Physicochemical characteristics of shrimp ponds on mangrove ecosystems in Kannur District of Kerala, India

Mangrove forests are one of the most productive ecosystems in the world and are known for their ecological, economic, and social importance. Large-scale shrimp farming severely threatens mangrove ecosystems since shrimp productivity is correlated with mangrove ecosystems. The present study was carried out to determine the physicochemical characteristics of soil and water of traditional and non-traditional shrimp ponds near mangroves for understating the variation from the natural mangrove ecosystems of the Kannur district. Different parameters such as pH, electrical conductivity, BOD, DO, alkalinity, acidity, fluoride, iron, sulphate, nitrate, calcium, magnesium, and total hardness of collected water sample and pH, electrical conductivity, nitrogen, phosphorus, potassium, organic carbon and heavy metal contents of collected soil samples were determined by respective instruments and methods. From the analysis, it was found that all the parameters of traditional, as well as non-traditional shrimp ponds showed significant variation from the natural mangrove ecosystems. The result from the statistical analysis such as multivariate analysis (partial eta squared) concluded that the parameters of water such as pH, electrical conductivity, temperature, turbidity, alkalinity, nitrate, sulphate and iron contents of traditional shrimp ponds, and electrical conductivity, temperature, nitrate, sulphate and total hardness of non-traditional shrimp ponds significantly varied from its corresponding natural mangrove ecosystems. In addition, the potassium content in soil samples from traditional shrimp ponds and the pH, electrical conductivity, phosphorus, lead, and chromium in soil from non-traditional shrimp ponds significantly varied from corresponding natural mangroves. Changes in those physicochemical parameters of soil and water will affect the associated organisms and restrict further restoration of mangroves in the long term.