EcologyStudy of interactions of organisms with each other and their

environment

Level of organization

• Cells -> organisms -> population -> community -> ecosystems -> biosphere – All connected so they all affect one another• When something happens to one; all affected –

domino effect

Environment

• All external factors affecting an organism– Abiotic –light, temperature, salinity, turbidity,

weather conditions, pH, waves, currents– Biotic-predators, prey, parasites, etc.

Habitat-Where they live– Examples: rocky shores (cali and Maine), sandy

shores (jax beach), mangroves (south FL), coral reefs (keys), deep sea (Hydrothermal vents)

Niche –Role in ecosystem “their job”

• Can be viewed on an abiotic side OR a biotic side, looking at both at same time gets very complex and is difficult to illustrate

• Lets take a look at the biotic side……

Competition

• Occurs when organisms require same limited resources (food, light, space, mates)– Can be within same species (intraspecific) OR

between similar species (interspecific) – Prevents 2 groups of organisms from occupying

the same niche– Usually no 2 organisms can use exactly the same

resources in exactly the same place at exactly the same time……..WHY?????????

Sooo…..

• Some species have adaptations that have allowed them to be successful?– Plankton feeding fish• Sea bass- eat close to reef• Damselfish-each further away (adaption to feeding in

different location)• Now these two species are feeding on the same thing

BUT not in the same space.

Predator Prey relationships

• Number of individuals is dependant on the abundance of their food source.– Ex: if the number of bull sharks were too increase

to massive numbers because of a lot of food, then the number of fish they eat would go down, then eventually bull sharks populations would also decrease

Keystone species• Has great effects on Foodwebs/ecosystems• Increases biodiversity • Example: sea otters in Pacific Coast

(Washington State)

• http://www.youtube.com/watch?v=LYtxz1dqZW0&feature=related&safety_mode=true&persist_safety_mode=1&safe=active

Symbiosis-”living together” cohabitating

• 3 main types– 1. mutualism- both benefit– 2. commensalism- one benefits, other neither

harmed nor helped– 3. parasitism- one lives off another• Parasite benefits and host is harmed

Mutualism• Clownfish gets home• Anemone-gets protection so other fish

don’t eat tentacles

So dependent on each other that need each other to survive. Coral give zooxanthellae N, P, and CO2 and zoo give corals carbohydrates

Commensalism

• Shark-no benefit or harm; remoras get free ride and eat leftover food

Barnacle gets ride and place to live; whale no benefit or harm

Parasitism• Sea

Cucumber – pearl fish feed on respiratory tissue and reproductive organs

So how do scientist sample to make inferences about ecosystem health?

• Population sampling– 2 main types for marine ecosystems• Transect line• Quadrat

Transect line

Quadrat

We will be using Quadrat method in lab 6 and 7!!!