Day 4 Part 1: Killarney National Park- From the Victorian fern craze to the most primitive vertebrate species alive today

15/11/18

Killarney National Park

We spent the final day of our field trip in the biodiversity hotspot that is Killarney National Park. This is a 10,289 hectares park that is an important are of conservation for lots of species ranging from plants to invertebrates, fish, birds and mammals. Killarney National Park is part of the Killarney National Park, Macgillycuddy’s Reeks and Caragh River Catchment SAC (Special Area of Conservation) and is also a SPA (Special Protection Area) [1].

We first entered the park at the Muckross entrance where we walked down to Muckross lake. Here we discussed some of the species that are found in this park, both those that are listed as qualifying interests for it to be assigned as a SAC, and other species that occur here. To learn about some of the following habitats and species, read on!

• Habitats and Plants
• Invertebrates
• Amphibians and Reptiles
• Fish

Habitats and Plants:

There are a range of different types of habitats in Killarney National Park that have contributed to its assignment as a SAC. These include various oligotrophic (low nutrient) waters, heaths such as Northern Atlantic wet heaths and European dry heaths, calcareous grasslands and blanket bogs. Killarney also has the most extensive areas of natural woodland in Ireland with old sessile oak woods and alluvial forests, to name a few [1]. Two plant species that are also listed as being of ‘qualifying interest’ and are Annex II species are the Killarney fern, which is one of the ‘rarest and most celebrated species in the British and Irish vascular flora’ [2], and slender naiad, a freshwater annual plant [3]. Killarney fern was once abundant in the park but the popularity of ferns in the 19^th century by Victorians, led to only a few populations still surviving in the park. Slender naiad is found in Lough Leane but is thought to be threatened here by nutrient enrichment as it requires oligotrophic (low nutrient, clear) waters [3].

Invertebrates:

More than 500 invertebrate species have been recorded in Killarney National Park. I will discuss some that are of interest. However, a more extensive list can be found on page 138 of the document found HERE.

Three molluscan species are found in the park. Two of which, the freshwater pearl mussel and the Kerry slug, are Annex II and SAC qualifying species [1]. The freshwater pearl mussel is listed as endangered on the IUCN red list [4]. and is critically endangered across Ireland and Europe with a 90% reduction in their numbers in the last century [5]. Around Ireland the forestry industry has contributed largely to the decline of the freshwater pearl mussel due to the influx of sediment and nutrients into freshwater systems in which the mussels are found [6]. However, the population in Killarney is reported to be reasonably healthy despite threats to it due to gravel extraction in the past and nutrient enrichment (eutrophication) [3].

The Kerry slug is only found in Kerry, West Cork and in northern Spain and Portugal. It is hypothesised that the slug was passively brought over to Ireland on cargo ships during the middle ages. Ireland’s Kerry slug population has low genetic diversity, which is thought to have arisen due to the founder effect. This occurs when a new population arises from a small number of individuals that came from a larger population. Unfortunately, this leaves the slug more vulnerable to environmental change [7]. The Kerry slug is also threatened by the invasive species Rhododendron pontificus, commercial afforestation and uncontrolled burning. Rhododendron is also a threat to the slug in Killarney National Park, but management procedures are in place where rhododendron is being removed from habitats thought to be suitable for the Kerry slug. The Kerry slug is particularly found in areas where there are outcroppings of Devonian old red sandstone and where there is lichen, liverwort and/or mosses for it shelter in and feed on [8].

Brown and black colour morphs of the Kerry slug. Picture source: Aidannnuigalway [CC BY-SA 4.0], from Wikimedia Commons.

Freshwater pearl mussel. Picture source: I, Boldie [CC BY-SA 3.0], from Wikimedia Commons. Photoraph by I, Boldie [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0/)%5D

Of the 13-dragonfly species found in Ireland, two are listed as endangered on the IUCN red list and are found in Killarney National Park. These are the northern emerald (Somatochlora arctica) and the downy emerald (Cordulia aenea). The northern emerald is Ireland’s rarest odonate (damselflies and dragonflies) species only occurring in 2 discrete areas in Killarney Park. This species is also threatened by rhododendron which encroaches on their habitat, particularly breeding sites. The future prospects of these 2-dragonfly species in Ireland are poor due to decreasing habitat quality and the fact that they are confined to only a few small areas [9].

The marsh fritillary butterfly is also found in the park and it is Irelands only insect species listed under Annex II of the EU habitats directive [10]. Its host plant is devil’s bit scabious Succisa pratensis. This means that it lays its eggs on this plant and offspring feed on it, making this plant essential for its this species lifecycle. This butterfly is vulnerable to both its own parasites and parasites of its host plant, to grazing animals and is weather sensitive. This results in local extinctions being commonplace. However, it also has a high dispersal rate meaning that frequent re-colonisation events counterbalance these local extinctions [11].

