Stay in the ZoneSara Painter and Vanessa Thulsiraj

Ocean ZonesCategorized by light, depth and distance

Photic versus Aphotic zoneSunlight Availability

Photic zone:• Euphotic zone-

portion of photic zone where photosynthesis occurs

• 0-200 meters• The sunlit zone

• Critters:

Aphotic zone:• 200 meters to ocean

floor• Little to no sunlit zone

Intertidal, Neritic and Oceanic ZonesDistance from coastal shoreline

• Intertidal zone = area between high and low tide

• Neritic zone = area between the low tide and continental shelf

• Oceanic zone = area beyond the continental shelf (open ocean)

• Critters

Pelagic, Benthic and Abyssal ZonesWater Depth

• Pelagic zone = all depths of the open ocean.

• Benthic zone = all sea bottom surfaces

• Abyssal zone = part of benthic zone in deep ocean floor (abyssal plains)

Critters

Benthos• Benthos means “bottom”• Any organisms living on or in the ocean bottom• Most found in shallow costal ocean floor • Examples include sea stars, corals, crabs,

seaweeds, snails, sea cucumbers, and sea squirts

Nekton• Nekton means “swimming”• Any organisms that is strong enough to move against

the ocean currents, by swimming or propulsion• Can determine their position in environment and some

are capable of migrating long distances• Include many adult fish, adult squid, marine mammals

and marine reptiles

Plankton• Plankton means “drifter” or “wanderer”• Any organisms that is not strong enough to swim

against the currents• Phytoplankton = plants which need light for

photosynthesis• Zooplankton = small animals that feed on other

plankton

The Sinking Problem

• All plankton must stay in the photic zone

• Either they need sunlight for photosynthesis

• Or they are part of a food chain who’s foundation is phytoplankton

• Phytoplankton are the basis of the marine food chain

Phytoplankton produce half of the worlds oxygen!

Form and Function

Plankton avoid sinking by:

• increasing their surface area

• or decreasing their density

• Spines and flattened bodies