Eutrophication: Global Scenario and Local Threat to Dynamics of Aquatic Ecosystems

Khan, Fareed Ahmad; Naushin, Fauzia; Rehman, Farha; Masoodi, Ather; Irfan, Mudasir; Hashmi, Farah; Ansari, Abid Ali

doi:10.1007/978-94-007-7814-6_2

Cited by 25 publications

(15 citation statements)

References 38 publications

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“…A ACP corroborou a informação de que no período chuvoso, com o aumento do escoamento superficial na bacia observa-se em geral maiores concentrações de sólidos na água (Lucas et al, 2010; Bucci e Oliveira, 2014) e nutrientes. A maior disponibilidade de nutrientes favorece consequentemente o aumento da produtividade primária (Khan et al, 2014), medida indiretamente pela concentração de Cl-a. A redução de OD observada no período chuvoso pode ser explicada pela decomposição da matéria orgânica (Melo et al, 2005), respiração de organismos aquáticos e oxidação de íons metálicos (Esteves, 2011).…”

Section: Resultsunclassified

Heterogeneidade espacial e temporal de variáveis limnológicas no reservatório de Itupararanga associadas com o uso do solo na Bacia do Alto Sorocaba-SP

et al. 2015

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RESUMODentre as diversas atividades desenvolvidas no entorno de corpos de água, a poluição por agroquímicos e o lançamento de efluentes acarretam a carga excessiva de nutrientes que contribuem para o processo de eutrofização artificial e degradação destes ecossistemas. Neste contexto, os objetivos deste trabalho foram: determinar a heterogeneidade sazonal e espacial nas águas superficiais do reservatório Itupararanga e verificar a influência dos usos do entorno sobre a qualidade da água do reservatório localizado na cidade de Ibiúna, São Paulo, Brasil. Analisou-se o Índice de Estado Trófico (IET) e variáveis limnológicas em duas estações distintas -período seco e chuvoso de 2013. Os dados foram comparados com mapa de usos do solo e com parâmetros estabelecidos pela resolução CONAMA n° 357 de 2005. Os resultados demostraram que o fósforo total não esteve em conformidade com as especificações CONAMA. O reservatório apresentou heterogeneidade sazonal e espacial em relação ao IET e às variáveis limnológicas. Por meio da análise de agrupamento com os dados de qualidade de água e uso e ocupação dos solos foi comprovada a heterogeneidade espacial. A análise de agrupamento indicou que a cobertura florestal é um importante fator para a contenção da entrada de sólidos em suspensão. Indicou também que o uso agrícola é a principal fonte de nitrogênio para o meio enquanto que os rios formadores contribuem, principalmente com cargas de fósforo. Assim, por se tratar de uma área de importância social e econômica, medidas de preservação devem ser tomadas a fim de mitigar os avanços das atividades potencialmente impactantes.

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Section: Resultsunclassified

Heterogeneidade espacial e temporal de variáveis limnológicas no reservatório de Itupararanga associadas com o uso do solo na Bacia do Alto Sorocaba-SP

et al. 2015

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“…In some cases, this rapid contribution may be excessive, and nutrient excess, as well as nutrient deficiency, can have deleterious effects on plant growth. Moreover, nutrient excess may cause them to be transferred to surface and ground water, resulting in environmental problems (Khan et al, 2014). Therefore, a sound management of fertilization should reconcile the maintenance of high crop yields with reduced costs, resource economy and environmental issues.…”

Section: Introductionmentioning

confidence: 99%

Nitrogen, phosphorus, potassium, calcium and magnesium release from two compressed fertilizers: column experiments

