Pontoporia blainvillei (Rio Grande do Sul/Uruguay subpopulation): Secchi, E. & Wang, J.Y.

Author(s):  
Author(s):  
Daniel Danilewicz ◽  
Eduardo R. Secchi ◽  
Paulo H. Ott ◽  
Ignacio B. Moreno ◽  
Manuela Bassoi ◽  
...  

The patterns of habitat use by the franciscana dolphins (Pontoporia blainvillei) along its distribution are poorly known. This study investigates the patterns of habitat use with respect to depth for 181 individuals of different age, size, gender and reproductive condition off Rio Grande do Sul, southern Brazil. The results reveal that franciscanas are very homogeneously distributed according to depth. Individuals from all lengths utilize nearly the entire range of depths of the surveyed area. Larger or older animals do not use deeper waters than younger animals, indicating that body size and age are not limiting factors for franciscanas that occupy deeper or offshore waters. Gestation seems to not cause a change in the distribution of females. Although the sex-ratio of the overall data did not vary from 1:1 in different depth intervals, a small-scale comparison between the northern and southern coast demonstrated the existence of some kind of sexual segregation. Franciscana by-catch in Rio Grande do Sul is not sustainable and it is agreed that management procedures are needed. Nevertheless, the available data on species distribution do not allow the designing of a protected area in order to minimize the by-catches of a particular sex/reproductive class.


2007 ◽  
Vol 88 (5) ◽  
pp. 1335-1341 ◽  
Author(s):  
Glauco Caon ◽  
Clarice Bernhardt Fialho ◽  
Daniel Danilewicz

2007 ◽  
Vol 55 (3) ◽  
pp. 179-186 ◽  
Author(s):  
Paulo Renato Dorneles ◽  
José Lailson-Brito ◽  
Eduardo Resende Secchi ◽  
Manuela Bassoi ◽  
Catarina Pereira Coutinho Lozinsky ◽  
...  

Franciscana dolphins were used as source of information on the bioavailability of cadmium in the neritic waters off South Brazilian Coast. Liver samples obtained from 44 individuals incidentally captured off Rio Grande do Sul State were analyzed by electrothermal AAS. Cadmium concentrations, age, total weight and length of the analyzed dolphins varied between 39 and 4144 µg.kg-1 (wet weight), one and five years, 17.5 and 49.2 kg, and between 105.3 and 156.8 cm, respectively. Concerning hepatic cadmium concentrations of franciscanas, there was no significant difference between data raised by the present study and information from literature, regarding Rio de Janeiro State. The low cadmium concentrations observed may be attributed to the fact that loliginid squids constitute the main cephalopod prey for franciscanas. This study corroborates investigations on cadmium levels in Brazilian squids and strengthened the hypothesis that cephalopods of Loliginidae Family do not constitute important vectors of the transfer of cadmium to cetaceans.


1998 ◽  
Vol 76 (9) ◽  
pp. 1622-1627 ◽  
Author(s):  
Eduardo R Secchi ◽  
John Y Wang ◽  
Brent W Murray ◽  
Claudia C Rocha-Campos ◽  
Bradley N White

The franciscana, Pontoporia blainvillei, is a dolphin that experiences extensive incidental mortality in fisheries throughout its restricted distribution and is perhaps the most exploited species along the Atlantic coast of South America. However, the basic information required for effective conservation of this species is lacking. To understand the population structure of this platanistoid dolphin, we sequenced 418 base pairs (bp) of the control region and 68 bp of the adjacent pro-tRNA gene of the mtDNA from 20 franciscana that were captured incidentally by gill-net fisheries of Rio Grande do Sul and Rio de Janeiro, Brazil. Of 11 haplotypes found, 5 were exclusive to franciscana from Rio Grande do Sul and 6 were found only in franciscana from Rio de Janeiro and no haplotypes were shared between locations. Reconstruction of the phylogenetic relationships among the haplotypes through a maximum-likelihood analysis of sequences revealed two distinct lineages that were consistent with the geographic sampling locations. Analysis of molecular variance also showed the population structure (phiST = 0.403, p < 0.0001). Furthermore, the estimate of nucleotide diversity for the northern population (0.38 ± 0.13%) was significantly lower than for the southern population (1.01 ± 0.30%). The genetic evidence indicated that at least two populations of franciscana exist.


Author(s):  
Karen Leandra ávila da Silva ◽  
Marcelo Félix Alonso ◽  
Sabrina Feltes de Moura ◽  
Túlio Felipe Verdi Filho

Resumo O monitoramento contínuo da qualidade do ar local é extremamente importante para a gestão ambiental de uma cidade, mas nem sempre viável pelo alto custo dos equipamentos. Por conta disso, investe-se muito na utilização da modelagem numérica no estudo da qualidade do ar, que é altamente dependente de inventários de emissões dos poluentes e seus precursores. Nesse contexto o objetivo deste trabalho foi realizar um estudo da dispersão do monóxido de carbono (CO) na Região Metropolitana de Porto Alegre, no estado do Rio Grande do Sul, utilizando o sistema de modelagem numérica CCATT-BRAMS, com ênfase nas fontes veiculares. Foram analisados dois períodos - janeiro de 2009 e janeiro de 2016 - utilizando-se as informações dos inventários de gases precursores elaborados pela FEPAM para os anos base de 2009 e 2013, respectivamente, distribuídos espacialmente com o auxílio do pré-processador de emissões PREP-CHEM-SRC utilizado pelo CCATT-BRAMS. No geral, as simulações representaram coerentemente os dados observados pela rede de monitoramento, com RMSE abaixo de 0,3 na maioria das estações avaliadas. Análises de sensibilidade também revelaram que, para o período avaliado, aproximadamente 40% da concentração de CO sobre a cidade de Porto Alegre foi devido ao transporte de larga escala, proveniente das cidades localizadas ao norte, dentro da Região Metropolitana.


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