Sea and ocean

Aquatic mammal with front flippers and a horizontal caudal fin – the tail -. For example, whales, sperm whales and dolphins are cetaceans

High elevation zone that leads from the edge of the continental shelf to the abyssal plain.

Flat expanse that covers the bottom of the oceans, at the level of the abyssal floor at an average depth of 4.000 meters. The abyssal plain corresponds to 80% of the total ocean surface.

Part of the continent below sea level, from the coastal zone up to 200 m deep. The continental shelf ends with the continental slope, which continues with a steep drop to the abyssal plains.

Part of slow-flowing aquatic environments, where the bottom is too deep to allow plants to grow.

Part of slow-flowing aquatic environments that extend from the shore to the limit of light penetration.

Part of the aquatic environment corresponding to the bottom of a body of water, including the sediment surface and layer if there is any.

Submerged turbine that uses the energy of marine currents, and sometimes fluvial, to produce electricity.

Water contained in large tanks that can correct the trim of the boat and its balance. Ballast water is a problem during the emptying of the tank (deballasting) because species living in one part of the world are released into another zone, creating ecological disturbances. With the growth of international trade, and especially transoceanic maritime transport, problems arise because of this contribution of living organisms foreign to the local environment. Now, biological and chemical treatment systems must treat these volumes of water to limit the exchange of invasive species.