Evaluation of the trophic status index of Lake Acu ubicado en el campus Seropedica de la Universidade Federal Rural do Rio de Janeiro

• Published in: GeSec : Revista de Gestão e Secretariado 2024-09, Vol.15 (9)
• Main Authors: Silva, Felipe Guimaraes Costa da, Tavares, Gabriel Dias, de Campos, David Vilas Boas, Silva, Leonardo Duarte Batista da, Brasil, Felipe da Costa, Nascentes, Alexandre Lioi
• Format: Article
• Language: Portuguese
• Subjects: Analysis; Aquatic resources; Chlorophyll; Eutrophication; Management; Water; Water quality
• ISSN: 2178-9010; 2178-9010
• DOI: 10.7769/gesec.v15i9.4272

Eutrophication is the enrichment of a water body with nutrients, leading to excessive algal growth. While this process can occur naturally, human activities have exacerbated eutrophication, resulting in significant impacts on the water quality of lakes and reservoirs. Eutrophication is primarily caused by the input of nutrients (mainly phosphorus and nitrogen) from untreated domestic and agro-industrial effluents. The Trophic State Index (TSI) is a method used to classify the extent of eutrophication by assessing parameters such as Chlorophyll a, Total Phosphorus, dissolved oxygen, pH, solids, among others. This index allows for the classification of a water body on a scale ranging from Ultraoligotrophic to Hypereutrophic. In this context, the present study aims to determine the Trophic State Index of Lake Acu, also known as the Lake of the Institute of Agronomy at the Federal Rural University of Rio de Janeiro (UFRRJ). To this end, two sampling campaigns were conducted (August 26, 2022, and December 14, 2022), during which samples were collected from 40 (forty) points across the lake using an aluminum boat. The results were plotted on maps with color scales to visualize the distribution of the values found. The average TSI values obtained for each of the two campaigns were 77.3 and 76.3, respectively, classifying the lake as Hypereutrophic on both dates, which is the worst condition on the eutrophication scale. Keywords: Water Resources Management. Eutrophication. Chlorophyll a. Phosphorus. A eutrofizacao consiste no enriquecimento de um corpo d'agua por nutrientes, ocasionando o crescimento excessivo de algas. Este processo pode ocorrer naturalmente, mas em decorrencia das atividades humanas, observa-se um agravamento da eutrofizacao com consequente impacto para a qualidade das aguas de lagos e reservatorios. A eutrofizacao e causada pelo aporte de nutrientes (principalmente fosforo e nitrogenio) provenientes de efluentes domesticos e agroindustriais sem tratamento adequado. Uma forma de se classificar a magnitude dessa eutrofizacao e o Indice de Estado Trofico (IET), que pondera os resultados de parametros como Clorofila a, Fosforo Total, oxigenio dissolvido, pH, solidos, dentre outros, e permite classificar o corpo d'agua em uma escala que vai de Ultraoligotrofico a Hipereutrofico. Nesse contexto, este estudo tem como objetivo determinar o Indice de Estado Trofico do Lago Acu, tambem conhecido como Lago do Instituto de Agronomia na Universidade Federal