Download hardbottom poster4-22-12.indd - Surfrider Sebastian Inlet Chapter

Cities in the Surf
Juvenile fishes
Striped croaker
(Threatened)
Blennies
Juvenile
green turtle
(Endangered)
Sharks
Predatory fishes
Macro-algae
Sponges
Stone crabs
Sea anemones
Juvenile
spiny lobster
Hermit crabs
Mollusks
• Nearshore reefs (nearshore hardbottom) are unique marine
habitats within the surf zone that are often exposed at low tide.
• Most nearshore reefs have a foundation of limestone built upon
by colonies of corals or reef-building worms, which enhance the
species diversity of this shallow-water habitat.
• Inhabitants include a wide variety of invertebrates, fishes, and
sea turtles that cannot live over bare sand bottom.
Sea cucumbers
Sea urchins
Hard sea bottom just off the beach provides
habitat for a unique marine community. This
"hardbottom" consists of limestone with
additional structure created by corals,
sponges, algae, and reef-building worms.
These colonizers vary with sea temperature
and wave energy, giving us several reef
types from the Keys to north Florida.
What is Worm Rock?
Worm rock is made by colonies of the reef-building
tubeworm (Phragmatopoma lapidosa). The soft "rock"
consists of sand grains cemented together with a
protein glue secreted by the worms. The reefs can
grow up to 1½ inches a week in the calm summer,
but they diminish with strong surf from fall storms.
The honeycomb
texture
of a reeftex
building
tubeworm
b
"rock." The
openings allow
the worms to
feed.
• These reefs benefit people by providing shoreline protection from
storm waves, habitat for many seafood species, and recreational
opportunities for those interested in fishing, snorkeling, or
exploring tide pools. Reef breaks also provide great surfing.
• In addition to providing habitat for commercially important
species, nearshore reefs are critical for endangered species like
the green turtle, staghorn coral, and striped croaker.
Hardbottom Diversity
Florida's nearshore reefs are home to more
than a thousand species of marine organisms,
including roughly 520 invertebrate species,
250 fishes, and 300 types of algae. Many
seabirds, wading birds, and sea turtles also
depend on this habitat.
Closeup
view of a reefbuilding
tubeworm's head
showing its
feeding tentacles
A Foundation for Life
Nearshore reefs allow the attachment of many
colonial organisms that would otherwise be washed
away by waves. Soft corals (octocorals), stony corals,
sponges, tube worms, and macro-algae all occupy
these seashore oases.
Many nearshore reefs provide excellent opportunities
for shallow-water snorkeling.
Nearshore Reef Distribution
The Florida peninsula is rimmed with patchy to extensive stretches
of exposed limestone. Colonizers vary from soft corals (octocorals)
to reef-building worms. A relic reef in southwest Florida consists
of intertwined tubes from a gastropod (Vermetid) mollusk.
Threats to Our Nearshore Reefs
• Dredge-and-fill beach nourishment that results in artificially
wide beaches can smother nearshore reefs.
• Fertilizer and runoff from coastal development causes blooms
of harmful algae on reefs.
• Turbidity from eroding artificial beaches and runoff from
coastal development can kill sensitive reef organisms.
• Nearshore reefs are damaged by careless boat anchoring,
debris, and graffiti vandalism.
Patchy
Extensive
You Can Help
• Never pass the opportunity to remove fishing line
and other entangling debris from the beach and
nearby waters.
• To help water quality, eliminate lawn fertilization or
use only small amounts of slow-release fertilizers.
• Learn about the dynamic balance between beaches
and reefs and share your concerns with others.
• Report activities that threaten our reefs. The nearshore
reefs of east central Florida are federally designated
as Habitat Areas of Particular Concern among areas
of Essential Fish Habitat. The Florida Coral Reef
Protection Act provides state agencies the authority
to protect all coral reefs from direct damage.
Coquina and
Limestone
Hardbottom
Worm Rock Reef
Octocoral
Hardbottom
Vermetid
(Gastropod) Reef
INWATER RESEARCH GROUP
• Standing on the fragile worm rock reef can cause significant
damage. Explore tide pools carefully.
A 501 c(3) not-for-profit organization
www.inwater.org
Poster Series No. 3
Copyright © 2012 Dawn Witherington