Fig 12-3, p.238

Flow of energythrough a living system;energy is degraded w/ each step

Fig 12-6, p.241

Generalized trophic pyramid

Fig 12-7, p.242

Simplified foodweb

Factors that effect…

• Light

• Temperature

• (among others…that you already know…)

Fig 12-9, p.244

Fig 12-11, p.247

Life in the Ocean

• The PELAGIC community!

• A “Pelagic community” is a community of organisms that live suspended in the water column…they either float (plankton) or swim (nekton).

• This is different than those that live on shore, on the bottom (etc.)

Fig 13-1, p.258

PelagicCommunitiy,PlanktonAndnekton

Bony fish examples

Deep sea angler fish

Fig 13-21, p.275

MarineMammalsthat live inthe pelagiczone(Baleen)

Fig 13-21, p.276

MarineMammalsthat live inthe pelagiczone(Toothed)

Next…

• Since we know some of the organisms that live there, we can also study their interactions (w/ each other and w/I the community structure)

Marine Ecology

• The study of interactions of marine organisms with each other and with their environment

Population

• A group of organisms of the same species occupying a specific area

Community

• Many populations of organisms that interact with each other at a particular location

Community Composition

• Physical factors– temperature, salinity, dessication, pressure– can all limit where an organism can survive

• Biological factors – larval supply, competition, predation,

parasitism,– can also limit where an organism can be found

Physical Factors

• range of tolerance

• Steno = narrow

• Eury = wide or broad

• Examples:– stenothermal or eurythermal– stenohaline or euryhaline

Biological Factors

• Competition

• Predation

• Symbiosis

Competition

• limited supply of resources

• Intraspecific competition– between individuals of the same species– Leads to adaptation

• Interspecific competition– between individuals of different species– may lead to competitive exclusion

Predation

• Can also affect community structure

• Allows for increased diversity when superior competitor is preferred prey

Symbiosis

• the co-occurrence of two species in which the life of one is closely tied with the life of another

Symbiosis

• Three types– mutualism (++)

• Anemone fish, cleaner shrimp, zooxanthellae

– commensalism (+0)• Pea crabs, pilotfish & shark

– parasitism (+-)• roundworms