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July 2010 cover image 12 Why Water Matters

Marine Meadows

Seagrass helps anglers, but they must handle it with care.

By Kathryn McGranahan

Imagine a meadow of long, flowering plants, waving gently in the breeze. Imagine the intricate ecosystems that call this meadow home — various animals flitting through, their young trailing behind them in the sunshine. Now imagine it all underwater.

Seagrass, one of Texas’ essential aquatic natural resources, is getting some conservation attention. Protecting seagrass means protecting a wide range of wildlife dependent on these marine meadows. The five species of Texas seagrass — widgeon, turtle, manatee, star and shoal seagrass — are found in shallow waters in the higher salinity parts of Texas bays and estuaries. The location makes seagrass a marine life backbone: It is shelter, nursery and food all in one for many different species. But seagrass isn’t just about sustaining ecosystems; it also sustains nutrient cycling, improves water quality, naturally decreases coastal erosion and provides some of the best angling around.

Unfortunately, it’s the angling that hurts seagrass. Propeller scars, or “prop” scars, form when propellers cut the roots and leaves of seagrass plants. This damage leads to bare-bottom exposure, which leads to coastal erosion, which leads to more floating sediment, which increases turbidity and decreases seagrass access to sunlight. Depending on wave action and other elements, prop scars can take several years to heal.

It’s a vicious cycle the Texas Parks and Wildlife Department hoped to stop when it created Redfish Bay State Scientific Area, a 32,000-acre area near Port Aransas, in 2000. Results from a study conducted in 1997 showed moderate to severe seagrass scarring throughout the vegetated areas of the bay.

When voluntary compliance with no-prop zones proved ineffective, TPWD decided to take further action. In 2006, the Texas Parks and Wildlife Department made it illegal to uproot seagrass in Redfish Bay. Waterproof brochures, signs at boat ramps and other educational outreach efforts heightened boater awareness of seagrass functions and regulations.

Meanwhile, aerial photographs and field studies were used to monitor a scar road map. “We found a 45 percent decrease in the average number of scars from 2005 to 2009,” reports Ed Hegen, regional director for the lower coast in the Coastal Fisheries Division. Research even showed healed scars, he said, “giving us needed information on scar recovery.”

Area boaters also reported positive results in a recent mail-out survey. “Eighty-seven percent modified behavior to protect seagrass, like using a pole or a trolling motor and looking at tide depth at boat ramps before launching,” says Hegen.

This solution is easy: lift your motor, drift your boat, pole your boat through or troll your motor. If your boat has a muddy wake, your propeller is too close to the bottom. “Run to the flats, not through the flats,” suggests the TPWD website.

This year, the seagrass regulation is up for renewal. Hegen is confident the results speak in the seagrass’s favor. They also speak to boaters’ responsibility and awareness: “They get all the accolades,” he says. “They’ve accepted it, and are abiding by the regulation.”

For more information on seagrass or the Redfish Bay State Scientific Area, visit www.tpwd.state.tx.us/seagrass

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