Transforming open mining pits into fish farms: Moving towards sustainability

The legacy of mining activities has typically been land 'returned to wildlife', or, at some sites, degraded to such an extent that it is unsuitable for any alternate use. Progress towards sustainability is made when value is added in terms of the ecological, social and economic well-being of the community. In keeping with the principles of sustainable development, the innovative use of flooded open pits and tailings impoundments as commercial, recreational or ornamental fish farms should be considered in some locations, as it could make a significant contribution to the social equity, economic vitality and environmental integrity of mining communities. This article highlights the growing significance of aquaculture and explores the benefits and barriers to transforming flooded pits and impoundments into aquaculture operations. Among other benefits, aquaculture may provide a much-needed source of revenue, employment and, in some cases, food to communities impacted by mine closure. Further, aquaculture in a controlled closed environment may be more acceptable to critics of fish farming who are concerned about fish escapes and viral transmissions to wild populations. Despite the potential benefits, aquaculture in flooded pits and impoundments is not without its complications - it requires a site-specific design approach that must consider issues ranging from metals uptake by fish, to the long-term viability of the aquatic system as fish habitat, to the overall contribution of aquaculture to sustainability. © 2004 United Nations. Published by Blackwell Publishing.

Ichthyofauna of two streams (silted and reference) in the Upper Paraná river basin, Southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Natural and artificially-induced habitat complexity and freshwater fish species composition

The effects of habitat complexity, induced by construction of artificial reefs, on the fish assemblages in the Barra Bonita reservoir, Brazil, and in the lotic zone immediately below the dam were studied. Four artificial reefs were constructed in each habitat at variable distances from the shore. Multiple correspondence analysis showed that the factors distance from the shore and type of habitat were determinants for the group formation, and artificial reefs had a lesser effect. Fish species composition was about the same at locations with and without reefs.

Effects of physical habitat degradation on the stream fish assemblage structure in a pasture region

We compared the fish assemblage structure from streams with different intensities of physical habitat degradation and chemical water pollution by domestic sewage in southeastern Brazil. Eight streams (R1-R8) showing less disturbed or more disturbed conditions of chemical water quality and of physical habitat quality were selected. Cumulative abundance and biomass, combined in ABC plots, revealed (i) biomass curves above the abundance curves, represented by the streams R1-R2 (water and habitat less disturbed) and R5-R6 (water more disturbed and habitat less disturbed), and (ii) biomass curves below the abundance curves, represented by the streams R3-R4 (water less disturbed and habitat more disturbed) and R7-R8 (water and habitat more disturbed). The quantitative structure of the ichthyofauna showed significant correspondence with physical habitat condition but not with chemical water quality. The most significant species to cause the dissimilarity between less disturbed and more disturbed physical habitats was the exotic Poecilia reticulata. Such results indicate that in the focused region-with little influence of industrial pollution, noncritical domestic sewage discharge, and soil predominantly used for pasture-streams with high physical habitat integrity possess a differently structured ichthyofauna than streams with relatively low physical habitat integrity, reinforcing the importance of the physical habitat quality and riparian conservation along these water courses, warranting the conservation of these systems. Indeed, our results also reinforce the importance of including biotic descriptors, particularly of the ichthyo-fauna, in water-monitoring programs designed to reveal signs of human interference.

Stream fish, water and habitat quality in a pasture dominated basin, southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Disentangling the influences of habitat structure and limnological predictors on stream fish communities of a coastal basin, southeastern Brazil

Em ambientes de riacho, fatores relacionados à estrutura dos habitats e limnologia interagem regulando os padrões de transferência de energia e matéria, afetando a composição da comunidade de peixes. Em bacias costeiras do sudeste do Brasil as características limnológicas e estrutura dos habitats diferem entre riachos de águas claras e pretas. Os primeiros são compostos por uma variedade de tipos de substrato, possuem velocidades de corrente mais elevadas e baixa condutividade, enquanto os últimos apresentam substrato arenoso, baixas velocidades de corrente e águas escuras e ácidas. Neste trabalho analisamos a importância relativa da estrutura dos habitats e das variáveis limnológicas como preditores dos padrões de composição em comunidades de peixes de riachos. Oito riachos de primeira a terceira ordem foram amostrados na planície costeira da bacia do rio Itanhaém. Capturamos 34 espécies e verificamos que a composição das comunidades foi influenciada por fatores estruturais e limnológicos, sendo os primeiros mais importantes. Uma fração de variação que não pode ser totalmente decomposta, deve-se à influência conjunta da limnologia e estrutura dos habitats. Algumas das espécies restritas aos riachos de águas pretas provavelmente apresentam adaptações fisiológicas e comportamentais para lidar com os baixos níveis de pH. Quando foram examinados somente os riachos de águas claras, toda a variação explicada na composição da comunidade de peixes foi atribuída aos fatores estruturais, devido a preferências específicas por diferentes características de hábitats.

