Collaboration on humpback dolphin (Sousa plumbea) research and conservation in South and East Africa

Humpback dolphins in the Indian Ocean were recently recognised as a distinct species (Sousa plumbea) that occurs in coastal waters from South Africa to India (link to earlier news article).  The species occurs in very near-shore habitat, generally in water less than 30 m deep and typically less than 2 km from shore, and is therefore exposed to high levels of human activity throughout its range. The conservation status of all four Sousa species is currently being assessed for the Red List, and S. plumbea has been proposed (but has not yet been listed) as “Endangered”.

Humpback dolphins are considered to be South Africa’s most endangered marine mammals.  They were recently re-assessed for the South African National Red List, and the status was changed from Vulnerable to Endangered due to declining sighting rates and group sizes, in comparison to previous assessments, as well as newly available estimates of abundance from discrete areas that suggest the overall population size in South Africa is very small [1].

In early 2016, a Memorandum of Understanding (MOU) that established the “SouSA Consortium” was signed by 16 scientists and research groups in South Africa.

Figure 1: Some of the signatories of the SouSA Consortium Memorandum of Understanding in South Africa

Figure 1: Some of the signatories of the SouSA Consortium Memorandum of Understanding in South Africa

The consortium is designed to facilitate the collection and sharing of humpback dolphin data across the country, which is hoped to make a substantial contribution towards the conservation of this species.   Specifically, the consortium aims to generate data and analyses on a larger geographical scale, something that is impossible for individual research groups. The specific objectives of the project are to:

  • produce an estimate of the total population size and trend of humpback dolphins in South African waters
  • characterize the movement patterns of humpback dolphins along the entire South African coastline
  • determine spatial and temporal patterns of humpback dolphin distribution and assess connectivity between areas
  • evaluate population viability (incorporating estimates of abundance, reproduction and survival) of humpback dolphins in South Africa.

In Kenya and Tanzania (East Africa), knowledge of humpback dolphins is less extensive than in South Africa, but populations appear to be similarly small and subject to many threats [2]. Funding is secured and plans are in place to sign a MOU to establish an East African Cetacean Working Group that will collaborate on coastal dolphin research and conservation in Kenya and Tanzania.  The East African working group will have similar objectives to the South African SouSA Consortium, and the two groups intend to work together in future to answer broad-scale regional questions related to humpback dolphin conservation.

These types of collaborations are important and to be encouraged in areas where knowledge and resources are limited, but conservation concerns are high, something that is true for many regions and marine mammal species. Fisheries bycatch and the loss of habitat through coastal development are major conservation concerns for coastal small cetaceans that can rarely be addressed adequately by projects working in isolation. Recent reviews of the status of all four species in the genus Sousa (S. teuszii [3]; S. plumbea [2]; S. chinensis [4] and S. sahulensis [5] provide evidence for significant declines in most areas, and much more work is needed to increase scientific knowledge and raise public awareness.

 

References

  1. Plön, S., V.G. Cockcroft, and W.P. Froneman. 2015 Chapter Six – The Natural History and Conservation of Indian Ocean Humpback Dolphins (Sousa plumbea) in South African Waters, in Advances in Marine Biology, T.A. Jefferson and B.E. Curry, Editors, Academic Press. p. 143-162.
  2. Braulik, G.T., K. Findlay, S. Cerchio, and R. Baldwin. 2015 Chapter Five – Assessment of the Conservation Status of the Indian Ocean Humpback Dolphin (Sousa plumbea) Using the IUCN Red List Criteria, in Advances in Marine Biology, T.A. Jefferson and B.E. Curry, Editors, Academic Press. p. 119-141.
  3. Collins, T. 2015 Chapter Three – Re-assessment of the Conservation Status of the Atlantic Humpback Dolphin, Sousa teuszii (Kükenthal, 1892), Using the IUCN Red List Criteria, in Advances in Marine Biology, T.A. Jefferson and B.E. Curry, Editors, Academic Press. p. 47-77.
  4. Jefferson, T.A. and B.D. Smith. 2016 Chapter One – Re-assessment of the Conservation Status of the Indo-Pacific Humpback Dolphin (Sousa chinensis) Using the IUCN Red List Criteria, in Advances in Marine Biology, T.A. Jefferson and B.E. Curry, Editors, Academic Press. p. 1-26.
  5. Parra, G.J. and D. Cagnazzi. 2016 Chapter Seven – Conservation Status of the Australian Humpback Dolphin (Sousa sahulensis) Using the IUCN Red List Criteria, in Advances in Marine Biology, T.A. Jefferson and B.E. Curry, Editors, Academic Press. p. 157-192.

