Do Now 10/310/3 Chapter 3.3 2010/3 Pg 3-23 #1-8 21

WOD: CARNIVORE(KAR ni vour) n.

a flesh-eating animal

What is the theory of evolution? In general terms, how does this theory explain the origin of the different organisms that exist today?

Chapter 3.3- Ocean Zones and Life StylesINB Pg 20

Environment classification methods• Marine scientists classify marine environments

into many different regions based on physical characteristics. They may classify parts of the ocean into different zones or regions based on the light, depth, temperature, density, latitude, and distance from shore or a combination of these.

Location• The most basic division of the ocean based on

location is between the water column and the bottom.

The Pelagic ZoneThe Pelagic zone is the water column portion. The pelagic zone is divided into two horizontal zones:• 1. Neritic zone is the water area between the low tide

mark to the edge of the continental shelf.• 2. Oceanic zone is the open water area beyond the

neritic zone.

The Pelagic Zone• The five vertical regions

of the oceanic zone:1. Epipelagic zone - top layer sunlight penetrates.2. Mesopelagic zone - sunlight reaches but not strongly enough to support much life.3. Bathypelagic zone - deep water in open ocean.4. Abyssalpelagic zone - evendeeper water in oceanic trenches.5. Hadalpelagic zone - is the deepestwater in the ocean trenches.

Benthic zone• The bottom is the Benthic zone. • This zone is divided based on depth-moving from

shore to open ocean. • Supralittoral zone• Littoral zone• Continental shelf

Benthic zone• Supralittoral zone - This is the zone that water splashes,

but it does not remain submerged.• Littoral zone - The bottom area between the high- and

low-tide mark so that it is sometimes submerged and sometimes above water.

Benthic zone• Continental shelf - Area beyond the littoral

zone. This area is divided further.• Sublittoral zone - ocean bottom close to shore.• Outer sublittoral zone - ocean bottom out to edge of

continental shelf.• Bathyal* zone - is the bottom along the continental

slope down to deep open ocean bottom.• Abyssal* zone - deep open ocean bottom.• Hadal* zone - deepest zone; below 6,000 meters

(19,685 feet).*Also called the deep sea floor.

Marine lifestyles• Marine life is incredibly diverse. Scientists use

groups and subgroups based on common physical characteristics to discuss them.

Plankton • Plankton are the group of organisms that exist adrift in

the ocean currents.• Neuston is an important subgroup of plankton.

Neuston are those plankton that float at the surface, for example the Portuguese man-of-war.

Nekton • Nekton are the organisms that swim, from small

invertebrates to large whales. Most of the seas’ predators are nekton. The majority of nektonare vertebrates.

Benthos• Benthos are organisms that live on or in the bottom.• They can move about or be sessile. Sessile organisms are

attached to the sea floor.

Benthos •Benthos are divided into:• Epifauna are those

animals, such as crabs, that live on the sea floor.

• Epiflora are plants, such as seagrasses, that live on the sea floor.

• Infauna are organisms that are partially or completely buried in the sea floor, such as clams, sand dollars, tubeworms, and sea pens.

Benthos • Most infauna are

either deposit feeders or suspension feeders.• Deposit feeders feed off

detritus drifting down from above.

• Suspension feeders filter particles(mostly plankton) suspended inthe water for food.