Investigating long-term host-parasite dynamics in odontocetes in Southern Africa

• Main Author: Adams, Inge Alison
• Format: Master Thesis
• Language: English
• Published: Nelson Mandela University 2018
• Subjects: Biological invasions > Environmental aspects; Cetacea > Indian Ocean; Ecological disturbances; Pacific; Indian; Sperm whale
• Online Access: http://hdl.handle.net/10948/23437; https://corycommons.ru.ac.za/vital/access/manager/Repository/vital:30543

Cetaceans are a very diverse family and globally, various aspects about their biology have been studied, including infection by parasites. Twenty-five dolphin species can be found in the South African subregion and very little information is available detailing which parasites are infecting them. Parasite samples have been collected opportunistically since the 1970’s from dolphins incidentally caught in shark nets off the KwaZulu-Natal coastline as well as from dolphins stranded along the Eastern Cape coastline. These samples have been stored in the Graham Ross Marine Mammal Collection at the Port Elizabeth Museum and samples belonging to eight odontocete species have been used in the present analysis. These eight species are: the Indian Ocean Humpback Dolphin (Sousa plumbea), the Indo-Pacific Bottlenose Dolphin (Tursiops aduncus), the Long-beaked Common Dolphin (Delphinus capensis), the Risso’s Dolphin (Grampus griseus), the Pantropical Spotted Dolphin (Stenella attenuata), the Striped Dolphin (Stenella coeruleoalba), the Pygmy Sperm Whale (Kogia breviceps) and the Dwarf Sperm Whale (Kogia breviceps). This study aims to investigate which parasites are infecting odontocetes in Southern Africa. Secondly, this study aims to investigate whether any trends in infection exist between sexes, age groups, cause of death and over time. Eighteen parasite species were found to infect odontocetes in Southern Africa. Two could only be identified to family level, seven to genus level and eight to species level. Only one parasite, a trematode, could not be identified and several parasite species were new host records for the subregion. Results showed that the prevalence of parasitic infection has increased over the last four decades, prompting questions regarding the health of our oceans. This study is the first to comprehensively investigate which parasite species are found in these eight odontocete species in Southern Africa. This baseline data will contribute greatly to other types of research involving parasites and ...