Michael Bruen

• Professor at University College Dublin

The environmental fate of microplastics (MPs) added to agricultural soils remains poorly understood, particularly regarding their mobility in soils. Here we investigate the potential for MP export from soil to surface waters and groundwater in two agricultural settings with a 20-year history of biosolid treatment. A third site where biosolids had n...

Population growth in conjunction with rapid urbanization and industrialization has put immense pressure on global land use and land cover (LULC) patterns, and subsequently, adversely affect the water quantity and quality of associated water resources. The involved rate of change, spatio-temporal distribution of altered LULC classes, and the corresp...

As plastic production continues to increase, we are seeing significant quantities of microplastics (MPs), a contaminant of emerging concern, being recorded worldwide. This research project has identified key challenges and recommendations that target MP pollution, highlighting immediate measures that could manage MP debris at known sources. This wi...

Despite peatlands' important feedbacks on the climate and global biogeochemical cycles, predicting their dynamics involves many uncertainties and an overwhelming variety of available models. This paper reviews the most widely used process-based models for simulating peatlands' dynamics, i.e., the exchanges of energy and mass (water, carbon, and nit...

Peatlands cover over 20% of Ireland’s landscape, but most have been disturbed by human activities, including land use changes, which alter their natural hydrological functions. As a result, there is a growing need for restoration measures, which require reliable predictive modelling tools for assessing their feasibility and effectiveness. However,...

Monitoring systems, data analysis and decision-making tools are becoming increasingly automated and integrated into ecosystem management. Along with new technology, this presents an opportunity to advance peatland management and move beyond traditional labour-intensive and experience-based approaches to create more informed, efficient, and sustaina...

Climate change is likely to impact water quality, resource availability and riverine ecosystems. While large ensembles are available to assess future impacts (e.g., the Coupled Model Intercomparison Projects (CMIP) and/or CORDEX) many countries have developed their own high-resolution ensembles. This poses a selection problem with robust adaptation...

Recent research has highlighted the need to refocus research and management on small streams to address wider catchment water quality and biodiversity concerns, together with the sustainable management of ecosystem services. A novel and transferable method for the characterisation of nutrients in non-compliant small streams in Ireland is presented....

We present a spatially hierarchical, hydrogeomorphological stream classification, based on data collected in Ireland and reflecting our hypothesis that local (site scale) stream physical habitat characteristics are related to the physical properties of the extended reach within which a site is located, and, in turn, to the physical character of the...

Real-time soil moisture measurements are essential to manage for adaptive dynamic management of climate change adaptation and reduction of nutrient losses and greenhouse gas emissions from agriculture and forestry. Soil moisture status influences crop growth, run-off, groundwater recharge, land surface-atmospheric exchange dynamics and greenhouse g...

Managers of coastal systems must consider the combined effects of climate change and multiple other stressors. Various monitoring programmes try to capture environmental and ecological trends and regularly report their findings synthesised as individual metrics or indices. Often, however, there is a lack of framework-overarching, integrated analysi...

Rivers are a key part of the hydrological cycle and a vital conduit of water resources, but are under increasing threat from anthropogenic pressures. Linking pressures with ecosystem services is challenging because the processes interconnecting the physico-chemical, biological and socio-economic elements are usually captured using heterogenous meth...

Riparian zones are the paragon of transitional ecosystems, providing critical habitat and ecosystem services that are especially threatened by global change. Following consultation with experts, 10 key challenges were identified to be addressed for riparian vegetation science and management improvement: (1) Create a distinct scientific community by...

The ubiquitous nature of microplastics in aquatic ecosystems may have serious implications for aquatic biota. While microplastic research in freshwater ecosystems is increasing, very few studies have assessed the physical presence of microplastics among top predators. The Eurasian otter (Lutra lutra), a top predator of aquatic ecosystems, is one of...

