Glossary M

Magnetic north
The geographical region towards which all magnetic needles point. The point is approximately 1,300 miles south of true north.

Mangroves
The only trees that grow in salt water. Mangroves protect tropical coastlines from storm surges, and their extensive root system attracts a variety of shallow water game fish.

Marsh
A type of freshwater, brackish water or saltwater wetland that is found along rivers, pond, lakes and coasts. Marsh plants grow up out of the water.

Mayfly
The most beautiful of aquatic insects, the mayfly is characterized by an upswept wing and long, delicate two or three-stranded tail.

Meander
Something that meanders follows a winding path.

Merging currents
A dead spot of calm water created where two currents come together.

Mesa
A land formation with a flat area on top and steep walls - usually occurring in dry areas.

Millpond
A reservoir built to provide flowing water to a watermill.

Milt
The sperm of fishes.

Moat
A deep, broad trench, filled with water, surrounding a structure, installation, or town.

Mollusks
Oysters, scallops, mussels, snails, squid, octopuses.

Montane
A mountainous region.

Mountain
A very tall high, natural place on Earth - higher than a hill.

Mountain Range
A long chain of mountains; a row of connected mountains.

Mouth (of a river)
Place where a river empties into a larger body of water; the end of a river.