Dear MARMAM subscribers,

 

My co-authors and I are pleased to announce a new publication on humpback dolphins (Sousa plumbea) in South Africa:

 

R. P. Koper, L. Karczmarski, D. Du Preez, and S. Plön (2015)

Sixteen years later: Occurrence, group size, and habitat use of humpback dolphins (Sousa plumbea) in Algoa Bay, South Africa

Marine Mammal Science. DOI: 10.1111/mms.12279.

 

Abstract:

Coastal dolphins are more prone to cumulative impacts of environmental and

anthropogenic changes than pelagic species. However, few studies use historical

comparisons to evaluate those impacts across a temporal scale. The study presented

here describes the pattern of occurrence, group size, behavior, and habitat use of

humpback dolphins in Algoa Bay and compares these to a similar study conducted

in the early 1990s. Results indicate a considerable change in the frequency of occurrence.

Furthermore, the mean group size has decreased from six to three individuals,

mainly due to an increase in occurrence of solitary individuals (36.3% vs. 15.4%).

Foraging, which was previously the predominant activity (64%), has now been

replaced by traveling (49%). Moreover, dolphins showed a negative reaction towards

a variety of watercrafts and swimmers. These observed differences could be due to a

change in prey abundance, direct anthropogenic disturbance, and/or population

decline. We emphasize the need for long-term environmental and biological data

series and long-term monitoring of the demographics of this population to accurately

assess any changes observed in future.

 

For any further info please contact stephanie.plon@nmmu.ac.za.

 

Dr. Stephanie Plön

Coastal and Marine Research Institute

Nelson Mandela Metropolitan University

PO Box 77000

Port Elizabeth, 6031

 

Tel: 041-5042877

Cell: 076-3791067

Fax: 041-5832317