Globally, peatlands are important carbon and freshwater storage areas that have been extensively degraded by anthropogenic and natural disturbances. Considering the interconnected processes and high degree of heterogeneity in peatlands, simplified modelling approaches for peatland dynamics are prone to uncertainty, which has contributed to a prolif...

Models of ecological response to multiple stressors and of the consequences for ecosystem services (ES) delivery are scarce. This paper describes a methodology for constructing a BBN combining catchment and water quality model output, data, and expert knowledge that can support the integration of ES into water resources management. It proposes “sma...

Microplastics are a pervasive pollutant of aquatic ecosystems and are reported to interact with a wide range of aquatic biota. The complexities of natural food webs means that the transfer and accumulation of microplastics is difficult to assess, and only a handful of studies have attempted to quantify trophic transfer in freshwater biota. Bioaccum...

Coarse sediment transport in fluvial systems serves an important role in determining in-stream physical habitat, spawning potential and benthic community structure. However, despite more than a decade of pressure in Europe to restore stream continuity under the Water Framework Directive (WFD), there have been relatively few empirical studies on how...

The SCOPUS and Wed of Science bibliometric databases were searched for papers related to the use of multi-criteria methods in civil engineering related disciplines. The results were analyzed for information on the reported geographical distribution of usage, the methods used, the application areas with most usage and the software tools used. There...

River infrastructure is one of the primary threats to riverine ecosystems globally, altering hydromorphological processes and isolating habitats. Instream barriers and low-head dams can have significant effects on system connectivity, but despite this, very few empirical studies have assessed the impacts of these structures on suspended sediment tr...

The poster demonstrates how to combine Bow-Ties and BBN methodology to inform environmental decision-making in coastal areas. The poster is part of the the international research project Land2Sea, where the focus is how to do integrated modelling of the consequences of terrestrial activities and climate change for aquatic biodiversity and ecosystem...

River infrastructure is one of the primary threats to riverine ecosystems globally, altering hydromorphological processes and isolating habitats. Instream barriers and low-head dams can have significant effects on system connectivity, but despite this, very few empirical studies have assessed the impacts of these structures on suspended sediment tr...

Significance Rapid groundwater depletion represents a significant threat to food and water security because groundwater supplies more than 20% of global water use, especially for crop irrigation. A large swath of the US High Plains, which produces more than 50 million tons of grain yearly, depends on the Ogallala aquifer for more than 90% of its ir...

Rivers play an important role in the overall transport of microplastic pollution (1 μm to 5 mm), with fluvial dynamics expected to influence biotic interactions, particularly for fish. So far, there have been few assessments of microplastics in freshwater salmonids. The prevalence (i.e. percentage occurrence) and burden (i.e. abundance per fish) of...

Nutrient enrichment and eutrophication can increase when urbanisation and intensification of agriculture production occurs without accompanying mitigation measures to offset impacts from land use transitions. The identification of measures to protect or restore water quality is a challenging exercise, particularly in the context of increasing popul...

Sediment connectivity, though typically viewed as subsidiary to concerns surrounding fish passage, serves an important role in a functioning riverine ecosystem, with both substrate stability and particle size distribution acting as key determinants of benthic community structure and spawning habitat. However, despite more than a decade of pressure...

The ESManage project tested an eight-step methodological framework to help embed ecosystem services and the ecosystem services approach into policy and decision-making for the sustainable management of water resources, as required by the Water Framework Directive (WFD).

Nature‐based solutions for water‐resources challenges require advances in the science of ecohydrology. Current understanding is limited by a shortage of observations and theories that can further our capability to synthesize complex processes across scales ranging from sub‐millimeters to tens of kilometers. Recent developments in environmental sens...

The ecological integrity of freshwater ecosystems is intimately linked to natural fluctuations in the river flow regime. In catchments with little human-induced alterations of the flow regime (e.g. abstractions and regulations), existing hydrological models can be used to predict changes in the local flow regime to assess any changes in its rivers'...

