BoatUS ANGLER: RecycledFish Stewardship Tips

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Seagrasses are grass-like, flowering plants that live completely submerged in marine and estuarine waters.  Found throughout coastal areas in the Gulf of Mexico, seagrasses help maintain water clarity by trapping fine sediments with their leaves and stabilize the bottom with their roots and rhizomes. 

Seagrasses also provide shelter for fishes, crustaceans, and shellfish.  They protect juvenile drum, sea bass, snappers, and grunts from larger predators.  In many areas, such as Redfish Bay in Texas, seagrasses are the reason that there are good fish populations.

Seagrasses, though, are in decline.  In 1950, Florida had over 5 million acres of seagrasses.  Today there are only 2.2.  Coastal construction and dredge operations have dug up many seagrass beds.  Shoreline stabilization projects have redirected and intensified currents.  This often results in erosion or sediments being dumped on seagrasses.

Prop scars, trenches cut into the seagrass bed by boat propellers, are also responsible for the decline of seagrasses.  Prop scars heal at various rates depending on the species of seagrass and they type of sediment on the bottom.   A scar in a sandy shoal grass flat may heal in about a year.  Scars in turtle grass make take up to seven years.  Scars that channel currents can erode and widen; they may never recover.

As boaters, we can help to prevent prop scars.  The Florida Department of Environmental Protection has issued the following guidelines:

  • Familiarize yourself with the local waters where you plan to boat.
  • Always use up-to-date nautical charts of the area.
  • Use marked channels where they exist and stay in deep water.
  • Remember this jingle..."Brown, Brown Run Aground; White, White You Just Might; Blue, Blue Sail on Through; Green, Green Nice and Clean". 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.
  • When in doubt about the depth, slow down and idle. Make sure the bow of the boat is down and the motor is trimmed or tilted up.
  • Keep track of the tides. The greatest range of tides (shallowest and deepest water) occurs during a full moon and new moon. Use extra caution when boating on a low tide.
  • If you do run into a seagrass flat, you will be leaving a sediment trail behind your boat, making the water murky and probably cutting seagrass roots. Stop immediately and tilt your engine.

Prop scars adversely impact seagrasses unnecessarily.  We can control that impact.  Always remember to study your charts, read the waters, and know your depth and draft.

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