12 research outputs found

    Nutrient enrichment and fisheries exploitation: interactive effects on estuarine living resources and their management

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    Both fisheries exploitation and increased nutrient loadings strongly affect fish and shellfish abundance and production in estuaries. These stressors do not act independently; instead, they jointly influence food webs, and each affects the sensitivity of species and ecosystems to the other. Nutrient enrichment and the habitat degradation it sometimes causes can affect sustainable yields of fisheries, and fisheries exploitation can affect the ability of estuarine systems to process nutrients. The total biomass of fisheries landings in estuaries and semi-enclosed seas tends to increase with nitrogen loadings in spite of hypoxia, but hypoxia and other negative effects of nutrient over-enrichment cause declines in individual species and in parts of systems most severely affected. More thoroughly integrated management of nutrients and fisheries will permit more effective management responses to systems affected by both stressors, including the application of fisheries regulations to rebuild stocks negatively affected by eutrophication. Reducing fishing mortality may lead to the recovery of depressed populations even when eutrophication contributes to population declines if actions are taken while the population retains sufficient reproductive potential. New advances in modeling, statistics, and technology promise to provide the information needed to improve the understanding and management of systems subject to both nutrient enrichment and fisheries exploitation

    Adições à flora de briófitas de Mato Grosso do Sul, Brasil Additions to the flora of bryophytes from Mato Grosso do Sul State, Brazil

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    Nesse levantamento foram encontrados 133 táxons no Estado de Mato Grosso do Sul, sendo um pertencente à divisão Anthocerotophyta em um gênero e uma família, 83 pertencentes à divisão Bryophyta, distribuídos em 54 gêneros e 27 famílias, e 49 à divisão Hepatophyta, distribuídos em 27 gêneros e 13 famílias. Destes, 100 (1 antócero, 59 musgos e 40 hepáticas) são novas citações para o Estado.<br>In this taxonomic survey 133 taxa were found in Mato Grosso do Sul State, one belonging to Anthocerotophyta, distributed into one genus and one family, 83 belonging to Bryophyta, distributed into 54 genera and 27 families, and 49 belonging to Hepatophyta, distributed into 27 genera and 13 families. Of these, 100 (one hornworts, 59 mosses and 40 hepatics) are new records for the State
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