Alabama Coastal Connection, Wetland Birds, Dunes, Barrier Islands & Butterflies

Wetland Birds

The tidal marshes of Alabama feed a rich bird community. The newly created salt marsh is a prime feeding habitat for herons, egrets, pelicans, terns, sandpipers, and blackbirds. As the arch matures, the diversity and abundance of birds will increase. 

At least Sandpiper (Calidris minutilla) 

The marsh at low tide brings sandpipers moving in unison across the wet sand areas. 

Snowy Egret (Egretta thula), American Egret (Casmerodius albus), Great Blue Heron (Ardea Herodias)

The Snowy Egret, American Egret, and Great Blue Heron feed on fish and invertebrates from the marsh. 

Least Tern (Sterna antillarum) 

The open sand dune area provides primary nesting sites for the Least Tern, which have been threatened with habitat loss.  

Brown Pelican (Pelecanus occidentalis)

Old pilings in the water provide a resting site for Southern Brown Pelicans, which once were near extinction in this area. 

Ruddy Turnstone(Arenaria interpres)

Cruising along the rock is the Ruddy Turnstone. This bird turns over oysters and clam shells in search of food. 

Black Skimmer (Rynchops niger)

Gifted with a graceful wing beat and beautiful coloration, the Black Skimmer grazes along the surface of the water in search of fish.

The large (Phragmites) to the East of the marsh are utilized for nesting by Red-Winged Blackbirds and Boat-tailed Grackles. 

Boat-tailed Grackle (Quiscalus major) Red-winged Blackbird (Agelaius phoeniceus)

Barrier Islands

Shaped by Wind and Water

Sea levels began rising 18-20,000 years ago, moving sandbars toward the mainland. The rate of rise slowed 6,000 years ago, allowing the sandbar to emerge as the present barrier islands. 

The dune land plants stabilize the wind-blown sands, building ridges and mounds called dunes in the highest areas of the beach, dunes are very important because as a storm attacks a beach, water and gravity roll the sand downhill away from the dunes. 

This builds up an offshore sandbar, absorbing energy from the waves of the storm and protecting what is left of the beaches and dune lands. 

After the storm, the offshore bar provides sand for rebuilding the beach. 

Barrier islands perform two functions:

1. Barrier islands protect the mainland from erosion by absorbing much of a storm’s energy. 
2. Barrier islands trap a mixture of fresh and salty Gulf waters, contributing to the formation of estuaries. Coastal seafood species are dependent upon the abundant food and brackish water habitat the estuarine environment provides

Alabama Coastal Connection

Dune Plants survive in a harsh environment.

Adaptation allows plants to survive salt and freshwater flooding, extreme high and low temperatures, and hurricane-force winds. 

These plants reproduce from cuttings created by storms and wave action. They all rebuild the beach and dune system by trapping wind-b town sand. 

Sea Rocket (Cakile constricts)

A common succulent found just above the high tide line, Sea Rocket has thick fleshy leaves to help conserve water.

Large leaf Pennywort (Hydrocotyle bonariensis)

A creeping perennial that spreads by far-reaching underground stems, Pennywort grows to about 6 inches tall and has clusters of tiny white or pale-green flowers on a 3-inch stem. 

Coastal Panicgrass (Panicum amarulum)

A dense, upright perennial bunchgrass, Panicgrass helps anchor the shifting sands with deeply buried root systems.

Sea Oats (Uniola paniculata)

As the most important and widespread grass on southern coastal dunes, the Sea Oats' recovery following storm impact is the first step in dune rebuilding. 

Morning Glory (Ipomoea stolonifera)

This vine, with trumpet-shaped, white flowers, grows low to the ground, escaping the killing effects of salt spray. The stems may extend over the sand surface for 30 to 50 feet. 

Butterflies of Dauphin Island 

Dauphin Island Marsh and Wetlands

Whether the Weather

Look for the weather station seen in the photo below. It is maintained by the Dauphin Island Sea Lab, along with several others in and around Mobile Bay.

What does this Station Measure?

Atmospheric measurements:

>air temperature

>relative humidity

> Wind direction and speed

>air pressure

>solar radiation

>precipitation

Underwater measurements:

>water temperature

>water level

>salinity

>dissolved oxygen

>chlorophyll

>turbidity

How is the Data Used?

