Oar: Instrument for propelling
a rowing boat forward.
about objects and events, collected by using
one or more of your senses.
Occupational Health and Safety:
Safety issues related to the workplace,
e.g. wearing a helmet.
Ocean currents: Movements
of sea water caused by many factors including
wind and the Earth's movement.
Oceanic: To do with the
open ocean waters beyond the edge of the
Oceanic trench: Deep,
steep-sided depression in the ocean floor,
formed when one plate of the earth's crust
is pushed beneath another plate.
Oceanography: The scientific
study and exploration of the oceans and
seas in all their aspects, including all
processes in the oceans and interactions
and relations with Earth.
Ochre star: A yellowish
sea star that lives in the intertidal zone.
Octopus: A soft-bodied
marine animal that has eight arms covered
with suction discs. Octopuses are related
to squid and cuttlefishes.
Omnivore: A plant and
On the plane: When a
speed boat accelerates then levels out while
travelling at speed.
Ooze: Fine-grained deep-sea
sediments of biological origin, composed
(in part) of the remains of small marine
Operculum: Bony covering
over the gill slits of fish; or, in gastropod
molluscs, the calcareous plate over the
shell opening that protects the body when
the animal withdraws into the shell.
Opportunist: An animal
that eats almost any plant or animal that
comes its way.
Oral-arm: Dangling structures
a jelly uses to transfer food from its tentacles
to its mouth; also called a palp.
Orange roughy: A bright
orange fish that lives in the deep sea near
Australia and New Zealand. Orange roughy
grow very slowly—the orange roughy sold
for people to eat may be 50 to 80 years
Orca: A black and white
whale that hunts in packs; also called the
killer whale. Orcas are actually the largest
member of the dolphin family.
Order: In biology, a
category that's part of the scientific system
for grouping together related plants, animals
and other organisms (kingdom, phylum, class,
order, family, genus, species). Order is
the category that ranks below a class and
above a family.
Organism: A living thing--a
plant, animal, bacterium or other life form.
Organic: From a living
thing or organism; originating in nature
rather than being made artificially.
used to fertilise plants.
Otoliths: Ear stones
Ovary: The female reproductive
organ that makes eggs.
too many fish; fishing so much that the
fish cannot sustain their population. The
fish get fewer and fewer, until finally
there are none to catch.
Overflow current: Rough
rapid-like water caused by tides running
over submerged rocks.
Ovules: Small rounded
bodies in the ovary of a flower, each ovule
contains an ovum (egg cell).
Oxidation: Process by
which oxygen is added to metals. Causes
Oxygen: A colorless,
odorless, tasteless gas. Most life on earth
requires oxygen to live. Animals breathe
oxygen out of the air or water. Plants also
need oxygen, even though they produce oxygen
Oxygen minimum layer:
A zone in the deep sea, usually around depths
of 2,000 to 2,950 feet (600-900 meters)
where oxygen reaches its lowest level. A
special community of organisms is adapted
to live in this habitat.
Ozone hole: Area where
the thinning of the upper atmosphere each
spring over Antarctica lets harmful ultraviolet
rays through. Can have devastating effects
on life on Earth.