Marcos César de Oliveira Santos

Skin diseases in Guiana dolphins (Sotalia guianensis) from the Paranaguá estuary, Brazil: A possible indicator of a compromised marine environment

We report on the presence of lobomycosis-like disease (LLD) and nodular skin disease (NSD) in a community of Guiana dolphins (Sotalia guianensis) inhabiting the biologically and chemically contaminated Paranaguá estuary (Brazil) and on their absence in the community living in the cleaner Cananéia estuary. Prevalence rates of LLD and NSD were 3.9% and 12.6%, respectively, in 103 photo-identified (PI) dolphins from the Paranaguá estuary in the period 2006-2007. Adults and calves were affected. Lobomycosis-like lesions may be extensive and form large plaques. Skin nodules were sometimes ulcerated and associated with cutaneous traumas suggesting that traumatic injuries may play a role in the pathogenesis of this condition. In two adult dolphins, NSD evoked the beginning of LLD. In 1996-2007 none of the 200 PI Cananéia S. guianensis had LLD or NSD, a highly significant difference. Interestingly, these dolphins were reported to harbour relatively low concentrations of organochlorines. LLD and NSD are possibly indicators of environmental changes.

Social Organization of Marine Tucuxi Dolphins, Sotalia guianensis, in the Cananéia Estuary of Southeastern Brazil

Abstract Social organization is an important component of the population biology of a species that influences gene flow, the spatial pattern and scale of movements, and the effects of predation or exploitation by humans. An important element of social structure in mammals is group fidelity, which can be quantified through association indices. To describe the social organization of marine tucuxi dolphins (Sotalia guianensis) found in the Cananéia estuary, southeastern Brazil, association indices were applied to photo-identification data to characterize the temporal stability of relationships among members of this population. Eighty-seven days of fieldwork were conducted from May 2000 to July 2003, resulting in direct observations of 374 distinct groups. A total of 138 dolphins were identified on 1–38 distinct field days. Lone dolphins were rarely seen, whereas groups were composed of up to 60 individuals (mean ± 1 SD = 12.4 ± 11.4 individuals per group). A total of 29,327 photographs were analyzed, of which 6,312 (21.5%) were considered useful for identifying individuals. Half-weight and simple ratio indices were used to investigate associations among S. guianensis as revealed by the entire data set, data from the core study site, and data from groups composed of ≤10 individuals. Monte Carlo methods indicated that only 3 (9.3%) of 32 association matrices differed significantly from expectations based on random association. Thus, our study suggests that stable associations are not characteristic of S. guianensis in the Cananéia estuary.

Contamination by chlorinated pesticides, PCBs and PBDEs in Atlantic spotted dolphin (Stenella frontalis) in western South Atlantic

Chlorinated pesticides, PCBs and PBDEs were analysed in nine blubber samples of Atlantic spotted dolphins, Stenella frontalis, incidentally captured during fishing operations in southern and southeastern Brazil between 2005 and 2007. The majority of compounds analysed were detected, suggesting widespread contamination over the region. Although the samples came from a location far from main coastal industrial areas, the results revealed an influence from such sources. Therefore, levels of PCBs (774-23659 ng g(-1) lipid wt.) and PBDEs (23-1326 ng g(-1) lipid wt.) detected seem to be related to the movement of individuals throughout near-shore and offshore waters. The sample from a lactating female exhibited a lower level of contamination and a distinct pattern, indicating selective transfer favouring less lipophilic compounds.

Cetacean records along São Paulo state coast, Southeastern Brazil

A costa do Estado de Sao Paulo (SP) (23o18S, 44o42O; 25o14S, 48o01O) apresenta aproximadamente 600 km de extensao voltada para o Oceano Atlântico Ocidental no sudeste do Brasil. Registros de encalhes e de avistamentos de cetaceos vem sendo realizados ao longo desse litoral. Desde 1993, dados obtidos em literatura cientifica, material osteologico encontrado em museus, fotografias e artigos de arquivos de jornais, universidades e aquarios foram organizados e atualizados. Investigacoes efetuadas em campo referentes a encalhes e avistamentos de cetaceos tambem foram conduzidas. Um total de 29 especies de cetaceos foi registrado, incluindo 7 misticetos e 22 odontocetos, como indicados a seguir: Balaenoptera physalus, B. borealis, B. edeni, B. acutorostrata, B. bonaerensis, Megaptera novaeangliae, Eubalaena australis, Physeter macrocephalus, Kogia breviceps, K. sima, Berardius arnuxii, Mesoplodon europaeus, M. mirus, Ziphius cavirostris, Orcinus orca, Feresa attenuata, Globicephala melas, G. macrorhynchus, Pseudorca crassidens, Delphinus capensis, Lagenodelphis hosei, Steno bredanensis, Tursiops truncatus, Stenella frontalis, S. longirostris, S. coeruleoalba, Lissodelphis peronii, Sotalia guianensis e Pontoporia blainvillei. Algumas especies foram observadas apenas em uma ocasiao e incluem tanto vagantes de suas areas comuns de distribuicao, assim como de conhecidas areas de distribuicoes preferenciais oceânicas. Outras, como P. blainvillei e S. guianensis, sao comumente encontradas em aguas rasas o ano todo. Z. cavirostris, P. crassidens e L. hosei sao listados pela primeira vez para a costa de SP.

