Marine Biology Lecture #17

Which of the following is characteristic of an estuary?

• where salt and freshwater meet

• semi-enclosed region

• fully-enclosed region

• must be a nursery to young, growing fish

The San Fransisco Bay is an example of which kind of estuary?

• coastal plain estuary

• semi-enclosed bay/lagoon

• tectonic estuary

• fjord

What kind of estuary is present in Indian River, Florida?

• semi-enclosed bay/lagoon

• fjord

• tectonic estuary

• coastal plain esttuary

Which of the following estuaries are built by a drowned river valley from sea level rise?

• coastal plain estuary

• fjord

• tectonic estuary

• semi-enclosed estuary/lagoon

Which of the following estuaries is formed by sand-bars?

• semi-enclosed bay/lagoon

• tectonic estuary

• fjord

• coastal plain estuary

Which of the following estuaries are formed by subduction?

• tectonic estuary

• fjord

• costal-plain estuary

• semi-enclosed bay/lagoon

Which of the following estuaries are formed by receding glaciers that cut through valleys?

• fjord

• coastal-plain estuary

• semi-enclosed bay/lagoon

• tectonic estuary

Water is going to be __ on the top of the water column in estuaries

• saltier

• fresher

Answer explanation

Salt water is more dense than fresh water, so it will sink.

Substantial water outflow, isohalines (lines of equal salinity) form at angles, deeper waters more saline

• salt wedge (positive estuary)

• homogenous estuary

• evaporative estuary (reverse estuary)

Salinity is more constant from top to bottom

• homogenous estuary

• evaporative estuary (reverse estuary)

• salt wedge (positive estuary)