Spat settlement collectors were constructed by affixing 2-3 wire strings, each containing 12 adult oyster shells, to private and public docks or stand-alone wooden pilings, throughout BBCPS study system. Settlement collectors were deployed on June 7th and 21st and again on August 1st and 16th of 2012 and retrieved approximately 2 weeks later as part of an ongoing settlement sampling program (Eggleston and Puckett, unpubl.data). Recovered settlement collectors were frozen until individual spat could be counted and removed from adult oyster shells with a tungsten probe. Spat were divided by collection site and collection period and refrozen at -23°C.