14 research outputs found
Epidemiology of lobomycosis-like disease in bottlenose dolphins Tursiops spp. from South America and southern Africa
We report on the epidemiology of lobomycosis-like disease (LLD), a cutaneous disorder
evoking lobomycosis, in 658 common bottlenose dolphins Tursiops truncatus from South America
and 94 Indo-Pacific bottlenose dolphins T. aduncus from southern Africa. Photographs and stranding
records of 387 inshore residents, 60 inshore non-residents and 305 specimens of undetermined origin
(inshore and offshore) were examined for the presence of LLD lesions from 2004 to 2015. Seventeen
residents, 3 non-residents and 1 inshore dolphin of unknown residence status were positive.
LLD lesions appeared as single or multiple, light grey to whitish nodules and plaques that may ulcerate
and increase in size over time. Among resident dolphins, prevalence varied significantly
among 4 communities, being low in Posorja (2.35%, n = 85), Ecuador, and high in Salinas, Ecuador
(16.7%, n = 18), and Laguna, Brazil (14.3%, n = 42). LLD prevalence increased in 36 T. truncatus
from Laguna from 5.6% in 2007â2009 to 13.9% in 2013â2014, albeit not significantly. The disease
has persisted for years in dolphins from Mayotte, Laguna, Salinas, the Sanquianga National Park
and BahĂa MĂĄlaga (Colombia) but vanished from the TramandaĂ Estuary and the Mampituba River
(Brazil). The geographical range of LLD has expanded in Brazil, South Africa and Ecuador, in areas
that have been regularly surveyed for 10 to 35 yr. Two of the 21 LLD-affected dolphins were found
dead with extensive lesions in southern Brazil, and 2 others disappeared, and presumably died, in
Ecuador. These observations stress the need for targeted epidemiological, histological and
molecular studies of LLD in dolphins, especially in the Southern Hemisphere.The Conselho Nacional de Desenvolvimento CientĂfico e
TecnolĂłgico (CNPq) to E.R.S. (PQ 307846/2014-8) and P.H.O.
(Process 572180/2008-0), and L.F. was sponsored by Petrobras through Petrobras Socio
Ambiental.http://www.int-res.com/journals/dao/dao-home/2020-11-30am201
Factors driving patterns and trends in strandings of small cetaceans
The incidence of cetacean strandings is expected to depend on a combination of factors, including the dis- tribution and abundance of the cetaceans, their prey, and causes of mortality (e.g. natural, fishery bycatch), as well as currents and winds which affect whether carcasses reach the shore. We investigated spatiotemporal patterns and trends in the numbers of strandings of three species of small cetacean in Galicia (NW Spain) and their relationships with meteoro- logical, oceanographic, prey abundance and fishing-related variables, aiming to disentangle the relationship that may exist between these factors, cetacean abundance and mor- tality off the coast. Strandings of 1166 common dolphins (Delphinus delphis), 118 bottlenose dolphins (Tursiops truncatus) and 90 harbour porpoises (Phocoena phocoena) during 2000â2013 were analysed. Generalised additive and generalised additive-mixed model results showed that the variables which best explained the pattern of strandings of the three cetacean species were those related with local ocean meteorology (strength and direction of the Northâ South component of the winds and the number of days with South-West winds) and the winter North Atlantic Oscil- lation Index. There were no significant relationships with indices of fishing effort or landings. Only bottlenose dolphin showed possible fluctuations in local abundance over the study period. There was no evidence of long-term trends in number of strandings in any of the species and their abun- dances were, therefore, considered to have been relatively stable during the study period.VersiĂłn del editor2,01
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