Test #2 Results by Next Week

Biological Productivity 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

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. factors regulating the distribution and abundance of organisms in the ocean. influence of physical and chemical parameters on organisms in the various ecosystems that constitute the ocean. 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 Figure 9-1

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.

Research Video Clips: “Live fast, die young...”

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. Temperature, salinity … Temperature controls rates of chemical reactions and thus metabolic rates, growth rates, feeding rates, etc. Salinity used for growth as well, tolerance to salinity affects distribution

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) pressure at seafloor of Juan de Fuca R?

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 - Sat. , June 3rd dusk. geo. orst Oregon Coast Field Trip - Sat., June 3rd dusk.geo.orst.edu/oceans/field.html 12:30 - Seal Rock volcanic rocks and tide pools 1:30ish - Return to Corvallis Back by ~3:00 Be here by 8:30 a.m. 8:45 - Busses leave from Wilkinson lot 10:00 - HMSC Visitor Center 11:30 - Travel to Sea Rock & Lunch at Seal Rock park (bring your own)

Required Field Trip Guide dusk.geo.orst.edu/oceans/field.html Answers to bolded questions in guide Turn assignment in to your TA Due by 5:00 p.m., June 9th This constitutes LAB 9