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Preliminary
Report (Part 2) Ireland's Most Threatened and Rare Freshwater Fish Institute
of Fisheries Management - Irish Branch
Spring Seminar in co-operation
with the
Afternoon Session
Mr Declan Quigley - Smelt Mr Declan Quigley gave a presentation about the distribution of smelt Osmerus eperlanus in Ireland. Smelt are known to have been present at the following locations: on the coast at Larne, R. Foyle, Belfast Lough, R. Corrib, R. Fergus, R. Shannon, R. Feale, Waterford Harbour, R. Blackwater, and possibly on R. Nore and R. Suir. Smelt have also been found in the stomach of cormorants on Little Saltee Island off the South East Coast. The 3 known spawning populations in Ireland are located in Rivers Shannon Fergus and Foyle. It is possible that smelt also spawn in the Southern Rivers such as the Barrow, Nore and Suir, but we need more information and data collection to determine this. Declan also outlined his own interest in unusual fish over the years and the essential neglect of these species by the relevant authorities. He quite succinctly put the main threat to these species as IGNORANCE. This is a sentiment that the ICCG would whole heartily agrees with, which is why we emphasise the importance of education in the conservation of Arctic char and other rare fish. Dr Fran Igoe -Smelt Dr Fran Igoe gave an account of a recent fish kill on the River Shannon in Limerick City, which had killed an estimated 10,000 smelt and a lesser amount of juvenile salmon and trout. He gave an account of the investigation conducted by staff of the Shannon Regional Fisheries Board into the ecology of the species. They inspected many sites along the River margins for evidence of smelt eggs. Dr Igoe also talked about other risks to the Shannon, such as diesel spillages by machinery working in the River. He also referred to the Smelt Working Group, set up to gather more information on the species here in Ireland.
Dr Fran Igoe –Arctic char Dr Igoe went onto talk about Arctic Char Salvelinus alpinus in Ireland. He mentioned the complexity in the classification of the species and suggested that reference to char as members of the Arctic char species complex, was more appropriate, to take into account variation that occurs (phenotypically and genetically) throughout their range. Even in Ireland, six different forms of char were identified in Ireland in the past, see picture:
S.colii - Lough Eske (most common form)
S.scarrffi -Lough Ennell and Owel S.grayii- Lough Melvin
S.fimbriatus- Lough Coomasaharn S.trevellyani- Lough Finn S.obtusus - Lough Dan, Tay, Killarney and Accoose
To illustrate the extent that this variation can occur, Dr Igoe showed an example of the variation in colouration that can take place even in char from one lake (Lough Eske, Co. Donegal). He demonstrated that in char taken from this lake in November 1999 and November 2000, there was a variation in dominant upper body colour (silver-lilac, through blue-brown to orange and orange-brown). The number of parr marks on char also varied, but the most common number of parr marks on char was 13 in both years. Although early work by Prof. Ferguson in Queens university showed the char to be conspecific, Fran suggested that each char population in Ireland should be recognised in its own right due to their reproductive isolation since the last ice age. Conservation measures should therefore be on this (lake by lake) basis.
He gave an overview of the worldwide distribution of char, the natural history of the species and how the Irish char fit into the picture. Essentially the Irish char are marginal in their location and do not show the great variations in size or morphs as evident in other countries. However little research has yet been carried out in Ireland. He showed details of length frequency distributions, diet studies and ageing studies of char in a number of Irish lakes. He also showed the spatial and vertical distribution of Lough Mask Char from netting surveys of the lake and the associated CPUE in comparison with those of other fish caught in the survey. Fran showed the most up to date current distribution of Arctic char here in Ireland, which is worrying. Firstly, up to 40% of our known populations could be extinct. Secondly, all known char populations, east of the River Shannon are now extinct. He also showed a table showing a break down of char lake status to Regional Fisheries Board Areas. 100% of char populations are extinct in the Eastern and Shannon Regional Board Areas. Dr Igoe gave details of survey questionnaire sheets which had been circulated to the Regional Fisheries Boards and thanked the staff for their response. The results illustrate the change that char lakes have undergone in recent years and illustrate the pressure that they face. Additionally it is evident that in general lakes where char have become extinct show greatest change. He summarised that the main threats to the species are: 1. Reduced water quality because of municipal and agricultural pollution. 2. Fish introductions. 3.Acidification 4.Aquaculture –possible genetic impacts on native strains 5.Climate change He recommended the following measures for Conservation of the species: 1. Control movements of exotic species-therefore live bait byelaw was a good idea. 2. Water quality maintenance and improvement 3. Legislation to protect habitats 4.Good planning for aquaculture 5.Education and increase public and institutional awareness 6.Funding for research into both biology/ecology of the species in Ireland 7.Translocations of unique strains Fran gave a brief overview of what the Irish Char Conservation Group is about and announce that the ICCG plan on hosting the next workshop of the International Society of Arctic Char Fanatics in Ireland, next year.
Dr Jimmy King Dr Jimmy King talked about the distribution and spawning sites of shad Allosa fallax, Allosa allosa, and lamprey Lampetra sp. in Ireland. Dr King gave details of recent investigations he had conducted with colleagues from the Central and Regional Fisheries Boards to determine the status of lamprey species in Ireland. He gave an account of the lamprey life cycle. He demonstrated that barriers, such as weir often obstructed lamprey passage up river and that many spawning redds were in the downstream vicinity of a weir and gave examples along the Nore and Suir Rivers. He said that selection of SAC’s for lampreys were based on the presence of all three lamprey species.
He highlighted 4 areas designated as SAC’s for shad these were:
Weirs also proved to be potential obstructions to shad movement as for lampreys. He explained the criteria used by the Irish Specimen Fish Committee to decide specimen shad weights. He concluded by highlighting the threats to both lamprey and shad species, amongst these were water quality and habitat loss.
Dr Robert Rosell Dr Robert Rosell spoke about the distribution of Pollan in Ireland. Pollan Coregonus autumnalis occur (highlighted) or may have occurred in: 1 Lough Neagh 2 Lough Corrib 3 Lough Ree 4 Lough Derg 5 Lough Erne (Lower) 6 Lough Mask There have also been reports of pollan in the past in Lough Garadice, Co. Leitrim, but not in recent years. Lough Erne pollan were commercially fished until 1960, but no commercial licences have been issued since 1995. Repeated margin netting surveys of Lough Erne by Dr Rossell and his team did not locate any pollan. As pollan need large expanses of water, a Simrad Echosounder and nets rigged to fish a mid-water position pollan (and some good advice from a local pollan fisherman) were finally successful at locating pollan. Robert showed a number of echograms illustrating the difficulty even with hydroaccoustics in surveying this elusive species. The main threats to Pollan includes competition for zooplankton with roach and increased roach numbers had jeopardised the survival of pollan. Small Pollan seemed to have changed their behaviour, traditionally they had been found in the shallows, but no longer seem to be in the shallows of Lough Erne, this change is probably to avoid competition with roach. Pollan are certainly one of our most if not the most threatened freshwater fish species in Ireland today, although Robert did also call attention to one of cyprinid species (the Rudd) which is now less widespread that before. Another victim to the mighty roach.
 Copyright
2003. ICCG ©2003 |
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