Dataset: Survey disease oysters

Site Selection- From Hanley et. al 2019, this was a multi-step process that first involved using ArcGIS to partition the bay’s oyster reefs (commercial and non-commercial) into six zones. Zone assignment was based on the reef’s relative distance by water from the river input (near, mid, far) as well as a reef’s east-west orientation to the river (East Apalachicola and West Apalachicola). Next, we randomly selected three reefs out of all possible reefs (including the experimental reefs) within each zone.

Surveys- Methods for surveys done from 2013-2016 were taken from Hanley et al. 2019.

Surveys 2013-2016: On each reef subtidal reef, we obtained spatially balanced samples by extending four 20 m transects at 90 degree angles from the boat. Along each transect, we overlaid a 0.25 m2 weighted quadrat at the 5, 10, 15, and 20 m marks. For each quadrat, we collected the entire contents of the quadrat into a uniquely labeled mesh bag, transported the bag to the surface, and placed the bag on ice to be processed at the lab. For intertidal reefs, we sampled 2 quadrats per reef, ‘low’ (located at the low water level) and ‘high’ (2 m above the low transect) quadrats centered along a 20 m transect on each reef.

Lab Processing of samples collected during the survey: In the laboratory, we processed each quadrat sample to obtain the total mass (g), the size of the first 100 oysters encountered (not all samples contained 100 oysters), the density of all juvenile oysters (length < 25 mm), the density of all adult oysters (length > 25 mm), and the density of recently deceased oysters (valves intact and absence of sessile invertebrates within the internal shell cavity).