Tidal Zones and Estuaries

Coastal plain estuaries were formed when...

• Sand bars developed along the coast as a result of an accumulation of sediment

• The ocean invaded lowlands and river mouths

• Retreating glaciers cut a valley along the coast

• The sea level fell during glaciation

In an estuary, the salinity of the water generally increases as:

• Depth increases

• One moves inland

• Depth decreases

• Evaporation Decreases

The most common type of substrate in estuaries:

• Mud

• Rock

• Coarse Sand

• Fine Sand

What is the most important role that estuaries play with regard to the entire world oceanic ecosystem?

• They serve as reservoirs for nutrients

• They are breeding grounds for many marine species

• They are sources of freshwater

• They are buffers against storm surge for man-made structures

Blood rich in hemoglobin is an adaptation to:

• Fluctuating Salinities

• Wide variations in temperature

• Soft sediments

• Low oxygen concentrations

Mangroves belong to which of the following groups?

• Green Algae

• Brown Algae

• Flowering Plants

• Sea Grasses

The loss of estuaries and mangrove forests is particularly serious because these ecosystems:

• Provide nesting or resting areas to many sea birds

• Are among the most productive of all marine ecosystems

• Provide nursery habitats to many species

• All of the above choices are correct.

Pneumatophores are used for:

• Excretion of excess salts

• Horizontal Growth

• Aeration of plant tissues

• Downward growth

Fjords are formed as a result of which of the following?

• Raising of sea level and glaciation

• Subsidence of land

• Lowering of sea level

• Cutting of the coast by a river

Well-formed estuaries are least likely to be formed by:

• Sea level rise

• Retreating glaciers

• Active continental margins

• Passive continental margins