Table 1.
Summary of the PCR and ELISA results for each cyanotoxin measured per sampling site.
| Cyanotoxins | MC | CYN | ATX | SXT | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Assessment | PCR | ELISA (µg/L) | PCR | ELISA (µg/L) | PCR | ELISA (µg/L) | PCR | ELISA (µg/L) | |||||||||||
| Location | mcyA | mcyB | mcyC | mcyD | mcyE | mcyG | cyrA | cyrB | cyrC | cyrJ | anaC | anab/anac | sxtA | sxtG | sxtI | ||||
| River Tâmega | |||||||||||||||||||
| April | + | - | - | + | - | - | 0.3 | - | - | - | - | ND | - | - | 0.2 | - | - | - | 0.0 |
| May | + | - | - | + | + | - | 0.2 | - | - | - | - | ND | - | - | 0.7 | - | - | - | 0.1 |
| June | + | - | + | - | + | - | 0.5 | - | - | + | - | ND | - | - | 0.2 | - | - | - | 0.1 |
| July | + | + | + | + | + | + | 0.4 | - | - | - | - | ND | + | - | 0.3 | - | + | + | 0.1 |
| August | + | + | + | + | + | + | 18.8 | - | - | - | - | ND | + | - | 1.0 | - | + | + | 1.1 |
| September | + | + | + | + | + | + | 17.0 | - | - | - | - | ND | + | - | 0.8 | - | + | - | 0.1 |
| Torrão Reservoir | |||||||||||||||||||
| April | + | + | + | + | - | - | 2.7 | - | - | + | - | ND | + | - | 0.3 | - | - | + | 0.1 |
| May | - | - | - | - | - | - | 0.3 | - | - | - | - | ND | + | - | 1.0 | - | - | - | 0.1 |
| June | + | - | + | - | + | - | 0.3 | - | - | + | - | ND | - | - | 0.4 | - | - | - | 0.1 |
| July | + | + | + | + | + | + | 0.2 | - | - | + | - | ND | + | - | 0.2 | - | + | + | 0.3 |
| August | + | + | + | + | + | + | 16.0 | - | - | - | - | ND | + | - | 0.3 | - | + | + | 0.7 |
| September | + | + | + | + | + | + | 5.0 | - | + | - | - | ND | + | - | 0.2 | - | + | + | 0.2 |
| Porto City Lake 1 | |||||||||||||||||||
| April | + | + | + | + | - | - | 4.3 | - | - | - | - | ND | - | - | 5.2 | - | - | − | 0.2 |
| May | + | + | + | + | + | - | 11.3 | - | - | - | - | ND | + | - | 2.1 | - | - | - | 0.3 |
| June | + | + | + | + | + | - | 3.5 | - | + | - | - | ND | + | - | 6.8 | - | - | - | 0.2 |
| July | + | + | + | + | + | + | 1.6 | - | - | - | - | ND | - | - | 0.4 | - | + | - | 0.1 |
| August | + | + | + | + | + | + | 2.1 | - | - | - | - | ND | + | - | 1.9 | - | + | + | 0.3 |
| September | + | + | + | + | + | + | 2.6 | - | - | - | - | ND | + | - | 1.6 | - | + | + | 0.5 |
| Porto City Lake 2 | |||||||||||||||||||
| April | - | - | + | - | - | - | 0.3 | - | - | - | - | ND | - | - | 0.2 | - | - | - | 0.2 |
| May | + | + | + | + | + | - | 2.0 | - | - | - | - | ND | - | - | 0.4 | - | - | + | 0.2 |
| June | + | + | + | + | + | - | 13.3 | - | - | - | - | ND | - | - | 1.5 | - | - | - | 0.3 |
| July | + | - | + | + | + | + | 3.9 | - | - | + | - | ND | + | - | 0.4 | - | + | + | 0.9 |
| August | + | + | + | + | + | + | 4.8 | - | - | + | - | ND | + | - | 0.9 | - | + | + | 4.3 |
| September | + | + | + | + | + | + | 6.5 | - | - | + | - | ND | + | - | 0.6 | - | + | + | 2.6 |
| Porto City Lake 3 | |||||||||||||||||||
| April | + | - | - | + | - | - | 0.3 | - | - | - | - | ND | - | - | 1.8 | - | - | - | 0.1 |
| May | - | - | - | - | - | - | 0.2 | - | - | - | - | ND | - | - | 0.4 | - | - | - | 0.2 |
| June | - | - | + | - | - | - | 0.1 | - | - | - | - | ND | - | - | 1.0 | - | - | - | 0.2 |
| July | + | - | + | + | + | + | 0.2 | - | - | - | - | ND | - | - | 1.1 | - | + | - | 0.2 |
| August | + | + | + | + | + | + | 0.4 | - | - | + | - | ND | - | - | 0.3 | - | + | - | 0.2 |
| September | + | + | + | + | + | + | 1.9 | - | - | + | - | ND | - | - | 0.4 | - | + | + | 0.2 |
| Mira Lagoon | |||||||||||||||||||
| April | - | - | - | - | - | - | 0.5 | - | - | - | - | ND | - | - | 0.4 | - | - | - | 0.1 |
| May | - | - | - | - | - | - | 0.3 | - | - | - | - | ND | - | - | 0.5 | - | - | + | 0.2 |
| June | - | - | - | - | - | - | 0.3 | - | - | + | - | ND | - | - | 0.5 | - | - | + | 0.6 |
| July | + | + | + | + | + | - | 0.6 | - | - | + | - | ND | - | - | 2.1 | - | - | + | 0.3 |
| August | + | + | + | + | + | - | 0.3 | - | - | - | - | ND | - | - | 0.6 | - | - | + | 0.5 |
| September | + | + | + | + | + | + | 1.9 | - | - | + | - | ND | + | - | 1.0 | - | + | + | 1.3 |
| Vela Lagoon | |||||||||||||||||||
| April | - | - | - | - | - | - | 0.3 | - | - | - | - | 0.1 | - | - | 1.6 | - | - | - | 1.9 |
| May | + | - | - | - | - | - | 0.3 | - | - | - | - | 0.1 | - | - | 0.5 | - | - | + | 1.4 |
| June | - | - | - | - | - | - | 0.4 | - | - | + | - | 0.1 | - | - | 1.7 | - | - | + | 1.8 |
| July | + | + | + | + | + | + | 2.1 | - | - | + | - | 0.0 | - | - | 0.9 | - | + | - | 1.9 |
| August | + | - | - | + | + | + | 0.9 | - | - | - | - | 0.1 | + | - | 0.8 | - | + | + | 1.8 |
| September | + | - | - | + | - | + | 8.7 | - | - | - | - | 0.0 | - | - | 1.1 | - | + | - | 2.4 |
(+)—positive amplification (PCR); (-)—no amplification; ND—not determined. mcyA amplification resulted in a positive ELISA assay in 78% of the samples; anaC resulted in 40%; sxtG in 45%; sxtI in 48%; cyrB in 0%; cyrC in 16.7%.