These data can be used in many different ways. Here are just a few examples: Researchers at Dauphin Island Sea Lab might use them to better understand phenomena such as low-oxygen events that result in fish kills in Mobile Bay. Climate scientists might input the data into a model that will predict sea level rise. It might be used to analyze hurricane strength as the storm passes the station. 

Who is NOAA?

“NOAA” stands for National Oceanic and Atmospheric Administration. The U. S. Government formed this scientific agency in 1970. It has many responsibilities, including research into Earth’s weather, climate, and oceans, issuing daily weather forecasts and severe storm warnings, and providing citizens, planners, emergency managers, and policymakers with reliable information when they need it. Some NOAA offices that you may be familiar with include the National Weather Service, the National Marine Fisheries Service, and the National Ocean Service.

What is a Computer Model?

You might be familiar with weather or storm prediction models that are used by the forecasters on your local news stations. Computer models are algorithms that use the measured data to make simulations of systems. The simulations might make predictions or illustrate predictions that have already happened. 

The speed at which computers can process numbers has made the use of models possible on a practical level. Accuracy depends on the quality of understanding of natural processes in different systems, and algorithms of simulating systems are all improved. The more data that goes into a model, the more precise it can be. 

The image below left shows a computer model’s prediction of storm surge from Hurricane Ivan. 

This kind of prediction is used to issue warnings to residents of areas that are expected to flood. 

The image below the middle shows the measured track of Hurricane Ivan. Its landfall was 30 miles east of what was predicted. One major limitation forecasters have to work with is incomplete data coverage, especially over the oceans. Much of the needed data is only collected by data boys at a few points on the surface of the ocean. 

The image below right was created with measured data, not to make a prediction but to illustrate the actual storm flooding from Hurricane Ivan.

Invertebrate Trail 

The invertebrate trail is an action based on the award-winning Public Broadcasting system series  “The Shape of Life.”

These plaques represent 8 different Phyla, or groups of invertebrate animals with specific body plans, from simple to complex. Each phylum appeared in the oceans during the Cambrian Period, about 530 million years ago. These plaques are designed so that students can make a rubbing of each one to study in the classroom.

The Living Marsh 

Dedicated to the Memory of Beth Ladner; 1974-1991

“ A Teacher’s Friend” Discovery Hall Student 1985, 1989, 1990

Research on March Restoration at Dauphin Island Sea Lab

Salt marshes are among the most productive ecosystems on earth.

They provide food, refuge, and user habitats for many animals, filter runoff that drains into our coastal waters, and buffer our coastlines from damaging storm surges. Salt marshes are declining at an alarming rate due to coastal development and erosion brought on by environmental stress.

The devices installed in the Living Marsh are called flume traps. They are part of a study designed to determine how closely the ecology of this created marsh mirrors that of a natural marsh also located on Dauphin Island (above). The flume traps sample animals that enter the vegetation to forage and hide from predators. 

Flume traps allow the animals to enter the marsh vegetation as the tide rises (A, Above center). The trap is closed at high tide (B), and as the tide goes out, fish, crabs, shrimp, and other animals are collected in the net. 

We then identify and count the animals we catch in the created marsh and compare them to the animals caught in the reference marsh.

We also compare the animals that live in the mud and among the roots of the marsh grass by taking cores from the marsh bottom (below). These small animals, many of which require a microscope to see, including worms and small shrimp, burrow into the sediment. 

We also compare how the animals interact with each other in the retired and natural marshes. We are particularly interested in how intensely blue crabs feed on marsh periwinkles (see below) We teeter snails to the bases if marsh-grass shoots at each marsh and allow crabs to attack and eat the bait during a set period. We also compare the number of repaired shell cracks (signs of failed attacks by crabs) in the snail populations at each site. This allows us to compare how intensively crabs are using resources in the marsh. 

We hope this research will help us understand how new marshes develop over time and what we can do to help newly created marshes provide all of the benefits of natural salt marsh habitats. 

Above: Periwinkles climbing on marsh grass

Upper Right: Blue crab

Right: Snail tethered to marsh grass and (inset) shell scar inflicted by the blue crab. Marked by the arrow.