Abstract:
The Indian Ocean humpback dolphin (Sousa plumbea) is “endangered” with likely
less than 500 animals remaining in South African waters. Established in 2016, the
SouSA Consortium is a formalised network of scientists and conservationists to
combine knowledge and research efforts, and make coordinated decisions with the
aim of conserving the species. The first collaborative project collated available photoidentification
data in an attempt to refine a national population estimate and investigate
movements between research sites. This work was able to identify 250 uniquely marked
individuals, with the population divided into the south-coast (Agulhas bioregion) and
east-coast (Natal bioregion) populations. Environmental factors almost certainly play
a role in the declining numbers of the species in South African waters. However,
individual threats and solutions are challenging to identify as the South African marine
environment is undergoing significant natural and anthropogenic changes with major
shifts in the distribution and numbers of some prey, competitor and predator species.
Therefore, we believe that a continued investigation of potential contributing factors and
their interaction will take too long, inevitably resulting in another case of documenting
extinction. With this in mind, we present the results of a SWOT (Strengths, Weaknesses,
Opportunities, and Threats) analysis in an effort to help us identify the next steps
to take toward the conservation of humpback dolphins in South African waters. We
unanimously conclude that no single cause for the rapid decline of humpback dolphins
Frontiers in in South African waters can be identified, and that the cumulative effects of multiple
stressors, which are difficult to pinpoint and mitigate, are impacting population numbers.
While highlighting the need for continued research, we suggest a shift toward more
action-focused conservation efforts, the first concrete steps being the development of
a Conservation Management Plan with input from other stakeholders.
