Hematological Parameters in Oreochromis niloticus Collected in Lakes Under the Influence of Metallurgical Industries

LUANA CARVALHO; MICHELLY SOARES; IARA SOUZA; SILVIA MATSUMOTO; MAGDALENA MONFERRAN; DANIEL WUNDERLIN; MARISA FERNANDES

Congreso; SETAC Latin America 15th Biennial Meeting; 2023

SETAC Latin America

The industrial revolution resulted in an intense urbanization process that generated anthropic impacts on the environment, such as the contamination of water resources. Brazil is one of the largest producers and exporters of iron in the world have high metallurgical activity and the largest metallurgical complexes is the Tubarão Complex located in the Espírito Santo state, Brazil. The present study evaluates the physiological changes in the blood Oreochromis niloticus collected in estuarine lakes under influence of metallurgical industries (Maemba –sites P1 and P2 and Carapebus) and a lake (Alegre), distant 150km from this industrial complex, as a reference site. O. niloticus has a worldwide distribution, it is abundant in Brazilian reservoirs and has a well-known physiology. Several biomarkers as cortisol; glucose; ions (chloride, sodium and potassium ions); osmolality; lysozyme; leukocyte burst; total plasma protein; total thrombocyte and leukocyte; differential leukocyte number (monocyte, lymphocyte, neutrophil, granular leukocyte PASpositive and eosinophil); micronucleus; hematocrit; hemoglobin; erythrocyte number and hematologicalindices (MCV; MCHC and MCH) were analyzed to diagnose the environmental conditions in which they are living. Alegre fishes had a higher number of neutrophils, granular leukocyte and erythrocytes and lower leukocyte respiratory activity (burst) and MCV than the other lakes; Carapebus fishes had higher concentration of cortisol, chloride and sodium ions in plasma, eosinophils and micronuclei; Maemba fishes has higher concentration of lysozyme and total plasmatic protein, fishes from P1 site presented more number of leukocytes and MCV and lower osmolality, lymphocyte number, hemoglobin, MCHC and MCH compared to the other lakes and P2 site presented higher lymphocyte number and MCH compared to the other lakes and P1. The higher cortisol level in Carapebus indicated stress condition and the higher lymphocytes in fish from P2 site , in Maemba may indicate an immune response to inflammation. Therefore, O. niloticus from lakes under industrial influence presented stress responses suggest low water quality.