Animals of the Benthic
Environment.
Animals of the Benthic Environment.
There are well over 300,000 known species in
the ocean.
• 98% of them live in the benthic environment
(diversity)
Animals of the Benthic Environment.
I. Distribution
A. The most prominent factors affecting
diversity in the Benthic are:
1. Temperature – warmer waters increase
diversity.
2. Currents – upwelling increases
nutrients.
3. Wave energy – high wave energy
decreases diversity.
Animals of the Benthic Environment.
B. The Rocky Shore1. Spray (supralittoral) Zone – Area above
the intertidal zone.
-Affected by storms and tsunamis.
-Species include isopods (sea roaches),
Periwinkle snails and limpet.
Animals of the Benthic Environment.
2. Intertidal zone:
a. High-Tide zone – Only covered by water
during high-tide.
- Species often include Buckshot barnacle,
Rockweed, Periwinkle snails, Limpet and
Chiton.
Animals of the Benthic Environment.
b. Middle-Tide Zone – Area of intertidal
which is equally covered and uncovered by
water.
-Higher biomass and diversity than Hightide zone.
Animals of the Benthic Environment.
-Tide Pools often
form here. Two
obvious species are
Sea anemone and
Hermit Crabs.
Animals of the Benthic Environment.
c. Low-Tide zone – Covered most of the
time.
-Species dominated by plants and algae.
- An obvious animal of the Low-Tide zone
is the shore crab (eats algae).
Animals of the Benthic Environment.
C. Animals of Sediment-covered Shore.
1. Burrowing is the most successful adaptation in
sediment shores.
Animals of the Benthic Environment
a. Bivalves having a
hinged shell are adept
at burrowing.
-They use a siphon for
feeding and it must
remain above the
sediment.
-The depth of
burrowing is limited
by the length of the
siphon.
Animals of the Benthic Environment.
2. Other animals of the sediment shore
include amphipods, lugworm and Sand Stars.
Animals of the Benthic Environment.
D. Animals of the Shallow Offshore Ocean Floor.
1. Sublittoral (The Rocky Bottom) – In the euphotic
zone allowing for much algae
-example: Kelp is the dominant organism.
-Animals include large crustaceans, Oysters and sea
urchins.
Animals of the Benthic Environment.
E. Coral Reefs.
1. Have the highest
biodiversity of animals
species than any other
marine environment.
-Water temp typically
exceeds 18 degrees C.
-Primarily found in the
tropics.
Animals of the Benthic Environment
a. Coral reefs are formed
by Cniderians that
secrete calcium
carbonate to form a
hard exoskeleton.
As they accumulate
reefs are formed.
Animals of the Benthic Environment.
-This coral buildup creates a highly
productive environment.
-25% of all marine species are found in
coral reefs.
Animals of the Benthic Environment.
2. Threats to Coral Reefs:
-Threats include Fishing, Boat collisions,
Suspended sediment, and increases in
water nutrient levels, and increasing
ACIDITY (CO2).
Animals of the Benthic Environment.
a. Nutrient increases (dumping of fertilizers)
favors suspension feeders and reduces clarity,
thus threatening photosynthetic algae needed
by the coral.
Animals of the Benthic Environment.
b. Coral bleaching- condition of loss of color
and death of coral.
-Coral have a mutulistic relationship with
Zooxanthellae algae (nutrients for
protection.
- Coral bleaching is caused by the loss of
zooxanthellae = Coral dies.
Animals of the Benthic Environment.
F. Animals of the deepocean floor.
- No light
-Very cold
-Up to 1000atm of
pressure
-Primarily covered in
sediment.
-Difficult to study
Animals of the Benthic Environment.
1. Deep-Sea Hydrothermal Vent
Biocommunities.
a. Sulfur-oxidizing bacteria are the
producers of the hydrothermal vent
community.
-These bacteria live within the tissues of other
organisms in the community thus maintaining
a mutualistic relationship.
Animals of the Benthic Environment.
-Tube worms are an example of organisms
maintaining this type of relationship.
Animals of the Benthic Environment.
There is a lot of other stuff to discuss regarding
the ocean, however, this has been the
abbreviated version.
Ciao.