Evaluating the Nutrient Uptake Potential of Bivalves, Physiological Energetics, and Optimal Environmental Conditions

Bivalves are efficient engineers, functioning as effective bioremediators. This study proved crucial for evaluating effective bioremediators and identifying optimal conditions for integration into aquaculture systems. Five bivalve Species were grouped, as well as the factors influencing bioremediation, were evaluated. Species include Perna viridis, Crassostrea hongkongensis, Crassostrea sikamea, Meretrix lyrata, and Cyclina sinensis. After 96 h exposure of bivalves to synthetic eutrophic water in the P. viridis, the filtration rates and percentage changes for total suspended solids (TSS) were 2.86 (39.67%), NH₄⁺ 2.13 (53.60%), NO₃^- 0.77 (11.98%), NO₂ ^- 0.66 (15.50%), Dissolved inorganic nitrogen (DIN) 2.98 (21.19%), PO₄^3-1.43 (45.75%), and chemical oxygen demand (COD) 1.43 (45.75%). For C. hongkongensis, TSS 2.99 (40.30%), NH₄⁺ 0.65 (16.46%), NO₃^- 0.28 (4.30%), NO₂ ^- 0.25 (5.92%), DIN 0.38 (2.60%), PO₄^3-0.78 (19.75%), and COD 0.78 (19.75%), whereas other groups maintained higher nutrient levels. Physiological energetics showed similar trends in P. viridis and C. hongkongensis, including clearance rate (CR; 0.92 ± 0.076 and 0.85 ± 0.058 L h^-1 g^-1), assimilation efficiency (AE; 88.06% ± 2.12% and 82.24% ± 2.43%), and ingestion rate (IR; 0.38 ± 0.004 and 0.36 ± 0.0042 mg h^-1), all of which were significantly higher than those of C. sikamea, which showed moderate performance, whereas lower in M. lyrata and C. sinensis. P. viridis maintains optimal CR at 21°C-31°C, 30‰, whereas C. hongkongensis maintained high CR at 21-ppt salinity, 6- to 8-mg/L DO, and pH 8.1. Moreover, a positive correlation was noticed between shell length and CR. P. viridis and C. hongkongensis proved to have superior filtration rates, signifying their effective role as biofilters in eutrophic water.