Diego Rodríguez

Marine Biodiversity in the Atlantic and Pacific Coasts of South America: Knowledge and Gaps

The marine areas of South America (SA) include almost 30,000 km of coastline and encompass three different oceanic domains--the Caribbean, the Pacific, and the Atlantic--ranging in latitude from 12∘N to 55∘S. The 10 countries that border these coasts have different research capabilities and taxonomic traditions that affect taxonomic knowledge. This paper analyzes the status of knowledge of marine biodiversity in five subregions along the Atlantic and Pacific coasts of South America (SA): the Tropical East Pacific, the Humboldt Current,the Patagonian Shelf, the Brazilian Shelves, and the Tropical West Atlantic, and it provides a review of ecosystem threats and regional marine conservation strategies. South American marine biodiversity is least well known in the tropical subregions (with the exception of Costa Rica and Panama). Differences in total biodiversity were observed between the Atlantic and Pacific oceans at the same latitude. In the north of the continent, the Tropical East Pacific is richer in species than the Tropical West Atlantic, however, when standardized by coastal length, there is very little difference among them. In the south, the Humboldt Current system is much richer than the Patagonian Shelf. An analysis of endemism shows that 75% of the species are reported within only one of the SA regions, while about 22% of the species of SA are not reported elsewhere in the world. National and regional initiatives focusing on new exploration, especially to unknown areas and ecosystems, as well as collaboration among countries are fundamental to achieving the goal of completing inventories of species diversity and distribution.These inventories will allow accurate interpretation of the biogeography of its two oceanic coasts and latitudinal trends,and will also provide relevant information for science based policies.

Tissue distribution of heavy metals in small cetaceans from the Southwestern Atlantic Ocean

Abstract Tissue distribution of heavy metals (total mercury, cadmium, zinc and copper) were studied in specimens of Bottlenose Dolphin (Tursiops gephyreus), Franciscana Dolphin (Pontoporia blainvillei) and Pigmy Sperm Whale (Kogia breviceps) stranded in SW Atlantic beaches in Argentina. Heavy metal determinations were carried out by atomic absorption spectrophotometry. Liver is the most important Hg, Zn, and Cu accumulator organ in the studied specimens, while kidney is so for Cd. The importance of the trophic habits and ecological characteristics of each species related to corresponding heavy metal concentrations was emphasized, as well as the animal age vs. pollutant contents relationship. Based on these results the suitability of using these small cetaceans species as ‘heavy metals bioindicators’ in the considered environment was discussed.

Environmental contamination and marine mammals in coastal waters from Argentina : an overview

Environmental contamination become an increasing global problem. Different scientific strategies have been developed in order to assess the impact of pollutants on marine ecosystems. The distribution of toxic contaminants in tissues of different marine mammal species--both cetaceans and pinnipeds--has been studied in many ecosystems, as well as several related ecological processes, like pollutant accumulation or transfer through the food web. A research program directed towards evaluating the occurrence of pollutants in marine mammals from the coastal waters of Argentina (southwestern Atlantic Ocean) has been developed since 1985, and includes the study of heavy metal contents in stranded or incidentally caught animals. The marine mammal species studied during this period were: the seals Otaria flavescens and Arctocephalus australis, and small cetaceans Tursiops gephyreus, Pontoporia blainvillei, Kogia breviceps and Ziphius cavirostris. In most of the cases, high contents of heavy metals (total mercury, cadmium, zinc, and copper) have been recorded. Moreover, liver showed the maximum capability for accumulation of heavy metals in all studied species. The biological and ecological characteristics of each species of the above-mentioned marine mammals (feeding habits, age, migratory pathways, or sex) contributed to the understanding of the metal sources. Considering the results as obtained during the study period it can be assumed that: (1) The global distribution of toxic contaminants also affects the southwestern Atlantic Ocean ecosystems, and (2) Marine mammals could be appropriate bioindicator species in order to assess this kind of environmental problem.

