Closing the door before the horse has bolted

Report on recent attempts to set up a refuge population should the char of Lough Melvin disappear

Fran Igoe

Lough Melvin is a 2,125 ha lake with a very unique fish fauna. Five salmonid species occur within the lake. The lake is of international importance due to the presence of three brown trout species, Ferox, Gillaroo and Sonaghen. Atlantic salmon and Arctic char are also present. At one time it was believed that the Arctic char in Lough Melvin were a distinct and separate species from the other Arctic char populations in Ireland, and they were given their own species name, Salvelinus grayii.

However Professor Andy Ferguson of Queens University examined the genetic relationship of Irish and concluded that the Melvin char and char from a number of other Irish lakes originated from the same ancestor. He recommended that Irish char populations be identified from their place of origin, and that considering these populations have been isolated since the retreat of the glaciers of the last Ice age, they have evolved genetic characteristics specific to their lakes.

Lough Melvin is the only lake in Ireland to contain Arctic char, which spans the Irish Republic and Northern Ireland, and is also therefore the only lake in Northern Ireland to contain Arctic char today. Lough Neagh also held char at one time, but lost its population sometime in the 19th Century.

At one time the char population in Lough Melvin was considerable and they were harvested for human consumption. Went (1945) quotes an extract from a letter dated 15th November, 1838, written by Viscount Cole (recorded in William Thompson’s Natural History of Ireland, 1856 – incidentally there is a copy of this excellent book in the Royal Irish Academy’s Library on Dorset Street, in Dublin, which is well worth a visit!). Anyhow, Cole wrote “ I can procure any number (i.e., of Melvin char) you wish, as people are now taking them in cart loads. The flesh of such as I send is white and soft and different from what that of char in any other lough.” These char were also referred to as “freshwater herring”. Went 1945, gives a fuller account of the char in Lough Melvin.

From the above extract, it is obvious that the Arctic char were plentiful in the lake and were probably taken during the spawning season by local people. This contrasts markedly with our experience in 2003, which I will describe below. In more recent times fishery surveys aimed at assessing the populations of the three Melvin brown trout species, failed to encounter large numbers of char compared to similar survey expeditions in other Irish char lakes such as Lough Mask or Lough Conn (before this population became extinct in the 1990’s). In 1975 thirty three specimens were taken by netting in October 1975 (Ferguson 1981). A subsequent survey by the Central Fisheries Board in 1986 recorded 42 char. Low numbers (eight specimens) were taken by Dr.Gavin Alexander from Glasgow University in 1997. In 2001 the Central Fisheries Board repeated its survey and only captured 12 char compared to 457 trout, i.e., Ferox, Gillaroo and Sonaghen combined (Delanty and O’Grady 2001).

Although the above surveys prove that Arctic char are still present in the lake, the apparent low numbers now present are a cause for concern. Although the lake is still in a relatively good ecological state, a number of changes have been noticed in recent years. These include the introduction of the non-indigenous cyprinid Rudd some 20 years ago. More recently a Rudd/Roach hybrid was captured (Delanty and O’Grady 2001), suggesting recent introduction of roach to the lake. The lake has also experiencing greater inputs of phosphorous from the surrounding catchment, which is causing concern particularly amongst the angling community.

Last autumn (November 2003) the Department of Culture, Arts & Leisure attempted to collect a brood stock of Melvin char with a view to translocation of the Melvin genetic stock to recipient reservoirs in Co. Tyrone, which would then serve as refuge populations should anything happen to the Melvin population. The operation was organised and lead by John Kane. Initially 30 fyke nets were set at a range of depths, however these efforts proved unsuccessful. There will be further efforts to obtain brood stock in the future and it would appear that co-operation with the local angling clubs with a depth of knowledge of the lough, will be forthcoming.

The Irish Char Conservation Group were carrying out its annual investigations in Lough Eske, Co. Donegal, which is close by and joined up with John to try and lend a hand to the conservation efforts. We carried out a snorkelling investigation of a number of shore lines that showed promise but failed to locate any sign of spawning activity. Although the gravel substrates were perfect the slope of the beds were either too steep or no step enough, in comparison to known spawning beds in other Irish lakes. We set two large fyke nets seeing as we were in the areas anyhow and the echosounder was recording a lot of fish activity which could have been char. Regrettably these fish turned out to be rudd and no char were encountered during the entire exercise. Lets hope that our failure to locate the char was due to a combination of incorrect timing and wrong location as opposed to a population on its last legs.

This project is a worthy exercise and it is nice to see a state agency taking a proactive approach to protecting our char as opposed to the usual wringing of hands followed by little or no action.
Next year it is planned to repeat the exercise after establishing the probable spawning beds in Melvin. Hopefully the project will meet with more success and provide a refuge population of Melvin char should the unthinkable happen, as has already happened to the Loughs Corrib and Conn char not so long ago.

References

Delanty, K and O’Grady, M.F. (2001) Lough Melvin fish stock report-2001. Central Fisheries Board, November 2002.
Ferguson, A. (1981) Systematics of Irish char as indicated by electrophoretic analysis of tissue proteins. Biochem. Syst. Ecol. 9, 225-232.
Thompson, W. (1956) The Natural History of Ireland. Vol, IV, London
Went, AEJ (1945) The distribution of Irish char (Salvelinus sp.) Proceedings of the Royal Irish Academy. Volume L, Section B, No. 8