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Nenagh, Ireland

Minchin D.,Marine Organism Investigations | Minchin D.,Lough Derg Science Group
European Journal of Entomology | Year: 2010

Several thousands of the seven-spot ladybird Coccinella septempunctata L., descended upon a cruise ship over several hours in daylight while in port in Morocco in April 2009. The ship had recently arrived from South America. Despite a treatment of fumigation beetles were found living after fourteen days following the inoculation event. This observation indicates an ocean transmission of large numbers of this species could take place and might have happened in the past. © 2003 Institute of Entomology. Source

Penk M.R.,Trinity College Dublin | Minchin D.,Klaipeda University | Minchin D.,Lough Derg Science Group
Hydrobiologia | Year: 2014

Temporal migrations by aquatic organisms have important implications for fundamental ecosystem processes and community interactions. Mysid crustaceans, key planktivores and fish prey in aquatic food webs, frequently undertake diurnal vertical migrations, but there are limited reports of horizontal movements. Using seasonal and diurnal field surveys in Lough Derg on the Shannon River (Ireland), we tested the hypotheses that (i) the euryhaline mysid Mysis salemaai expands seasonally its horizontal distribution and that (ii) the diurnal pattern of vertical migration within the shallows overlaps with the introduced mysid Hemimysis anomala. M. salemaai, previously considered an exclusively offshore species, changed its horizontal distribution significantly with seasons, being restricted to ≥8 m in summer and extending to all depths in winter. During winter, the distribution of M. salemaai overlapped with H. anomala in shallows and there was a highly significant overlap in their diurnal emergence in the open water, indicating a strong temporal synchrony of planktonic foraging. The seasonal range expansion of M. salemaai is likely to have important implications for horizontal redistribution of nutrients. Interactions with the sympatric H. anomala are likely, adding to existing physico-chemical pressures on the glacial relict M. salemaai and potentially contributing to its further extirpations. © 2013 Springer Science+Business Media Dordrecht. Source

Boelens R.,Lough Derg Science Group | Minchin D.,Lough Derg Science Group
Biology and Environment | Year: 2013

The filamentous and euryhaline red alga Bangia atropurpurea (Rhodophyta, Bangiophyceae) is a littleknown member of the Irish aquatic flora. Although a common freshwater species in the northern hemisphere, it seems that the lower Shannon Navigation is one of the principal freshwater localities for the species in Ireland. It was recorded from thirteen sites in Lough Derg in 1972 and in the 2010 survey reported here at 40 sites including islands and navigation buoys as well as on lock gates. It attaches to rocks and other hard surfaces immediately above and below the waterline. It may have been introduced to Lough Derg on the hulls of commercial vessels. Changes in climatic conditions, eutrophication, competition from other filamentous algae and fluctuating lake levels are all pressures that could affect the sustainability of Bangia within the Shannon Navigation. Nevertheless, this study shows that B. atropurpurea has persisted for at least 40 years in Lough Derg and remains widespread despite highly variable environmental conditions. © ROYAL IRISH ACADEMY. Source

Minchin D.,Lough Derg Science Group | Boelens R.,Lough Derg Science Group
Aquatic Invasions | Year: 2010

The Ponto-Caspian mysid shrimp Hemimysis anomala was found in Ireland for the first time in April 2008. During 2009 it was found throughout most of the Shannon River Navigation (~250km) occurring in swarms at estimated densities of ~6 per litre in shallows and in lower densities at depths of ~20m where its distribution overlaps with the native Mysis salemaai. Broods were found from March to September. It occurs mainly in lakes but small numbers were found at one river site. In summer, shallow-water specimens were found only during the night but in winter could be captured in daytime. It is not known by what means the species arrived in Ireland, or when. © 2010 The Author(s). Source

Minchin D.,Lough Derg Science Group | Boelens R.,Lough Derg Science Group
Biology and Environment | Year: 2011

Seven alien aquatic plants occur on the Shannon Navigation. Six ornamental plants have been recorded in Lough Derg. Two, Elodea canadensis and Lemna minuta, are widely distributed in the lough, locally abundant within the Navigation and the only alien plants found in Lough Ree. The species with the greatest impact, Elodea nuttallii, was first recognised in 2004 in harbours and cuts about the southern region of Lough Derg. It spread northwards by drifting fragments and almost certainly by leisure craft. Likewise, the fertile water violet, Hottonia palustris, originally found on the eastern side of the lake, has become abundant in sheltered shallows, reedbeds, canals and drains on the western side of the lake and continues to spread northwards and southwards. Confined populations of Stratiotes aloides occur only on the western side of Lough Derg and may have been there for several years. An isolated population of a pink cultivar of Nymphaea alba, present for at least four decades, occurs in Lough Derg beside a lakeside domaine. Since the introduction of the zebra mussel, Dreissena polymorpha, in c. 1993/4 there have been increases in water transparency that have presumably enabled some macrophytes to extend their ranges into deeper water. Given the likelihood of further range expansions or new introductions, regulation of the sale and distribution of alien aquatic species is needed to prevent further exotic plants from entering Irish waterways. © ROYAL IRISH ACADEMY. Source

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