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Cyanobacterial composition and microcystin accumulation in catfish pond
Author(s)
Date Issued
January 1, 2014
Type
Article
Abstract
Cyanobacterial blooms frequently occur in catfish ponds, but the potential effects of its secondary metabolites on cultured animals in ponds and human beings remain largely unknown. In the present study, high chlorophyll-a levels (1.28-2.06 mg/L) indicated massive phytoplankton blooms in the studied ponds, with a maximum density of 52 × 106 cells/L of potentially toxic cyanobacteria, composed mainly of Microcystis aeruginosa, Oscillatoria spp., Lyngbya sp., Pseudanabaena spp., Anabaena spp., Anabaenopsis sp., and Cylindrospermopsis sp. However, microcystins were not detected by liquid chromatography-mass spectrometry in samples of water and fish. Instead, microcystin-RR in phytoplankton was estimated to be between 0.014 and 0.202, and correlated positively with the density of Anabaena spp. (r=0.33, p<0.05), alkalinity (r=0.37, p<0.05), and ammonia (r=0.48, p<0.01). Microcystin was not detected in the fish in this study, but microcystin accumulation was found in 43% of analyzed phytoplankton samples. Therefore, long-term monitoring is recommended in order to fully understand microcystin accumulation patterns at all degrees of phytoplankton bloom.
Citation
Chiang Mai Journal of Science, 41(1), 27-38, 2014