Salt marshes

Rebecca AxelssonMathias LudvigssonLinn JohannessonRobin ListerbergViktor PetterssonAndreas Grömlund

BABORDS VAKTApril 2009

Introduktion• Objectives of the presentation• Theoretical background• Material and methods and zoon of

study• Results and discussion

Theoretical background

• Estuaries are partially enclosed coastal regions where fresh water from rivers meets and mixes with seawater

Salt marshes are dominated by cordgrasses, mud and other marsh plants

• The dominant primary producers on mudflats are diatoms and bacteria. Most of the animals are burrowing deposit and suspension feeders that feed on detritus.

Theoretical background

• Estaurier can be made in 4 different ways. The name of them are: drowned river valleys, bar-built, tectonic and fjords

• The first one is called Drowned rivervalleys and they are the most common type of estuaries. They were formed when the sea level rose because of the melting of ice at the end of the last ice age, about 18000

years ago. The sea invaded lowlands and river mouths in the process.

• The second type of estuaries is the bar-built estuary. Here the accumulation of sediments along the coast builds up sand bars and barrier islands that act as a wall between the ocean and fresh water from rivers.

• One of the other estuaries were created when the land sank, as the results of movements of the crust. These are called tectonic estuaries.

• The last type of estuaries are called fjords and they were created when retreating glaciers cut deep, often spectacular, valleys along the coast. The valleys were partially submerged when sea level

rose, and rivers now flow into them.

Material and methods and zoon of study

• The materials we used when we researched the litoral zone were bags, riverpants, plastic waterscope and cameras

• We walked around in the saltmarsh and looked for organisms and different effects on the marsh.

• The place were we went researching was a saltmarsh in Charleston

Results and discussion• We saw organisms who used different

strategies to survive in special areas.

A strategy that was used was a crab hiding beneath a stone, to protect itself against dehydration and land predators that can be able to eat them when the tides running low.

Results and discussion

Another strategy that a clam was using was to close itself to keep water inside to not dry out. The clam had some kind of a root that kept it in place when abiotic factors like waves and tides were affecting the clam.

Short summery

Sources

• Marine Biology, Peter Castro, Michael E. Huber. 2007. Published by The McGraw-Hill companies inc.

• Havet, Fabien Cousteau. 2007. Published by Globe Förlaget.