Where diffuse losses of nutrients from agriculture is a major challenge for integrated catchment management and the achievement of Water Framework Directive objectives, modelling tools can be used to target the high-risk areas and focus the limited resources available for mitigation measures. The Catchment Characterisation Tool (CCT) is a GIS-based...

Knowledge of the location, physical attributes and impacts of obstacles on river connectivity is a requirement for any mitigating action aimed at restoring the connectivity of a river system. Here, we present a study that recorded the numbers and physical diversity of obstacles in 10 river catchments in Ireland, together with the impact these struc...

This paper presents an empirical study that uses the movement of RFID tracers to investigate the impacts of low-head dams on solid transport dynamics in coarse-bedded streams. Here we report on the influence of two structures located in Ireland's South-East, both of which indicate that particles greater than the reach D90 can be carried through and...

The ecological integrity of freshwater ecosystems is intimately linked to natural fluctuations in the river flow regime. Anthropogenic alterations in flow regimes threaten water security and freshwater biodiversity in many regions of the world. The impacts of climate change on the hydrological cycle change local flow regimes and thus impact on the...

This report is a response to the growing public and official pressure for Ireland to develop a world class flood forecasting capability to enhance the security of its citizens. It addresses some of the technical and modelling issues that must be resolved to respond to the pressure for an effective flood forecasting service. River flooding is a seri...

This paper outlines the research being undertaken by the recently-initiated four-year (to March 2022) project on the small stream network in Ireland (SSNet) funded by the Irish Environmental Protection Agency (EPA). The overarching objective of SSNet is to advance knowledge on the role of small streams in water quality, biodiversity and ecosystem s...

This study evaluates two desk‐based approaches for building an inventory of man‐made river obstacles. The creation of a river obstacle inventory is a vital first step in developing a prioritization process for obstacle removal and/or modification. In this study, a desktop geographical information system analysis of two rivers and their tributary ne...

Free access at: https://authors.elsevier.com/a/1W85lB8cccof2 (till 18th Jan 2018). Estimates of sediment yield are important for ecological and geomorphological assessment of fluvial systems and for assessment of soil erosion within a catchment. Many regulatory frameworks, such as the Convention for the Protection of the Marine Environment of the N...

Climate change brings new threats and uncertainties but also opportunities. It challenges us to both mitigate the threats and gain from the opportunities. This project looked specifically at the threats from natural hazards. A large number of these, such as floods, droughts, landslides, and wildfires will be more intense and more frequent in many a...

Microplastic (MP) polymers, 0.1 µm - 5 mm in size, are ubiquitous within aquatic environments. Due to their small size there is a risk that they may infiltrate and transfer within aquatic food webs. Though a limited number of laboratory studies can facilitate our understanding of species susceptibility, the lack of field data from freshwater enviro...

Freshwater ecosystems contribute to many ecosystem services, many of which are being threatened by human activities such as land use change, river morphological changes, and climate change. Many disciplines have studied the processes underlying freshwater ecosystem functions, ranging from hydrology to ecology, including water quality, and a panoply...

The impact of fine sediments on both habitat quality and macroinvertebrate communities of riverine systems has been well documented over recent years. However, there is a paucity of studies examining the mechanisms that relate macroinvertebrate sensitivity and responses of individual macroinvertebrate species to burial by sediment. Laboratory-based...

More than half of surface water bodies in Europe are at less than good ecological status according to Water Framework Directive assessments, and diffuse pollution from agriculture remains a major, but not the only, cause of this poor performance. Agri-environmental policy and land management practices have, in many areas, reduced nutrient emissions...

Rapid urbanization and growing agriculture with accompanying land use transitions can substantially impact on water quality in a region. Hence, decision makers need adequate tools to better understand and evaluate the effects of policy interventions on water management and quality control in urban regions. Developing a new state-of-the-art model is...