Amphibians and Reptiles:

Of the three-amphibian species found in Ireland, the common frog and smooth newt are found in the park, both of which are protected under the wildlife act. The common frog is listed as internationally important and under Annex V of the EU Habitats Directive and is widespread in the park and all over Ireland, breeding in even small puddles of water [3]. Still or slow-moving waters are essential habitats for the smooth newt so the preservation of such habitats in the park is critical. Although the smooth newt is listed as least concern in the Irish red data book and is distributed widely across the country their dependence on wetland habitats makes them vulnerable to environmental change and reductions in suitable habitats for them [12].

Ireland has 2 reptile species and only one of the these is endemic to Ireland: the viviparous lizard. Unlike most reptiles which lay eggs, the viviparous lizard gives birth to live young. St. Patrick is famously known to have scared all of the snakes out of Ireland, but if you come across the slow worm, the other reptile species found in Irelad, you may think snakes have returned to our island. The slow worm is deceptive, from its name you would think it’s a worm, from its appearance it looks like a snake. However, it is actually a legless lizard! The slow worm was introduced in the Burren, Co. Clare, from Britain in 1970 so it has only very recently colonised Ireland [13].

Smooth newt. Gailhampshire from Cradley, Malvern, U.K [CC BY 2.0], via Wikimedia Commons.

Slow worm. Image source: pixabay.com

Fish:

14 fish species are found in Killarney Parks lakes and rivers. Of particular note are the Arctic charr and the Killarney shad. Lough Leane is the only place in the world where the Killarney shad can be found, and it is listed as endangered in Irelands red data book and Annx II and IV of the Habitats Directive. It is a sub-species of the twaite shad which is an anadromous species meaning that it spends its lifecycle in both freshwater and the marine environment. However, the Killarney shad has become land locked and has adapted to a purely freshwater existence [3]. Genetic studies have found that two colonisation events have occurred in Lough Leane. One right after the last Ice Age and one after the Younger Dryas, which was a period of around 1000 years during which the earth experience rapid cooling again not long after the end of the last Ice Age [14]. There are some lakes in Italy where purely freshwater shads have evolved in a similar way [3].

The Arctic char is listed as vulnerable on Irelands red data book. Like the Killarney shad the Arctic char is typically an anadromous fish but has adapted to a permanent freshwater environment. Arctic char has the most northerly distribution of any freshwater fish, being found in arctic waters. However, it is also found in areas as far south as Ireland where it is found in mountainous lakes that most resemble arctic conditions [3]. There are thought to be around 50,000 discrete isolated populations of arctic char globally which has led to a long debate of whether these constitute separate species or only sub-species. The population found in Killarney National Park (both Lough Muckross and Lough Leane) was documented as Salvelinus obtusus, or blunt snouted char, by Regan in 1908, with this same ‘species’ of arctic char recorded in the nearby Lough Acoose and Lough Luggala in Co. Wicklow in the east of Ireland [15].

A recent study has found that acoustic monitoring can be used to detect not only the specific location of spawning grounds of arctic char, but also important information regarding spawning activity such as diel pattern and length of spawning activities. Gathering this type of behavioural information is crucial for achieving conservation objectives of species and this provides a non-invasive way of improving our knowledge [16].

All three species of lamprey that are present in Ireland, brook, sea and river lamprey, can be found in Killarney [3]. Lamprey are considered the most primitive of all extant vertebrates and together with the hagfish, make up the jawless vertebrates (superclass agnathans) still alive today. They are entirely cartilaginous and have a round sucker-like disc with several rows of strong horny teeth. The jawed vertebrates (gnathostomes) make up the rest of the vertebrate sub-phylum which includes sharks, bony fish, amphibians, reptiles, birds and mammals. While river and brook lamprey are listed as least concern in Ireland’s red data book, sea lamprey is listed as near threatened. All 3 species are on Annex II of the Habitats Directive and River Lamprey is listed on both Annex II and Annex V. Although not a very attractive fish, lamprey have important functional roles in ecosystems through nutrient processing, storage and cycling and as a food source for other animals [17,18,19].

Salmon and trout, economic value through recreational and commercial fishing, also spawn in rivers within the park and are present in its lakes. Salmon is listed as internationally important on the Irish Red Data Book and on Annex II and V of the EU Habitats Directive [3].

Atlantic Salmon, image source: Hans-Petter Fjeld (CC BY-SA 2.5) via wikimedia commons.

Sea lamprey, Image source: NOAA Great Lakes Environmental Research Laboratory [CC BY-SA 2.0], via Wikimedia Commons

Species of birds and mammals in the park that peaked my interest are covered in my next blog post ‘Killarney National Park- From the mysterious merlin to Ireland’s only surviving lineage of native red deer’.

References

[1] NPWS (2017) Conservation Objectives: Killarney National Park, Macgillycuddy’s Reeks and Caragh River Catchment SAC 000365. Version 1. National Parks and Wildlife Service, Department of Culture, Heritage and the Gaeltacht.

