiwake Reef), Latitude (decimal degrees), Longitude (decimal degrees), Depth (meters), Date (M/DD/YYYY), Time (GMT-5:00), Salinity (ppt), Temperature (℃), Dissolved Oxygen (mg/L), Conductivity (µS/cm), pH, Specific Conductance (μS/cm), Number (as specified). The worksheet "YSI Water Quality" contains the location where water quality was tested (latitude and longitude) and water quality data (salinity, temperature, dissolved oxygen, conductivity, pH) measured at surface and bottom using YSI professional plus handheld multi-parameter meter quality meter. The worksheet "Dredge Data" contains the GPS coordinates of the dredge pulls (start and end position/latitude and longitude), the numbers of living and dead adult oysters, living and dead spat, clutch shells and whether or not mussels were present. The worksheet “TNC Reef Salinity+Temperature” contains a seafloor platform observed temperature, specific conductance, and salinity at one of the reef site (TNC Bay St. Louis Reef) every five minutes. Note: "-9999" is no "no data value" as data could not be collected within the water column.

Methods:

Water sampling and dredging at reef sites were performed.

Instruments:

YSI™ Professional Plus Handheld Multiparameter meter HOBOware® conductivity logger

Provenance and Historical References:

This dataset was initially published on 2020-01-08 and was revised again on 2020-04-16 to add the GPS coordinates of the dredge pulls. The dataset now includes both the originally submitted (labeled 'Version_1') file as well as the revised version (labeled 'Version_2').

Individual Files: