Showing posts with label dunes. Show all posts
Showing posts with label dunes. Show all posts

Sunday, February 11, 2018

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 Environment Marine

Energy from the Sands of Time
The platform that you can see east of Dauphin Island is operated by ExxonMobil, one of many oil companies operating in Alabama waters. These platforms are extracting natural gas (methane), a clean-burning petroleum product. The platform itself lies in 11 feet of water, with dripping operations to depths of over 20,000 feet. Once natural gas is found and brought to the surface, it is transferred via an underwater pipeline to processing plants on the mainland. 
These photographs demonstrate the porous quality of sandstone, which is millions of years old. Ten percent of the sandstone volume is natural gas, compressed within these. 
Pores to a pressure between 10,000 and 20,000 pounds per square inch. 

The natural gas field found within Mobile Bay and the Alabama Water is the largest field discovered in the continental United States. Concerned citizens, scientists, and state regulators worked with the oil companies to implement an environmentally safe, clean operation with a zero-discharge policy. This policy prohibits the discharge of drilling fluids, petroleum products, and treated sewage from the platform into state waters. Instead, these materials are offloaded and taken to the mainland for proper disposal. 

Mr. Sand and his friends Part II
The grains collect and grow into dunes. Even as they grow, they move as the wind blows them. 
Shifting and growing, the dunes stabilize once dune grasses, like sea oats, start sprouting on them. The plant's roots help anchor them, encouraging further dune growth. And the more due growth, the more plant growth —- a friendly relationship.
These stabilized dunes attract even more plants, like wax myrtle, yucca, and, eventually, the majestic live oak. 
These rooting plants add moisture and shelter and promote even more plant colonization. 
More and more animals are attracted to plant growth, from plant-eating insects to insect-eating beach mice to owls. Hawks and raccoons.
Thriving with plant life, a dune will continue to grow. 

But the bigger it gets, the more exposed it becomes to aeolian (wind) and marine (water) forces, like erosion. 

Mr. Sand and his friends, Park III
During the autumn and winter storms, the sand will be blown offshore. Someday, they’ll be carried back onshore to build new dunes. 
So, as the seasons change, do the dunes. In the spring, with gentle wind and waves, sand heaps onshore, forming new dunes. In the summer, sea oats and plants help them grow. In the stormy winter, the dunes erode (wear down).
Susceptible to strong onshore winds, Mr. Sand and his friends have a tendency to move inland, covering everything in their path. 
We need to help Mr. Sand and his friends by not walking or driving on the dunes. Many places have boardwalks built over the dunes and plants to protect them. 
Along with boardwalks, sand fences are another way of protecting dunes, serving as obstructions so the grains can collect and form new dunes. Planting grasses like sea oats can also help in exposed areas and along pathways. 
These conservation practices can only help if we cooperate. Mr. Sand and his friends, along with the forces of nature, form dunes and beaches for you to enjoy. 

Let’s take care of them in the future. 

Mr. Sand and his friends Part I
Come let Mr. Sand guide you through the life of a dune. Learn how to protect the sand dunes, Mr. Sand, and his friends who live with him. 
Once upon a time, about 250 million years ago, bedrock was formed. The hot molten rock formed granite and emerged as the Appalachian Mountains. As the granite and other rocks eroded from the mountains, they formed grains of sand. This sand washed down to the Gulf of Mexico and was deposited onto beaches and dunes, which are now underwater. 
Waves and currents washed Mr. Sand away from these old deposits. Mr. Sand and his friends moved up onto the beaches we see now. 
The more Mr. Sand and his friends wash along the beach, the more they wear down. They become rounder and more uniform in size and texture. 
Away from the mainland, underwater mountains of sand grow grain by grain, becoming “offshore bars.” Some can grow so much they emerge above sea level and become “barrier islands.” 
Dry grains of sand are susceptible to wind, drifting until the wind speed drops.

Once Mr. Sand and his friends land, they collect on the “lee,” or sheltered side of obstacles along their flight path.
Marine Debris: A Silent Killer
Marine debris Timeline
What is marine debris?

.Marine debris is the name given to trash that liters our coasts and oceans.
It includes all the objects found in the marine and coastal environments that do not naturally occur there. Marine debris is not only a hazard to ships, divers, and beach-goers, but it also creates a serious threat to our precious marine life. 

.Marine debris consists of articles that have been made by people and deliberately discarded or accidentally lost. In most cases, it is the result of careless handling or disposal of items of solid waste, including containers of liquid waste. However, it can also be materials lost at sea in bad weather, like fishing gear and cargo.

.Marine debris consists mostly of snowy degradable waste items made of persistent materials such as plastic, polystyrene, metals, and glass from a large number of different sources.
(thrown or lost into the sea): brought indirectly to the sea with rivers, sewage, stormwater, or winds: left by people on beaches and shores. 

Where is marine debris found:
. Marine debris is found everywhere around the world, in marine and coastal environments.
.Marine debris can be blown around and is found floating on the water's surface. Almost 90% of floating marine debris is plastic. 
. Marine debris is found mixed in the water column, from the surface to the bottom of the ocean.
.Marine debris is found on the seabed. It could be that as much as 70% of all marine debris sinks to the bottom of the seabed, both in shallow coastal areas and deeper parts of the ocean. 
.Marine debris is found lying on beaches and shores. 

How does marine debris harm wildlife?
. Entanglement 
Common items like fishing lines, strapping bands, and six-pack rings can hamper the movement of marine animals. Once entangled, animals have trouble eating, breathing, or swimming, all of which can have fatal results. Plastics take hundreds of years to break down and may continue to trap and kill animals year after year. Smaller marine creatures get stuck inside plastic and glass containers to die a slow death. 
Ingestion
Birds, fish, and mammals often mistake plastic for food. Some birds even feed it to their young. With plastic filling their stomachs, animals have a false feeling of being full and may die of starvation. Sea turtles mistake plastic bags for jellyfish, one of their favorite foods. Due to its durability, buoyancy, and ability to absorb and concentrate toxins present in the ocean, plastic is especially harmful to marine life. 
Other threats to wildlife 
The smothering of the seabed, accumulation, and dispersion of toxic substances, environmental changes due to invasive species, and habitat disturbances due to mechanical cleaning of marine debris. 

How does marine debris harm people?
.Contamination of the beaches and harbors creates health hazards to people

.Marine debris also endangers the safety and livelihood of fishermen and recreational boaters. Nets and monofilament fishing lines can obstruct propellers, and plastic sheeting and bags can block cooling intakes. 

Where am I?
Dauphin Island is at the junction of Mobile Bay, Mississippi Sound, and the Gulf of Mexico. Dauphin Island is the easternmost in a series of changing barrier islands, which form the southern boundary of Mississippi Sound. 
Mobile Bay is 53 kilometers (35 mi) long, 16 kilometers (10 mi) wide, and averages 3 meters  (10ft) deep. The bay is a drowned river valley, which at one time was deeper and extended farther north. About 6,000 years ago, the Mobile-Tensaw River Delta formed as Mobile Bay became wider and shallower. Mobile Bay has the seventh-largest river discharge in North America (219 to 13,977 cubic meters per second or 5 to 322 billion gallons per day) and is the third-largest in the Gulf of Mexico. 
Most of the ocean waters that enter the Gulf of Mexico come through the Yucatan Channel between Mexico and Cuba. 

These waters form circling currents that move across the continental shelf and mix with the freshwater from the land. The water exits the Gulf of Mexico through the Straits of Florida between Florida and Cuba. 
Life in a Salt Marsh
A real partnership 
The important grasslike plants of Coastal Alabama salt marshes are Black Needle rush and Smooth Cordgrass. They provide oxygen to organisms that live below the salt marsh surface and refuge for many animals. 
Decomposing plant matter in an environment without oxygen produces the “rotten egg” odor familiar to marshes. However, Cordgrass and Needlerush root systems are very spongy and porous, allowing oxygen into the waterlogged soil. This allows the survival of organisms below the surface of the marsh. 
Fiddler Crab (Uca  spp) 
Fiddler Crabs and other small mud crabs burrow into the marsh surface, feeding on the plant matter. Their aquatic larval stages contribute significantly to the food chain.
Smooth Cordgrass (Spartina alterniflora)
Smooth Cordgrass forms a border along the edge of the open water, below the average high tide line. Cordgrass has flattened leaves and a light green color. 
Black Needlerush (Juncus roemerianus)
The Black Needlerush comprises the largest vegetated zone of Alabama’s salt marshes and is found near and above the average high tide line. 
Needlerush leaves are round with pointed tips. 
Marsh Periwinkle (Littorina irrorata)
The Marsh Periwinkle is a small snail inhabiting shallow bays, ponds, and tidal marshes. It is often seen climbing and Spartina stalks to feed on algae and avoid predators. 
Ribbed Mussel (Geukensia demissa)

The Ribbed Mussel attaches to mature plants at the mud surface and hardens the marsh. This helps resist erosion. These mussels filter a gallon of seawater an hour for food, fertilize the marsh with their waste, and are food for crabs, birds, and mammals. 


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