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Applied Ecology

The goals of our applied research are to:

(i) quantify the impacts of human disturbance on ecosystems;
(ii) develop ecological assessment tools that help to identify the level of disturbance rapidly and robustly; and
(iii) develop appropriate management strategies that help to enhance the resistance and resilience of biotic communities to disturbance.

Most of our applied research focuses on freshwater ecosystems, both tropical and temperate, from small streams, through large lakes to estuaries, deltas and marine coastal shores. We use a range of tools to do this work, including small- and large-scale experiments, palaeolimnological methods, stable isotope analyses and modelling. Funding for this work has been provided by the EU, Irish Environmental Protection Agency, Earthwatch, the Irish Research Council, Enterprise Ireland, the Global Environment Facility and United Nations Development Programme. In recent years, much of our more applied research has focussed on quantification of the impacts of nutrient enrichment, hydromorphological alteration and water level fluctuations, soil erosion and increased sediment loading and invasive species on aquatic ecosystems.


Nutrient enrichment

Nutrient enrichment of lakes and rivers is key driver of ecological change throughout the globe

Nutrient enrichment comprises one of the most pervasive human pressures on the biosphere, altering the structure, functioning and dynamics of both aquatic and terrestrial systems throughout the globe. Our research applies a holistic catchment food-web-based approach to examination of the effects of nutrient enrichment on aquatic ecosystems. In recent years, we have been strongly involved with developing ecological assessment tools for quantifying the ecological impacts of nutrient enrichment on lake ecosystems throughout Europe. Some of our publications on this topic include:

White, L., Donohue, I., Emmerson, M.C. & O’Connor, N.E. (2018) Combined effects of warming and nutrients on marine systems are moderated by predators and vary across functional groups. Global Change Biology 24: 5853-5866.

O’Connor, N.E., Bracken, M.E.S., Crowe, T.P. & Donohue, I. (2015) Nutrient enrichment alters the consequences of species loss. Journal of Ecology 103: 862-870

O'Connor, N.E. & Donohue, I. (2013) Environmental context determines the multi-trophic effects of consumer species loss. Global Change Biology 19: 431-440

Donohue, I., Leira, M., Hobbs, W., León-Vintró, L., O’Reilly, J. & Irvine, K. (2010) Rapid ecosystem recovery from diffuse pollution after the Great Irish Famine. Ecological Applications 20: 1733-1743.

García-Molinos, J. & Donohue, I. (2010) Interactions among temporal patterns determine the effects of multiple stressors. Ecological Applications 20: 1794-1800

Donohue, I., Jackson, A.L., Pusch, M.T. & Irvine, K. (2009) Nutrient enrichment homogenizes lake benthic assemblages at local and regional scales. Ecology 90: 3470-3477

Donohue, I., Donohue, L.A., Ní Ainín, B. & Irvine, K. (2009) Assessment of eutrophication pressure on lakes using littoral invertebrates. Hydrobiologia 633: 105-122

Donohue, I. & Irvine, K. (2008) Quantifying variability within water samples: The need for adequate subsampling. Water Research 42: 476-482

O'Toole, C., Donohue, I., Moe, J. & Irvine, K. (2008) Nutrient optima and tolerances of benthic invertebrates, the effects of taxonomic resolution and testing of selected metrics in lakes using an extensive European data base. Aquatic Ecology 42: 277-291

Donohue, I., McGarrigle, M. & Mills, P. (2006) Linking catchment characteristics and water chemistry with the ecological status of Irish rivers. Water Research 40: 91-98

Solimini, A.G., Free, G., Donohue, I., Irvine, K., Push, M., Rossaro, B., Sandin, L. & Cardoso, A.C. (2006) Using benthic macroinvertebrates to assess ecological status of lakes: current knowledge and way forward to support WFD implementation. EUR 22347 Office for Official Publications of the European Communities, Luxembourg

Donohue, I., Styles, D. Coxon, C.E. & Irvine K. (2005) Importance of spatial and temporal patterns for assessment of risk of diffuse emissions to surface waters. Journal of Hydrology 304: 183-192

Hobbs, W., Irvine, K. & Donohue, I. (2005) Using sediments to assess the resistance of a calcareous lake to diffuse nutrient loading. Archiv für Hydrobiologie 164: 109-125


Hydromorphological alteration and water level fluctuations

Fluctuating water levels in Lough Pollaphuca, Ireland. Photo taken by Vesela Evtimova Diminishing global water reserves is rapidly becoming a key driver of water, food and energy insecurity. Over the last five decades, humans have more than tripled water withdrawals. Consequently, human-induced amplification of water level fluctuations is rapidly becoming one of the major disturbances of aquatic ecosystems globally, endangering not only the integrity of ecosystems but also the provision of ecosystem goods and services. Moreover, the predicted increase of global mean temperature, coupled with increased climatic variability, may exacerbate considerably the variability of water level fluctuations on a global scale. Through examination of long-term (up to 50 years) daily water level data and conducting experiments in mesocosms and in the field, our research is quantifying the effects of water level fluctuations on lake ecosystems and developing rapid ecological assessment techniques to help identify the level of impact. Some of our recent publications on this topic include:

Evtimova, V.V. & Donohue, I. (2016) Water level fluctuations regulate the structure and functioning of natural lakes. Freshwater Biology 61: 251-254.

García-Molinos, J., Viana, M., Brennan, M. & Donohue, I. (2015) Importance of long-term cycles for predicting water level dynamics in natural lakes. PLoS One 10(3): e0119253.

