2 research outputs found
A standardized necropsy protocol for health investigations of small cetaceansin southern Africa
Globally, the increasing need to conduct both research and surveillance of the health of wild
animal populations has been recognized as an important tool in conservation and management.
While such studies on terrestrial wildlife are frequent in the southern African
sub-region, their counterparts in the marine environment seem to be largely lacking. Here we
report on our experience in establishing and testing a standardized necropsy protocol for
small cetaceans adapted for the local context, with the specific aim of sampling for health
investigations and monitoring. The necessity, challenge and value of regional standardization
in data collection specifically aimed at health investigations, inter-disciplinary collaboration,
long-term data banking,and sample storage are discussed in addition to practical and safety
considerations. The developed protocol, focusing on the necropsy technique and tissue
sample collection, as well as a list of required equipment are available as online supplementary
material.The
National Research Foundation (DFG-NRF collaboration
programme grant number 70714 and
SEAChange grant number 74241, both awarded
to S. Plön).http://www.sawma.co.zaam201
A systematic health assessment of two dolphin species by-caught in shark nets off the KwaZulu-Natal Coast, South Africa
Coastal dolphin populations are indicators of environmental health and may be sensitive to
anthropogenic influences. An observed increase in lesions during routine necropsies of
dolphins prompted the first systematic health assessment of dolphins incidentally caught in
shark nets off the KwaZulu-Natal coast. A detailed standard dissecting and sampling
protocol for small cetaceans was developed for use in South Africa. Thirty five Indian Ocean
bottlenose dolphins (Tursiops aduncus) and five Indo-Pacific humpback dolphins (Sousa
chinensis), incidentally caught between 2010 and 2012, were subsequently evaluated by full
necropsy and sampling using this protocol.
All animals were considered to be in good nutritional condition, based on blubber thickness
measurements and muscle condition. A large proportion of dolphins had lesions with
parasitic aetiology, including pneumonia (34/40), bronchiolar epithelial mineralisation
(33/40), gastroenteritis (28/40), hepatitis (24/39); endometritis (11/26), capsular inflammation
of various abdominal and thoracic organs (30/40), and splenic capsular tags (18/40). Four
parasite species (Halocercus sp., Crassicauda sp., Brachycladiinae, and Xenobalanus
globicipitis) were recovered from six animals. Non-specific encephalomeningitis was found in
7/18 animals. Adrenal cortical hyperplasia (18/37,) possibly related to chronic stress, was
also found, as well as myocardial fibrosis (10/39). Pulmonary pneumoconiosis and lymph
node foreign material accumulation, possibly indicating exposure to polluted air, was seen in
three animals. Lesions suggestive of morbillivirus, Toxoplasma gondii, or Brucella spp.
tested negative on immunohistochemistry. The first confirmed cases of lobomycosis and
sarcocystosis in South Africa were found. Most lesions were mild, although their high and
apparently increasing prevalence may indicate a change in the host/parasite interface. This
may be attributed to anthropogenic factors, such as stress or environmental pollution,
suggesting degradation of the marine environment. This could also negatively impact human
populations associated with the marine environment.
The results indicate a need for continued health monitoring of coastal dolphin populations
and for further research into disease pathophysiology and anthropogenic factors affecting
these populations. This standard necropsy protocol will encourage a more complete health
investigation of incidentally caught and stranded cetaceans in the region and will assist in
expanding the current knowledge of diseases affecting dolphin populations in southern
Africa. Furthermore, we provide valuable information regarding the baseline of disease
affecting these populations, which may be used to determine and monitor temporal trends.Dissertation (MSc)--University of Pretoria, 2013.gm2014Production Animal Studiesunrestricte