Introduction to the Barrier Island Ecology of the Texas Coast

The University of Texas at Austin Marine Science Institute

• located on the northeast corner of Mustang Island

• facilities include: classrooms, library, research laboratories, and two large research vessels

Marine Education Visitor’s Center

RV Katy

What is Marine Biology?

...the study of the function and ecology of marine life.

• how organisms carry out their basic functions

• interaction of organisms and their physical and biotic environment

Ecology is studied at many interacting hierarchical levels.

Biosphere Ecosystem Community Population Individual

Physiography and Geology• young, dynamic system of barrier

islands

• shaped by prevailing southeasterly winds

• mostly 20-50 ft above sea level

• Padre is the longest barrier island in North America at 113 miles

General Features Habitats on the outer side barrier

islands:

wave action salinity temperature

Major Divisions of Marine Habitats

Habitats Include:• sand-shell beaches• fore island dunes• stabilized dunes• vegetated barrier flat• wind-tidal flat• lagoon grass flat• Laguna Madre- separates Padre from the Texas mainland

More Habitats & Communities Jetties & Groins Sandy Beaches

Flotsam & Jetsam Offshore Bottoms

Bay Shore: Mudflats Oyster Reefs

Plankton & Nekton

Sandy Beach with Sargassum

Jetties & Groins

the northwestern gulf coast’s only rocky intertidal habitats

crevice habitats splash zone

Jetty

Groin

Sea Wall

Breakwater

Other Jetty Inhabitants

• Rock Louse• Hermit Crab• Sea Urchins

Spartina

Sandy Beaches• abrasive sand• alternating periods of dry and wet• pounding waves

Result: most animals that cannot swim well or crawl fast burrow into the sand.

Sandy Beach and Near-Shore Inhabitants

• tube-building worms• sand dollars• Calico Crab, Hepatus• Purse Crab, Persephona• Spider Crab, Libinia

Tube Dwellers

Flotsam and Jetsam

Organisms are carried ashore from deeper waters offshore.

Offshore Bottoms

• depth up to 200m• commercial shrimping• sediments and shell fragments

provide habitat