Group size and composition of Guiana dolphins (Sotalia guianensis) (Van Bénèden, 1864) in the Paranaguá Estuarine Complex, Brazil

The aim of the present study was to describe the characteristics of Guiana dolphins (S. guianensis) group size and composition in the Paranaguá Estuarine Complex (25 degrees 15-25 degrees 36 S and 48 degrees 02-48 degrees 45 W), Paraná State, as well as to verify the existence of relationships between a given environmental variable (water depth, salinity, transparency and temperature) and group size. An area of around 124 km(2) was surveyed by boat from April 2006 to February 2008 in the following subsets of the estuary: Canal do Superagui (approximately 28 km(2)), Pinheiros bay (approximately 34 km(2)), part of Laranjeiras bay, which included the Guaraqueçaba sub-estuary (approximately 38 km(2)), and part of the Mixture Section of the Paranaguá Estuarine Complex (approximately 24 km(2)). In 45 survey days, a total of 147 hours were spent observing 286 groups of S. guianensis. Groups varied from two individuals to aggregations of up to 90 individuals (mean +/- SD: 11.5 +/- 14.4 individuals). Solitary individuals were seen only on five occasions (1.7% of all observations). Groups with calves (n = 247) represented 86.4% overall and were more common in all sub-areas when compared to groups without calves. Groups without calves were found in all sub-areas and were usually smaller and composed of up to 12 individuals. A usual group composition of 70% of adults and 30% of calves was observed considering all sub-areas and seasons. No correlations were found between group size and water temperature (Spearmans rank test, r = 0.0059, p = 0.9338), transparency (Spearmans rank test, r = 0.0597, p = 0.9333), depth (Spearmans rank test, r = 0.1421, p = 0.4698), and salinity (Spearmans rank test, r = -0.1938, p = 0.0665). While Guiana dolphin groups were seen in the entire surveyed area, group size varied significantly among the three main surveyed sub-areas (Kruskal Wallis, H2,196 = 29.85, p = 0.0000). Groups were larger in Laranjeiras bay and smaller in Canal do Superagui. The physical environment, risk of predation, seasonal distribution and abundance of prey are the main possible factors driving larger groups in inner and protected waters.

Records of a male killer whale (Orcinus orca) off Southeastern Brazil

Universidade Estadual Paulista Julio de Mesquita Filho (UNESP) Instituto de Biociencias, Departamento de Zoologia Projeto Atlantis, Laboratorio de Biologia da Conservacao de Cetaceos (Campus Rio Claro, Av. 24-A, 1.515, Bela Vista, 13506-900 Rio Claro, SP, Brasil) E-mail: sotalia@gmail.com Killer whales (

Home ranges of Guiana dolphins (Sotalia guianensis) (Cetacea: Delphinidae) in the Cananéia estuary, Brazil

Home ranges of seven Guiana dolphins (Sotalia guianensis) (Van Beneden, 1864) were studied in the Cananeia estuary (~25°03S 47°55W), south-eastern Brazil. Boat-based observations were conducted from May 2000 to July 2003 in ~132 km 2 of protected inner waters. The photo-identification technique was used to follow naturally marked individuals through time and space. From a total of 13 8 catalogued individuals, five males and two females presented 20+ sightings and were used for home range estimation. Sightings were plotted and analysed in a Geographic Information System (GIS). With the Home Range Tools extension the fixed kernel density estimator with band width (smoothing parameter) chosen via least squares cross-validation was performed for each individual. The fixed kernel method was used to estimate the non-parametric utility distribution of each dolphin, keeping band width (h) constant for a data set. The first polygons created by these parameters had an amoeboid shape and in some cases more than one centre of activity. The 95% home range estimated outlines varied from 1.6 to 22.9 km 2 ( 7 . 9 ± 8. 3 km 2 ). This large interval shows strong evidences on individual variation in S. guianensis home ranges. Several individuals showed small home ranges when compared to other cetacean species. An overlap of home ranges of different sizes and shapes were observed for Guiana dolphins with large range movements. Centres of activity were concentrated in the main entrance of the Cananeia estuary. This was a first attempt to understand the way S. guianensis uses the Cananeia estuary and such data are essential for conservation and management purposes.

