Environments and Primary Productivity

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

200 m Neritic

1000 m 4000 m 200 m Oceanic Epipelagic Mesopelagic Bathypelagic

Light zones in ocean Photic Light for photosynthesis Usually m Aphotic Without light Deeper than 1000 m

Benthic Environment Similar zones as pelagic Omit details and new names

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

Primary productivity Photosynthesis carbon dioxide + water sugar + oxygen 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 Basically the opposite of photosynthesis Releases nutrients back into the ocean 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 Algae Diatoms Coccolithophores Dinoflagellates Basis of food webs and ecosystems

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