Wednesday, March 31, 2010

The Wildlife Forecast - Raking the wrack wrecks coastal wildlife’s home



By Patricia Behnke
Florida Fish and Wildlife Conservation Commission

Raking the wrack wrecks coastal wildlife’s home

What is brown, teeming with life and raked off our beaches frequently? You may be struggling with an answer if the beach you frequent in Florida receives a clean sweep of all debris – both human-made and natural – before you put one big toe on the sand.
Beach wrack is the answer, and it is necessary to beach life, just as air is necessary to breathing. So why is it destroyed before the beach lovers hit the coast? It’s not sexy. Or at least on the surface, it’s not.
But that brown clump of seaweed teems with life and provides food and shelter for many animals that feed upon it. Beach wrack may not look like it, but it’s a pivotal part of the beach ecosystem. Yet, many beach lovers have never had the chance to ponder what lies beneath the surface.
“Local governments allot large amounts of money to beach raking every year,” said Nancy Douglass, a biologist who monitors shorebirds for the Florida Fish and Wildlife Conservation Commission (FWC). “They do that because they are under the assumption everyone wants it done.”
But do we really want that? Do we want to take away a source of food for already stressed shorebirds pinched by sea level rise on one side and development on the other? Before answering those questions, take a stroll through Beach Wrack 101 with me to learn more.
Beach wrack consists of seagrass and marine algae mixed with shells, sand dollars, starfish, tiny shrimp, driftwood, sponges, coral and other biotic treasures that have drifted at sea before washing ashore, especially after storms. After landing on dry land, beach wrack becomes host to a diverse cast of insects and other tiny invertebrate animals, such as jumping beach hoppers, which are harmless rice-sized crustaceans. The tiny animals, in turn, serve as food for many other creatures.
Migrating shorebirds fly thousands of miles each year to munch on the nutritious meals found in that clump of seaweed.
Wrack also provides a safe haven for many animals that escape predators by hiding under it or by blending in with it. A shorebird can “disappear” while napping among the similarly colored shades of seaweed browns and grays.
Beach wrack also is critical to the health of the dunes by providing plant nutrients and stabilizing windblown sand. The wrack carries seeds from many dune plants, such as beach morning glory and sea rocket. As sand builds up and the seeds within the beach wrack take root, new dunes grow.
On some beaches, the sand is machine-raked; new dunes are manicured away; and the wrack is removed. These efforts cost taxpayers, but there is a price paid by the beach system as well. A natural wrack line is a key component of a healthy beach ecosystem.
“While a natural beach may not look as manicured as a raked beach, the diversity and richness of a natural, functioning beach is infinitely more interesting than the sterile landscape of one that is groomed,” Douglass said. “We can strengthen the health of habitats that are already being pinched by leaving more wrack so beaches can support migratory and wintering birds that use the wrack for both food and cover.”
However, Douglass cautions that stopping the raking of beaches alone is not a panacea for what is inevitable in Florida. Sea level rise is squeezing an already narrow, linear habitat that is limited even under the most natural of conditions. Unfortunately, shorebirds are being pinched between rising water levels and a solid line of roads and buildings in the most congested areas. Combined with sea level rise, beach habitat becomes an even narrower corridor for wildlife. And raking those narrow corridors creates sterile beaches that are not friendly to wildlife.
“In the short term, we can’t move the condos, and we can’t stop sea level rise,” Douglass said. “But we can try to be more responsible in how we manage our beaches. Stopping the removal of beach wrack will serve as a stopgap measure for shorebirds that are in trouble now. Individuals can contribute by making their voices heard in the community.”
Douglass suggests that folks voice their opinions about how their beaches are managed to community leaders and beach businesses, as well to the tourist councils that may encourage raking the beaches to attract visitors.
Wildlife needs the wrack, but there are other benefits. Wrack provides a line of protection for structures during tropical storms by lessening the impact of storm surge. It also saves municipalities money and lessens our carbon footprint by keeping those big machines off the beach.
Maybe that makes beach wrack sexy after all.
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Contact Patricia Behnke at pat.behnke@myfwc.com.

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