The influence of habitat homogenization on the trophic structure of fish fauna in tropical streams

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Improvement of gamete quality and its short-term storage: an approach for biotechnology in laboratory fish

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of Aloe vera extract on the improvement of the respiratory activity of leukocytes of matrinxã during the transport stress

This study evaluated the effect of extract of Aloe vera in the transport water of matrinxã (Brycon amazonicus) fish on stress response and leukocyte respiratory activity. Fish was transported for 4 h in water containing Aloe at levels 0; 0.02; 0.2 and 2 mg/L, and sampled before transport 2, 4, 24 and 96 h after for determination of plasma glucose and respiratory activity of leukocytes. An additional in vitro assay was conducted with another fish species, pacu (Piaractus mesopotamicus), to test the respiratory burst of leukocytes exposed to Aloe extract (0.0, phosphate-buffered saline (PBS) only) at 0.1, 0.2, 0.5 and 1 mg/L). Plasma glucose increased after 2 and 4 h of transport and returned to control levels within 24 h, but the addition of Aloe in the transport water did not affect the level of blood glucose. However, at 2 h of transport, Aloe enhanced the respiratory activity of leukocytes in a dose-dependent way. The highest value of respiratory burst activity of leukocytes was observed in the fish transported in water containing Aloe at 2 mg/L. The enhancing effect of the plant extract on the production of oxygen radicals was confirmed in vitro in leukocytes of pacu incubated in Aloe at concentrations 0.1 and 0.2 mg/L. The results suggest that Aloe vera is a modulator of the immune system in fish improving the innate immune response tested.

Decreased oxidative stress in patients with ulcerative colitis supplemented with fish oil omega-3 fatty acids

OBJECTIVE: the potential pathogenicity of free radicals may have a pivotal role in ulcerative colitis. Fish oil omega-3 fatty acids exert anti-inflammatory effects on patients with ulcerative colitis (UC), but the precise mechanism of the action of fish oil on oxidative stress is still controversial. The aim of the present work was to verify the blood oxidative stress in patients with UC and determine whether the association of sulfasalazine to fish oil omega-3 fatty acids is more effective than isolated use of sulfasalazine to reduce the oxidative stress.METHODS:, Nine patients (seven female and two male; me. an age = 40 +/- 11 y) with mild or moderate active UC were studied in a randomized crossover design. In addition to their usual medication (2 g/d of sulfasalazine), they received fish oil omega-3 fatty acids (4.5 g/d) or placebo for 2-mo treatment periods that were separated by 2 mo, when they only received sulfasalazine. Nine healthy individuals served as control subjects to study the oxidative stress status. Disease activity was assessed by laboratory indicators (C-reactive protein, alpha(1)-acid glycoprotein, alpha(1)-antitrypsin, erythrocyte sedimentation rate, albumin, hemoglobin, and platelet count), sigmoidoscopy, and histology scores. Analysis of oxidative stress was assessed by plasma chemiluminescence and erythrocyte lipid peroxidation, both induced by tert butyl hydroperoxide (t-BuOOH) and by plasma malondialdehyde. Antioxidant status was assayed by total plasma antioxidant capacity (TRAP) and microsomal lipid peroxidation inhibition (LPI). Superoxide dismutase (SOD) and catalase erythrocyte enzymatic activities were also determined.RESULTS: No significant changes were observed in any laboratory indicator or in the sigmoidoscopy or histology scores, with the exception of erythrocyte sedimentation rate, which decreased with both treatments. Oxidative stress was demonstrated by significant decreases in TRAP and LPI levels, increased chemiluminescence induced by t-BuOOH, and higher SOD activity in patients with UC. Treatment with fish oil omega-3 fatty acids reverted the chemiluminescence induced by t-BuOOH and LPI to baseline levels but that did not occur when patients received only sulfasalazine. Levels of plasma malondialdehyde, erythrocyte lipid peroxidation, and catalase were not different from those in the control group.CONCLUSIONS: the results indicated that plasma oxidative stress occurs in patients with UC, and there was a significant decrease when the patients used sulfasalazine plus fish oil omega-3 fatty acids. However, there was no improvement in most laboratory indicators, sigmoidoscopy, and histology scores. The results suggested that omega-3 fatty acids may act as free radical scavengers protecting the patients against the overall effect of oxidative stress. (C)Elsevier B.V. 2003.

