On a recent fishing trip with Samuel, the Wilderness Calls salt water professional fisherman, I took advantage of the opportunity to observe the seagrass beds in the coastal marine area. I observed a lower number of zigzag patterns on the seagrass flats than I anticipated, considering the ratio between the large numbers of boaters and the small number of prop dredge scars. There are areas the prop dredge scars greatly out number the vessels. Perhaps understanding the essential importance of seagrass habitat and knowledge of damage prevention are contributing factors resulting in the difference.
Seagrasses are submerged, grass-like, plants found in shallow marine waters, such as the shallows of Ocean and Gulf waters, bays, lagoons, and rivers. Seagrasses represent one of the most productive and important habitats in the coastal marine systems. The physical habitats of sea grass purvey an essential part of the marine ecosystem; sea grasses provides sustenance and habitat for various organisms, providing refuge from predators, nursery areas for numerous vertebrate and invertebrate species, stabilizing marine floors, modify sedimentation rates while maintaining water quality, and is esential for the propagation and growth of various species.
There are only fifty species of seagrass in the world; the seagrass community of South Florida is the largest seagrass meadow in the world. The three prominent seagrasses in the Florida Keys are: turtle grass, manatee grass, and shoal grass. Turtles grass covers the greatest area of sea bottom, forming extensive meadows. The name is derived from its appeal to green sea turtles. The round leafed Manatee grass is found in mixed seagrass beds or in small nonspecific patches. Shoal grasses are a colonizing species that grows in disturbed areas where turtle and manatee grasses have been excluded by environmental conditions.
Seagrasses are important species in determining the overall health of the coastal ecosystems due to their biodiversity of sensitivity to changes in water quality inherent in seagrasses. Seagrasses are quite vulnerable to impact of human population growth and attendant forms of human impact, and this has been associated with substantial losses of seagrass!
One human factor upon seagrasses can be noticed, from the air, bridges, and flats boats. It is the zigzag patterns on the seagrass flats. These are prop dredge scars caused by inadvertent or careless boating practices. Damage to seagrass flats from boats is an increasing problem with amateur boaters. I met with the fishing pro division of Wilderness Calls which provided some tips for boating in near shore habitats:
Enroll in boater safety course. (Check with the U.S. Coast Guard Auxiliary in your area for courses)
Learn to read and utilize current nautical charts for the boating area.
Learn to read and utilize current tide charts.
Utilize marked channels when present and be underway in deep water.
Know your depth of draft and remember depth measuring devices are usually mounted in the rear of a boat.
"When in doubt, slow down, bow down, and trim-up"
Shallow water appears very dark to the observer while deeper water appears blue or green Sand covered bottoms appear white and may or may not be deep enough for your vessel to navigate
"Brown, Brown Run Aground: White, White You Just Might; Blue, Blue Sail on Through; Green, Green Nice and Clean"
How do you know if you're prop-dredging and seagrass scarring? If you run into a seagrass flat, you will be leaving a sediment trail behind your boat, making the water murky and probably cutting seagrass roots. Prop dredging and seagrass scarring is an unnecessary impact to the natural resources that you can control.
Boat by the moon, remember, the deepest and shallowest water occurs during new-moon and full-moon. Use extra caution when boating on a low tide during these moons.
It is up to you to preserve and protect our seagrass habitat and the future outlook for costal habitats. So have a happy, safe, and prop-dredge free boating experience!