Marine Ecosystems
Biology
The Divisions of the Ocean
• The ocean can separate the shore, littoral
zone, from the open, or pelagic zone,
from the ocean floor, benthic zone.
• The presence, photic zone, or absence,
aphotic zone, of light also differentiates
between areas of the ocean.
• The ocean is also separated into zones
based on its distance from the shoreline
and water depths.
1. Intertidal zone – strip of land between the
high and low tide lines
2. Neritic zone – from the intertidal zone out to
the edge of the continental shelf.
3. Bathyal zone – from the edge of the neritic
zone to the base of the continental shelf.
4. Abyssal zone – lies below 2000 meters and
is in incomplete darkness.
Intertidal
Neritic
Life in the Neritic Zone
• Most of the biomass in this zone in
plankton, tiny free floating organisms that
live in the water.
• Zooplankton is another terms for animal
plankton and phytoplankton are
photosynthetic plankton.
Coastal Waters
• Coral reefs are found in tropical climate
zones.
• Corals are animals that have a mutualistic
relationship with algae.
• Corals are very delicate and are in decline
around the world.
• In contrast to corals, kelp forests live in
cold waters and consist of kelp, or
seaweed.
• The point where a river flows into an
ocean is called an estuary.
• The distinctive feature of an estuary is the
mixture of fresh and salt water.
• This area is nutrient rich and are very
productive environments. They also
provide habitats for a number of
endangered and threatened species.
• A watershed is the region of land that
drains into a river or another body of
water.
• Its important to know that water can be
standing (wetland, swamps and lakes) or
moving (rivers, streams, oceans).