We'd like to draw your attention to our paper "Guiana dolphins (Sotalia guianensis) as marine ecosystem
sentinels: ecotoxicology and emerging diseases” which was recently published in “Reviews of Environmental Contamination and Toxicology (Springer)”. The
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Moura J.M., Hauser-Davis R.A., Lemos L., Emin-Lima R., Siciliano S. (2014) Guiana dolphins (Sotalia guianensis)as marine ecosystem sentinels: ecotoxicology and emerging diseases. D.M. Whitacre (ed.) Reviews of Environmental Contamination and Toxicology, 228, 1-29.
DOI: 10.1007/978-3-319-01619-1_1
Guiana dolphins (Sotalia guianensis) are small cetaceans
that inhabit coastal regions down to a 50 m depth. As a coastally distributed
species, they are exposed to a variety of human-induced risks that include
passive fishing nets, persistent environmental pollution, and emerging
diseases. As a top predator S. guianensis
occupies an important ecological niche in marine ecosystems. However, this
niche also exposes this dolphin to extensive biomagnification of marine
contaminants that may accumulate and be stored throughout their life of about
30 years. In this paper, we have compiled available data on the Guiana dolphin
as regards its exposure to chemical pollutants, pathogenic microbes, infectious
diseases, and injuries caused by interactions with passive fishing gears. Our
analysis of the data shows that Guiana dolphins are particularly sensitive to
environmental changes. Although the major mortal threat to dolphins results from
contact with fishing, other human-related activities in coastal zones also pose
risks and need more attention. Such human-related risks include the presence of
persistent toxicants in the marine environment, such as PCBs and PBDEs.
Residues of these chemicals have been detected in Guiana dolphin’s tissues at
similar or higher levels that exist in cetaceans from other known polluted
areas. Another risk encountered by this species is the nonlethal injuries
caused by fishing gear. Several incidents of this sort have occurred along the
Brazilian coast with this species. When injuries are produced by interaction
with fishing gear, the dorsal fin is the part of the dolphin anatomy that is
more affected, commonly causing severe laceration or even total loss. The
Guiana dolphins also face risks from infectious diseases. The major ones thus
far identified include giardiasis, lobomycosis, toxoplasmosis, skin and
skeletal lesions. Many bacterial pathogens from the family Aeromonadaceae and Vibrionaceae
have been isolated from Guiana dolphins. Several helminth species have also
been observed to affect S. guianensis
. These results suggest a vulnerability of this species to environmental
disturbances. Moreover, there is some evidence that the effects of some infectious
diseases may be enhanced from stress caused by habitat impairment. For example,
certain diseases and pathogenic organisms in S. guianensis may be associated with the high levels of
endocrine-disruptor contaminants (e.g., PCBs; DDTs; PBDEs) that have been
detected in marine waters. Although the data available on S. guianensis is growing, most of the work has been focused on a
small portion of the species total area of distribution. Most studies, to date,
have been carried out in the Southern region of the distribution, and in northeastern
Brazil. Few studies have been conducted in the northern region of the South
America or in Central America. Therefore, future studies should be conducted that
address the heterogeneity of this species total distribution. The biology and
ecology of the Guiana dolphin renders this species potentially useful as a
sentinel species for detecting environmental changes, such as chemical and
biological pollution. Research about this dolphin is encouraged as a way to assess
what coastal environmental changes have occurred and to continue evaluating the
health status of this vulnerable species in a changing environment.
Requests for reprints can be sent to: jailsonfm@gmail.com
All the best,
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