Control and management of cynophycean (Spirulina platensis) bloom in Padmatheertham, Thiruvananthapuram, India

The blue–green algal (BGA) bloom that appeared in Padmatheertham, the sacred pond in Sree Padmanabha Swamy Temple, Thiruvananthapuram, Kerala, India is associated with Spirulina platensis, a cyanobacterium rich in proteins, considered as a safe, functional food. Considering the unaesthetic appearance of the BGA bloom and its foul odour on open decomposition, various non-chemical methods were employed for its control. Several methods for nutrient remediation in the pond system were also explored. The efficacy of using decomposing rice straw to inhibit algal growth was studied. The possibility of control of BGA by stocking tilapia and filter-feeding bivalve, Villorita cyprinoides capable of ingesting and digesting the algae was analysed. Experimental assays carried out on V. cyprinoides revealed that it helped in the rapid utilization of BGA. The present study reinforces our understanding of the fundamental ecosystem services that filter-feeder communities provide to counter the invasive effects of eutrophication through consumption and assimilation