Organism sizes on oyster reef quadrats from surveys in Apalachicola Bay and Ocholckonee Bay, FL, 2013-2019 (NCEI Accession 0291489)

Acquisition Description:
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.

Surveys 2019- Sites were selected from previously sampled reefs. Subtidal surveys were conducted by divers on SCUBA. A buoy was dropped at the sites. The divers attached a 10m transect to the buoy and surveyed the area in the four cardinal directions (North, South, East and West). We characterized the substrate 0.5m on each side of the transect as mud, sand or shell hash, as well as quantified the amount of oyster shells and counted the number of Oyster Drills (Stramonita haemastoma). If there were oysters or shells at meter 5 or meter 10 along the transect then everything in a 0.25m2 quadrat was collected and processed at the lab. We only sampled the intertidal sites in December 2019. We laid a transect across the crest of the reef and then divided the length of the transect by 7 to get a consistent sampling interval. At each sampling interval we recorded the width of the sampling side and then placed a 0.0625m2 quadrat at the midpoint of the sampling width and collected all the contents to be brought back to the lab and processed.