Monitoring and manipulation of a sublittoral hard bottom biocoenosis in Balsfjord, northern Norway
Sublittoral hard bottom biocoenoses in Balsfjord, Norway (69°31? N, 19°1? E), were monitored using underwater stereophotogrammetry. The study includes manipulation of natural densities of organisms and testing the importance of biological interactions and “key species ” for the structure of biocoenoses. Underwater photography has the advantages of being a non-destructive method, but it is selective because small or hidden organisms cannot always be observed. Field experiments with exclusion of organisms from cages seem suitable for testing hypotheses concerning which animals are “key species ” in certain biocoenoses. Sea-urchins(Strongylocentrotus droebachiensis, S. pallidus) were suspected to be “key species ” in the present study, and their removal from cages caused an increase in abundance of barnacles(Balanus balanoides), the limpetAcmaea testudinalis and algal cover.
- 1 - sciences appliquees, technologies et medecines
- 2 - sciences biologiques et medicales
- 3 - sciences biologiques fondamentales et appliquees. psychologie
- 4 - vertebres: mouvements corporels. posture. locomotion. vol. nage. exercice physique. repos. sports
- 1 - Physical Sciences ; 2 - Earth and Planetary Sciences ; 3 - General Earth and Planetary Sciences
- 1 - Physical Sciences ; 2 - Environmental Science ; 3 - General Environmental Science