Most current bioexposure assessments for UV filters focus on contaminants concentrations in fish from river and lake. To date there is not information available on the occurrence of UV filters in ...marine mammals. This is the first study to investigate the presence of sunscreen agents in tissue liver of Franciscana dolphin (Pontoporia blainvillei), a species under special measures for conservation. Fifty six liver tissue samples were taken from dead individuals accidentally caught or found stranded along the Brazilian coastal area (six states). The extensively used octocrylene (2-ethylhexyl-2-cyano-3,3-diphenyl-2-propenoate, OCT) was frequently found in the samples investigated (21 out of 56) at concentrations in the range 89-782 ng·g(-1) lipid weight. São Paulo was found to be the most polluted area (70% frequency of detection). Nevertheless, the highest concentration was observed in the dolphins from Rio Grande do Sul (42% frequency of detection within that area). These findings constitute the first data reported on the occurrence of UV filters in marine mammals worldwide.
To catalog the diversity and abundance of halogenated organic compounds (HOCs) accumulating in high trophic marine species from the southwestern Atlantic Ocean, tissue from bottlenose dolphins ...(Tursiops truncatus) stranded or incidentally captured along the coast of Rio de Janeiro, Brazil, were analyzed by a nontargeted approach based on GC×GC/TOF-MS. A total of 158 individual HOCs from 32 different structural classes were detected in the blubber of 4 adult male T. truncatus. Nearly 90% of the detected compounds are not routinely monitored in the environment. DDT-related and mirex/dechlorane-related compounds were the most abundant classes of anthropogenic origin. Methoxy-brominated diphenyl ethers (MeO-BDEs) and chlorinated methyl- and dimethyl bipyrroles (MBPs and DMBPs) were the most abundant natural products. Reported for the first time in southwestern Atlantic cetaceans and in contrast to North American marine mammals, chlorinated MBPs and DMBPs were more abundant than their brominated and/or mixed halogenated counterparts. HOC profiles in coastal T. truncatus from Brazil and California revealed a distinct difference, with a higher abundance of MeO-BDEs, mirex/dechloranes and chlorinated bipyrroles in the Brazilian dolphins. Thirty-six percent of the detected HOCs had an unknown structure. These results suggest broad geographical differences in the patterns of bioaccumulative chemicals found in the marine environment and indicate the need to develop more complete catalogs of HOCs from various marine environments.
This paper reviews the available data on brominated flame retardants, the polybrominated diphenyl ethers (PBDEs), as well as on the naturally-produced methoxylated polybrominated diphenyl ethers ...(MeO-PBDEs) in cetacean tissues around the world. Levels and possible sources of both compound classes are discussed. Odontocete cetaceans accumulate higher PBDE concentrations than mysticete species. PBDE contamination was higher in cetaceans from the Northern hemisphere, whereas MeO-PBDE levels were higher in animals from the Southern hemisphere. Southern resident killer whales from NE Pacific presented the highest levels reported in biota, followed by bottlenose dolphins from North Atlantic (U.K. and U.S. coast). Many species presented PBDE concentrations above threshold levels for health effects in odontocetes. Time trend studies indicate that PBDE concentrations in odontocetes from Japan, China, U.S. and Canada coastal zones have increased significantly over the past 30years. Studies from U.K. waters and NE Atlantic showed a decrease and/or stability of PBDE levels in cetacean tissues in recent decades. The highest MeO-PBDE concentrations were found in dolphins from Tanzania (Indian Ocean), bottlenose dolphins from Queensland, Australia (SW Pacific), and odontocetes from coastal and continental shelf waters off southeastern Brazil (SW Atlantic). The upwelling phenomenon and the presence of coral reef complexes in these tropical oceans may explain the large amounts of the naturally-produced organobromines. Considering that these bioaccumulative chemicals have properties that could cause many deleterious effects in those animals, future studies are required to evaluate the potential ecotoxicological risks.
•PBDE contamination is higher in cetaceans from Northern than Southern hemisphere.•The opposite occurs in relation to MeO-BDEs contamination.•Only in UK the PBDE concentrations in cetaceans decreased in the last decades.•Studies presented PBDE levels higher than the threshold to potential health effects in marine mammals.