Tuberculosis in a Wild Subantarctic Fur Seal from Argentina

The first case of tuberculosis is described in a wild subantarctic fur seal (Arctocephalus tropicalis) found on the Argentine coast. There was hydrothorax and white firm granulomatous lesions of 40–50 mm in diameter in the lungs. Lesions consisted of a central area of caseous necrosis, an intermediate zone of epithelioid and lymphocytic mononuclear cells, and a peripheral zone of connective tissue. Biochemical and drug sensitivity tests and inoculation of Guinea pigs confirmed the identification as Mycobacterium tuberculosis complex. Arctocephalus tropicalis is the fifth pinniped species in which the M. tuberculosis complex has been detected. Since subantarctic fur seals are widely distributed in the Southern Hemisphere, it is possible that the tuberculosis cases may have a common origin and could spread to other austral regions and species.

Molecular identification, morphological characterization and new insights into the ecology of larval Pseudoterranova cattani in fishes from the Argentine coast with its differentiation from the Antarctic species, P. decipiens sp. E (Nematoda: Anisakidae).

Larvae of the genus Pseudoterranova constitute a risk for human health when ingested through raw or undercooked fish. They can provoke pseudoterranovosis in humans, a fish-borne zoonotic disease whose pathogenicity varies with the species involved, making their correct specific identification a necessary step in the knowledge of this zoonosis. Larvae of Pseudoterranova decipiens s.l. have been reported in several fish species from off the Argentine coasts; however, there are no studies dealing with their specific identification in this region. Here, a genetic identification and morphological characterization of larval Pseudoterranova spp. from three fish species sampled from Argentine waters and from Notothenia coriiceps from Antarctic waters was carried out. Larvae were sequenced for their genetic/molecular identification, including the mitochondrial cytochrome c oxidase subunit II (mtDNA cox2), the first (ITS-1) and the second (ITS-2) internal transcribed spacers of the nuclear ribosomal DNA, and compared with all species of the P. decipiens (sensu lato) species complex (sequences available in GenBank). Further, adults of Pseudoterranova spp. from the definitive host, the southern sea lion, Otaria flavescens, from Argentine and Chilean coasts were sequenced at the same genes. The sequences obtained at the ITS-1 and ITS-2 genes from all the larvae examined from fish of Argentine waters, as well as the adult worms, matched 100% the sequences for the species P. cattani. The sequences obtained at mtDNA cox2 gene for Antarctic larvae matched 99% those available in GenBank for the sibling P. decipiens sp. E. Both MP and BI phylogenetic trees strongly supported P. cattani and P. decipiens sp. E as two distinct phylogenetic lineages and depicted the species P. decipiens sp. E as sister taxon to the remaining taxa of the P. decipiens complex. Larval morphometry was similar between specimens of P. cattani from Argentina, but significantly different from those of P. decipiens sp. E, indicating that larval forms can be distinguished based on their morphology. Pseudoterranova cattani is common and abundant in a variety of fish species from Chile, whereas few host species harbour these larvae in Argentina where they show low levels of parasitism. This pattern could arise from a combination of factors, including environmental conditions, density and dietary preferences of definitive hosts and life-cycle pathways of the parasite. Finally, this study revealed that the life-cycle of P. cattani involves mainly demersal and benthic organisms, with a marked preference by large-sized benthophagous fish.

