Oysters and Freshwater Flow, Strategies for Oyster Restoration

Title: Oysters and Freshwater Flow, Strategies for Oyster Restoration

Discussion Group Leaders: Jay Leverone and Mike Jones

• First step: look at current situation, meaning where oysters were, their condition, looking at historical view of where oysters were in the mid 19th century.

• Keeping temperature down is good for oysters in the summertime. Summer 2003 has ideal conditions for oysters in this area.

• Water quality background for that part of the bay coinciding with healthy oysters.

• Oysters as an environmental indicator in Sarasota County: Oyster monitoring program to look at oysters in tidal creeks. Use scoring system with the % of live to dead oysters found in the area.

• Rainfall is a driver for main things, rainfall is not evenly distributed throughout the County. Each watershed has different average rainfalls.

• Around Venice Inlet have longer term data set. Took two years and compared them, chosen by similar amounts of rainfall during the wet season. Freshwater doubled when gates were open, rather than closed. In comparison, the gates open were related to a large drop in salinity.

• Compared % of dead/live oysters to:
  • Discharge
  • Rainfall
  • Salinity

• Oyster beds in Sarasota are not, in large part, commercially harvested.

• Any freshwater mussels protected in Sarasota and if so are their health related to oyster health?

• Are oysters adaptable? Could they be planted in an area and thrive? Response: Generally growing in areas regardless of fluctuation. Have to have massive alterations in freshwater flow for oysters to respond.

• Oysters, if provided with a hard substrate, they will colonize it. Oysters like the intertidal area.

• Sea Wall: have habitat in it to promote restoration. This would allow water to be filtered, also increasing diversity. Sea wall facing would be option to homeowners to break up just cement.

• Idea: Modification of the side of a sea wall would have potential. Modification would be individual selection by people with private buyers. Similar situation: reef balls.

• Average oyster will filter about 5L of water a day. Not a solution to water quality issue because oysters produce waste as well.

• What is the prospect for Restoration? Response: Manufacturing substrate off of which oysters can build. Often combined with work on habitats, like increasing wave control. Lots of work with oysters that are not geared towards ‘saving the oyster’.

• We are fortunate that we have no diseases that are killing our oysters.

• Opportunity for oyster bar creation: artificial drainage systems bury substrate oysters could have colonized. 34th St. in Bradenton is a good example to put oyster bars out there and increase the quality of the area.

• Opportunity for oyster restoration. They filter the water and seem to be relatively hearty. Referred to as keystone species because they build a structure which allows other species to be a part of the oyster clump.

• Oyster habitats are unique and have some of the greatest variety.

• Oyster habitat can be part of saving mangrove island communities.

• These works require continued monitoring and maintenance until they stabilize.