Mammal

An animal that feeds its young with milk secreted from mammary glands and has hair on its skin.

Managed Growth

Growth or expansion that is controlled so as not to be harmful.

Marine

Having to do with the ocean world or environment.

Methane

A hydrocarbon that is a greenhouse gas with a global warming potential most recently estimated at 23 times that of carbon dioxide (CO2). Methane is produced through anaerobic (without oxygen) decomposition of waste in landfills, animal digestion, decomposition of animal wastes, production and distribution of natural gas and petroleum, coal production, and incomplete fossil fuel combustion.

Microorganism

An organism that can be seen only with the aid of a microscope and that typically consists of only a single cell.

Microplastics

A small piece of plastic, 5 millimeters or smaller in size. Microplastics may have been produced at that small size or their size may be the result of the breakdown of water bottles, plastic bags or other things that started out larger.

Mine Tailings

Crushed waste rock deposited on the ground during mining and ore processing, including some of the rock in which the ore is found. Unless they are handled carefully, they frequently release contaminants.

Molecules

A group of atoms held together by chemical forces.

Moratorium

Legislative action which prevents a federal agency from taking a specific action or implementing a specific law.

Mulch

Leaves, straw or compost used to cover growing plants to protect them from the wind or cold.