Radio-tagged ferox trout being released.

Ferox Trout Study on Lough Corrib and Lough Mask

Ferox trout are large lake trout known to be genetically different from the normal brown trout stock in Ireland. These fish have being heavily exploited by angling in the recent past, and little is known of their biology or spawning locations in major Irish lakes.

Developing our understanding

The Ferox Trout Study began in 2005 in Lough Corrib with the aim of determining spawning locations and developing long-term protection measures for the ferox stock. This project used acoustic telemetry: fish are captured, tagged with surgically implanted radio transmitters, released and then tracked using radio receivers.

Informing policy through scientific investigation

The study showed that the vast majority of tagged ferox trout in Lough Corrib spawned in the Cong River. This led to the introduction of a conservation bye-law on that river in 2008, which extended the closed season for ferox trout angling as a means of protecting the stock during the vulnerable spawning period.

Moving the focus elsewhere

On the basis of that success, this study moved to Lough Mask in 2008 and revealed that the Cong Canal, which connects Lough Mask and Lough Corrib, is the primary spawning location for that lake. Again, conservation measures resulted from this work to protect ferox trout stocks in Lough Mask.