At present, there are still populations of different balaenopterids that have never been acoustically recorded and observed simultaneously. In an opportunistic sighting of dwarf minke whales during ...winter in southeastern Brazil, we have registered six individuals and recorded over 200 acoustic signals. Signals were quantified and had their acoustic parameters extracted; the calling rate was estimated as the number of sounds per minute, and the repetition rate was estimated as the number of calls of the same type emitted per minute. Four call types were described: Ba1, Ba2, Ba3 and Ba4. The most common and distinctive call was the Ba1, composed of three components: one had a peak frequency of 615.0 ± 189.8 Hz, and the other had peak frequencies of 1632.0 ± 191.5 and 5038.2 ± 195.1 Hz. Ba1 repetition varied from 2.4 to 11.1 repetitions/min. Ba2 was the second most common call with a peak frequency of 485.2 ± 421.9 Hz. The total calling rate varied from 4.4 to 11.1 calls/min. The signals are in the same frequency range reported for other areas but contain different structures.
1. The common dolphins (genus Delphinus) have one of most problematic taxonomies and complex distribution patterns of all cetaceans. Although the taxonomy and the distribution seem to have been ...clarified somewhat in the eastern North Pacific and Indo-Pacific Oceans, many questions remain in the Southwestern Atlantic Ocean (SWA). We review the biogeography of Delphinus in the SWA. 2. We reviewed data from strandings, incidental catches and sightings since 1922. Systematic surveys were conducted in five major areas. Twenty-one natural history collections were examined, and 135 skulls were measured. 3. A total of 184 records of common dolphins were compiled. Delphinus apparently occurs in three stocks in the SWA: one located in northern Brazil and two from southeastern Brazil (~22°S) to central Argentina (~42°S). Two distinct patterns in habitat use were observed by depth: in southeastern Brazil, sightings were restricted to coastal waters with water depths ranging from 18m to 70m. On the other hand, in the area that extends from southern Brazil to Central Argentina (from 28°S to 42°S), sightings were recorded in deeper waters, ranging from 71m to 1435m, with the exception of occasional coastal sightings. The cranial analyses demonstrated that both short-beaked common dolphins Delphinus delphis and long-beaked common dolphins Dephinus capensis occur in the SWA. 4. In the SWA, Delphinus seems to occur near areas of high productivity. One stock is associated with the productive waters discharged by the Amazon River and possibily with the coastal upwelling system off the coast of Venezuela, while the other stocks are associated with the Cabo Frio upwelling system and the Subtropical Convergence. Our results indicate that the current taxonomy does not adequately reflect the amount of variation within the genus in the world.
Acoustic studies of Guiana dolphin have been focused on whistles, with little known about pulse signals in this species. This study characterized the temporal and spectral properties of Guiana ...dolphin burst pulses. Groups of 2 to 23 Guiana dolphins were recorded while feeding and socializing in shallow waters in Guanabara Bay, southeastern Brazil, in 2013 and 2014. Burst pulse analysis involved two steps: signal detection and acoustic parameter analysis. Eight variables were analyzed for 197 total burst pulses: number of clicks, burst pulse duration, interclick interval, click duration, peak frequency, center frequency, -3 dB bandwidth, and -10 dB bandwidth. Mean burst pulse duration was 108.6 ms standard deviation (SD) = 91.3 with a mean of 168 clicks (SD = 137.3). Burst pulses had short interclick interval (0.7 ms, SD = 0.3) and mean click duration of 300 μs (SD = 100). Mean peak frequency and center frequency were 28 kHz (SD = 11.6) and 29 kHz (SD = 11.0), respectively. Mean -3 dB bandwidth was 15 kHz (SD = 7.5) and mean -10 dB bandwidth was 40.5 kHz (SD = 14.3). The quantitative characterization of Guiana dolphin burst pulses is an important step in describing the full acoustic repertoire of this species.
This study focused on whistles produced by Guiana dolphin under different noise conditions in Guanabara Bay, southeastern Brazil. Recording sessions were performed with a fully calibrated recording ...system. Whistles and underwater noise levels registered during two behavioral states were compared separately between two areas. Noise levels differed between the two areas across all frequencies. Whistle duration differed between areas and was negatively correlated with noise levels. Whistling rate was positively correlated with noise levels, showing that whistling rate was higher in noisier conditions. Results demonstrated that underwater noise influenced Guiana dolphin acoustic behavior.
•Acoustic parameters of Guiana dolphin whistles were investigated in relation to noise levels.•Guiana dolphin whistles were shorter in areas with higher noise levels.•Guiana dolphins emitted more whistles when in noisier situations.•Guiana dolphin strategies to avoid masking varies with behavior.
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