Analysis of three strategies to increase screening coverage for cervical cancer in the general population of women aged 60 to 70 years: the CRICERVA study

BackgroundCervical cancer is a frequently diagnosed cancer in women worldwide. Despite having easy preventive and therapeutic approaches, it is an important cause of mortality among women.MethodsThe CRICERVA study is a cluster clinical trial which assigned one of three interventions to the target population registered in Cerdanyola, Barcelona. Among the 5,707 resident women aged 60 to 70 years in the study area, women with no record of cervical cytology over the last three years were selected. The study included four arms: three interventions all including a pre-assigned date for screening visit and i) personalized invitation letter; ii) adding to i) an informative leaflet; and, iii) in addition to ii) a personalized appointment reminder phone call, and iv) no specific action taken (control group). Participants were offered a personal interview about social-demographic characteristics and about screening attitudes. Cervical cytology and HPV DNA test (HC2) were offered as screening tests. In the case of screening positive in any of these tests, the women were followed up until a full diagnosis could be obtained. The effect size of each study arm was estimated as the absolute gain in coverage between the original coverage and the final coverage.ResultsFrom the intervention groups (4,775 women), we identified 3,616 who were not appropriately screened, of which 2,560 women answered the trial call and 1,376 were amenable to screening. HPV was tested in 920 women and cervical cytology in all 1,376. Overall, there was an absolute gain in coverage of 28.8% in the intervention groups compared to 6% in the control group. Coverage increased from 51.2% to 76.0% in strategy i); from 47.4% to 79.0% in strategy ii) and from 44.5% to 74.6% in strategy iii). Lack of information about the relevance of screening was the most important factor for not attending the screening program.ConclusionsThe study confirms that actively contacting women and including a date for a screening visit, notably increased participation in the screening program. Efforts to improve health education in preventative activities are warranted.Trial registrationClinical Trials.gov Identifier NCT01373723. Registered 14 June 2011.

Diet composition of franciscana dolphin Pontoporia blainvillei from southern Buenos Aires, Argentina and its interaction with fisheries

Fil: Paso Viola, Maria Natalia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Austral de Investigaciones Cientificas; Argentina

Biological parameters of franciscana dolphins, Pontoporia blainvillei , by-caught in artisanal fisheries off southern Buenos Aires, Argentina

Fil: Negri, Maria Fernanda. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Austral de Investigaciones Cientificas; Argentina

Marine debris ingestion by the South American Fur Seal from the Southwest Atlantic Ocean

In this paper, we examined the ingestion of marine debris (MD) in South American fur seals (SAFS), Arctocephalus australis, found dead in coastal beaches of northern Argentina and southern Brazil. Seven percent of 133 SAFS analyzed presented marine debris in their stomach (n=10), with no differences between sampling countries (Brazil n=7, Argentina n=3) and sexes (female=3; male=6). However, significant differences were observed between ages classes, with MD exclusively present in stomach contents of young specimens. Plastics represents 90% of MD ingested by the SAFS, whereas regarding the source, fishery-related items (e.g. monofilament lines) were the main MD (70%), with a lesser proportion of packaging (e.g. pieces of bags). Low numbers but large size pieces of MD were found in each stomach affected. Negative effects on the individuals could not be fully evaluated. Therefore, the potential impacts of the marine debris to the SAFS deserve further elucidation.

Resting metabolic rate and heat increment of feeding in juvenile South American fur seals (Arctocephalus australis)

Bio-energetic models used to characterize an animals energy budget require the accurate estimate of different variables such as the resting metabolic rate (RMR) and the heat increment of feeding (HIF). In this study, we estimated the in air RMR of wild juvenile South American fur seals (SAFS; Arctocephalus australis) temporarily held in captivity by measuring oxygen consumption while at rest in a postabsorptive condition. HIF, which is an increase in metabolic rate associated with digestion, assimilation and nutrient interconversion, was estimated as the difference in resting metabolic rate between the postabsorptive condition and the first 3.5h postprandial. As data were hierarchically structured, linear mixed effect models were used to compare RMR measures under both physiological conditions. Results indicated a significant increase (61%) for the postprandial RMR compared to the postabsorptive condition, estimated at 17.93±1.84 and 11.15±1.91mL O2 min(-1)kg(-1), respectively. These values constitute the first estimation of RMR and HIF in this species, and should be considered in the energy budgets for juvenile SAFS foraging at-sea.