The use of turbidity for indicating environmentally detrimental levels of suspended and colloidal matter in freshwater systems, and for defining acceptable water quality standards in national and European drinking water regulations, is well established. Turbidity is therefore frequently adopted as a surrogate for suspended sediment concentrations (...

EGU General Assembly 2017

In the simplest of terms, ecosystem services are defined as “the contributions that ecosystems make to human well-being”. Ecosystem services and the ecosystem services framework are considered a means of embedding biological and ecological thinking into policy and practice. The framework is seen as an effective means of communicating to all stakeho...

In order to incorporate the ecosystem services framework into policy related to the management of freshwater resources the full range of Ireland’s freshwater ecosystems and their underlying biological resources must be identified. This report consolidates this knowledge and outlines current pressures and management structures relating to freshwater...

Identify Pressures Ireland’s freshwaters are among the best in Europe. However, they are under increasing pressure from a range of land-use and other anthropogenic pressures, especially from elevated nutrients (nitrogen and phosphorus) and sediment inputs, but also increasingly from pesticides, water abstractions, and invasive species. The continui...

A model for predicting the sources of nutrient loads (phosphorus and nitrogen) to water has been developed to support Water Framework Directive (WFD) implementation. The Source Load Apportionment Model (SLAM) framework described in this paper integrates catchment data and pressure information from point discharges and diffuse sources to enable char...

A combination of statistical hypothesis testing methods (Mann-Whitney, Mann-Kendall and Spearman’s Rho) and visual exploratory analysis were used to investigate trends in Irish 7-day sustained low-flow (7SLF) series possibly driven by changes in summer rainfall patterns. River flow data from 33 gauging stations covering most major Irish rivers were...

Predictions of river flow dynamics provide vital information for many aspects of water management including water resource planning, climate adaptation, and flood and drought assessments. Many of the subjective choices that modellers make including model and criteria selection can have a significant impact on the magnitude and distribution of the o...

Identify pressures Ireland’s freshwaters are among the best in Europe. However, they are under increasing pressure from a range of land-use and other anthropogenic pressures, especially from elevated nutrients (nitrogen and phosphorus) and sediment inputs. The continuing loss of high status waters is a key concern. Planned future land-use intensif...

This paper shows the output of a research study that involves developing a new model for diffuse source pollution requiring the integration of a complex distributed catchment model with a model of contaminant transport. It explains in details the various model components, modifications and assumptions that have been made in the construction of the...

The identification of ecosystem services (ES) and their valuation for potential use in environmental, social and political decision making is a fast growing research area. The ES literature is growing exponentially from less than 200 papers per year at the beginning of the Millennium to over 1600 per annum at the moment. While the ability to ide...

An ongoing research challenge is the detection of biological responses to elevated sediment and the identification of sediment-specific bioassessment metrics to evaluate these biological responses. Laboratory mesocosms and field observations in rivers in Ireland were used to evaluate the relationship between a range of biological and sediment metri...

Over the last few decades, hydro-meteorological forecasting, warning and decision making has benefited greatly from advances in the natural, physical, computing and social sciences. A fast developing computing capability has enabled meteorologists to produce ensemble prediction systems (EPS) that quantify the uncertainty in forecasting and simulati...

A wide range of methods are commonly used to measure deposited fine sediment and quantify substrate quality in rivers as part of bioassessment or monitoring programmes. In this laboratory-based experiment known amounts of three sediment types (sand, topsoil, peat) were added to mesocosms and four methods of measuring deposited fine sediment; turbid...

Unrestricted cattle access to rivers and streams represent a potentially significant localised pressure on freshwater systems. However there is no consensus in the literature on the occurrence and extent of impact and limited research has examined the effects on aquatic biota in the humid temperate environment examined in the present study. Further...

Increasing pressures on water quality due to intensification of agriculture have increased the need for environmental modelling to accurately simulate the movement of diffuse (nonpoint) nutrients in catchments. As hydrological flows drive the movement and attenuation of nutrients, individual hydrological processes in models should be adequately rep...

