INTRODUCTION TO ECOLOGY THROUGH THE STUDY OF ESTUARIES:

From the largest landscape features to the smallest microscopic organisms, an estuary is a fascinating place. When viewing an estuary from the air, for example, one is awed by striking river bends as freshwater finds its way back to the sea, the vast expanse of marsh grasses, mangroves, or mudflats, extending out into the calm waters, or perhaps the elegant curve of an expansive barrier beach. Wherever there are estuaries, there is a unique beauty, as rivers meet the sea, and both ocean and land contribute to a unique ecosystem of specialized plants and animals.

At high tide, seawater changes estuaries, submerging the plants and flooding creeks, marshes, pannes, mudflats, or mangroves, until what once was land is now water. Throughout the tides, the days, and the years, an estuary is cradled between outreaching headlands and is buttressed on its vulnerable seaward side by fingers of sand or mud.

Estuaries metamorphosize with the tides, the incoming waters seemingly bringing back to life organisms that have sought shelter from their temporary exposure to the non-aquatic world. As the tides ebb, organisms return to their protective postures, receding into sediments and adjusting to changing temperatures and exposure to differing degrees of sunlight and different kinds of weather.

Flocks of shorebirds stilt through the shallows, lunging long bills at their abundant prey of fish, worms, crabs or clams. Within the sediments, whether mud, silt, sand, or rocks, live billions of microscopic bacteria, a lower level of the food web based largely on decaying plants.

Estuaries are tidally-influenced ecological systems where rivers meet the sea and fresh water mixes with salt water.

Estuaries provide:

HABITAT: Tens of thousands of birds, mammals, fish, and other wildlife depend on estuaries.

NURSERY: Many marine organisms, most commercially valuable fish species included, depend on estuaries at some point during their development.

PRODUCTIVITY: A healthy, untended estuary produces from four to ten times the weight of organic matter produced by a cultivated corn field of the same size.

WATER FILTRATION: Water draining off the uplands carries a load of sediments and nutrients. As the water flows through salt marsh peat and the dense mesh of marsh grass blades, much of the sediment and nutrient load is filtered out. This filtration process creates cleaner and clearer water.

FLOOD CONTROL: Porous, resilient salt marsh soils and grasses absorb flood waters and dissipate storm surges. Salt marsh dominated estuaries provide natural buffers between the land and the ocean. They protect upland organisms as well as billions of dollars of human real estate.

Estuaries are crucial transition zones between land and water that provide an environment for lessons in biology, geology, chemistry, physics, history, and social issues.

Examples of the Estuarine Ecology document: Main body and Reference Section.

---

Please return to the Estuary-Net Home Page if you wish to request more information about the Estuary-Net Project.

---

Estuary-Net Home Page | Information On Estuaries | Estuarine Ecology Water Quality Monitoring | Data Management | Quality Assurance Project Plan Sample Curriculum Activities | Data Directory | Complete Curriculum