The Standing Scientific Committee (SSC) derived rod exploitation rates from rivers with fish counters where the run of salmon and the catch by anglers (the exploitation rate) was known. Three bands of salmon exploitation rates were set, low (average 5%) medium (average 15%) and high (average 35%). Each river was allocated a rod exploitation rate based on the level of salmon angling taking place. Generally, rivers open for catch and release were categorised as the low rod exploitation rate. However, if fishery staff indicate a higher rod exploitation rate, then this higher rate is applied to predict the total salmon run. Where the level of salmon angling has increased, the rod exploitation rate has also increased.
To account for the low fishing pressure during summer 2018 due to the exceptionally dry and hot weather conditions, the exploitation rates were reduced generally by 50%, where the catch figure was used to estimate the stock. In rivers such as the Barrow, Nore and Suir which jointly considers the one-sea-winter grilse and multi-sea-winter stock components, the reduction was generally applied only to the one-sea-winter grilse portion of the total angling catch. However, the 2018 exploitation rate for the River Suir was subsequently reassigned to a standard low exploitation rate as the 2018 catch records showed over double the estimated catch originally provided for.
For salmon rivers without fish counters like the Barrow, Nore and Suir, the Technical Expert Group on Salmon (TEGOS) use the recorded salmon rod catch on each river for the most recent five-year period in conjunction with a range of rod exploitation rates to provide an estimate of the total salmon run. A five-year average is used to avoid a disproportionate impact from a good or bad year. Counter data is one of a number of indices used to estimate salmon runs and IFI has a range of fish counters nationwide from which index data may be extrapolated. There are currently no plans to install fish counters on the Suir, Nore and the Barrow.
