The data described in this addendum are provided to enhance the resolution and/or expand the temporal scope of the information already provided in the final report (Kellogg et al. 2018). High-resolution water quality transect data were collected at all four sites in Summer 2017, at White Stone (Windmill Point site) and Lynnhaven River in Fall 2017, and at White Stone (North Point site) in Spring 2018. During each sampling period, data were collected from multiple transects through and outside of each farm. Resulting data were detrended as needed based on temporal and salinity-related patterns found in data collected outside the farm footprint. Comparison of the resulting data from inside and outside the farm identified significant differences between water quality inside the farm footprint and outside for the majority of site x season combinations for all parameters. However, differences were consistently small enough to have no biologically significant impact, positive or negative, on farm-scale water quality.
Benthic macrofaunal communities inside and outside the farms were assessed at White Stone’s Windmill Point site and at the Lynnhaven River site in Fall 2017 and White Stone’s North Point site in Spring 2018. Data on species richness, macrofauna abundance, and macrofauna biomass were compared between samples taken inside the farm footprint and outside the farm footprint for all site x season combinations. These data were compared to data previously reported from Summer 2017 collected at all four aquaculture sites. Overall, patterns in species richness and macrofauna abundance were not consistent across seasons within site, across sites within seasons or within gear type. With the exception of one of the farm sites studied, there was a trend towards increased macrofauna biomass inside the footprint of aquaculture farms. This pattern is consistent with the assumption that food for benthic macrofauna at these sites is enhanced by oyster biodeposition. Overall, we found no biologically significant negative impacts on macrofaunal communities inside aquaculture farms and some evidence that suggests a possible positive impact on benthic macrofauna production
