You know that the elvers have arrived in Limerick when the locals start fishing for trout from the bridges in the city using elvers as bait. Elvers are collected at low tide and are mounted on small hooks and fished at depth using a stop knot and quill float.
This is a traditional practice that has been undertaken in Limerick for generations and, regardless of the current legal standing of this practice in Ireland, it is an interesting and unique activity. Elvers were visible in the water column this weekend and some trout could be seen taking elvers from the surface. It is clear that there is a major elver run underway on the River Shannon at present.
The trout that these anglers are fishing for are ‘slob’ trout, which are believed to be recruits from the main river Shannon and small catchments discharging into the Shannon estuary. ‘Slob trout’ is a local term used for a brown trout phenotype which has spent part of it’s life in brackish or salt water and which did not become a smolt before descending into tidal waters. These fish are not true sea trout and their estuarine residence is thought to be largely related to better feeding opportunities. The ‘slob trout’ term describes a continuum between trout found in slightly brackish water to fish almost impossible to distinguish from genuine sea trout. Unlike sea trout, slob trout (with the exception of spawning migrations) appear to move up and down an estuary only in the search of food. Anglers in Limerick City have said that these trout follow upstream migrating glass eels from the estuary to the tidal head at Limerick city.
- For further information on this practice see this document ‘Interactions of juvenile eels, Brown trout (Salmo trutta, L) and other predators in the tidal section of the lower River Shannon‘.
There is every indication that the elver run on the River Shannon is exceptional this year, and it is disappointing that these eels are not being captured efficiently and moved upstream to the Shannon lakes to support a sustainable eel fishery. These elvers cannot get there by themselves due to the presence of the Shannon hydroelectric scheme. The elver traps run by the ESB are inadequate, not managed optimally and only catch a very small percentage of the elvers migrating upstream.