Comparison of soil nutrients, pH and electrical conductivity among fish ponds of different ages in Noakhali, Bangladesh

Das B.K., Saha A., Das A.K., Chandra P., Mondal K., Kayal T., Chakraborty S., Bhattacharya S., Sahoo B.K., Jana C.

IntroductionBottom sediments play a pivotal role in wetland productivity, and here, eight Gangetic floodplain wetlands of India were studied to assess the sediment physicochemical characteristics and textural analysis.MethodsSediment samples that were collected from each wetland in monsoon and non-monsoon seasons were analysed. ANOVA, Principal component analysis and multiple correlation analysis were used for statistical analysis.Results and DiscussionThroughout the study period, pH (6.90–8.04), EC (0.20–1.64 dS/m), CaCO3 (1.75%–14.50%), available nitrogen (10.22–22.23 mg/100 g sediment), total nitrogen (80.4–333.8 mg/100 g sediment), available phosphorus (0.20–5.61 mg/100 g sediment), and total phosphorus (19.63–173.33 mg/100 g sediment) were recorded. The sediment quality parameters differ significantly (p > 0.05) among the wetlands. Seasonal variation was only observed on total nitrogen and total phosphorus contents. Sediments were dominated by sand. Sediment nutrient (C, N, and P) stoichiometry of wetlands depicted a comparatively little higher C/P (5.96–66.32) ratio and lower C/N (3.34–22.76) and N/P (1.12–9.25) ratios, which revealed that the physicochemical characteristics of the sediments are influenced by anthropogenic sources. Principal component analysis showed the influence of both natural and anthropogenic causes on wetland ecosystems. The geographic information system (GIS) interpolation approach was used in combination with laboratory analysis methods to give a complete spatial resolution of the sediment quality of each wetland. The study suggests that these wetlands’ sediment quality is favorable for fish culture but requires proper management practices to achieve sustainable production. As it is the first time where monitoring physicochemical properties of sediments of these wetlands are presented, this study can be used as a baseline data for comparison in future environmental assessments of the wetlands.

Krishnapriya P., Bijith P., Sandeep S.

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.

Shafi J., Waheed K.N., Mirza Z.S., Zafarullah M.

Krishnapriya P., Bijith P., Sandeep S.

Abstract 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, t-test, concluded that the parameters of water such as pH, temperature, alkalinity, dissolved oxygen (DO), biological oxygen demand (BOD), fluoride, nitrate, and iron contents of traditional shrimp ponds, and pH, BOD, nitrate, sulphate and total hardness of non-traditional shrimp ponds significantly varied from its corresponding natural mangrove ecosystems. In addition, the phosphorus content in soil samples from traditional shrimp ponds and the pH, electrical conductivity, phosphorus, potassium, 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.