A study of skin diseases and traumata and the etiology of these lesions in Inshore/ Indian Ocean Bottlenose Dolphins (Tursiops aduncus) in the Ponta do Ouro – Santa Maria Area, Southern Mozambique

Abstract

Abstract

There is an increasing interest and awareness concerning the health of cetacean species worldwide. However because of a lacking in non-invasive methods with minimal disturbance of the animal it remains difficult to evaluate the status of their health. Recently more research has been done on skin lesions of the cetacean and the possibility to extrapolate this to their immune status and health in general, using our knowledge of other species. During this study a population of inshore bottlenose dolphins (Tursiops aduncus) in Ponta du Ouro, Mozambique, were studied through top and in-water observations as well as through photographs taken during previous years. This data was analyzed and categorized according to the lesions described in previous study papers. The following lesion categories were used; skin disease, lesions of unknown origin, trauma, parasites and deformities. These were again differentiated and showed the following results of dolphins affected; Remora, 36 (8.40%), Stalked barnacles, 36 (8.40%), Open wounds, 57 (13.3%), Tattoo lesions, 26 (6.10%), Tattoo-like lesions, 11 (2.60%), Round cutaneous lesions, 16 (3.70%), White marks, 111 (25.90%), Traumatic lesions, 15 (3.5%), Scars and rake marks, 96 (22.70%), Tumors, 5 (1.20%) and Vesicular skin disease, 18 (4.20%). The origin of many of these lesions is unknown and further studies could provide more insight as to their exact mechanisms and influence on the cetacean’s general health. When comparing these lesions found to those in South American waters the main difference seems to be the pollutant effect of the water. Many lesions in those regions can be related to or contributed to anthropogenic factors in the water. In Mozambiquan waters the lesions more often present to be due to inter- and intra- species interaction and other natural causes. There is no statistical significance found between the occurrence of the different lesions of between the different body areas that the lesions are on. Further research would be useful when biopsies of different lesions could be taken to determine and further differentiate their etiology.