Trophic state and water turn-over time in six choked coastal lagoons in Brazil

• DOI: 10.1007/bf00002903
• Publication Date: 2004-08-22T22:07:22Z
• Authors: Bastiaan Knoppers; Bj�rn Kjerfve; Jean-Pierre Carmouze
• Keywords: 13. Climate action; 15. Life on land; 6. Clean water

Comparison of total phosphorus and chlorophyll-a concentration, nutrient loading, and water turn-over time in six shallow choked lagoons along the coast of the state of Rio de Janeiro, Brazil, established that water turn-over time is related to the trophic state of the lagoons with additional anthropogenic nutrient loading affecting this relationship. Turnover time was calculated as a flushing half-life from rainfall, evaporation, runoff, and tidal exchange data, and trophic state was calculated from the quantity and quality of dissolved inorganic nutrients, total phosphorus, and chlorophyll-a standing stock. Flushing half-life of the lagoons ranged between 1 and 27 days, annual phosphorus areal loading from 3 to 18 mg m−2d−1, and chlorophyll-a standing stock from 6 to 160 mg M−2