Marine Environments The environment itself Major groups of organisms in ocean Basics of ecosystems.

Marine EnvironmentsThe environment itself Major groups of organisms in oceanBasics of ecosystems

EnvironmentsPelagic……the waterBenthic…..the bottom

Neritic NearshoreShallower than 200mOmit many details here

200 m

Neritic

OceanicAway from continental shelfDepth zones

Oceanic provincesEpipelagic

Surface down to 200m

Mesopelagic200-1000m

Bathypelagic1000-4000m

1000 m

4000 m

200 m

Oceanic

Epipelagic

Mesopelagic

Bathypelagic

Light zones in oceanEuphotic

Light for photosynthesisUsually 0-100 m

AphoticWithout lightDeeper than 1000 m

Benthic EnvironmentSimilar zones as pelagicOmit details and new names

Organisms (in general)

Plankton: floatersMany varieties

Nekton: swimmersWon’t deal with these in this course

Benthos: bottom dwellersA few varieties

PlanktonPhytoplankton

Carry on photosynthesisDiatoms, coccolithophores, dinoflagellates

PHYTOPLANKTON

Plankton (2)Zooplankton

ConsumersRadiolarians, forams, others

ZOOPLANKTON

Plankton (3)Meroplankton

Part of life as a planktonPart of life as nekton or benthosExamples (oysters, barnacles, crabs, fish egg)

Plankton (4)Holoplankton

Whole life in planktonic formExamples (diatoms, for instance)

Benthic organismsEpifuana

Lives on top of sedimentsExamples (barnacles, starfish, crabs)

InfaunaLives within sedimentsExamples (clams, worms)

Epifauna

Infauna (a, b, c, e)

Distribution of lifeLand vs. seaBenthic vs. Pelagic

Land 86%Sea 14%

Benthic 98%Pelagic 2%

Why these patterns?

Making a living in the ocean

Food chains and food websPrimary productivity, respiration, decompositionDepth zone differencesRelationship between resources and numbers of organismsDifferences between “climate” zones

Food webs and chains

Primary productivityPhotosynthesiscarbon dioxide + water

sugar + oxygen

Chemosynthesishydrogen sulfide + water + oxygen +

carbon dioxide sugar + sulfuric acid

Respiration and decayBasically the opposite of photosynthesisReleases nutrients back into the oceanUses oxygen (consider other sources of oxygen to the ocean)

Oxygen with depth (red)Nutrients with depth ( green)

Example of primary producers

AlgaeDiatomsCoccolithophoresDinoflagellates

Basis of food webs and ecosystems

Variations in productivity verses latitude

Photic zone important for photosynthesisSome areas of ocean are light limited, some are nutrient limited, some are bothPictures can tell the story of relationships ……….