Geography and Oceanography - Chapter 23 pps

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. Open Ocean Food Webs Barrie Kovish Vicki Fabry ARCOD@ims.uaf.edu Pacific Salmon Copepods Coccolithophores Pteropods S i n k i n g O r g a n i c D e b r i s Present Ocean Food Web – Complex ecosystem interactions based on a low CO 2 ocean Microbial Remineralization Primary Producers Z o o p l a n k t o n F o o d W e b U p p e r T r o p h i c L e v e l s Seafloor community Provided by James Barry MBARI Ocean 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 [...]... of the thermocline is returned to sunlit surface waters by way of upwelling CZCS 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... 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... 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 ” Hydrostatic Pressure Pressure caused by the height of water Function of water height and water density... w/ Dissolved Oxygen? 6H2O + 6CO2 + energy + nutrients = C6H12O6 + 6O2 O2 is high in the surface and mixed layer O2 decreases to a minimum at base of thermocline O2 then steadily increases with depth Dissolved O2 Reverse of Nutrients 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... 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...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... 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 . (-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. 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. 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