14 research outputs found

    Abrolhos Bank Reef Health Evaluated by Means of Water Quality, Microbial Diversity, Benthic Cover, and Fish Biomass Data

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    The health of the coral reefs of the Abrolhos Bank (southwestern Atlantic) was characterized with a holistic approach using measurements of four ecosystem components: (i) inorganic and organic nutrient concentrations, [1] fish biomass, [1] macroalgal and coral cover and (iv) microbial community composition and abundance. The possible benefits of protection from fishing were particularly evaluated by comparing sites with varying levels of protection. Two reefs within the well-enforced no-take area of the National Marine Park of Abrolhos (Parcel dos Abrolhos and California) were compared with two unprotected coastal reefs (Sebastião Gomes and Pedra de Leste) and one legally protected but poorly enforced coastal reef (the “paper park” of Timbebas Reef). The fish biomass was lower and the fleshy macroalgal cover was higher in the unprotected reefs compared with the protected areas. The unprotected and protected reefs had similar seawater chemistry. Lower vibrio CFU counts were observed in the fully protected area of California Reef. Metagenome analysis showed that the unprotected reefs had a higher abundance of archaeal and viral sequences and more bacterial pathogens, while the protected reefs had a higher abundance of genes related to photosynthesis. Similar to other reef systems in the world, there was evidence that reductions in the biomass of herbivorous fishes and the consequent increase in macroalgal cover in the Abrolhos Bank may be affecting microbial diversity and abundance. Through the integration of different types of ecological data, the present study showed that protection from fishing may lead to greater reef health. The data presented herein suggest that protected coral reefs have higher microbial diversity, with the most degraded reef (Sebastião Gomes) showing a marked reduction in microbial species richness. It is concluded that ecological conditions in unprotected reefs may promote the growth and rapid evolution of opportunistic microbial pathogens

    Artisanal fisheries in urban reservoirs: a case study from Brazil (Billings Reservoir, Sao Paulo Metropolitan Region)

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    Billings Reservoir is an urban reservoir located in the Sao Paulo Metropolitan Region. Tt supports 101 active artisanal fishermen. To describe this fishery, landings were recorded daily between February 1996 and January 1997 at Colonia (23 degrees 50' 57" S; 46 degrees 40' 02" W). In every landing, a data collector recorded catch, effort, fishing gears and fishing grounds. A total of 147 593 kg of fish were recorded in 3515 fishing trips. The exotic Nile tilapia, Oreochromis niloticus (L.), was the main species exploited (81.4% of the annual catches). Five other species were also targeted: the characid Astyanax eigenmaniorum (Cope) (13.0% of the annual catches); the erythrinid Hoplias aff malabaricus (Block) (2.1%); the exotic cyprinid Cyprinus carpio L. (Campos & Fernandez-Yepez) (2.4%); the curimatid Cyphocharax modestus L. (1.1%); and the pimelodid Rhamdia sp. (0.1%). Two main groups of fishermen were discriminated using Principal Components Analysis; these were associated with the type of fishing gear and fishing strategies, i.e. those who exploited Nile tilapia with cast nets and beating gill nets, and those who exploited other species with set gill nets. Management and maintenance of this fishery should consider the positive top-down effects that Nile tilapia could have in controlling eutrophication and also the social benefits.7653754

    Time and seasonal patterns of activity of phyllostomid in fragments of a stational semidecidual forest from the Upper Paraná River, Southern Brazil

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    Bats may exhibit different patterns of activity, considering aspects concerning niche dynamics as well as the establishment and permanence of the communities in the ecosystems. In this way, the present study analyzed the time and seasonal patterns of activity in different species of frequent phyllostomid bats in remnants of the stational semidecidual forest from the Upper Paraná River, Southern Brazil. Captures were performed between January and December, 2006, using 32 mist nets set above the soil along the nocturnal period during the four seasons of the year. The daily and seasonal patterns of activity of each species was modeled using generalized linear models with Poisson error. The best model was selected using Akaike's Information Criterion (AICc). Artibeus planirostris (Spix, 1823) did not exhibit a conspicuous time pattern, whereas A. lituratus (Olfers, 1818) was more frequent after the sixth hour and A. fimbriatus Gray, 1838 had an activity increase along the night. Platyrrhinus lineatus (E. Geoffroy, 1810) was registered during all sampling hours. Carollia perspicillata (Linnaeus, 1758) and Sturnira lilium (E. Geoffroy, 1810) were the most active during the first four hours. Concerning seasonal pattern, the highest activity of these species was verified during the summer. These data contribute to the information about the ecology of bats in the region, highlighting the high adaptive potential of the species studied in relation to the use of space throughout the night and in to variations in environmental conditions

    Time and seasonal patterns of activity of phyllostomid in fragments of a stational semidecidual forest from the Upper Paran\ue1 River, Southern Brazil

    No full text
    Bats may exhibit different patterns of activity, considering aspects concerning niche dynamics as well as the establishment and permanence of the communities in the ecosystems. In this way, the present study analyzed the time and seasonal patterns of activity in different species of frequent phyllostomid bats in remnants of the stational semidecidual forest from the Upper Paraná River, Southern Brazil. Captures were performed between January and December, 2006, using 32 mist nets set above the soil along the nocturnal period during the four seasons of the year. The daily and seasonal patterns of activity of each species was modeled using generalized linear models with Poisson error. The best model was selected using Akaike's Information Criterion (AICc). Artibeus planirostris (Spix, 1823) did not exhibit a conspicuous time pattern, whereas A. lituratus (Olfers, 1818) was more frequent after the sixth hour and A. fimbriatus Gray, 1838 had an activity increase along the night. Platyrrhinus lineatus (E. Geoffroy, 1810) was registered during all sampling hours. Carollia perspicillata (Linnaeus, 1758) and Sturnira lilium (E. Geoffroy, 1810) were the most active during the first four hours. Concerning seasonal pattern, the highest activity of these species was verified during the summer. These data contribute to the information about the ecology of bats in the region, highlighting the high adaptive potential of the species studied in relation to the use of space throughout the night and in to variations in environmental conditions
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