Transcript Factors Affecting Life and Ocean Zones Biological Oceanography:

Biological Oceanography:
Factors Affecting
Life and
Ocean Zones
Factors Affecting Life:
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Light
Dissolved Nutrients
Temperature
Salinity
Dissolved Gases
pH
Pressure
Light
• Needed for
photosynthesis. Must
occur in the first few
100 m of ocean.
• Also trigger breeding
some species.
Classification by Light:
Dissolved Nutrients
• Nutrients are substances that provide
nourishment and growth.
• Required for production of organic (carbon
based) matter.
• Problems:
– Phosphorous Loading – detergents
– Nutrient Loading in Halifax Harbour
Dissolved Nutrients
Temperature
• The mixed layer is near the surface
where the temperature is roughly
that of surface water.
• In the thermocline, the temperature
decreases rapidly from the mixed
layer temperature to the much
colder deep water temperature.
• The mixed layer and the deep
water layer are relatively uniform in
temperature, while the thermocline
represents the transition zone
between the two.
Temperature
• Cold Blooded:
– Changes in temperature will directly affect
metabolic rate.
• Warm Blooded:
– Have blubber that acts as insulation.
Salinity
• Salt content in ocean directly effects
buoyancy of organism.
– Species have adapted physical features to
combat this problem.
• Eg. Fish – Swim Bladder
• Interior salinity of most marine life is equal
to ocean’s salinity.
Dissolved Gases
• CO2 and O2 are needed to stay alive in the
ocean.
• O2 does not dissolve easily in ocean.
– 100 X more gaseous oxygen in air than
ocean.
• CO2 dissolves more easily in ocean.
– 60 X more carbon dioxide in ocean than air.
pH
• Pure Water =
7
• Seawater = 8
Pressure
 Increases drastically with depth.
-Sea Level: 14.7 psi
-Under 33 feet: 30 psi
-Under one mile: 2 333 psi
Ocean Zones by Light
1. Photic Zone
• 0-200m
• sunlit layer at the ocean’s surface
• upper part of photic zone is where photosynthesis
occur
2. Disphotic Zone
• 200 – 1000m
• where animals can see but not enough light for
photosynthesis
3. Aphotic Zone
• 1000m and below
• largest region, no light
Ocean Zones by
Surface Location
1. Neritic zone
• spans from the low-tide line to the edge
of the continental shelf in oceans
• near coast
2. Oceanic zone
• is the part of the open sea or ocean that
is not near the coast
Ocean Zones by Depth
1. Pelagic = Belonging to the upper layers
of the open sea.
2. Benthic = relating to the ocean bottom,
living in or on the bottom of a body of
water
Pelagic zone
•Is subdivided into the epipelagic,
mesopelagic, and bathypelagic zones.
1. Epipelagic zone receives
enough sunlight to support
photosynthesis.
2. Mesopelagic zone, where
only small amounts of light
penetrate
3.Bathypelagic zone into which
no light penetrates.
Sub-divisions of the Bottom
• Benthic Zone
1)Littoral Zone – The shallow water area between high
and low tides.
2) Sublittoral Zone - Ocean bottom near shore and out
to edge of continental shelf
3) Bathyal Zone- seabed on the slopes
4) Hadal Zone or Abyssal Zone - deepest sea bed,
trenches and floors
OCEAN ZONES