Cadmium concentrations in franciscana dolphin (Pontoporia blainvillei) from south brazilian coast

Franciscanas foram utilizadas como fonte de informação sobre a biodisponibilidade de cádmio em águas neríticas da Costa Sul do Brasil. Amostras de fígado, obtidas de 44 indivíduos capturados acidentalmente ao largo da costa do Rio Grande do Sul, foram analisadas através de EAA eletrotérmica. Concentrações de cádmio, idade, peso e comprimento totais dos golfinhos analisados variaram entre 39 e 4144 µg.kg-1 (peso úmido), um e cinco anos, 17,5 e 49,2 kg, e entre 105,3 e 156,8 cm, respectivamente. Em relação às concentrações hepáticas de cádmio em franciscanas, não houve diferença significativa entre os dados gerados pelo presente estudo e informação proveniente da literatura, referente ao Estado do Rio de Janeiro. As baixas concentrações de cádmio observadas podem ser atribuídas ao fato de as lulas da Família Loliginidae constituírem a principal presa para franciscanas, dentre os cefalópodes. Este estudo corrobora investigações sobre níveis de cádmio em lulas brasileiras e reforça a hipótese de que cefalópodes loliginídeos não constituem vetores importantes da transferência de cádmio para cetáceos.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

Impact of sea ice on the structure of phytoplankton communities in the northern Antarctic Peninsula

The seasonal advance and retreat of sea ice around the northern Antarctic Peninsula can have a significant impact on phytoplankton, mainly due to alterations in the availability of ice-free areas, micronutrient inputs by meltwater and variations in water column structure. The aim of this work was to evaluate the effect of sea ice conditions on phytoplankton biomass and community composition in an area off the northern Antarctic Peninsula, a region undergoing important warming processes. In two consecutive summer cruises (2013 and 2014), seawater samples were analysed for nutrients and phytoplankton (through HPLC-CHEMTAX approach), and measurements were made for water column physical structure evaluation. Two contrasting conditions were studied: a strong environmental gradient around the sea ice edge, with a marked meltwater signal (summer 2013) and the same area with little indication of meltwater and no detectable sea ice conditions (summer 2014). In the first year, the phytoplankton communities were massively dominated by nanoflagellates such as cryptophytes, small dinoflagellates and Phaeocystis antarctica, but with differences between stations with less influence of meltwater (dominance of dinoflagellates type B, mainly Gymnodinium spp., mean chlorophyll a = 1.37 mg m−3) and stations closer to the sea ice edge (dominance of cryptophytes, mean chlorophyll a = 0.98 mg m−3). In the second year, cryptophytes were apparently replaced by diatoms type B (mainly Pseudonitzschia spp., 24% contribution, mean chlorophyll a = 0.93 mg m−3), although dinoflagellates were also important. Therefore, there was a clear distinction between the phytoplankton communities under sea ice influence, where mainly cryptophytes were associated with shallow mixed layers and high water column stability in 2013 and an important presence of diatoms in 2014, associated with deeper mixed layers, lower silicic acid concentrations and higher magnitudes of both salinity and temperature, under very little sea ice influence. Gymnodinioid dinoflagellates were an important component in both years, apparently occupying sites/conditions less favourable to cryptophytes. These results support previous suggestions that climate factors leading to shortening of the sea ice season in the region do have an important impact particularly in shaping the dominance of the main phytoplankton functional groups in the region

Large diatom bloom off the Antarctic Peninsula during cool conditions associated with the 2015/2016 El Niño

Diatoms play crucial functions in trophic structure and biogeochemical cycles. Due to poleward warming, there has been a substantial decrease in diatom biomass, especially in Antarctic regions that experience strong physical changes. Here we analyze the phytoplankton contents of water samples collected in the spring/summer of 2015/2016 off the North Antarctic Peninsula during the extreme El Niño event and compare them with corresponding satellite chlorophyll-a data. The results suggest a close link between large diatom blooms, upper ocean physical structures and sea ice cover, as a consequence of the El Niño effects. We observed massive concentrations (up to 40 mg m–3 of in situ chlorophyll-a) of diatoms coupled with substantially colder atmospheric and oceanic temperatures and high mean salinity values associated with a lower input of meltwater. We hypothesize that increased meltwater concentration due to continued atmospheric and oceanic warming trends will lead to diatom blooms becoming more episodic and spatially/temporally restricted

Assessing bias in aerial surveys for cetaceans: Results from experiments conducted with the franciscana dolphin

