https://www.quadrat.ac.uk/wp-content/uploads/sites/15/2024/10/Liam-Brennan-Copy-1024x761.jpg
Academic Year 2024-2025
Email lbrennan13@qub.ac.uk
Institution Queen's University, Belfast

Biography

School: School of Biological Sciences

Project: Understanding the Drivers of Change in the UK’s Largest Freshwater Ecosystem

Supervisors: Dr Sarah Helyar, Prof Stuart Piertney & Dr Paul Caplat

Undergraduate Education: BSc (Hons) Environmental Science, Ulster University

Postgraduate Education: N/A

Research: Lough Neagh is the largest freshwater lake in the British Isles, covering 383 km2 with a mean depth of 8.9 meters. It is fed by 6 main rivers, and is surrounded by wetlands, marshes, and agricultural land as well as several towns and villages with a total population of around 470,000 people living within the catchment. The Lough supports a rich biodiversity, and is recognised as important for both fish and birds, including wintering waterfowl, breeding waders, and protected fish species.

In 2023, Lough Neagh experienced an unprecedented bloom of harmful blue-green algae, raising concerns about the lake’s health. The bloom was likely caused by a combination of factors, including nutrient pollution, atypical weather patterns and the impacts of invasive species on the ecosystem – notably zebra mussels (Dreissena polymorpha), which compete with native species for resources and alter water and sediment quality. With climate change, it is anticipated that the frequency and magnitude of these algal blooms may increase, impacting both the ecosystem and economy. The events of 2023 have highlighted the need for enhanced understanding of the phenomena and effective management strategies to address nutrient pollution and eutrophication. To address this the Agri-Food and Biosciences Institute (AFBI) are developing a Soil and Water Assessment Tool (SWAT) model for the Lough Neagh watershed (similar to those for the ‘Living With Water’ and ‘SWELL’ projects), which will quantify the agricultural and urban runoff, urban wastewater discharges, agricultural land use and management practices in the Lough Neagh catchment.

This PhD project will build upon this work combining aspects of ecology, modelling and genomics to refine the model and extend to a full ecosystem analysis explicitly including the Lough body. It is anticipated that the main questions addressed in this project will involve: 1) The ecological response to physical and chemical drivers – such as the impacts of increased temperatures and eutrophication on the community structure, and impacts of algal blooms on biodiversity by building on AFBI’s existing modelling framework. 2) The role of invasive species – in particular, the potential role of D. polymorpha; through increasing light penetration; cycling of nutrients and carbon between water and sediment; and selective feeding behaviour (to include feeding experiments and the use of eDNA and metabarcoding) and the downstream impacts of those changes on oxygen budgets and freshwater fauna. 3) Scenario modelling of mitigation strategies, such as management strategies for reducing nutrient loads from agricultural land; urban and industrial sources; and the modelling of nature-based solutions such as riparian buffer zones. I also aim to investigate climate changes impact on the Lough Neagh ecosystem, with the aim of understanding the interactions between active policy development by DAERA and future climates in Northern Ireland. Overall, this research aspires to inform legislation establishment and environmental management decisions to aid in the recovery of Lough Neagh’s eutrophication crisis.

Other: 

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