Erythrocyte Recovery in Oreochromis niloticus Fish Exposed to Urban Effluents.

Urban activities pollute aquatic ecosystems, and the integrity of organisms such as fish. The use of cytological techniques, such as the analysis of blood cellular integrity using the Micronucleus test, can help detect mutagenic damage as a result to urban effluents exposure. In this context, this study aimed to evaluate the frequency of micronucleus and other nuclear abnormalities in Oreochromis niloticus fish environmentally exposed to urban effluents in relation to their erythrocyte recovery capacity when exposed to clean water (30 and 45 days). The results indicated high copper, dissolved iron, nickel, and thermotolerant coliform levels in the urban stream. There was no difference in the frequency of micronuclei. In contrast, cells with nuclear nuclei, binucleates, kidney-shaped nuclei, notched nuclei, lobed nuclei, and segmented nuclei decreased according to the time the fish were exposed to clean water. When exposed to clean water, we conclude that urban fish recover from genotoxic and cytotoxic damage.

Habitat differences affect the nuclear morphology of the erythrocytes and the hepatic melanin in Leptodactylus fuscus (Anura) in the Brazilian Cerrado savanna.

The sensitivity of anuran to the effects of habitat destruction and contamination has led to a preoccupying global decline in their populations. Morphological biomarkers such as micronuclei and other erythrocyte nuclear abnormalities (ENAs), as well as the occurrence of hepatic melanin, can be used to evaluate the effects of habitat impacts. In the present study, these two parameters were combined for the in situ assessment of the effects of soybean cultivation on the grassfrog, Leptodactylus fuscus. Specimens were also collected from a protected area to provide a reference site (non-agricultural environment). The frequency of some of the nuclear abnormalities in the animals from the soybean plantation was much higher than that recorded at the reference site, in particular micronuclei, which were 3.6 times more frequent in the plantation, lobulated nuclei (3.4 times more frequent), and reniform nuclei, which were four times more common than at the reference site. The combined analysis of all the ENAs together also revealed a frequency approximately 1.4 times higher in the animals from the soybean plantation, in comparison with the protected area. Smaller areas of hepatic melanin were observed in the specimens from the soybean plantation. These results provide further evidence of the sensitivity of anurans to habitat impacts and indicate that animals found in soybean plantations are susceptible to systematic alterations of their cells.

Multi-taxon inventory and landscape characterization in an agrosystem of the Brazilian Midwest targeted for payment for environmental services / Inventário multi-táxon e caracterização da paisagem em um agrossistema no Centro-Oeste brasileiro alvo de pagamento por serviços ambientais

Abstract: The replacement of natural landscapes by anthropic environments has led to habitat loss and consequently, to the decline and extinction of many species populations. Several strategies, such as the creation of protected areas (PAs) and payment for ecosystem services have been adopted to mitigate the consequences of this biodiversity crisis. In Rio Verde, Goiás, Brazil, a Water Producer Program (WPP) was established, which provides payment for ecosystem services for the maintenance of riparian vegetation in the region of the Ribeirão Abóbora, a river which supplies the city and metropolitan area. In the absence of environmental diagnostic studies in the region, this present study contributes to reducing some knowledge gaps, through the: (i) characterization of the landscape in the WPP area, (ii) characterization of species of fauna (amphibians, birds, fish, and medium and large terrestrial mammals) and woody flora that occur in this area, and (iii) comparison of species diversity (fauna and flora) found in our study area with the diversity observed in the Cerrado protected area network. Our results reveal a low native vegetation cover (~21% of total area), but we recorded 300 total species: 20 species of anuran amphibians, 100 birds, 10 fish, 16 terrestrial mammals (medium and large), and 154 woody plants. Our sample comprises species considered endemic to the Cerrado (e.g., Anuran - Barycholos terntezi and Mammal - Callithrix penicillata), threatened species (e.g., Mammals - Herpailurus yagouaroundi, Myrmecophaga tridactyla and Tapirus terrestris), and exotic invasive species (Mammal - Sus scrofa). The results presented in this study are relevant and may help in the proposal of management actions within the scope of this important program of payment for environmental services.

Resumo: A substituição das paisagens naturais por ambientes antropizados tem levado à perda de habitat e, consequentemente, ao declínio populacional e extinção de muitas espécies. Várias estratégias como a criação de Unidades de Conservação (UCs) e o pagamento de serviços ecossistêmicos têm sido adotadas para mitigar as consequências da crise de biodiversidade. Em Rio Verde, estado de Goiás, foi estabelecido um Programa Produtores de Água (PPA) que prevê o pagamento de serviços ecossistêmicos pela manutenção da vegetação ripária na região do ribeirão Abobora que abastece a cidade. Diante da ausência de estudos de diagnóstico ambiental da região, o presente estudo contribui para reduzir algumas lacunas de conhecimento, através da: i) caracterização da paisagem na área deste PPA, ii) caracterização das espécies da fauna (anfíbios, aves, peixes e mamíferos terrestres de médio e grande porte) e flora lenhosa que ocorrem neste local, iii) comparação da diversidade de espécies (fauna e flora) encontrada na área de estudo com aquela observada na rede de áreas protegidas do Cerrado. Nossos resultados revelam baixo índice de cobertura vegetal nativa (~21% da área total), mas por outro lado, registramos 300 espécies, sendo 20 de anfíbios anuros, 100 aves, 10 peixes, 16 mamíferos terrestres (médio e grande porte) e 154 plantas lenhosas. A nossa amostragem compreende espécies que são consideradas endêmicas do Cerrado (p.ex. Anfíbio - Barycholos terntezi e Mamífero - Callithrix penicillata), ameaçadas de extinção (p.ex. Mamíferos - Herpailurus yagouaroundi, Myrmecophaga tridactyla e Tapirus terrestris) ou exótica invasora (Mamífero - Sus scrofa). Os resultados apresentados no presente estudo são relevantes e podem auxiliar na proposição de ações de manejo no âmbito deste importante programa de pagamento por serviços ambientais.