Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Rocky Intertidal Zone
Document related concepts
Transcript
Rocky Intertidal Zone General Characteristics Steep coasts without large amounts of sediment West coast of US – Active margin – Uplift Northeast Coast of US & Canada – Ice sheets scraped sediment from the shelf Conditions Plenty of food – Shallow water = lots of light – Nutrients Detritus – Brought in by waves & tides – Most important food source in many communities Organisms in Rocky Intertidal Mainly epifauna Adaptations for attachment: – Byssal threads – Holdfasts – Tube feet – Cement Barnacles Periwinkles Sea Star Sea Anemones Lobsters Sea Urchin Mussels Palm Seaweed Rocky Coast Communities West coast of US has more mature communities – Less seasonal changes – Main limiting factor is predation East coast is less mature – Seasonal population changes – Main limiting factor is climate Competition for Space Sessile attach Space Ways organisms need place to is limited to outcompete other species – Large # larva – Loosen competition from rock – Grow over competitors Ecological Succession Vertical Zonation In rocky intertidal, species not found throughout; rather in a particular range Distinct bands of organisms at characteristic height in intertidal Upper limit usu. determined by physical factors Lower limit determined by biological factors – predation, competition Keystone Predator STARFISH FEEDING ON MUSSEL BED
