Vienna (FWF) – Calcareous red algae originally lived in peaceful co-existence with corals. Their rapid spread, however, has now rendered them the greatest threat to coral reefs. In his new project, which is supported by the Austrian Science Fund (FWF), Arnfried Antonius from the Institute of Palaeontology at Vienna University investigates the reasons for the rapid increase of these reef inhabitants in tropical seas. His research results show the main reasons for this development to be ocean pollution and global warming.

Coral reefs are the oases of the oceans. They best thrive in low-nutrient water, thus creating habitats for countless ocean inhabitants. Most reefs, however, are threatened with extinction - in Central America alone, half of the Caribbean reefs have become deserted in the past 20 years.
Antonius' investigations show that the calcareous red algae, an old reef inhabitant, is to blame for a large percentage of the destroyed reefs. The scientist holds human-induced environmental changes
responsible for the fact that these algae have turned into a truly dangerous threat to the reefs in recent years: "Calcareous red algae thrive in times of food surplus. Additional environmental pollution and warming of the oceans destroy the ecological balance in the reef, and the algae spread like wildfire." The algae completely overgrow the reef corals like a second skin, prevent the supply of food and light and destroy any live tissue.

There is no doubt that fertilisers and untreated effluent are the main food sources of the algae, while toxic industrial waste water destroys the corals' defences. If the environmental pollution of the world's oceans is not stopped immediately, this could mean the definite end to the offshore coral reefs. Antonius comments: "We are currently witnessing the extinction of all offshore corals in the western Atlantic and we are also seeing the start of this development in the Indo-Pacific. If we do not react immediately and rigorously deprive the calcareous red algae of their food source, there will be no future for offshore coral reefs!" The destruction of the reefs would have unpredictable consequences for the entire ecosystem of our oceans.

Contact
Dr. Arnfried Antonius
Institute of Palaeontology
Vienna University
P + 43 1 4277 53534
arnfried.antonius(at)univie.ac.at