Dataset: Seawater properties at two locations in a northeast Florida estuary measured using HydroCAT CTD between July 2019 and April 2020 as part of an oyster reciprocal transplant experiment

A reciprocal transplant experiment was conducted at two sites in an estuary in NE Florida, USA that encompassed different environmental (salinity, aerial exposure) and biotic (predators) stressors. Juvenile oysters were reciprocally transplanted within and between the two locations within the Guana Tolomato Matanzas National Estuarine Research Reserve (GTMNERR)--the Butler site at 29.77002 N, -81.2641 W, and the Pellicer site at 29.62923 N, -81.2144 W. 

To obtain site-specific information on seawater properties, a SeaBird HydroCAT-EP CTD instrument was deployed just seaward of the reefs. Measurements include temperature, conductivity, pressure, salinity, and oxygen. The HydroCAT ODO by Seabird was put in the water in front of the oyster reefs for the duration of the experiment, Butler (7/23/2019 8:00 to 4/2/2020 14:45) and Pellicer (8/19/2019 10:30 to 4/2/2020 14:45). The instrument was deployed in a PVC housing with the CTD in a 2 inch PVC pipe with drilled 1/2 inch holes to allow water flow. The frame of the housing was made up of 1 inch PVC pipe with the 2 inch PVC pipe resting on the edge of the housing at a 45 degree angle so the end with the sensors was lower in the water than the top of the instrument. The housing and sensor were deployed seaward at approximately three meters from the middle of the oyster reef.

In order to secure the CTD, the housing frame was pressed into sediment with the CTD being above the sediment. At each end of the housing frame, we also attached two pieces of rope and used rebar stakes to secure the rope into the ground. Samples were taken every 15 minutes but if the CTD was out of the water the observations were discarded; for Butler this was determined as salinity less than 25 and pressure less than 1 dbar, for Pellicer it was salinity less than 15 psu and pressure less than 0.008 dbar. Throughout the experiment, the CTDs were removed from the water to download data and cleaned prior to re-deployment. 

Problem report:
No conductivity on 9/20/2019 through 4/2/2020 at Butler. Similarly, no conductivity beginning 11/15/2019 through 4/2/2020 at Pellicer, but specific conductivity was still measured at both sites at those times.