Dock Study Summary of Intentions and Protocol

Purpose: The purpose of the dock study is to determine if the construction guidelines used for docks built in areas where Johnson’s seagrass is known to occur are having an impact on its distribution and abundance. The guidelines call for grated decking, which allows for more light to transmit through the water column than normal decking.

Intent: Ideally, 5 to 10 docks will be identified that have been built to the standards required for Johnson’s seagrass areas, and an additional 5 to 10 will be identified that are scheduled to be built within the next several months. It may also be beneficial to identify an equal number of docks that have been built in areas known for Johnson’s seagrass but were not built to the dock criteria standards.

This allows then for three possible scenarios, all of which assume the potential presence of Johnson’s seagrass:

1. Dock built without grated decking.

2. Dock built with grated decking.

3. Dock scheduled to be built with grated decking.

Johnson’s grows along the east coast of Florida between Sebastian Inlet in the north and northern Biscayne Bay in the south. It would be beneficial to have an equal number of each scenario in each area sampled, so that the three can be compared to one another. For example, if one dock with grated decking is located in the northern area of the plants geographic extent, there should also be one dock scheduled to be built near there and another that already has been built there without grated decking.

An initial sampling of these docks will take place in early February 2006 in conjunction with the Johnson’s seagrass transect sampling trip and the Johnson’s seagrass implementation team annual meeting.

Measurements to be taken at each dock (pending permission, all to be done with Trimble):

Dock Measurements

1. length and width of total dock.

2. shape of dock

3. orientation of dock

4. if present, length and width of grated decking

5. material used to build docks

6. number of boat slips and lifts

7. size and draft/displacement of boats (pending presence of boat)

8. age of dock (if information can be obtained)

Physical and Plant Parameters

9. braun-blanquet value of all seagrass and macroalgae species along transects

10. sub-sample Leaf Pair Counts

11. water depth at beginning and end of dock (tidally corrected)

12. secchi depth

13. light (pending permission to install data loggers)

14. temperature

15. salinity

Transects

At least three transects will be done perpendicular to the dock to include the dock itself and associated vessels.

Length of transect will depend on dock configuration and associated vessel moorings. 

Distance apart will vary depending on footprint of the area.

This design applies to all docks, with or without grating and whether or not they have been built yet. Transects will be done in area where construction is proposed if the dock has not yet been built.

Links

Click here for Dock Study Power Point

Click here to view the Key for Construction Conditions for Docks or Other Minor Structures Constructed in or over Johnson's Seagrass

Click here to view the Dock Construction Guidelines in Florida for Docks or Other Minor Structures constructed in or over Submerged Aquatic Vegetation (SAV), Marsh or Mangrove Habitat

Click here to view the SAJ-42 Regional General Permit

Dock Study EndNote Library

Dock References