This study tested hypotheses associated with the model that H. banksii assemblages and coralline turfs are alternative stable states whereby the coralline turfs are maintained by exclusion of successful recruitment of H. banksii propagules through structural aspects of the turf.
Site Selection Criteria:
All selected sites were intertidal rock platforms of dune limestone/sandstone conglomerates in Victoria, Australia. Sites were chosen that had been historically impacted by sewage outfalls, with a resulting change in algal assemblages, while other sites had no sewage outfalls nearby.
Cause Of Decline:
In many parts of Japan, algal beds have been reduced by many factors, including grazing by herbivores, higher water temperatures/low nutrients, sedimentation and enhanced typhoons. In southern Japan, reduction of seaweed beds is becoming more serious than in other parts of the country. This is because the shallower waters experience higher water temperatures and they are largely oligotrophic, frequently affected by typhoons, and extensively inhabited by herbivorous fish and sea urchins.
Restoration of the habitat-forming fucoid alga Hormosira banksii at effluent-affected sites: competitive exclusion by coralline turfs
Marine Ecology Progress Series, Vol. 419.https://doi.org/10.3354/meps08843