lecture 3: rocky shore

chapter 6 from the book

discussion

  • why and where are there rocky substrates in the oceans?

    • the movement of water and currents create rocky formations, usually strong ones, lifiting the finer sediment and leaving behind the larger harder rocks

  • how is rock useful to organisms?

    • teh animals have to hold onto the substrate and prevent drifting away

    • it gives them protection in crevices

    • other vegetation on the rocks helps the animal hide or provide food for them

  • pros and cons for living on rocky substrates - how can organisms adapt?

    • the ones living on the higher part of the rocky shore makes them more prone to drying out, as the tide moves in and out. this also exposes them to all the elements and weather. so there are some species that are more tolerant to this than the other species, that are further under the sea

  • is there some sort of stratification in the littoral zone - why and what are the pressures?

lecture →

shores are accesible habitats and under increasing pressure

  • very rich in resources

  • …..

what is a shore?

  • many shores do not have strong tides - air pressure is more important there. still have intertidal flora and fauna

  • tides alone cannot explain abundance of biota

  • functional influence into terrestrial, and beyond surf zone

  • …..

wet dry gradient between air and water

  • tides do not create the gradient, but amplify it

  • find out a better explanaiton for this topic

zonation patterns depend on tides

  • rocky type shores will tend to have more lichens and brown algae, which will form distinctive bands on the rock and can be seen at low tide

  • more finer sediment will have marshes

environmental gradients

  • physics, competition, physiological abilities to occupy …….

wetness/dryness

  • zonation of two species along a generalised environmental gradient

  • Generally animals and plants on shore are marine. need access to complete life history

  • biological pressure (competition, predation) pushes them up

the size of particles determine what type of organisms can survive

  • large particels provide stable surfaces for attachement (epifauna and flora dominate)

  • fine particles (infauna and meiofauna)

  • intermediate …..

salinity gradients in estruaries

  • mixing

  • longitudinal gradients

  • distributionreflects average physical conditions

  • few freshwater organisms