The Endangered Wildlife Trust (EWT) is proud to announce the launch of the first paper in its Research & Technical Series, entitled ‘The potential impacts of anthropogenic noise on marine animals and recommendations for research in South Africa’. The purpose of the series is to disseminate project reports, scoping reports and analyses of datasets and other technical material to a broad audience, thereby bringing the scientific world of conservation into the homes of ordinary people. This first report, which was compiled by Renee Koper and Stephanie Plön, presents an overview of the state of our knowledge about the potentially important threat to marine biodiversity in South African waters.

Said Koper and Plön: “The oceans are often thought of as a silent world. However, in reality the oceans are filled with sounds from both natural and anthropogenic, or human generated, sound sources. In fact, during the last five decades, ocean ambient noise levels have increased with at least 10-12 dB within the 30-50 Hz frequency band. This frequency band falls within the hearing range of baleen whales, of which 42% of all species are endangered. As a result, there is a currently growing concern that anthropogenic sounds in the marine environment potentially have a substantial impact on marine organisms. The report investigates this matter and makes recommendations on how anthropogenic noise can be managed and its effects mitigated.”

Sounds generated by large container vessels, small recreational and fishing vessels, seismic surveys, naval sonar, and construction activities have all been related to negative impacts, both direct and indirect, on a variety of marine animals. Some anthropogenic sound sources produce noise as a simple by-product, while others produce noise intentionally. Unfortunately, the production of either type of noise cannot be prevented, but several mitigation measures have been developed to potentially reduce harm to marine life.

“These existing mitigation measures are highly valuable for a country such as South Africa, which has a rich coastal biodiversity and is an important habitat for threatened marine species such as the Humpback Dolphin Sousa chinensis, while experiencing a rapid increase in coastal industrial developments as well as oil and gas exploration. However, to date, no systematic formal research on the effects of ocean noise on marine animals has been conducted in South Africa,” continued the authors.

The report’s recommendations will enable the establishment of a balance between human industrial developments and marine wildlife conservation and management. To read and download the full document visit www.ewt.org.za. For further information about the report and the EWT’s Research and Technical Series please contact Dr Davies-Mostert onharrietd@ewt.org.za.