et al. 2014

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Abstract. The objective of this work was to study nutrients release from two compressed nitrogen-potassiumphosphorous (NPK) fertilizers. In the Lourizán Forest Center, tablet-type controlled-release fertilizers (CRF) were prepared by compressing various mixtures of fertilizers without covers or binders. We used soil columns (50 cm long and 7.3 cm inner diameter) that were filled with soil from the surface layer (0-20 cm) of an A horizon corresponding to a Cambic Umbrisol. Tablets of two slow-release NPK fertilizers (11-18-11 or 8-8-16) were placed into the soil (within the first 3 cm), and then water was percolated through the columns in a saturated regime for 80 days. Percolates were analyzed for N, P, K + , Ca 2+ and Mg 2+ . These elements were also determined in soil and fertilizer tablets at the end of the trials. Nutrient concentrations were high in the first leachates and reached a steady state when 1426 mm of water had been percolated, which is equivalent to approximately 1.5 years of rainfall in this geographic area. In the whole trial, both tablets lost more than 80 % of their initial N, P and K contents. However, K + , Ca 2+ and Mg 2+ were the most leached, whereas N and P were lost in leachates to a lesser extent. Nutrient release was slower from the tablet with a composition of 8-8-16 than from the 11-18-11 fertilizer. In view of that, the 8-8-16 tablet can be considered more adequate for crops with a nutrient demand sustained over time. At the end of the trial, the effects of these fertilizers on soil chemical parameters were still evident, with a significant increase of pH, available Ca 2+ , Mg 2+ , K + , P and effective cation exchange capacity (eCEC) in the fertilized columns, as well as a significant decrease in exchangeable Al 3+ , reaching values < 0.08 cmol (+) kg −1 .

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“…Since then, it has become more widespread and surveys showed that 54 % of lakes in Asia, 53 % in Europe, 48 % in North America, 41 % in South America and 28 % in Africa are in eutrophic state (Colin et al 2007). In Spain 80 % of the lakes, 70 % of the reservoirs and 60 % river sites were eutrophic in the 1990s with hypertrophy increasing downstream (Alvarez-Cobelas et al 2001;Khan and Ansari 2005;Khan et al 2014). Three large coastal marine ecosystems (Chesapeake Bay, Northern Gulf of Mexico, and Danish Straits) showed repeated hypoxic events have led to an increase in susceptibility of further hypoxia and accelerated eutrophication ).…”

Section: Discussionmentioning

confidence: 99%

Seasonal dynamics in the trophic status of water, floral and faunal density along some selected coastal areas of the Red Sea, Tabuk, Saudi Arabia

et al. 2015

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Eutrophication is posing a threat to the coastal marine ecosystems. The consequence of anthropogenic induced eutrophication of waters has resulted in severe deterioration of surface waters. In this research a preliminary data was collected on eutrophication by environmental monitoring on some selected coastal areas of the Red Sea near Tabuk, Saudi Arabia. Sampling sites were selected from Haql, Sharmaa and Duba (five for each station) and water samples collected in four different seasons (Oct 2013, Jan 2014, April 2014 and July 2014) to study seasonal dynamics of water quality parameters (especially in reference to the trophic status of water). Only one coastal site from each station was found with some eutrophic characteristics. Water samples collected from these eutrophic sites were more alkaline, turbid, with higher nutrient and low dissolved oxygen contents as compared to other sampling sites. Dynamics in relative densities of coastal flora and fauna were also found to be related with coastal water quality. Human settlements, fish markets, boating clubs and tourisms near these coastal areas of the Red Sea were observed as the primary causes of nutrient loading; run-offs during rains carrying nutrients also aggravate the problem. The results of this study may help in estimating the intensity of the problem and as a forecast for time frame to take an action for the conservation of affected coastal marine ecosystems and restoration of degraded coastal areas of the Red Sea.

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Eutrophication: Global Scenario and Local Threat to Dynamics of Aquatic Ecosystems

Cited by 25 publications

References 38 publications

Heterogeneidade espacial e temporal de variáveis limnológicas no reservatório de Itupararanga associadas com o uso do solo na Bacia do Alto Sorocaba-SP

Heterogeneidade espacial e temporal de variáveis limnológicas no reservatório de Itupararanga associadas com o uso do solo na Bacia do Alto Sorocaba-SP

Nitrogen, phosphorus, potassium, calcium and magnesium release from two compressed fertilizers: column experiments

Seasonal dynamics in the trophic status of water, floral and faunal density along some selected coastal areas of the Red Sea, Tabuk, Saudi Arabia

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