Aquascope Facts
Cliff and rocky beach ecology
Predating and grazing activities can be an important factor effecting the Biological variety of the specie. This can happen if one animal prefers to predate on another competing species and thereafter colonize the area in question. This predation and grazing can free space so that even other less competitive specie are able colonize these areas. Even though these creatures may not be able to defend their space as well, they may grow so they will not be eaten to same extent as another competing species. In this way, predators and grazers are able to stop other specie from competely taking over an area and and becaming the sole colonizers. Differences in the ability to colonize also affects predators and other superior competitiors cannot establish themselves on all spaces every year.
    In many countries it is common for people to visit the beach at low tide to collect different eatable specie.
Many different types of organisms are harvested, such as algae, shellfish, mussels, squid, crabs and others, all of which end up on the dinner table. In certain areas, this harvesting is so intensive, that it has an obvious effect on the beach environment. Several of those organisms that are collected and consumed are also found in Sweden, at least along the Swedish west coast. Nevertheless, it is uncommon in Sweden to take anything more than fish to eat from the beach.

Predating humans

Organisms as an environment for living

It can be very difficult for organisms that want to attach themselves to a rock or a stone to find some free space. Therefore, quite often they attach to other organisms and algae, a popular haunt for many organisms. Besides offering a space to colonize, they also provide a congenial environment for other organisms in many ways:
  • The algae can provide both temporary and permanent protection during low tide and against predation.
  • The algae catches sediment that contains amongst other things, food.
  • The algae can offer a food source by being edible themselves or having other edible plants that grow on the host alga.
  • The organisms living on the alga recieve help when they are carried up to the light and into the currents of nutritive water.
    Previous page Page 44 of 52 Next page
  • Cliffs and rocks are fantastic!
    Zoning and flecked occurrence
    Animals that are attached
    Modular construction
    Variation and change
    Variations in water level
    Wave exposure
    Both cliffs and rocks
    Freshwater and saltwater
    Geography, climate and history
    Organisms life cycles
    Organisms effect on each other
    Energy and the flow of material

    Home    Contents    Inspiration    Facts    Collaboration  

    © Aquascope 2000   Tjärnö Marine Biological Laboratory, Strömstad, Sweden
    Bo Johannesson | Martin Larsvik | Lars-Ove Loo | Helena Samuelsson