What is abiotic/biotic?
• pH value
• Dissolved Gases
• Exposure to Air
Biotic Levels of Organizations
• Individual: one organism
• Population: group of individuals of one
species (organisms) Habitat
• Communities: plants and animals
inhabiting the same physical area.
• Ecosystems: Many communities / large
Characteristics of an Ecosystem
1. Requires a source of energy.
2. Organisms capturing energy / produce
3. Organic material available to all.
4. Cycle nutrients between environments
• Pelagic Organisms: in the water Plankton-
drifting organisms. Nekton- swimmers
• Benthic Organisms: in or on substrate
(sand/rock) burrow, crawl, walk, or affixed
Epifauna:live on. Infauna:live within
Trophic (Feeding) Relationships
• Autorophs: absorb sunlight energy &
transform inorganic mineral nutrients into
organic molecules. Producers
• Heterotrophs: consumers / cannot
synthesize their own food. Need producers.
• Decomposers: live on dead plant and
animal. Break down organic material /
• Pyramid of numbers: numerical
relationship of trophic (feeding) levels.
• Energy Pyramid: energy distribution at
each trophic level.
Lost Energy/Energy Pyramid
1. Consumer do not consume (eat) entire
2. Energy used in capture (food).
3. Energy used in metabolism.
4. Energy lost as heat.
* 10% energy pass to next level.
Types of Food Relationships
• Predator-Prey: Predator Needs? Prey
• Scavenger: Feed on dead plants and
• Symbiotic/Symbiosis: nutritional
Symbiosis in Marine Animals
• Parasitism: (+;-) one benefits, one harmed
or interfered with body function.
• Commensalism: (+;0) one benefits, one
neither gains or loses.
• Mutualism: (+;+) both benefit.