Line transect aerial surveys are widely used for estimating abundance of biological populations, including threatened species. However, estimates obtained with data collected from aircraft are often underestimated because of visibility bias and bias in estimating group sizes from a fast-moving platform. An assessment of multiple sources of bias in aerial surveys were carried out in Brazilian coastal waters by experiments on multiple survey platforms (i.e., boat, airplane and helicopter). These studies focused on evaluating visibility bias (perception and availability bias) and potential differences in the estimation of group sizes from different types of platforms used in franciscana (Pontoporia blainvillei) abundance surveys. The ultimate goal was to develop correction factors to improve accuracy of estimates of density and population size for this threatened dolphin. Estimates of density and group sizes computed from boats were assumed to be unbiased and were compared to estimates of these quantities obtained from an airplane in the same area and period. In addition, helicopter surveys were conducted in two areas where water turbidity differed (clear vs. murky waters) to determine surfacing-diving intervals of franciscana groups and to estimate availability for aerial platforms. Abundance computed from the aerial survey data underestimated the true abundance by about 4-5 times, with ~70% of the total bias resulting from visibility bias (~80% from availability bias and ~20% from perception bias) and ~30% from bias in estimates of group size. The use of multiple survey platforms in contrasting habitats provided the opportunity to compute correction factors that can be used to refine range wide abundance estimates of the threatened franciscana given certain assumptions are met. Visibility bias and group size bias were substantial and clearly indicate the importance for accounting for such correction factors to produce unequivocal population assessment based on aerial survey data.Fil: Sucunza, Federico. Grupo de Estudio de Mamiferos Aquaticos de Rio Grande Do Sul.; Brasil. Universidade Federal de Juiz de Fora; Brasil. Instituto Aqualie; BrasilFil: Danilewicz, Daniel. Instituto Aqualie; Brasil. Grupo de Estudio de Mamiferos Aquaticos de Rio Grande Do Sul.; Brasil. Universidade Federal de Juiz de Fora; BrasilFil: Andriolo, Artur. Instituto Aqualie; Brasil. Universidade Federal de Juiz de Fora; BrasilFil: de Castro, Franciele R.. Instituto Aqualie; BrasilFil: Cremer, Marta. Universidade da Região de Joinville; BrasilFil: Denuncio, Pablo Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Ferreira, Emanuel. Associação R3 Animal; BrasilFil: Flores, Paulo A. C.. Instituto Chico Mendes para a Conservação da Biodiversidade; BrasilFil: Ott, Paulo H.. Universidade Estadual do Rio Grande do Sul; Brasil. Grupo de Estudio de Mamiferos Aquaticos de Rio Grande Do Sul.; BrasilFil: Perez, Martin S.. Grupo de Estudio de Mamiferos Aquaticos de Rio Grande Do Sul.; BrasilFil: Pretto, Dan. Instituto Chico Mendes Para A Conservação Da Biodiversidade; BrasilFil: Sartori, Camila M.. Universidade da Região de Joinville; BrasilFil: Secchi, Eduardo Resende. Universidade Federal do Rio Grande; BrasilFil: Zerbini, Alexandre. Marine Ecology And Telemetry Research; Estados Unidos. Cascadia Research Collective; Estados Unidos. Instituto Aqualie; Brasil. Universidade Federal de Juiz de Fora; Brasil. The George Washington University; Estados Unido

Assessment of the conservation status of a franciscana (Pontoporia blainvillei) stock in the Franciscana Management Area III following the IUCN Red List Process

