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)
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 tentaclesSo dependent on each other that need each otherto survive. Coral give zooxanthellae N, P, and CO2and 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