The Sea Search group is a collective of scientists and students from various local and international institutions who have a strong academic background in marine mammal science. Many of the team members are affiliated with the Mammal Research Institute (MRI) at the University of Pretoria (UP). The group is calling on members of the public who would like to actively contribute to science and research to help map the distribution of whales and dolphins in the western Cape.
South Africa’s coastline is recognised as a global hotspot for its diversity and abundance of whale and dolphin (cetacean) species, with over 30 species known to occur. This is mainly because of the diversity of habitats created by the confluence of the cool Benguela Current along the west coast and the warm Agulhas Current along the east coast, which meet and mix around the western Cape. The low latitude, high species diversity, proximity to range limits and highly variable oceanography make the area a globally unique location at which to study the influence of habitat extremes on multiple cetacean species at the same time.
According to Dr Simon Elwen, NRF Research Fellow in the MRI and Principal Scientist and Director of Sea Search Africa, there are clear signs that changes in the climate and the marine ecosystem around southern Africa are affecting a range of plant and animal species, a phenomenon that corresponds with global trends. Owing to their hard-to-access habitat and large ranges, however, whales and dolphins are among the least studied animals with respect to the impact climate change has had on them, and despite the fact that several populations around the world have shown changes in their abundance, distribution, range and reproductive success in response to environmental change, climate change-related impacts on cetaceans in southern Africa have not yet been studied.
As part of their latest project, E3C (Effect of Climate Change on Cetaceans), the team at Sea Search hopes to map the environmental conditions at the boundaries of the species ranges for five of the dolphin species whose ranges end around the western Cape – Heaviside’s dolphin, the dusky dolphin, the bottlenose dolphin, the common dolphin and the humpback dolphin. The team will use this information to predict how dolphins are likely to respond as environmental boundaries shift and change over time. To do this, they are using a multidisciplinary approach, which includes conducting scientific surveys by boat to find and identify animals, and observe their behaviour, using an array of hydrophones (microphones designed to be used underwater for recording or listening to underwater sounds) that will be in operation 24 hours a day. As the team unfortunately cannot have eyes everywhere, ‘water users’ – including tour operators, surfers, fisherman and even beach walkers – are encouraged to contribute to this research by submitting their own sighting records of dolphins and whales to the study. The combined sightings provided by different people along the coast will significantly increase the data collected and assist the team in mapping the distribution of these dolphin species more accurately. The information will also help researchers to understand why certain species occur in certain regions.
Aspiring citizen scientists can submit their sightings directly via email to [email protected], or add their observations to iSpot Nature (www.ispotnature.org). Alternatively, participants can simply tag Sea Search’s Facebook profile, Seasearch Sightings, in their photos or sightings of animals. Sightings should be submitted with as much detail as possible, including information about the species (if possible), date, location and size of the group. Photographs are extremely valuable in confirming information and most modern cell phones can be set to add the date and location to images.