Increasing pressures on water quality due to intensification of agriculture have raised demands for environmental modeling to accurately simulate the movement of diffuse (nonpoint) nutrients in catchments. As hydrological flows drive the movement and attenuation of nutrients, individual hydrological processes in models should be adequately represen...

Elevated suspended sediment concentrations in fluvial environments have important implications for system ecology and even small concentrations may have serious consequences for sensitive ecosystems or organisms, such as freshwater pearl mussels (Margaritifera margaritifera). Informed decision making is therefore required for land managers to under...

Windrowing is widely practised, across Europe and North America, in bole-only harvested coniferous forest plantations before replanting. Forest harvesting has been shown to significantly increase sediment and nutrient losses to watercourses in other studies but windrowing effects, which are as bad, have not been investigated in detail. To determine...

Overview In the interest of public health and amenity, the quality of bathing waters is controlled by the European Union Bathing Water Directive (1976); the well-known Blue Flag scheme is associated with this. The Directive regulates — among other parameters — the numbers of “indicator bacteria” permitted in the water; these microorganisms themselv...

The population of Dublin City and its suburbs currently stands at 1.3 million and is projected to reach 2.1 million by 2022. There is pressure on its water supply system (inadequate catchment sources, ageing infrastructure including treatment facilities, and distribution network) with little or no spare capacity despite Ireland’s relatively high ra...

Phosphorus (P) is one of the important limiting elements governing the quality of natural waters in Ireland. Good models that simulate the loss of P from catchments to water bodies are needed to understand the mechanism and transport of P and to assist in formulating appropriate policies and practices to control or manage the problem. In the presen...

The use of radar to provide rainfall estimates is becoming more attractive, especially with the number of rain-gauges in operation reducing year on year in many countries. However, while radars give very good spatial representations of rainfall, they tend to underestimate rainfall when compared to rain-gauges, for the selected area. To improve the...

The authors reviewed existing modelling platforms as part of a large study of water and pollution pathways through catchments in Ireland (Irish EPA Pathways project). Worldwide, work on producing catchment management tools (CMTs) has been underway for some time and some of the tools identified here date from as early as 1989. Some of the management...

A Catchment Management Tool (CMT) is being developed for the Irish Environmental Protection Agency (EPA) that will allow River Basin Managers to evaluate the environmental risk from organic and inorganic nutrient loadings due to various land uses and human activities. The CMT was built using Open Source GIS (Geographical Information System) softwar...

The redundancy and ill-conditioned nature of model identification and parameter estimation make it difficult to identify a hydrological model that can correctly split the flow dynamics and associated contaminant transport and transformation between each of its conceptual pathways. The Pathways project, funded by the Irish EPA, combines insights fro...

The COST 717 action is implemented by three working groups, each investigating different aspects of the use of radar observations in hydrological and NWP models. Working Group 1 (WG-1), the subject of this paper, looks at the use of radar observations in hydrological models. It has divided the work into 9 subject topics each being undertaken by tea...

Different definitions of the bankfull condition in rivers are based on morphological characteristics, boundary conditions and geometrical properties. Consequently, the magnitude and associated return period of the bankfull discharge can be ambiguous. Knowledge of this discharge is important in index flood estimation and subsequent regional flood fr...

A hydro-environmental model is used to investigate the effect of cessation of thermal discharges from a power plant on the bathing water quality of Dublin Bay. Before closing down, cooling water from the plant was mixed with sewage effluent prior to its discharge, creating a warmer, less-saline buoyant pollutant plume that adversely affects the wat...

Although ongoing technological advances have alleviated data restrictions and most of the computational barriers to distributed modelling, lumped, parsimonious, conceptual and rainfallrunoff models are still widely used for flood forecasting. However both optimum parameter values and the fluxes of water through individual model components change si...