The big freeze continues throughout the Lower Shannon Special Area of Conservation. Much of the Mulkear catchment has experienced sub-zero day-time temperatures for six consecutive days with night-time temperatures recorded as low as minus 9 degrees Celsius and indeed significantly lower temperatures in isolated areas with snowfields. The Big Freeze has continued for 26 days since late November 2010. Freezing fog around the Limerick area during daylight hours has resulted in sub-zero day time temperatures for much of this week. This has transformed the landscape. Trees and vegetation in the riparian zone along the Mulkear River and the main Shannon River resemble the arctic tundra.
Sheltered and shaded areas on the banks of the Shannon River, including the area immediately behind the IFI office in Limerick, have had ice cover for over a week and the fringes of the Shannon itself is iced over in sheltered areas.
Within the Mulkear catchment large stretches of the lower section of the main Mulkear channel, from Ballyclough Bridge down to Annacotty weir, is frozen on the surface. Large sections of river above Ballyclough weir are also frozen as are large sections of the Killeengarrif river at Barringtons Bridge. Ice and debris which had formed and blocked the fish pass at Annacotty has been removed.
These near Arctic weather conditions, which are set to continue until after Christmas, are having a very negative impact on birdlife throughout the Mulkear catchment but should suit our population of native Atlantic salmon. Atlantic salmon have been running in Irish rivers since the last ice age so the present cold snap is just a small reminder of times long past. Spawning of salmon and trout is triggered by such cues as water temperature, water levels as well as hereditary characteristics. However, water levels throughout the catchment have been extremely low over the last number of weeks and this may delay spawning of salmon on the Mulkear and other rivers in the catchment and in the Shannon basin. Given the fact that fish movement is triggered by water levels, salmon may holdout in lower stretches of the Mulkear river until favourable conditions prevail given the present low water levels. Under low water level conditions, like those presently prevailing, certain natural or man-made obstacles can prove more difficult for salmon to navigate – hence the removal of the build-up of ice and debris on the fish pass at Annacotty.
Weirs, like those at Annacotty and Ballyclough, in low water levels may not provide sufficient water for salmon to jump or may not provide sufficient attraction flows for the salmon. Certain in-stream features like bridge aprons or culverts could also dry out or, under high flows, provide too much velocity for the salmon to pass. By and large though, since the salmonids are Arctic species, these present very cold conditions favour their survival, providing high oxygenated water and generally less stressful conditions for the fish. Spawning has started in certain parts of the Mulkear and will continue into January. Under these cold conditions, egg hatching will take longer.
It is vital that these salmonids are given every chance of survival and observing the moratorium on in-stream work is critical. Needless to say, poaching of salmon from their spawning beds is a despicable act and the damage it causes is immeasurable. This is an illegal activity as is the purchasing or retention of any salmon at this time of year. Female salmon can contain thousands of eggs which contribute to the recruitment of salmon throughout the Mulkear catchment. Any illegal fishing activity in the Mulkear catchment or elsewhere in the Lower Shannon SAC should be reported to Inland Fisheries Ireland (Limerick Office) on 061 300 328. In addition, Inland Fisheries Ireland have just launched a new freefone number to enable members of the general public to report poaching and pollution incidences – 1890 34 74 24 or for easier recall 1890 FISH 24. This phone line is designed to encourage the reporting of incidences of illegal fishing and water pollution.
The MulkearLIFE Project Team would encourage all to note these important numbers. Likewise the project would ask all those out over the Christmas and New Year period to play their role in helping to protect biodiversity and the natural heritage of the Mulkear and the Lower Shannon Special Area of Conservation.
Happy Christmas From The MulkearLIFE Project Team