Texas Parks & Wildlife Magazine   


Keeping the Seagrass Greener

Dos and don’ts for navigating shallow coastal waters.

By Dan Oko

When Texas Parks and Wildlife biologist Dennis Pridgen starts talking about seagrasses, it’s immediately obvious that Gulf Coast sport fish need this aquatic vegetation as much as Longhorn cattle need range grass. Despite a minor outcry last year over rules that currently outlaw the destruction of seagrasses in the state’s 32,000-acre Redfish Bay Scientific Area, many conservation-minded recreationists are coming to understand that seagrass protection in Texas helps improve fish habitat. That, in short, improves the fishing — and makes learning how to navigate the shallow seagrasses along the length of the Texas Coast a useful way for anglers to help care for the valuable bay ecosystems they depend upon.

“For the lifecycle of many marine organisms, seagrass provides everything,” explains Pridgen. “For fish, it’s the nursery, the grocery store and the roof over their heads.”

There are five species of seagrass found from Galveston Island to the Lower Laguna Madre, and because they present a resource linked to both recreational and commercial fisheries, these aquatic meadows see a lot of boat traffic. In terms of damage, the easiest to identify, according to Pridgen, are prop scars that boaters sometimes leave behind, which in the worst cases stretch more than a mile. “Anytime you get into a grass flat, you have the potential to get into water that is too shallow for your boat,” he warns.

Pridgen provides much of his best advice in pithy sound bites, such as “Run to the grass, not through it.” For the past year and a half, the biologist has been part of a TPWD team “breathing, eating and sleeping seagrasses.” He adds that beyond habitat concerns, potential damage to pricey propellers and outboard engines should give pause to boaters who might otherwise flout the following strategies for promoting seagrass protection.

  1. Know your depth; know your boat. Most fishing maps of Texas bays show general water depths, and there’s really no excuse for not carrying a chart of the area you intend to explore, whether fishing or just out boating. Furthermore, depths can change a foot or more depending on the tide, so in addition to a map, make sure that you not only know what daily tide charts say for where you are headed, but also how they may match up with the sometimes-delayed tides seen along barrier islands. Likewise, it may take additional experience before boat owners fully understand the draft of their craft. It takes practice to be able to discern the differences between when the boat is on plane, going slowly or idling. Pridgen offers this advice: Have someone get out, measure water depth and mark it on the hull, then keep track of where this marker shows at various speeds.
  2. Watch your wash; keep your head. “If there is no evidence of mud turbidity or — heaven forbid — vegetation, you’re running clear,” says Pridgen, who likens prop wash to a car speedometer. Keep an eye on it, in other words, and if you are not trailing sediment, your depth is all right. Muddy wash behind the boat, however, indicates a problem. You could even run aground. If the water is sullied, especially in unfamiliar areas, it’s best to cut the engine and check water depth. In addition to sustaining fisheries, this is an effective way to protect your prop and keep unwanted sediment out of the engine’s water intake.
  3. Lift and drift, pole or troll. When you do find a fishy-looking grass bed, turn off the engine and lift or tilt it. Let the boat drift (a drift anchor slows things down and does negligible damage), use a pole to maneuver the shallows or start up your trolling motor.

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