Direction of migrations | Fishers (N) | Maximum points of movement towards the upstream (villages) | Fishers (N) |
---|---|---|---|
Towards the upstream | 23 | Melgaço | 21 |
Moves both upstream and downstream | 16 | Monção | 10 |
Do not know | 01 | São Gregório (Melgaço Municipality) | 04 |
Lapela (Monção Municipality) | 02 | ||
Ourense | 02 | ||
Illa Fillaboa | 01 | ||
Ways to get around barriers to migration | Citations | Migration delay factors | Citations |
Swimming | 32 | The strength of the water current | 11 |
Resting and leaning on the river rocks | 07 | The resting of the animal on rocks and other refuges | 10 |
Breaking barriers instinctively | 04 | Hydroelectric dams | 07 |
Parasitizing other fish | 04 | Predatory fishing | 07 |
Freshwater scarcity | 04 | ||
River flooding | 04 | ||
Do not know | 01 | ||
Preferred time to migrate | Citations | Food migration (months) | Citations |
Any time of the day | 32 | May | 08 |
Nocturnal period (Preference) | 10 | November | 07 |
According to tidal variation | 07 | December | 04 |
Just the Night | 04 | June | 03 |
According to the phases of the moon | 03 | January | 02 |
Morning | 01 | April, July, August, and September (each one) | 01 |
According to the arrival of the lamprey at the mouth of the river | 01 | ||
Do not know | 01 |