Organic waste
Carbon compounds remaining after raw sewage has been
treated for disposal.

Oncorhynchus
Slmon

Ooze
A soft deposit of mud, shells, and other remains found over
most of the ocean floor.

Oceanic region
The water beyond the continental shelf.

Ozone
Oxygen in the O3 state. Filters out harmful ultraviolet rays.

Osculum
The larger holes that can be seen in sponges. They are
excurrent water openings, whrer water leaves a living sponge.

Operculum
A hard plate attached to the foot of some Gastro-poods that
enables them to close the opening of their shell.

Ophiuroidea
Class containing the brittle or serpent stars.

Ossicles
Part of the structure of the sea star skeleton.