Evtimova, V.V. & Donohue, I. (2014) Quantifying ecological responses to amplified water level fluctuations in standing waters: an experimental approach. Journal of Applied Ecology 51: 1282-1291

García-Molinos, J. & Donohue, I. (2014) Downscaling the non-stationary effect of climate forcing on local-scale dynamics: the importance of environmental filters. Climatic Change 124: 333-346

Solimini, A.G., Free, G., Donohue, I., Irvine, K., Push, M., Rossaro, B., Sandin, L. & Cardoso, A.C. (2006) Using benthic macroinvertebrates to assess ecological status of lakes: current knowledge and way forward to support WFD implementation. EUR 22347 Office for Official Publications of the European Communities, Luxembourg


Soil erosion and increased sediment loading

Extreme water turbidity in Lake Baringo, Kenya, caused by dramatic levels of soil erosion in its catchment Excess loading with sediment comprises one of the most significant, widespread and pervasive forms of aquatic pollution globally. Although a natural and important component of aquatic ecosystems, the delivery of sediment increases typically five- to tenfold following major human impact, with considerable implications for biological diversity, ecological functioning and productivity. Increased sediment loading of aquatic systems comprises the most important off-site impact of soil erosion, which itself represents one of the most important environmental and social problems facing humanity. Our research involves examination of the effects of increased sediment loading on the structure, functioning and stability in aquatic ecosystems, in both the tropics and temperate zones:

Mrowicki, R.J., O'Connor, N.E. & Donohue, I. (2016) Temporal variability of a single population can determine the vulnerability of communities to perturbations. Journal of Ecology 104: 887-897.

García-Molinos, J. & Donohue, I. (2011) Temporal variability within disturbance events regulates their effects on natural commuities. Oecologia 166: 795-806

García-Molinos, J. & Donohue, I. (2010) Interactions among temporal patterns determine the effects of multiple stressors. Ecological Applications 20: 1794-1800

Donohue, I. & García-Molinos, J. (2009) Impacts of increased sediment loads on the ecology of lakes. Biological Reviews 84: 517-531

García Molinos, J. & Donohue, I. (2009) Differential contribution of concentration and exposure time to sediment dose effects on stream biota. Journal of the North American Benthological Society 28: 110-121

Donohue, I. & Irvine, K. (2004) Seasonal patterns of sediment loading and benthic invertebrate community dynamics in Lake Tanganyika, Africa. Freshwater Biology 49: 320-331

Donohue, I. & Irvine, K. (2004) Size-specific effects of increased sediment loads on gastropod communities in Lake Tanganyika, Africa. Hydrobiologia 522: 337-342

Donohue, I., Verheyen, E. & Irvine, K. (2003) >In-situ experiments on the effects of increased sediment loads on littoral rocky shore communities in Lake Tanganyika, East Africa. Freshwater Biology 48: 1603-1616

Donohue, I. & Irvine, K. (2003) Effects of sediment particle size composition on survivorship of benthic invertebrates from Lake Tanganyika, Africa. Archiv für Hydrobiologie 157: 131-144

Donohue, I., Duck, R.W. & Irvine, K. (2003) Land use, sediment loads and dispersal pathways from two catchments at the southern end of Lake Tanganyika, Africa: implications for lake management. Environmental Geology 44: 448-455


Invasive species

Louisiana swamp crayfish (Procambarus clarkii), a globally important invasive species. Picture taken beside Lake Naivasha, Kenya The increasingly rapid spread of biological invaders in recent decades comprises a key driver of global environmental change with major implications for biodiversity and ecosystem functioning. Invasive species can have dramatic and often irreversible effects on ecosystem services, frequently with considerable economic implications, particularly in aquatic ecosystems which tend to be especially susceptible to invasion. Our research involves examination of the trophic and non-trophic interactions that occur between functionally similar native and invasive species with the aim of developing management strategies that help to reduce the susceptability of ecosystems to invasion. See, for example:

Penk, M.R., Donohue, I. & Irvine, K. (2018) Temporally variable niche overlap and competitive potential of an introduced and a native mysid shrimp. Hydrobiologia 823: 109-119.

Penk, M., Saul, W.-C., Dick, J., Donohue, I., Alexander, M., Linzmaier, S. & Jeschke, J. (2017) A trophic interaction framework for identifying the invasive capacity of novel organisms. Methods in Ecology and Evolution. 8: 1786-1794.
**Highlighted in the Ecological Society of America and British Ecological Society Joint Special Issue on Biodiversity and Ecosystem Services

Jackson, M.C., Grey, J., Miller, K., Britton, J.R. & Donohue, I. (2016) Dietary niche constriction when invaders meet natives: evidence from freshwater decapods. Journal of Animal Ecology 85: 1098-1107.

Penk, M.R., Jeschke, J.M., Minchin, D. & Donohue, I. (2016) Warming can enhance invasion success through asymmetries in energetic performance. Journal of Animal Ecology 85: 419–426.

Penk, M., Irvine, K. & Donohue, I. (2015) Ecosystem-level effects of a globally-spreading invertebrate invader are not moderated by a functionally similar native. Journal of Animal Ecology 84: 1628-1636.

Jackson, M.C., Donohue, I., Jackson, A.L., Britton, J.R., Harper, D.M. & Grey, J. (2012) Population-level metrics of trophic structure based on stable isotopes and their application using invasion ecology. PLoS One 7: e31757