Effects of seasonal contaminant remobilization on the community trophic dynamics in a Brazilian tropical estuary.

In tropical estuaries, wet seasons are responsible for the downstream transport of allochthonous material from the upper basin and flooded plains. Although allochthonous matter is commonly associated to nutrient and detritus input, pollutants are also transported throughout the basin or suspended from the river bottom via strong streamflow remobilization and rainfall dynamics. We assessed community and population trophic niche-based patterns using organisms' stable isotopes signatures in the wet and the dry seasons to test if estuarine trophic diversity is affected by remobilization of metal-contaminated material from a mining dam collapse that occurred in the Doce river basin, Brazil. Trophic depletion was detected community-wide and in a key consumer group (bottom-dwelling fishes) at the end of the wet season in the impacted Doce river estuary (DRE). Conversely, higher trophic diversity values were recorded in a well-preserved estuary used as control site. Stable isotopes mixing models indicated in the DRE that G. genidens, a predator fish species, presented poor-quality diet based on pollutant-tolerant tiny organisms, a finding that strongly contrasts from diet described in other, little-impacted Brazilian estuaries. Although wet seasons are expected to increase trophic, functional and taxonomic diversity in tropical estuaries, in the DRE the rainfall-driven dynamics poses a threat to the community due to the presence of ore tailings.

Early evidences of niche shifts in estuarine fishes following one of the world's largest mining dam disasters.

The Fundão dam collapse occurred on November 2015 in Mariana city (Brazil), provoking a series of ecological impacts over the Doce river basin and its nearshore environment. However many impacts over fishery target fauna (fish and shrimp) are still unknown or underestimated due to the lack of baseline data in the region. In the present study we assessed the isotopic niches modeled from δ13C and δ15N signatures of six estuarine fish species before and after the impact to assign potential shifts at the population- and community-level. We showed isotopic niche has altered in all studied species irrespective of its trophic group and habitat use. Niche community metrics indicated a depletion of trophic diversity and basal resources of the whole community after the impact. Food web changes as we reported here can impair the energy transfer through the food chain and put at risk the sustainability of small fisheries that rely upon local resources.

Cancer in the Azores: initial results from a recently established population-based cancer registry.

INTRODUCTION: The Azores archipelago has long been the Portuguese region that presents the highest mortality rates for certain cancers. Lack of incidence data has prevented the evaluation of the actual burden of this disease in the Azorean population. METHODS: Malignant tumours (ICD-O 5th Digit /3) initially diagnosed between the January 1st 2000 and December 31st 2002 were retrieved from the database of the recently established population-based cancer registry. Crude, age-specific and age-standardized rates were calculated and confidence intervals were estimated using Poisson approximation. Relative risks of developing cancer in the Azores when compared to mainland Portugal have been represented by standardized ratios. Quality indicators, including Mortality:Incidence (M:I) ratios, were also assessed. RESULTS: Overall, the data shows a high incidence rate for some malignant diseases, specifically in men. Compared to those living in mainland Portugal, both Azorean men (RR 1.412; 99% CI 1.407-1.416) and women (1.127; 1.125-1.129) presented a significantly higher risk of developing cancer, all sites combined. When compared with other cancer registries, a less favourable cancer survival pattern is reported in the Azores, as emphasized by higher M:I ratios for several cancer sites. CONCLUSIONS: A preliminary analysis of the results suggests the presence of some major risk factors in the Azorean population, namely tobacco smoking in men. Higher M:I ratios would also point to survival disparities between the Azores archipelago and the continent, which should be further studied.

Cancer in the Azores: initial results from a recently established population-based cancer registry / Câncer nos Açores: primeiros resultados de um registro oncológico de base populacional recentemente criado

INTRODUCTION: The Azores archipelago has long been the Portuguese region that presents the highest mortality rates for certain cancers. Lack of incidence data has prevented the evaluation of the actual burden of this disease in the Azorean population. METHODS: Malignant tumours (ICD-O 5th Digit /3) initially diagnosed between the January 1st 2000 and December 31st 2002 were retrieved from the database of the recently established population-based cancer registry. Crude, age-specific and age-standardized rates were calculated and confidence intervals were estimated using Poisson approximation. Relative risks of developing cancer in the Azores when compared to mainland Portugal have been represented by standardized ratios. Quality indicators, including Mortality:Incidence (M:I) ratios, were also assessed. RESULTS: Overall, the data shows a high incidence rate for some malignant diseases, specifically in men. Compared to those living in mainland Portugal, both Azorean men (RR 1.412; 99% CI 1.407-1.416) and women (1.127; 1.125-1.129) presented a significantly higher risk of developing cancer, all sites combined. When compared with other cancer registries, a less favourable cancer survival pattern is reported in the Azores, as emphasized by higher M:I ratios for several cancer sites. CONCLUSIONS: A preliminary analysis of the results suggests the presence of some major risk factors in the Azorean population, namely tobacco smoking in men. Higher M:I ratios would also point to survival disparities between the Azores archipelago and the continent, which should be further studied.

INTRODUÇÃO: O arquipélago dos Açores é a região Portuguesa a apresentar as mais elevadas taxas de mortalidade por câncer desde há alguns anos. A ausência de dados de incidência tem constituído um obstáculo ao conhecimento da distribuição da doença oncológica na população açoriana. METODOLOGIA: Todos os tumores malignos (5º dígito da ICD-O: /3) diagnosticados pela primeira vez entre 1 de Janeiro de 2000 e 31 de Dezembro de 2002 foram retirados da base de dados do Registo Oncológico Regional dos Açores. Foram calculadas as taxas brutas, específicas por idade e padronizadas, e estimados os respectivos intervalos de confiança, bem como os riscos relativos de desenvolver câncer nos Açores, em relação a Portugal continental. Finalmente, foram estabelecidos alguns indicadores de qualidade do Registo, como a razão mortalidade:incidência. RESULTADOS: Em termos globais, os resultados demonstram que alguns cânceres, sobretudo nos homens, apresentam taxas de incidência relativamente elevadas. Considerando todas as localizações, quer os homens (RR 1.412; 99% IC 1.407-1.416) quer as mulheres açorianas (1.127; 1.125-1.129) apresentaram um risco significativamente maior de desenvolver câncer, quando comparados com Portugal continental. No que respeita à razão mortalidade:incidência, os resultados poderão eventualmente apontar para padrões de sobrevivência mais desfavoráveis nos Açores relativamente a outras regiões europeias, incluindo o continente. CONCLUSÃO: Uma análise preliminar dos resultados aponta para a existência de fatores de risco, como o consumo de tabaco, a contribuir para a elevada incidência de câncer do pulmão nos homens açorianos. Eventuais disparidades na sobrevivência por câncer entre os Açores e o continente deverão também ser futuramente estudadas.