E.coli: Bacteria that indicates water may be polluted.

EAR: Expired air resuscitation. A term used for the technique of filling a patient's lungs with air to supply blood to the brain in resuscitation.

Ebb: The horizontal outflow of tidal water to the sea.

Ebb tide: Out-flowing tide from high tide to low tide; compare with flood tide.

Echinoderm: One of a group of invertebrate animals identified by their spiny skin, including sea stars, sea urchins and sand dollars. "Echinos" means spiny; "derma" means skin.

Echinodermata: Phylum of benthic animals having bilateral symmetry in larval forms and usually a five-sided radial symmetry as adults; phylum includes sea stars and brittle stars.

Echo sounder: A machine that determines water depth by measuring the time it takes for sound waves to reach the seafloor and bounce or echo back to the surface.

Ecology: The scientific study of the relationships between plants, animals and their environment.

Ecologically sustainable development (ESD): Development which meets the needs of the present without compromising the ability of future generations to meet their needs.

Eco-ports: Ports that can help ships discharge wastes in an ecologically sustainable manner.

Ecosystem: The natural system in which energy and nutrients cycle between plants, animals and their environment.

Eco-tourism: Nature-based tourism that involves education and interpretation of the natural environment and is managed to be ecologically sustainable.

Eddies: Large circular moving bodies of water associated with ocean currents.

Eelgrass: A water plant with long, grass like leaves. Eelgrass is one of the few flowering plants that lives in salt water.

Egret: A wading bird with long legs.

El Niño: A southerly flowing warm current that generally develops off the coast of Ecuador shortly after Christmas. Associated with drought conditions in Australia.

Elder: One of the older and more influential members of an Aboriginal tribe. Can be male or female.

Elective: Refers to a module or learning competency that you can choose to do as part of a course.

Electroreceptor: an organ specialized to detect electric signals. Sharks have electroreceptors that help them find prey.

Emulsifier: A substance that lets oil and water mix into a smooth liquid.

Emulsion: A mixture of liquids of different types.

Energy: The ability to do work; there are many different forms of energy.

Encrust: To cover with a layer or crust.

Environmentally friendly: Term used to describe any item or practice that will not harm the environment.

Ephyra: A free-swimming young jelly produced when a polyp buds

EPIRB: Emergency position indicating radio beacon.

Equalise: In snorkelling, to make your ears comfortable when you dive underwater by compensating for changes in pressure.

Erosion: Process by which weathered material is carried away by water, wind or glaciers.

Epipelagic: The upper sunlit ocean layers to 350 feet deep (107 meters), also called the photic zone.

Estuaries: The areas of inlets or mouths of rivers which are influenced by the tides and where salt and fresh water mixes.

Ethnic backgrounds: Origin of a culture.

Evaluate: Consider the results of a set of measurements.

Evaporation: In which water molecules are captured by warmer air, causing them to become water vapour. This leads to the actual amount of water constantly decreasing.

Evolution: The process of gradual change over long periods of time.

Exclusive economic zone (EEZ): Concept proposed at the UN Law of the Sea Conference whereby coastal states assume jurisdiction over the exploration and exploitation of marine resources.

Extinct: No longer alive; no longer in existence.

Extinction: Process where no more of a species live on our planet, e.g. dinosaurs are extinct. Many species are threatened with extinction.

Eyespots: A jelly's light-sensing organs, usually found around the edge of the bell. Also colour patterns used by fish to confuse predators.