Table 2. Microcystin-LR concentrations (ppb) at the top, middle, and bottom of seawater tanks at two exposure concentrations (Tank 2 and Tank 31) and varying postexposure intervals.
| Inoculum 2,195 ppb | Tank 2 (low exposure)1 | |||||
| 1 H | 12 H | 24 H | 48 H | 72 H | 7 Days | |
| Surface | 2.34 | 0.87 | 5.18 | 0.75 | 1.32 | Nd2 |
| Middle | 0.756 | 0.71 | 1.37 | 0.87 | 1.03 | nd |
| Bottom | 0.500 | 0.650 | 1.90 | 1.32 | 1.01 | nd |
1
All samples from Tank 1 (seawater control) tested negative for microcystin-LR. All 3 tanks were flushed with fresh seawater starting 96 H postexposure).
2
nd = microcystin concentration was below minimum detection limits on liquid chromatography-tandem mass spectrophotometry.