Raking the wrack wrecks coastal wildlife's home
The Wildlife Forecast
Thursday, April 01, 2010
Media contact: Patricia Behnke
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.