Globally, human impacts through multiple stressors, such as urbanisation and nutrient loading, are causing significant declines of key species of algae that provide habitat and food to many marine organisms. As a consequence, the loss of habitat-forming algae has significant impacts on local productivity and biodiversity, and in turn, on ecosystem services. ‘Crayweed’ (Phyllospora comosa) is a key habitat-forming macroalga on rocky reefs in NSW that provides habitat and food to commercial species and supports biodiversity. Crayweed disappeared from the Sydney coast during the last 40 years, probably related to heavy sewage outfall discharges during 1970’s - 1980’s. Despite significant improvements in water-quality, crayweed has not re-established.
By conducting transplant experiments, we have shown that at small scales, crayweed can survive and successfully reproduce on reefs from which it has been missing for decades. Understanding the factors and processes that allow the reestablishment of macroalgae and the biodiversity they support is critical for the continuing development of successful strategies for restoration and management. For more information contact Dr Ezequiel Marzinelli, Dr Adriana Verges or Dr Alex Campbell.