Download MARINE ECOLOGY

MARINE ECOLOGY
Marine ecology is the study of the interactions of organisms with the
marine environment.
Basic Ecological Terms and Concepts - Review
Oikos = house - Introduced by Haekel (1866)
Autecology = Study of individual species
Synecology = Study of interacting groups (communities, ecosystems)
Population = Group of individuals of same species
Community = Interacting populations which are interdependent
Ecosystem = Community + physical (abiotic) environment
Biosphere (ecosphere) = Includes all parts of the earth where ecosystems operate.
Ecosystem Concepts:
Essential Structural Components of the Ecosystem
Community (producers, consumers, decomposers) + abiotic environment.
 Producers- Produce organics from inorganic energy sources
o Photosynthetic producers use sunlight as energy source – Plants
o Chemosynthetic producers use inorganic compounds as an energy
source (breakdown of hydrogen sulfide by bacteria)
 Consumers- Herbivores, carnivores, detritivores [predator and detrital food chains]
 Decomposers (mineralizers)- Organisms that breakdown organics returning
them to their elemental state (bacteria and fungi of decay).
Essential Nutritional Components of the Ecosystem
 Autotrophic Component- Do not require organics as their energy source.
Includes photosynthetic and chemosynthetic autotrophs (producers).
 Heterotrophic Component- Require an organic energy source. Includes
both consumers and decomposers.
Trophic Structure and Food Chains
Producers ---> Herbivores --->Carnivores --->Top Carnivore
Phytoplankton --> Zooplankton --> Shrimp --> Fish
Trophic Structure and Ecological Pyramids
CARNIVORES
CARNIVORES
HERBIVORES
PRODUCERS
4th trophic level
3rd trophic level
2nd trophic level
1st trophic level
Pyramids are graphic representation of trophic structure originally devised by
Charles Elton. There are three types: numbers, biomass, energy. (biomass =
living weight)
Trophic Structure and Energy
The energy pyramid shows that energy decreases as one moves up the food chain.
This is because energy does not recycle. (First and second laws of thermodynamics)
Unlike energy, nutrients do recycle in the ecosystem. Examples are the nitrogen
and phosphorus cycles. The nitrogen cycle is an example of a gaseous cycle and
the phosphorus cycle is an example of a sedimentary cycle.