Papers by Sarah Murnaghan
Modelling ecological pressures and responses in a west of Ireland lake
THESIS 9881Effective lake management requires an understanding of aquatic ecological pressure res... more THESIS 9881Effective lake management requires an understanding of aquatic ecological pressure response relationships. Deciphering the aquatic effects of multiple ecological pressures, such as climate variability and human activity, requires the analysis of long terni monitoring data. However, monitoring data are rarely available, particularly for the period prior to human impact. Palaeolimnology can be used to investigate long term aquatic ecological pressures and responses, and the benefits of palaeolimnology for lake management have been well-established. Dynamic ecological modelling can also be used to reconstruct ecological pressures-responses relationships. However, although recognised as a potentially valuable tool for water quality management, ecological modelling is not widely applied in lake management
An Effective Framework For assessing aquatic ECosysTem responses to implementation of the Phosphorous Regulations (EFFECT) Final Project Report EPA/STRIVE PROJECT # 2007-W-MS-3-S1
Reconstruction of the recent past in a west of Ireland catchment
Internationale Vereinigung für theoretische und angewandte Limnologie: Verhandlungen, 2008
The EU Water Framework Directive (WFD; Directive 2000/60/ EC) requires the water quality of Irish... more The EU Water Framework Directive (WFD; Directive 2000/60/ EC) requires the water quality of Irish lakes to be maintained or improved with reference to a baseline trophic status by 2015 (CLENAGHAN 2003). Establishment ofbaseline status can be difficult, however, where historical data are absent and where the previous human and environmental impacts were greater than at present. In Ireland, there have been major changes in population and landuse since the mid l9'h century (CSO 1997). The population fell from 6.5 million in 1841 to 4.4 million in 1861, following famines in the mid-l880s and subsequent immigration, and by 1926 stood at 2.6 million. It remained at this level until the 1970s and is now 4.2 million. Cattle numbers rose steadily from 5.1 million in 1949 to 6 million in 1964 and then more rapidly, peaking at 9 million in 1974 (CSO 1997). Agriculture and sewage have been linked to recent declines in water quality in Ireland (CLENAGHAN 2003). Little, however, is known of t...
Murnaghan S, Taylor D, Jennings E. Accepted. Reconstructing long-term trophic histories for lakes using two independent approaches: application of dynamic computer modelling and palaeolimnology to Lough Mask, Ireland . Proceedings of the Royal Irish Academy: Biology and Environment
Biology & Environment Proceedings of the Royal Irish Academy
Modelling natural and anthropogenic impacts on ecological dynamics in a calcareous lake
Past, current and future Interactions between pressures, chemicaL status and bioLogical qUality eleMents for lakes IN contrAsting catchmenTs in IrEland.(ILLUMINATE) Final Report EPA/ERTDI PROJECT # 2005-W-MS-40
Past, current and future interactions between pressures, chemical status and biological quality e... more Past, current and future interactions between pressures, chemical status and biological quality elements for lakes in contrasting catchments in Ireland (ILLUMINATE)
Journal of Paleolimnology, 2012
Geomorphologic, stratigraphic, faunistic, palynological and 14 C analyses were carried out in the... more Geomorphologic, stratigraphic, faunistic, palynological and 14 C analyses were carried out in the area of the mouth of the Garigliano River characterized by two strand plains that are referred to the Eutyrrhenian and the Holocene, rimming two depressed zones separated by the Garigliano River channel. This study depicts the palaeoenvironmental evolution over the last 8200 years and the landscape context at the time of Minturnae Roman colony. Between 8200 and 7500 yr BP, a wet zone occurred in the northern zone, whereas in the southern part, a lagoon developed. During the final transgression stage and the beginning of the sea level still stand (7500-5500 yr BP), a freshwater marsh formed in the northern zone, and the width of the southern lagoon decreased. Between 5500 and 3000 yr BP, the coastal barrier changed into a delta cusp, a freshwater marsh also appeared in the southern part and the river wandered between the twin marshes. Because of local uplift, previously unknown in this area, part of the floor of the southern marsh emerged, and after 4000 yr BP, both marshes became coastal ponds with prevailing clastic sedimentation. A progressive increment in anthropic forcing on the land took place after 3000 yr BP. The Marica sanctuary was built (7th century BC), and the Roman colony of Minturnae was developed beginning the 3rd century BC. The shallow depth of the ponds prevented their use as harbours, and saltwork plants can be ruled out based on the faunal and palynological data. The ongoing infilling of both ponds was never completed, and their reclamation is still in progress.
Biology and Environment: Proceedings of the Royal Irish Academy, 2015
An understanding of the extent to which natural variability has been and is being exceeded by the... more An understanding of the extent to which natural variability has been and is being exceeded by the effects of human activity can make an important contribution to the effective management of impacted water bodies, including their restoration. Frequently, however, the required monitoring data are not available, particularly for the period prior to human impact, or are of insufficient quality. Two methodological solutions to this problem are often proposed, both of which involve the reconstruction of past variations in water quality and associated ecological conditions through indirect means: computer (hindcast) modelling and sedimentary (palaeolimnological) analyses. Both proposed solutions are not without their own challenges, however. Here a series of dynamic computer models (a catchment model and an in-lake ecological response model) and palaeolimnological techniques (including sediment-based diatom-inferred total phosphorus, DI-TP), were used to reconstruct total phosphorus (TP) concentrations and measures of primary productivity in Lough Mask, Co. Mayo, for the period AD 1905Á2006. Although results from both approaches indicated similar patterns of nutrient enrichment in the lake during the twentieth century, sediment-based DI-TP values were consistently higher than hindcast-modelled in-lake TP concentrations. Both approaches indicated oligotrophic to mesotrophic conditions in Lough Mask prior to c. AD 1950. Elevated trophic conditions (in the range mesotrophicÁeutrophic) were evident from c. AD 1970. Modelling results indicated that increased diffuse phosphorus loading from agricultural sources was the main driver of nutrient enrichment from c. AD 1970. Eutrophication was also concurrent with climatic warming, which was manifested in strengthened thermal stratification in model simulations. Results generated by the two approaches suggest that pre-AD 1950 trophic conditions could be used as a reference baseline, representing conditions prior to major impacts from agricultural intensification, for defining current water quality management targets.
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Papers by Sarah Murnaghan