Download Marine Ecology 1a

From Friday’s The Blue Planet
PREDATOR
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PREY
 Sardines
 Flying fish
 Surgeonfish eggs
 Yellowfin tuna eggs
 PLANKTON
 NUTRIENTS
Striped tuna, Bluefin tuna
Marlin
Sei whale
Manta ray, Ray
Pacific Mackeral
Spotted Dolphin
Sailfish
Blue Shark
Deepwater crab
• Sunfish with half-moon fish and seagull
Wahoo
• Fish with flotsam
The Marine Food Web
Biological Productivity
Conditions for Life in the Sea
Consider the main biochemical reaction for
life in the sea, and on earth in general:
6H2O + 6CO2 + energy
=
C6H12O6 + 6O2
Focus on left side of equation
What is in short supply in the sea and thus
limits the amount of life in the ocean??
6H2O + 6CO2 + energy = C6H12O6 +6O2
 Phytoplankton
are
base of the food chain
 Most important
primary producers of
complex sugars and
oxygen
 80% of the world’s
photosynthesis
occurs in the sea.
Lauderia sp.
The Marine Food Web
Gasses & Water are absorbed
 through
diffusion
across a semipermeable membrane
Lauderia sp.
Diffusion:
molecules move from high to low concentrations
Which Elements are in Short
Supply?
 Nitrogen
(N) as Nitrate NO3 (-2)
 Phosphorus (P) as Phosphate PO4 (-2)
 Silicon (Si) as Silicate SiO4 (-2)
Phosphate and Nitrate in the Pacific
Silicate in the Pacific
Biolimiting Nutrients
 N,
P, and Si are exhausted first in Eq.
surface waters during photosynthesis
 Essential to the growth of phytoplankton
 Nutrients increase … life increases
 Nutrients decrease … life decreases
 Where would you expect to find the highest
biomass in the Pacific??
Global Primary Production in our Oceans
Dissolved O2 Reverse of
Nutrients
 O2
is high in the
surface mixed layer
 O2 decreases to a
minimum at base of
thermocline
 O2 then steadily
increases with depth
– Why?
Why is the Concentration of
Oxygen High in the Mixed Layer??
Hint #1: How and where is oxygen produced
in the sea???
6H2O + 6CO2 + energy + nutrients = C6H12O6 + 6O2
Hint #2: How can oxygen be mixed
downward from the atmosphere into the
ocean?
Global Primary Production
Marine Ecology
Basic Ecology
 physical
and chemical parameters
affecting distribution and abundance
 An ecosystem includes both the living
(biotic) and non-living (abiotic) portions
of the environment.
– Examples include: salt marshes, estuaries,
coral reefs, the North Pacific Gyre.
Classification of Organisms
by Environment
 horizontal:
neritic | oceanic
 vertical:
– epipelagic (top) / euphotic (good)
– mesopelagic (middle) / disphotic (low)
– bathypelagic (deep) / aphotic (without)
– abyssopelagic (“bottomless”)
Divisions of the Marine Environment
Classification of Organisms
by Lifestyle
 Scientists
have established another
classification scheme to categorize biota
on the basis of lifestyle. The major groups
are:
– plankton (floaters)
– nekton (swimmers)
– benthos (bottom dwellers)
Plankton
 weak
swimmers, drifters, unable to
counteract currents.
– Phytoplankton (plants)
– Zooplankton (animals)
Nekton
 active
swimmers capable of counteracting
currents.
– Fish
– Squids
– Reptiles
– Birds
– Mammals
Distribution of
Marine Lifestyles
 16.7%
of Earth’s animals are marine
 2% inhabit pelagic environment (most of
the oceans are cold and dark)
 98% are benthic!
Benthos
Epiflora
or epifauna live on the sea
bottom.
Infauna live in the sea bottom.
 Benthic
plants - restricted to shallow
waters (light)
 Benthic animals occur everywhere from
shallow depths to the deep sea.
Hydrostatic Pressure
 Pressure
caused by the height of water.
 Function of water height and water density
 Pressure generally increases at a rate of 1
atm per 10 m of water.
(or 16 psi per 10 m depth)
Hydrostatic Pressure
(Cont.)
 enormous
in the deep sea yet animals live
there.
 Animals do not contain gases.
 However, mesopelagic fish which have gasfilled swim bladders to help maintain neutral
buoyancy
– unable to move rapidly between depths
– pressure change could cause bladder to
explode.