INTRO TO MARINE ECOSYSTEMS

WHAT IS ECOLOGY?

Ecology- the scientific study of interactions between organisms and their

environments, focusing on energy transfer.

It is a science of relationships.

The environment is made up of two factors:

Biotic factors- all living organisms inhabiting the Earth

ex. How organisms interact/effect each other

Abiotic factors- nonliving parts of the environment temperature Soil Sunlight water/moisture air currents/wind Severe disturbances

Organism

Population

Community

Biosphere

Ecosystem

Levels of

Ecology!

Organism- any unicellular or multicellular form exhibiting all of the characteristics of life, an individual.

•The lowest level of organization

Bonefish ^ American Black Bear >

Population-a group of organisms of one species living in the same place at the same time that interbreed and compete with each other for resources (ex. food, mates, shelter)

Squirrelfish, Grizzly Bear

Community- several interacting populations that inhabit a common environment and are interdependent.

Ecosystem- populations in a community and the abiotic factors with which they interact (ex. marine, terrestrial)

Biosphere- life supporting portions of Earth composed of air, land, fresh water, and salt water.

•The highest level of organization

BIODIVERSITYNumber of different species present and the range of habitats and ecosystems.

Ex: Coral Reefs= high biodiversity, many different species, narrow niche

Sandy Shore= low biodiversity, few different species

Stable and not extreme: HIGH biodiversity

Unstable due to erosion, wind and water currents: LOW biodiversity

Extreme due to not many organisms can survive here: LOW biodiversity

NICHE

Each species unique living arrangement in a community

“Role” Think about a specific position player on

a team i.e. pitcher on a baseball team

Ex. Great white shark Top predator

Habitat vs. NicheNiche - the role a species plays in a community (job)

Habitat- the place in which an organism lives out its life (address)

Fundamental rule in ecology Competitive Exclusion Principle

2 species so similar in requirements that the same resource limits both population’s growth, and one species may succeed over another

No two species can occupy the same niche in the same habitat and the same time

Prevents un necessary competition

Specialized Niches: narrow range of food requirements or live in a specific habitat.

Ex: butterfly fish feed on corals and sea anemones

Generalized Niche- wider range of food sources and live in a wider range of habitats.

Ex: Tuna feed on different species of fish, squid, and crustacean.

Quadrat Sampling

Abundances of organisms found at the study site can be calculated using the number found per quadrat and the size of the quadrat area.

 series of squares (quadrats) of a set size are placed in a habitat of interest and the species within those quadrats are identified and recorded.