 

A tribute to the late Natalie Goodall and her museum at the end of the world

Peter Thomas at the Marine Mammal Commission kindly forwarded the following link, which we thought would be of interest to CSG members https://www.hakaimagazine.com/article-long/museum-end-world. Natalie was long active in the CSG, and many of you knew her and visited the unique collection of marine mammal material that she amassed in what was, by any measure, a remarkable life.

 

New SSC Panel: Advising on Dolphin Research and Conservation in China’s Pearl River Estuary

A Steering Committee chaired by Randall Reeves, with Bob Brownell, Rohan Currey, Frances Gulland, Randall Wells and Wang Ding as the other members, was recently established to assist Ocean Park Conservation Foundation Hong Kong (OPCFHK) in a long-term effort to support management measures and conservation-related research for Indo-Pacific humpback dolphins (Sousa chinensis), locally known as Chinese white dolphins (CWDs), in the Pearl River Estuary (PRE) and around Hong Kong. The first year of this initiative, which is founded on close collaboration among the CSG, the IUCN SSC Conservation Breeding Specialist Group (CBSG) and the Wildlife Health Specialist Group, has been funded through a grant to OPCFHK from the Hong Kong Airport Authority. To ensure transparency, relevant documentation (e.g. terms of reference, meeting agendas, reports) and updated information on activities within the program will be provided via a dedicated Special Projects page of the CSG website.

As a first step towards developing an overarching conservation framework and action plan, OPCFHK organized a Population Viability Analysis (PVA) workshop, led by Phil Miller of the CBSG, in Hong Kong from 30 March to 1 April 2016. In addition to the Steering Committee, the workshop was attended by Chinese and international scientists who have been studying the PRE CWD population, some of them for several decades – CSG members Bernd Würsig and Lindsay Porter, along with Samuel Hung, John Wang, and Leszek Karczmarski. CSG member Tom Jefferson, another PRE CWD expert, participated remotely for short periods. A workshop report that includes model specifications and initial results of the PVA is expected in September or October 2016. This will provide the basis for a CBSG-led conservation planning workshop with stakeholders, again in Hong Kong, in early 2017.

The Indo-Pacific humpback dolphin is currently red-listed as Near Threatened. The only subpopulation that has been formally assessed is in eastern Taiwan Strait (recently recognized as a subspecies, S. chinensis taiwanensis), listed as Critically Endangered. Both S. chinensis and the PRE subpopulation, along with the other three species currently recognized in the genus Sousa (S. sahulensis, S. plumbea and S. teuszii), were assessed at a CSG Red List workshop in May 2015. It is expected that the new assessments of all four Sousa species will be finalized before the end of this year but a formal Red List assessment of the PRE subpopulation is pending until the western extent of its range can be more clearly delineated. Meantime, however, it is clear that the PRE dolphins are in decline, living as they do in an environment that is being rapidly and massively degraded by myriad threats – intense vessel traffic (including high-speed ferries); commercial and recreational fishing; dredging and dumping to facilitate navigation and large-scale land ‘reclamation’; bridge and pier construction; and pollution from household, industrial and agricultural sources.

 

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