Feeding associations between Guiana dolphins, Sotalia guianensis (Van Bénèden, 1864) and seabirds in the Lagamar estuary, Brazil

The main objective of the present study was to describe the characteristics regarding interactions between Guiana dolphins, Sotalia guianensis and seabirds in feeding associations in two distinct areas of the Lagamar estuary, Brazil. Boat-based surveys directed towards photo-identification studies of S. guianensis were conducted in the Cananéia Estuary (CE) (25 degrees 01 S and 47 degrees 55 W) from July 2004 to March 2008, as well as in the Paranaguá Estuarine Complex (PEC) (25 degrees 24 S and 48 degrees 24 W) from April 2006 to February 2008. On all occasions when seabirds were observed engaging in multi-species feeding associations with S. guianensis, data on species involved and their numbers were gathered. From 435 observed groups of S. guianensis in the CE, 38 (8.7%) involved interactions with seabirds. In the PEC, from the 286 observed groups, 32 (11.2%) involved the mentioned interactions. The following seabirds were observed in feeding associations with S. guianensis: Fregata magnificens, Sula leucogaster, Phalacrocorax brasilianus, and Sterna sp. In the CE, S. leucogaster was more commonly observed in feeding associations with Guiana dolphins (chi2 = 22.84; d.f. = 3, p < 0.05), while in the PEC no differences were reported when comparing seabird species (chi2 = 5.78; d.f.=3, p = 0.1223). In the CE, feeding associations were significantly more frequent in inner waters (subset A0; chi2 = 9.52; d.f. = 2, p < 0.05), and in winter (chi2 = 12.46; d.f. = 1, p < 0.05). Within these events, 44.7% of the association groups were composed by more than one seabird species. Seasonality in feeding associations was also observed in the PEC (chi2 = 4.76; d.f. = 1, p < 0.05), with same patterns observed in the CE. Interactions were more frequent in inner waters of the Laranjeiras bay, PEC (chi2 = 11.65; d.f. = 2, p < 0.05). Within these events, 74.2% of the association groups were composed by more than one seabird species. Water transparency, prey and seabird abundance and distribution, cetacean group size, and the life cycle of prey and seabirds are listed as the main factors addressing multi-species feeding associations in the Lagamar estuary.

Sightings of franciscana dolphins (pontoporia blainvillei): the discovery of a population in the Paranaguá estuarine complex, Southern Brazil

Universidade Estadual Paulista Julio de Mesquita Filho (UNESP) Instituto de Biociencias, Departamento de Zoologia Projeto Atlantis, Laboratorio de Biologia da Conservacao de Cetaceos (Campus Rio Claro, Av. 24-A, 1.515, Bela Vista, 13506-900 Rio Claro, SP, Brasil) E-mail: sotalia@gmail.com Franciscana dolphins (

Guiana dolphin home range analysis based on 11 years of photo-identification research in a tropical estuary

Home range studies provide significant insights on social organization and interactions, limiting resources and habitat use. Knowledge on home range and habitat use by Guiana dolphins, Sotalia guianensis, is still scarce. The aim of this study was to identify and analyze individuals home ranges of Guiana dolphins in the Cananéia Estuary (∼25°03′S, 47°55′W), located in southeastern Brazil. Photo-identification efforts were conducted between 2000 and 2010. From a total of 135,918 pictures taken, 34,086 (25%) were useful for individual identification. Two-hundred and five individuals were cataloged based on permanent notches along dorsal fin borders. Of the cataloged individuals, 31 had been identified a minimum of 20 times, on distinct dates, prior to this analysis. Home ranges were estimated for these individuals using 4 methods: minimum convex polygon (MCP), adaptive kernel with least-squares cross-validation (AKLSCV), fixed kernel with reference bandwidth (FKHREF), and fixed kernel with least-squares cross-validation (FKLSCV). The sizes of the estimated home ranges varied between 2.2 and 43.8 km2 ( = 17.5 km2) with MCP, between 0.8 and 82.5 km2 ( = 15.6 km2) with AKLSCV, between 3.9 and 244 km2 (X = 72.4 km2) with FKHREF, and from 0.6 to 70.6 km2 ( = 13.5 km2) with FKLSCV Significant differences in size and shape of the generated areas were detected when comparing the 4 tested methods. Variation of individuals home range sizes and an extensive overlap among home ranges of different Guiana dolphins in the Cananéia Estuary provide evidence that the region supports important resources for this species. Therefore, preventing habitat loss in this region is essential to guaranteeing the persistence of this population.