Humpback dolphin conservation

The Indian Ocean humpback dolphin (Sousa plumbea) is an Endangered, near-shore species found in shallow coastal waters (generally under 30 m deep) along South Africa's coastline, where it faces mounting pressure from coastal development, boat traffic and habitat degradation. Our work spans passive acoustic monitoring, boat-based photo-identification, and long-term population studies, including Sasha's ongoing Rufford Foundation-funded project, which continues acoustic and boat-based monitoring of the species in Mossel Bay, a key area facing pressure from planned harbour expansion, to build the baseline data needed to inform environmental impact assessments and conservation policy.

Sea Search is part of the SouSA Consortium, a national partnership formed in 2016 between South African scientists and research groups to support range-wide estimates of population size and trends, movement and connectivity between regions, and population viability for Sousa plumbea in South African waters. Sasha now serves as coordinator of the SouSA Consortium, having joined the group during her PhD with Sea Search and Stellenbosch University.

We're also part of HuDoNet, the Indian Ocean Humpback Dolphin Conservation Network, which connects nearly 100 researchers and conservationists across 18 countries to conserve humpback dolphins throughout their global range. HuDoNet's work is organised into five Working Groups (Biological Research, Threats & Solutions, People, Policy, and Network Success), and Sasha and Simon both lead Working Groups within the network. HuDoNet's reports, including its Network Action Plan, are available here.

PUBLICATIONS on HUMPBACK DOLPHINS

Hermie the Humpback Dolphin – A Longitudinal Case Study Characterising the Acoustic Behaviour of an Endangered Indian Ocean Humpback Dolphin (Sousa plumbea)
Dines, S., Probert, R., Gullen, A., Elwen, S.H., Frainer, G., Gridley, T.
JASA Express Letters, 4(12). DOI: 10.1121/10.0034740

Rostrum Abnormalities in the Endangered Indian Ocean Humpback Dolphin (Sousa plumbea) in South Africa
Frainer, G., Elwen, S.H., Dines, S.F., James, B.S., Vermeulen, E., Penry, G., Vargas-Fonseca, A., Atkins, S., Conry, D., Gridley, T.
Integrative Zoology, 2022; 0: 1–14. DOI: 10.1111/1749-4877.12685

Science Alone Won't Do It! South Africa's Endangered Humpback Dolphins Sousa plumbea Face Complex Conservation Challenges
Plön, S. et al. (13 co-authors)
Frontiers in Marine Science, 2021.

Indian Ocean Humpback Dolphin (Sousa plumbea) Movement Patterns Along the South African Coast
Vermeulen, E., Bouveroux, T., et al. (14 authors in total), … Elwen, S.H.
Aquatic Conservation: Marine and Freshwater Ecosystems, 2017. DOI: 10.1002/aqc.2836

Abundance and Degree of Residency of Humpback Dolphins (Sousa plumbea) in Mossel Bay, South Africa
James, B.S., Bester, M.N., Penry, G.S., Gennari, E., Elwen, S.H.
African Journal of Marine Science, 2015; 37.

THESES on HUMPBACK DOLPHINS

Applied Passive Acoustic Monitoring of South Africa's Most Threatened Marine Mammal, the Indian Ocean Humpback Dolphin (Sousa plumbea)
Dines, S.F.
PhD thesis, Stellenbosch University, Dept. of Botany and Zoology, 2025.

Natural and Human Impacts on Habitat Use of Coastal Delphinids in the Mossel Bay Area, Western Cape, South Africa
James, B.S.
MSc thesis, University of Pretoria, Dept. of Zoology and Entomology, 2014.

Developing Methods to Use Static Acoustic Click Detectors for Long-term Monitoring of Coastal Delphinids Along the Cape South Coast, South Africa
Betts, M.E.
MSc thesis, University of Pretoria, Dept. of Zoology and Entomology, 2016.