1. BUILDING ECOSYSTEMS – BIOTIC FACTORS AFFECTING SURVIVAL
Other organisms can affect an individual’s chance of survival in many ways
Effects of same species:
1. Cooperation – protect against predators, protect against elements, hunting, social organization
2. Competition – for limited resources, nesting sites, territory, mates
- when resources are limited best competitors will survive and
reproduce

2. BUILDING ECOSYSTEMS – BIOTIC FACTORS AFFECTING SURVIVAL
Effects of different species:
When competition is fierce, communities form symbiotic relationships to improve survival odds and build healthy ecosystems.
Symbiosis – living together in close association of organisms from different species
- exhibited by more than half of all marine animals

3. Parasitism (+ - ) one benefits the other is harmed ex: worms, bacteria
2. Mutualism (++) both organisms benefit
ex. Wrasses set up “cleaning stations” where they are allowed to eat the parasites off larger reef fish. They get an easy meal and help reduce parasites on fish.
ex. Coral is an animal that allows zooxanthellae (algae) to live inside the protection of its hard skeleton. The algae makes food for the sessile animal.
NOAA

4. 3. Commensalism (+ o) one benefits, the other not affected
ex. The remora fish is allowed to attach itself to the chin of the shark, who is a very messy eater. The remora has someone to catch food for it. The shark is not affected.
4. Collaboration (++) different species benefiting each other, not necessarily continuous or even always between the same individuals
ex. Birds and dolphins hunting bait fish together

5. 5. Competition (+ -) between organisms for the same resources
ex. different types of seaweed compete for space in a tidal pool
6. Consumer/Predator (+-) eat other organisms for food
ex. sharks hunting seals

6. BUILDING ECOSYSTEMS – ABIOTIC FACTORS AFFECTING SURVIVAL
An organism’s habitat is the place where it lives
The environment is the set of conditions that exist within the habitat
Non–living environmental factors:
7. Depth
1. Sunlight – latitude, depth
8. Oxygen availability
2. Temperature range- depth, lat
9. Stability – waves, wind, currents, tides
3. Substrate – rocky, sandy, silty
4. Salinity
10. Exposure – attachment to rocks
5. Pressure
11. Nutrients
6. Water availability
12. Geographical Terrain – shelter