Test #2 Results by Next Week
Chapter 10: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 + nutrients = 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??
Absorbing Nutrients 6H2O + 6CO2 + energy + nutrients = C6H12O6 + 6O2
Phytoplankton are base of the food chain
Most important primary producers of complex sugars and oxygen
Lauderia sp.
The Marine Food Web
Absorbing Nutrients Nutrients absorbed by
plants through diffusion across a semi-permeable membrane
Lauderia sp.
Diffusion:molecules move from high to low concentrations
Which Nutrients 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 If these biolimiting nutrients increase in
sea water, life increases If these biolimiting nutrients decrease in
sea water, life decreases Where would you expect to find the
highest biomass in the Pacific??
CZCS Global Primary Production
How Does Nutrient Distribution Compare w/Dissolved Oxygen?
Dissolved O2 Reverse of Nutrients
O2 is high in the surface and mixed layer
O2 decreases to a minimum at base of thermocline
O2 then steadily increases with depth
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?
How is Oxygen Removed from the Thermocline & Slightly Below??
Dead and decaying organic matter sinks downward from surface waters
Rate of sinking decreases as it encounters the cold, dense water of the thermocline
Material decays (oxidizes) at the thermocline, which strips O2 out of the water and returns nutrients to the sea
Cold, nutrient-rich water of the thermocline is returned to sunlit surface waters by way of upwelling
CZCS Global Primary Production
Marine Ecology
Chapter 9
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 EnvironmentFigure 9-1
Classification of Organismsby 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 Plankton are weak swimmers, and are
known as drifters, unable to counteract currents. The group includes:
– Phytoplankton (plants)
– Zooplankton (animals)
Nekton Nekton are active swimmers capable
of counteracting currents. The group includes a diversity of organisms including:– 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
The benthos includes organisms attached to or living on or in the sea bed. This group includes plants and animals. – Epiflora or epifauna live on the sea bottom.– Infauna live in the sea bottom.
Benthic plants are restricted to shallow waters because of their requirement for light.
Benthic animals occur everywhere from shallow depths to the deep sea.
Basic Ecology physical and chemical parameters
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.
TemperatureFigure 9-10
controls rates of chemical reactions and thus metabolic rates, growth rates, feeding rates, etc.
Salinity Salinity is a basic property of seawater
and it too affects marine organisms.
– Many of the elements in seawater are utilized by marine organisms for growth.
– Salinity tolerance is also important in limiting distribution.
Diffusion:molecules move from high to low concentrations
Diffusion/OsmoregulationFigure 9-12
Some organisms can regulate the movement of water into and out of the cells by osmoregulation.
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)
Think You’re Under Pressure Now?
Hydrostatic Pressure(Cont.)
enormous in the deep sea yet animals live there.
Animals do not contain gases. However, mesopelagic fish which have
gas-filled swim bladders to help maintain neutral buoyancy – unable to move rapidly between depths– pressure change could cause bladder explode.
Oregon Coast Field Trip - Oregon Coast Field Trip - Sat., May 21st Sat., May 21st
dusk.geo.orst.edu/oceans/field.htmldusk.geo.orst.edu/oceans/field.html Be here by 7:00 a.m.Be here by 7:00 a.m. 7:15 - Busses 7:15 - Busses leaveleave from from
Wilkinson lotWilkinson lot 8:30 - Seal Rock volcanic 8:30 - Seal Rock volcanic
rocks and tide poolsrocks and tide pools 11:00 - Lunch at Seal Rock 11:00 - Lunch at Seal Rock
park park (bring your own)(bring your own)
12:00 - HMSC 12:00 - HMSC Visitor CenterVisitor Center
1:30ish - Return to 1:30ish - Return to CorvallisCorvallis
Back by 2:30-3:00Back by 2:30-3:00
Required Field Trip GuideRequired Field Trip Guidedusk.geo.orst.edu/oceans/field.htmldusk.geo.orst.edu/oceans/field.html
Answers to bolded questions in guide Answers to bolded questions in guide
–Turn assignment in to Turn assignment in to your TAyour TA–Due by 5:00 p.m., June 3rdDue by 5:00 p.m., June 3rd
Extra Credit #1A - Climate Change Lecture
Bruce Wielicki, NASA, April 4, 2005– Not enough room in LaSells that evening
Watch DVD finally on reserve in library, VR 695– 1-page reaction paper, typed, double-spaced– Overview, your reaction, and how content relates to this course
Due by 5:00, Thursday, June 2nd
– Hand in to your TA please !!!– Worth up to 10 pts. on final exam