Aggressiveness Overcomes Body-Size Effects in Fights Staged between Invasive and Native Fish Species with Overlapping Niches

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Anurofauna em área de cerrado aberto no município de Borebi, estado de São Paulo, Sudeste do Brasil: uso do habitat, abundância e variação sazonal

O bioma Cerrado encontra-se descaracterizado e menos de três por cento de suas áreas originais está legalmente protegida. A anurofauna desse bioma não é muito rica quando comparado a outros biomas, porém há um grande número de espécies endêmicas. Aqui apresentamos uma lista de espécies de anuros registrados em uma lagoa em área de cerrado aberto do município de Borebi, região Centro-Oeste do estado de São Paulo, sudeste do Brasil. Durante 24 meses de estudo (2008 e 2009) caracterizamos a distribuição das espécies na lagoa estudada e descrevemos a variação sazonal das espécies. Foram registradas 27 espécies pertencentes a seis famílias: Bufonidae (duas espécies), Cycloramphidae (uma espécie), Hylidae (13 espécies), Leiuperidae (quatro espécies), Leptodactylidae (cinco espécies) e Microhylidae (duas espécies). A riqueza de espécies e abundância estiveram relacionadas com a precipitação. Dendropsophus minutus foi a espécie mais abundante e com registro de vocalização durante o ano inteiro. Rhinella ornata e Odontophrynus americanus foram restritas ao período seco e frio (abril a agosto). As outras espécies tiveram seu período de maior atividade nos meses chuvosos e quentes (setembro a março). A ocupação da lagoa variou com o tipo de vegetação e conforme a variação do seu volume de água, principalmente nos período de estiagem. A alta riqueza e abundância de anuros da lagoa pode ser resultado da ausência de peixes predadores, dos diversos tipos de microambientes do local e da ausência de outros corpos d'água próximos.

Reduction of a native fish fauna by alien species: an example from Brazilian freshwater tropical lakes

The consequences of introducing Cichla cf. monoculus Spix & Agassiz, Astronotus ocellatus (Agassiz) and Pygocentrus nattereri Kner into lakes in the River Doce basin, Brazil, on richness, diversity and efficiency of aquatic macrophytes as natural refugia to native fishes was investigated. Samples were taken from lakes with and without alien fishes in areas with and without aquatic macrophytes. The presence of alien fishes reduced richness and diversity of the native fish community. The refugia function, which could be attributed to the clustering of aquatic macrophytes, does not exist in these lakes probably because the alien fishes exploit such habitats for reproduction. Since introductions threaten the native fish diversity of the region, studies on regional dispersion and factors that minimise the spread of alien fishes are needed.

Adaptation of the reservoir fish assemblage index (RFAI) for assessing the Barra Bonita Reservoir (São Paulo, Brazil)

In order to evaluate the environmental condition of the Barra Bonita Reservoir, we adapted the Index of Biotic Integrity (IBI). We chose 24 sampling sites in which three types of habitats were sampled: the mouths of tributaries, the central reservoir and the lateral reservoir. Fish were caught in two seasons (dry and rainy) using 10 gillnet gangs, with meshes ranging from 3 to 12 cm between opposite knots, and funnel traps. Abiotic and biotic variables were measured. Due to the artificial nature of the reservoir, the term biotic integrity was considered inappropriate and the term RFAI (Reservoir Fish Assemblage Index) was adopted. Twelve metrics from sixteen possibles were selected using the Pearson correlation coefficient. The reference conditions were set up based on the criteria of the best condition observed. For each metric, a score of 1, 3 or 5 was assigned as it strongly departs (1), slightly departs (3) or approaches (5) the reference condition. The index value is the sum of the metrics partial scores and ranges from 12 to 60. To evaluate the importance of the unit of measurement of the metric, the index was calculated in fish number (RFAI(N)) and in weight (RFAI(w)). The correlation between RFAIN and RFAIw was very high (r = 0.90, n = 46) indicating that the unit of measurement does not influence the final result of the index. Most of the sampling sites were classified in the 'reasonable' RFAI category. Only the central sites were classified as 'poor'. To validate the RFAI, another index, the Habitat Quality Index (HQI), was built starting from the physiochemical and habitat variables collected. The correlation of the RFAI with the HQI was highly significant (RFAIN, r = 0.37; RFAI(w), r = 0.47; n = 46), indicating that they respond in the same way to environmental degradation. The HQI metrics which most affect RFAI were depth, surrounding landscape and macrophyte presence/absence. Copyright C) 2007 John Wiley & Sons, Ltd.

Tendency towards homogenization in fish assemblages in the cascade reservoir system of the Tiete river basin, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)