The SMOLTrack team met in Monção, Portugal on the River Minho in June 2023, to discuss their ongoing work tracking salmon from rivers into the North Atlantic and back.
Continue reading “SMOLTrack meeting Portugal”SMOLTrack meeting Portugal
River Erriff – Getting ready for smolt season
Acoustic telemetry
IFI is getting ready to deploy acoustic receivers in River Errif and Killary harbour to track migrating Atlantic salmon smolts.
River Bush new infrastructure – PIT stations
The smolt trap at River Bush has been equipped with a PIT station, capable of detecting both the smolts on their way to the sea, and also the adults once they return!
River Erriff – Environmental parameters
Weather and temperature stations
These stations keep track of the environmental conditions in the rivers, and will play an important role in the results of the Work Package 3!
Fresh from the press!
Published results
Marine mortality in the river? Atlantic salmon smolts under high predation pressure in the last kilometres of a river monitored for stock assessment
Continue reading “Fresh from the press!”River Minho – 2019
Study type: Radio
Listening stations deployed: 2
(complemented with manual tracking)
Tagged smolts: 35 (25 wild & 10 naturalised*)
Succeeded: 17 (12 wild & 5 naturalised*)
* Naturalised fish were born in a hatchery environment but were released to the upper reaches of the river as young juveniles.
Survival rates (%)
Overall survival = Number of survivors / Total number of released fish * 100
Section survival = Fish that reached the end of the section / Fish that entered the section * 100
Study area
Red dots represent listening stations
Red flags represent release sites
River Bush – 2019
Study type: Radio
Listening stations deployed: 1
(complemented with manual tracking)
Tagged smolts: 35
Succeeded: 24
Survival rates (%)
Overall survival = Number of survivors / Total number of released fish * 100
Section survival = Fish that reached the end of the section / Fish that entered the section * 100
Study area
Red dots represent listening stations
Red flags represent release sites
River Erriff – 2019
Acoustic Study
Study type: Acoustic
Listening stations deployed: 13
Tagged smolts: 20
Succeeded: 16
Survival rates (%)
Overall survival = Number of survivors / Total number of released fish * 100
Section survival = Fish that reached the end of the section / Fish that entered the section * 100
Study area
Red dots represent listening stations
Red flags represent release sites
Radio study
Study type: Radio
Listening stations deployed: 4
(complemented with manual tracking)
Tagged smolts: 43
Succeeded: 20
Survival rates (%)
Overall survival = Number of survivors / Total number of released fish * 100
Section survival = Fish that reached the end of the section / Fish that entered the section * 100
Study area
Red dots represent listening stations
Red flags represent release sites
Tagging – First results!
Recovered tags
Recovering radio tags allows us to directly link the smolt predation to the predator. In this case, our smolt was eaten by a mammal, most likely an otter. Other common predators are herons, cormorants and bigger fish!
Fieldwork season begins!
Radio tracking
The SMOLTRACK fieldwork season started and all our partners are out in the field, looking for the tagged Atlantic salmon smolts!
