Marine Environments
The environment itself
Major groups of organisms in ocean
Basics of ecosystems
Environments
Pelagic……the water
Benthic…..the bottom
Neritic
Nearshore
Shallower than 200m
Omit many details here
Neritic
200 m
Oceanic
Away from continental shelf
Depth zones
Oceanic provinces
Epipelagic
Surface down to 200m
Mesopelagic
200-1000m
Bathypelagic
1000-4000m
Oceanic
Epipelagic
200 m
Mesopelagic
1000 m
Bathypelagic
4000 m
Light zones in ocean
Euphotic
Light for photosynthesis
Usually 0-100 m
Aphotic
Without light
Deeper than 1000 m
Benthic Environment
Similar zones as pelagic
Omit details and new names
Organisms
(in general)
Plankton: floaters
Many varieties
Nekton: swimmers
Won’t deal with these in this course
Benthos: bottom dwellers
A few varieties
Plankton
Phytoplankton
Carry on photosynthesis
Diatoms, coccolithophores, dinoflagellates
PHYTOPLANKTON
Plankton (2)
Zooplankton
Consumers
Radiolarians, forams, others
ZOOPLANKTON
Plankton (3)
Meroplankton
Part of life as a plankton
Part of life as nekton or benthos
Examples (oysters, barnacles, crabs, fish
egg)
Plankton (4)
Holoplankton
Whole life in planktonic form
Examples (diatoms, for instance)
Benthic organisms
Epifuana
Lives on top of sediments
Examples (barnacles, starfish, crabs)
Infauna
Lives within sediments
Examples (clams, worms)
Epifauna
Infauna
(a, b, c, e)
Distribution of life
Land vs. sea
Benthic vs. Pelagic
Why these patterns?
Land 86%
Sea 14%
Benthic 98%
Pelagic 2%
Making a living in the ocean
Food chains and food webs
Primary productivity, respiration,
decomposition
Depth zone differences
Relationship between resources and
numbers of organisms
Differences between “climate” zones
Food webs and chains
Primary productivity
Photosynthesis
carbon dioxide + water
sugar + oxygen
Chemosynthesis
hydrogen sulfide + water + oxygen +
carbon dioxide
sugar + sulfuric acid
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)
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 ……….