Environments and Primary Productivity Environments n Pelagicthe water

Environments and Primary Productivity

Environments n Pelagic……the water Neritic – over continental shelf n Oceanic n Epipelagic: down to 200 m n Mesopelagic: 200 -1000 m n Bathypelagic: 1000 -4000 m n n Benthic…. . the bottom

Neritic 200 m

Oceanic Epipelagic 200 m Mesopelagic 1000 m Bathypelagic 4000 m

Light zones in ocean n Photic n Light for photosynthesis n Usually 0 -100 m n Aphotic n Without light n Deeper than 1000 m

Benthic Environment n Similar zones as pelagic n Omit details and new names

Making a living in the ocean n Primary productivity, respiration, decomposition n Depth zone differences n Differences between “climate” zones n Food chains and food webs

Primary productivity n Photosynthesis carbon dioxide + water sugar + oxygen n Chemosynthesis hydrogen sulfide + water + oxygen + carbon dioxide sugar + sulfuric acid

Primary productivity: rate at which biomass is produced by photosynthesis or chemosynthesis

Respiration and decay n Basically the opposite of photosynthesis n Releases nutrients back into the ocean n Uses oxygen (consider other sources of oxygen to the ocean)

Oxygen with depth (red) Nutrients with depth ( green) Relate pattern to photosynthesis, respiration, decay and other processes

Example of primary producers n Algae n Diatoms n Coccolithophores n Dinoflagellates n Basis of food webs and ecosystems

Variations in productivity verses latitude n Photic zone important for photosynthesis n Some areas of ocean are light limited, some are nutrient limited, some are both n Pictures can tell the story of relationships n Polar region n Equatorial region n Temperate region of ocean

Global ocean productivity: What causes this pattern?

Food webs and chains

Efficiency of energy transfer: Relate to number of trophic levels Upwelling region Coastal region Open ocean