Managing fish counters
How we measure stock data for Irish rivers to establish if conservation limits are being maintained.
The fish counter programme was established in 1994 by the Regional Fisheries Boards and the Marine Institute. Responsibility for the programme was transferred to the Regional boards and subsequently to us when it was established in 2010.
The purpose of this programme is to establish accurate stock data for individual rivers. This information is used in the development of population models which help to establish if conservation limits are being achieved in Irish rivers.
As one of the few countries in western Europe with a good stock of salmon, Ireland has a key role in managing salmon and sea trout stocks in our many diverse but mostly small rivers. While in many cases the stocks of Atlantic salmon are overall in decline, we are working to preserve and protect the large number of genetically unique stocks in Irish rivers.
Fish counters are important in the management of salmon and sea trout stocks. The National Fish Counter Programme enables the organisation to verify the extent of the runs of salmon and sea trout without any physical interference with the migrating fish.
Ireland has led the way in terms of the extent of its fish counters programme and many of these counters are sited on important salmon and sea trout rivers. Fish counter data collected from a variety of locations and river types provides a national stocktake for the management of the resource. This information is indicative of run timing in many areas. This data when added with angling catches and electrofishing data is used to assess the extent of the stock.
How we do it
We operate two types of fish counters. The most versatile and robust is the Logie resistivity counter which can be operated in two configurations: a fibreglass tube or on a crump weir. Inland Fisheries Ireland have integrated camera software with these resistivity counters to enable it to verify each fish with video footage as it’s counted.
The second counter type is a VAKI Riverwatcher which is an optical counter using infra-red scanners. The Vaki Riverwatcher is used where the fish are required to swim through a narrow opening. This optical counter works extremely well where a fish pass or ladder exists or where a trapping facility is in place.
A significant part of the National Fish Counter programme is about data management which is accomplished by a website-based database. We have developed a policy which governs data collected by our network of fish counters. The policy sets out the rules regarding the storage, management and sharing of fish counter data.