Guaraíras Lagoon is a shallow coastal lagoon subject to human impacts, including shrimp aquaculture, urban expansion and agricultural activities. Guaraíras is part of a complex lagoon called the "Complexo Lagunar Estuarino Nísia Floresta-Papeba-Guaraíras", consisting of three interconnected lagoons of which Guaraíras is the largest. The lagoon is about 7 km long, and is a shallow lagoon with depths ranging from 0.5 to 2 m and up to 11 m in the narrow channels. The lagoon is part of the Rio Jacú hydrographic basin, and this river supplies the main inflow of fresh water, in the innermost part of the lagoon.
The description of the historical evolution of the morphology of the Guaraíras Lagoon reports that the system underwent successive natural changes in its dynamics, with some periods of isolation and others of connection to the sea. In 1923, a narrow canal was opened connecting the lagoon to the sea, with the objective of draining the lake during the rainy season. This canal rapidly widened, permanently linking the lake to the sea. Taking this into account, a lagoon regime was formed, with tidal action.
References:
Almeida, L.R., Costa, I.S., Eskinazi-Sant'Anna, E.M. 2012. Composition and abundance of zooplankton community of an impacted estuarine lagoon in Northeast Brazil. Brazilian Journal of Biology, 72 (1): 13-24
Lacerda, L. D., Campos, R. C., Santelli, R. E. 2013. Metals in water, sediments, and biota of an offshore oil exploration area in the Potiguar Basin, Northeastern Brazil. Environmental Monitoring and Assessment, 185: 4427-4447
Santiago, M. F., Passavante, J. Z. O., Silva-Cunha, M. G. G. 2005. Caracterização de parâmetros físicos, químicos e biológico em ambiente hipersalino, estuário do rio Pisa Sal (Galinhos, Rio Grande do Norte, Brasil). Tropical Oceanography, 33 (1): 39-55