Shimna River
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The Shimna River is a river in County Down. It is a spate river that rises on the slopes of Ott Mountain, in the Mourne Mountains, and enters the Irish Sea at Newcastle, on Dundrum Bay. It is acidic and nutrient-poor, as a result of which its most common flora are mosses and liverworts, including the rare Portuguese feather-moss and Holt's mouse-tail moss. Its principal fish are salmon and sea trout, and it is managed by the Shimna Angling Club. The river is an Area of Special Scientific Interest.
The Shimna has a history of flooding; the most serious recent flooding was in 2008. There have also been incidents of pollution, and there were serious fish kills in 2004, 2006 and 2009.
Course
The source of the river is in the Mourne Mountains on the slopes of Ott Mountain. The river then flows in a northerly direction to Fofanny Dam. It continues its flow but changes to a north-easterly direction flowing into Tollymore Forest Park where it meets other streams such as the Spinkwee and Trassey. The Shimna finally flows to the east, then takes a south easterly direction toward Newcastle where at one point it flows through Tipperary Wood. The final tributaries to join the river prior to it reaching the sea are the Burren River and the Tullybrannigan River, at Islands Park. Near the mouth it widens quite considerably to create a shallow boating pond which is popular with tourists. The river is an Area of Special Scientific Interest.[1]
Geology
The Shimna is a short, fast flowing "spate" river. Where the gradient is shallow it is made up of a sequences of riffles and pools, and the river bed is composed of pebbles and scattered boulders, with sandy margins. Where the gradient is steep the flow is faster with rapids and cascades, and the bed is composed of bedrock and boulders.[1]
The bedrock of the upper part of the river, located in the Mourne Mountains, is composed of granite formed approximately 50 million years ago.[2] The bedrock of the river as it flows through Tollymore is shale from the Silurian age, about 440 mya, and it forms step gorges along some sections of the river banks. Dark bands of basalt are found were molten basalt lava was forced through cracks in the bedrock about 60 million years ago. The river bed contains stones and gravel from as far away as Antrim, Tyrone and the Highlands, which were carried there by glacial ice sheets during the last ice age.[3]
Flooding
There was major flooding in the area on 16 and 17 August 2008, most occurring along Bryansford Avenue and the Shimna Road, close to the Burren River and Shimna River confluence, causing damage to approximately 40 properties, notwithstanding a flood alleviation scheme along the nearby Burren River.
Plantlife
The river is poor in nutrients and acidic which determines the type of plant life found there. Mosses and liverworts are the most common. Near the source, compressed flapwort (Nardia compressa) and green algae are the most dominant species. Closer to the mouth Scapania|water earwort (Scapania undulata), Feather moss and bulbous rush (Juncus bulbosus) are also found. Holt's mouse-tail moss (Isothecium holtii) is very common on the banks, the Shimna River is one of only three known sites for this species in Ulster. It is also the only know location in Ulster where Portuguese feather-moss (Platyhypnidium alopecuroides) is found.
Other notable species include:
- Rusty feather-moss (Brachythecium plumosum)
- Fox-tail feather-moss (Thamnobryum alopecurum)
- Yellow fringe-moss(Racomitrium aciculare)
- Overleaf pellia (Pellia epiphylla)
Fish, birds and beasts
Atlantic salmon, brown trout and sea trout use the river to spawn.[4] Other fish species found include Three-spined stickleback, minnow, stone loach, and eel. Dippers and Grey wagtails can also be seen feeding on insects along the river.[1] Invertebrates species found include leeches, Simulidae and Ancylidae. Various Mayfly families are found, such as; Baetidae, Ephemerellidae, Heptageniidae and Caenidae. Stoneflies (Nemouridae, Chloroperlidae and Perlodidae families) and caddis larvae (Hydropsychidae, Polycentropidae, Rhyacophilidae and Limnephilidae families) are also present.[5]
Angling
The river is partly owned by the Department of Culture, Arts and Leisure and partly leased by the Shimna Angling Club, and is managed by the latter club under a management agreement. The principal fish are salmon and sea trout.[6] Fishing season is from 1 March to 31 October.[4]
Pictures
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Newcastle and the Shimna River -
Headwater of the river -
The mouth of the river
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("Wikimedia Commons" has material about Shimna River) |
References
- ↑ 1.0 1.1 1.2 "Shimna River, a special place". http://www.doeni.gov.uk/niea/shimna_river_colour_leaflet.pdf. Retrieved 16 May 2012.
- ↑ "Geology of Mourne AONB". DOE. 25 January 2010. http://www.doeni.gov.uk/niea/places_to_visit_home/aonb/aonb_mourne/aonb_mourne_geology.htm. Retrieved June 14, 2012.
- ↑ Kirk, David (Spring 2011). "Tollymore, more than just trees.". Earth Science Ireland (9): 7, 8. SSN 1753-5271. http://www.habitas.org.uk/es2k/newsletter/Earth%20Science%20Ireland%20Issue%209.pdf.
- ↑ 4.0 4.1 "Key information about Shimna River". http://www.nidirect.gov.uk/angling-at-shimna-river.
- ↑ "Reference Condition Descriptions for Northern Ireland River Types". http://www.doeni.gov.uk/niea/riverrefcon.pdf. Retrieved May 16, 2012.
- ↑ "Shimna River". DCAL - A Selection of Angling Waters in Northern Ireland. http://www.dcal-fishingni.gov.uk/index/wild_salmon_trout_locations/shimna_river_wild.htm. Retrieved 28 February 2009.
Coordinates: 54°12′55″N 5°54′01″W / 54.21522°N 5.90026°W