[2] Ratcliffe, D., Birks, H. and Birks, H. (1993). The ecology and conservation of the Killarney Fern Trichomanes speciosum willd. In Britain and Ireland. Biological Conservation, 66(3), pp.231-247.

[3] The National Parks & Wildlife Service Department of the Environment, Heritage & Local Government (2005). Management Plan for Killarney National Park 2005-2009. [online] NPWS. Available at: https://www.npws.ie/sites/default/files/publications/pdf/KNPMP.pdf [Accessed 23 Jan. 2019].

[4] Moorkens, E., Cordeiro, J., Seddon, M.B., von Proschwitz, T. & Woolnough, D. (2018). Margaritifera margaritifera (errata version published in 2018). The IUCN Red List of Threatened Species 2018: e.T12799A128686456. http://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T12799A508865.en. Downloaded on 23 January 2019.

[5] Npws.ie. (n.d.). The Freshwater Pearl Mussel | National Parks & Wildlife Service. [online] Available at: https://www.npws.ie/research-projects/animal-species/invertebrates/freshwater-pearl-mussel [Accessed 23 Jan. 2019].

[6] McCarthy Keville O’Sullivan Ltd. (2018). Draft Plan for Forests and Freshwater Pearl Mussel in Ireland. [online] Forest Service, pp.134-135. Available at: https://www.agriculture.gov.ie/media/migration/forestry/publicconsultation/forestryfreshwaterpearlmussel/RevNATURAImpactStatememtForestsFPM100718.pdf [Accessed 23 Jan. 2019].

[7] Reich, I., Gormally, M., Allcock, A., McDonnell, R., Castillejo, J., Iglesias, J., Quinteiro, J. and Smith, C. (2015). Genetic study reveals close link between Irish and Northern Spanish specimens of the protected Lusitanian slugGeomalacus maculosus. Biological Journal of the Linnean Society, 116(1), pp.156-168.

[8] Mc Donnell, R.J. and Gormally, M.J. (2011). Distribution and population dynamics of the Kerry Slug, Geomalacus maculosus (Arionidae). Irish Wildlife Manual s, No. 54. National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht, Dublin, Ireland.

[9] Nelson, B., Ronayne, C. & Thompson, R. (2011) Ireland Red List No.6: Damselflies & Dragonflies (Odonata) National Parks and Wildlife Service, Department of the Environment, Heritage and Local Government, Dublin, Ireland.

[10] Npws.ie. (n.d.). Marsh Fritillary Euphydryas aurinia | National Parks & Wildlife Service. [online] Available at: https://www.npws.ie/research-projects/animal-species/invertebrates/marsh-fritillary-euphydryas-aurinia [Accessed 23 Jan. 2019].

[11] Barnett, L.K. and Warren, M.S. (1995) Species action plan. Marsh fritillary Eurodryas aurinia, Butterfly Convention, Wareham, Dorset.

[12] Irish Wildlife Trust (2013). IWT National Smooth Newt Survey. [online] Available at: https://iwt.ie/wp-content/uploads/2017/09/Newt-Survey-2013.pdf [Accessed 24 Jan. 2019].

[13] Irish Wildlife Trust. (2018). National Reptile Survey – Irish Wildlife Trust. [online] Available at: https://iwt.ie/what-we-do/citizen-science/national-reptile-survey/ [Accessed 24 Jan. 2019].

[14] Coscia, I., McDevitt, A., King, J., Roche, W., McLoughlin, C. and Mariani, S. (2013). A species-to-be? The genetic status and colonization history of the critically endangered Killarney shad. Molecular Phylogenetics and Evolution, 69(3), pp.1190-1195.

[15] Adams, C. and Maitland, P. (2007). Arctic charr in Britain and Ireland ? 15 species or one?. Ecology of Freshwater Fish, 16(1), pp.20-28.

[16] Bolgan, M., O’Brien, J., Chorazyczewska, E., Winfield, I., McCullough, P. and Gammell, M. (2017). The soundscape of Arctic Charr spawning grounds in lotic and lentic environments: can passive acoustic monitoring be used to detect spawning activities?. Bioacoustics, 27(1), pp.57-85.

[17] Lamprey Surveys. (n.d.). Lamprey species. [online] Available at: https://lampreysurveys.com/lamprey-species/ [Accessed 24 Jan. 2019].

[18] Weaver, D., Coghlan, S., Greig, H., Klemmer, A., Perkins, L. and Zydlewski, J. (2018). Subsidies from anadromous sea lamprey (Petromyzon marinus) carcasses function as a reciprocal nutrient exchange between marine and freshwaters. River Research and Applications, 34(7), pp.824-833.

[19] Gallagher, T., O’Gorman, N.M., Rooney, S.M., Coghlan, B., and King, J.J.  (2017) National Programme: Habitats Dire ctive and Red Data Book Species Summary Report 2016. Inland Fisheries Ireland, 3044 La ke Drive, Citywest, Dublin 24, Ireland