A Lista de Espécies Ameaçadas do Livro Vermelho da IUCN é o inventário sobre o estado de conservação de espécies mais abrangente e consultado. Recentemente, o programa de avaliação do estado de conservação das espécies segundo as categorias da IUCN tem passado por várias mudanças, as quais incluem uma série de critérios quantitativos de avaliação, tornando o processo mais objetivo e rigoroso. Na Lista do Livro Vermelho editado em 2000, a toninha (Pontoporia blainvillei) foi listada como Dados Insuficientes , indicando que os dados necessários para realizar uma avaliação não estão disponíveis. Considerando que a toninha possa ser o pequeno cetáceos mais impactado por atividades antropogênicas, especialmente devido às capturas acidentais em redes de emalhe, no Atlântico Sul Ocidental e, porque uma quantidade significativa de dados tem sido produzida nos últimos 15 anos, os participantes do 4 o Encontro para a Coordenação de Pesquisa e Manejo da Toninha no Atlântico Sul Ocidental (Porto Alegre, Brasil, 5-9 de novembro de 2000) recomendaram que uma reavaliação para a espécie fosse feita com brevidade. Devido à falta das informações cruciais para a maioria das regiões, uma avaliação ao nível de espécie não é possível e a toninha permanence classificada na categoria Dados Insuficientes . Entretanto, neste artigo, faz-se a avaliação do estado de conservação de um estoque de toninhas que habita as águas costeiras do estado do Rio Grande do Sul, sul do Brasil e Uruguai (Área III para o Manejo da Toninha FMA III). As informações disponíveis para a FMA III classificam o estoque como Ameaçado sob os sub-critérios 1d e 2d do critério A (EN A1d+2d). Este artigo visa demonstrar um estudo de caso (usando o estoque mais estudado) para salientar o tipo de informação e documentação necessária para produzir uma avaliação seguindo os critérios atuais da IUCN.The IUCN Red List of Threatened Species is the most widely followed and comprehensive inventory of the conservation status of species. Recently, the Red List programme changed in several ways including, revisions to the criteria for determining species statuses and the development of a process for challenging statuses. In the 2000 Red List, the franciscana (Pontoporia blainvillei) was listed as Data Deficient , which indicates that data were insufficient to determine the status of the species under the Red List criteria but the species may be deemed to belong to a category of threat once adequate data for assessment are available. Because franciscana is possibly the cetacean species most impacted by anthropogenic activities, especially by incidental catches in gillnet fisheries in the western South Atlantic and because much data has accumulated over the last 15 years, all participants in the 4th Workshop for the Co-ordination of Research and Conservation of Franciscana in the Western South Atlantic (Porto Alegre, Brazil, 5-9 November, 2000) recommended that a reassessment of the species be performed as soon as possible. But due to the lack of the required information (from most regions) for assessment, the status of the species remains as Data Deficient . However, in this paper, we assessed the conservation status of one franciscana stock inhabiting waters off Rio Grande do Sul State, southern Brazil and Uruguay (Franciscana Management Area III FMA III). The available information for FMA III resulted in this stock being classified as Endangered under sub-criterias 1d and 2d of criterion A (EN A1d+2d). The intention is to provide a case study (using the best known stock) to demonstrate the types of information and documentation required for a Red List assessment following the current criteria

Plastic debris ingested by a Blainville’s beaked whale, Mesoplodon densirostris, washed ashore in Brazil

Submitted by Thainã Moraes ([email protected]) on 2013-02-20T23:51:15Z No. of bitstreams: 1 Plastic debris ingested by a Blainville's beaked whale, Mesoplodon densirostris, washed ashore in Brazil.pdf: 233253 bytes, checksum: 4c83aa7e4c096930442dc9f370a93f56 (MD5)Approved for entry into archive by Michele Fernanda([email protected]) on 2013-03-22T15:34:41Z (GMT) No. of bitstreams: 1 Plastic debris ingested by a Blainville's beaked whale, Mesoplodon densirostris, washed ashore in Brazil.pdf: 233253 bytes, checksum: 4c83aa7e4c096930442dc9f370a93f56 (MD5)Made available in DSpace on 2013-03-22T15:34:41Z (GMT). No. of bitstreams: 1 Plastic debris ingested by a Blainville's beaked whale, Mesoplodon densirostris, washed ashore in Brazil.pdf: 233253 bytes, checksum: 4c83aa7e4c096930442dc9f370a93f56 (MD5) Previous issue date: 199

Occurrence of Hector's beaked whale, Mesoplodon hectori, in southern Brazil

In February 1994, a Hector’s beaked whale, Mesoplodon hectori, was found ashore 80 km north of Rio Grande (32)07*S, 52)05*W), southern Brazil.The skull (CBL=497 mm) and post-cranial skeleton(C 7, T 11, L 10, Ca 17=45) were collected and placed at the Museu Oceanogra´fico ’Prof. Eliézer de Carvalho Rios’ collection (MORG 0104). The whale was identified based on skull morphology and measurements, as well as shape and position of the mandibular teeth. The small size (skeletal length=236 cm), unfilled mesorostral channel, wide open tooth pulp cavity, and unfused vertebral epyphisis indicated that the animal was young. This whale is the first record of the species in Brazil. In addition, it extends northwards the known range of Hector’s beaked whale in the west South Atlantic Ocean by about 800 km and represents the northernmost record of the species