2. June 2019 Nils Kluger

Study published: Behaviour of White Sharks near kelp forests

(c) H. Futterknecht

The September issue of the Ocean and Coastal Management magazine will publish the results of a scientific study which provided the basis for Sharkproject’s support of the “Shark Safe Barrier” project.

Humans repeatedly encounter sharks near beaches. Although accidents are rare, they are always given top media coverage and are often followed by measures taken to “protect” the beaches from sharks. SHARKPROJECT has long been concerned about the use of nets to “ward off” sharks. The result is not only questionable, but these nets also become a deadly trap for many sea creatures, such as dolphins, turtles and sharks.

(c) Craig O’Connel

The now published study investigated how different densities of sea bamboo (Ecklonia maxima), a type of seaweed found in South African waters, can influence the presence of Great White Sharks (C. carcharias). The field study was conducted between May 2014 and August 2015 by a group of five researchers led by Dr. Craig O’Connel. With the help of BRUVS (“Baited remote underwater video systems”) bait boxes with an irresistible scent for white sharks, were placed in the middle of the designated kelp areas. In five different zones around Dyer Island (off Gaansbai, South Africa), three fields of kelp ranging from low, medium to high density were defined, and the evaluation showed whether and how close a Great White Shark approached the bait. A total of 31 different white sharks were identified in the study area and a total of 135 hours of video were collected at high, medium and low kelp density.

The study published in Ocean and Coastal Management concludes that, of the 31 documented sightings, none at all took place in dense kelp. The conclusion is that kelp, at a density of at least one plant per square meter, can act as a natural barrier against Great White Sharks.

This result led to the consideration of whether the installation of artificial kelp forests on relevant beach sections could be an animal-friendly alternative to the previously used nets. This idea finally led to Sharkproject giving its support to the “Shark Safe Barrier” project.

Read a summary of the study here.