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Vessel Grounding Management at Lignumvitae Key Botanical State Park. Lignumvitae Key Submerged Land Management Area (LKMA). Vessel Damage:. Results in scars, blowholes and trenches on grass beds, directly removes seagrass and coral, increases erosion and turbidity causing more seagrass loss.
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Vessel Grounding ManagementatLignumvitae Key Botanical State Park Lignumvitae Key Submerged Land Management Area (LKMA)
Vessel Damage: • Results in scars, blowholes and trenches on grass beds, • directly removes seagrass and coral, • increases erosion and turbidity causing more seagrass loss
EROSION DEEPENS AND WIDENS A BLOWHOLE LOSS OF ENTIRE FLAT OVER 137 ACRES OF SEAGRASS DAMAGE WAS VISIBLE ON 1997 AERIAL PHOTOGRAPHY OF LIGNUMVITAE MANAGEMENT AREA EROSION, LOSS OF ADDITIONAL GRASS
Four point management approach at Lignumvitae: • Education • Channel Marking • Enforcement • Limited-Motoring Zones
On-Site Restoration • Attempts to repair the most severe sites, • The following techniques are used: • fill for trenches and blow holes • seagrass transplants • temporary bird fertilization stakes to jump-start growth
This site was originally a twin propeller scar. It eventually eroded into a wide, deep trench. It was filled to stop further erosion and further loss of seagrass. The ultimate long-term goal for this site is recovery to seagrass habitat. Note the “no-motor” sign posted along the channel adjacent to this site to warn boaters.
Recovery of seagrass within grid setting of bird fertilization stakes on a heavily scarred flat (dark rectangles in the circle). Bird fertilization stakes in a newly restored site.
Costs of Restoration (2005) Filling • About $250 per cubic yard • Sites generally require 15 to 300 cubic yards of fill. Staking and Planting • About $35 per single stake and plant unit • Sites generally require from 25 to 200 units
SUCCESS OF RESTORATION • GOAL OF ARRESTING EROSION HAS BEEN 100% ACHIEVED ON ALL SITES. • GOAL OF RESTORING SEAGRASS HAS HAD MIXED SUCCESS DEPENDING ON THE SITE AND GENERALLY REQUIRES A LONG PERIOD OF TIME (OVER 2 YEARS).
When YOU Go Boating, Why Not: • Take a look at your chart for a minute before you leave, • Don’t be afraid to ask the locals for advice if you’re unfamiliar with the area, • If you’re out and about and not sure about the markers, slow down for a minute and be sure. What’s the hurry? • Save yourself, the environment, and the government some time and money by avoiding grounding when you can. • THANK YOU AND HAPPY BOATING!