Employing ISIMIP projections to model the phenology, production, and distribution of diadromous fish populations

Adrian will be working on a PhD under the supervision of Prof. Phil McGinnity and Dr Tom Reed (UCC), and Dr Elvira de Eyto (Marine Institute).  The work is part of the Marie Skłodowska-Curie Actions (MSCA) Innovative Training Network (ITN) called inventWater: Inventive forecasting tools for adapting water quality management to a new climate. In this PhD study, Adrian will aim to expand the range of geographically explicit models available through ISIMIP (Inter-Sectoral Impact Model Intercomparison Project https://www.isimip.org/ ) to include growth, phenology, distribution and, ultimately, production of freshwater fish, specifically focusing on diadromous Atlantic salmon across its native range. The project will cooperate with ISIMIP to define adaptations options to counteract the impacts of climate change on fishes.

Biodiversity conservation and restoration in the Wild Nephin National Park

Colin will be working on a PhD under the supervision of Dr Heather Lally and Dr Conor Graham (MFRC GMIT), and Dr Elvira de Eyto (Marine Institute).  The work is funded by the Marine Institute as part of their Cullen Scholarship Program. Wild Nephin National Park (WN-NP https://www.wildnephinnationalpark.ie/ ) is a large open expanse of active Atlantic blanket bog and mountainous terrain located along the Wild Atlantic Way in Co. Mayo, Ireland. The area is at the start of a multi-decadal conversion plan, with the long-term goal of creating one of the largest wilderness areas in Europe. Colin’s work will focus on the assessment of baseline terrestrial and aquatic biota, evaluating important interactions between aquatic and terrestrial habitats in the NP, and providing  a strong scientific bases for nature conservation and biodiversity enhancement activities within WN-NP. The project will run from September 2021- August 2025.

Investigation into the causes of early migration mortality in Atlantic salmon (Salmo salar) and sea trout (Salmo trutta) from the Burrishoole River using acoustic telemetry

Marine Institute Cullen Fellow

As anadromous species, Atlantic salmon and sea trout are dispersed across different habitat types which can make it difficult to identify the various pressures affecting the fish during their life cycle.  This project involves the use of acoustic telemetry in order to describe and map the migration routes taken by smolts during their seaward migration from the Burrishoole catchment and through Clew Bay, Co. Mayo.   In particular survival will be estimated, partitioning of mortality during this early seaward migration and the influence of factors such as predation, obstacles, habitat features and body size will be evaluated.

In addition, annual survival rates of tagged fish will be obtained from coded wire tag returns.  In 1980 the Irish National Coded Wire Tag (CWT) and Recovery Programme was introduced in order to increase the understanding of salmon populations and determine the exploitation rates of various fisheries (Hansen et al and Brown 1982).  This programme provides an extended time series of return rates for hatchery and wild fish that can be used to investigate regional and annual trends in survival and to evaluate the effectiveness of management interventions.  Effects of the drift net fishery closures (in 2007) on survival will be examined.  Changes in fish size over time and migration routes will also be investigated using catches from the drift net fisheries.

Finally, an extensive archive of salmon scales is held by the Marine Institute.  Potential relationships between local and global environmental drivers and changes in growth and survival will be investigated.

Hydrographic control of deep anoxia in a tidally influenced saline lagoon and associated ecological implications

Former Marine Institute Cullen Fellow

Low dissolved oxygen concentrations are of increasing concern in aquatic ecosystems, particularly those located at the interface between freshwater and marine environments. Hydrographic conditions, specifically vertical stratification of the water column and restricted horizontal exchange flow with adjacent oxygenated basins, can create hypoxic deep water conditions, with total anoxia developing in the extreme case. With climate change modifying these controlling hydrographic factors in coastal and estuarine systems, it remains to be seen what impacts the resulting changes to dissolved oxygen dynamics will be.

This project uses Lough Furnace, a protected, ecologically important coastal lagoon with naturally occurring deep anoxia, as a small scale test bed for studying the hydrodynamic processes that govern dissolved oxygen dynamics and to assess the ecological implications of anoxia. Specifically, it will look at how saline stratification and restricted input of oxygenated tidal water can lead to the isolation and long residence time of the deep basin water, with stagnant and oxygen deplete conditions persisting for years at a time. The study will assess the necessary combination of hydrographical and meteorological conditions that can lead to a renewal of this stagnant basin water and what the biological consequences are of these rare, dynamic renewal events. In addition, effects of the stratified structure of the lough on resident ecological communities will be investigated, primarily the importance of wind-driven upwelling of deep anoxic water into shallower, productive nearshore zones. It is anticipated that the overall results of this project will have wide application to aquatic systems susceptible to developing low dissolved oxygen zones, an increasingly common issue due climate and anthropogenic impacts.

Seán defended his PhD in 2019 and is now working as a computational limnologist at Inland Fisheries Ireland on the impacts of climate change on Irish fisheries sector.
@S_O_Ceallaigh

Resolving the organic carbon budget of a humic oligotrophic lake in the west of Ireland

Former Marine Institute Cullen Fellow

Waters draining peat catchments are generally coloured due to high levels of dissolved organic carbon.  This carbon can represent the main carbon source to downstream lakes and therefore fuel the lake food-web.  Human activities have greatly modified global carbon exchange between the atmosphere, land and freshwater bodies in recent decades, including in peatland catchments.  Knowledge about the redistribution of this carbon is crucial, not only to understand global cycling, but for mitigation and management in affected catchments.  This project is investigating the carbon cycle in Burrishoole, Co Mayo, which is a humic catchment, building on work that has already been undertaken in recent years.  Specifically it is using high frequency monitoring data from in-situ platforms in Lough Feeagh, and in its main inflows and outflows to:

1. Quantify the dissolved organic carbon and particulate organic carbon loads to Lough Feeagh.
2. Collect new data to measure the atmospheric carbon fluxes from Lough Feeagh.
3. Use these and other available historical data to resolve the carbon budget for the lake.

The information and insights gained from this project will help to inform on the main sources of carbon for the Burrishoole fish populations and on the carbon loading to down-stream ecosystems.

Dr Brian Doyle defended his PhD in 2021.

Former Marine Institute Cullen Fellow

Investigation of the early migration of salmon and brown trout from the Burrishoole National Index River using PIT tag technology in freshwater and brackish areas

It has been shown that salmonid performance and ultimately survival depend on close synchrony between onset of key phenological events, such as smoltification or the commencement of marine migration, and the environmental conditions subsequently encountered (i.e. sea surface temperature). The timing of these events is influenced by local environmental conditions such as water temperature and river height which may vary significantly between years. Consequently, the effects of predicted climate change are likely to impact salmonid phenology, potentially leading to a disruption of the synchrony between key life history events and the optimum environmental conditions for these events. Ultimately, such disruptions may lead to reduced fitness and, in the absence of rapid phenological adaptation, declining salmonid populations.

This project aims to examine the role of local freshwater environmental conditions in determining the phenological behaviour, growth and survival of salmon and brown trout with the ultimate goal of anticipating the effects of predicted climate change on these species. To this end, long term data on migration phenology, survival and concurrent climatic variables will be used in conjunction with modern PIT telemetry methods, facilitating an investigation at the individual and the population level.

Dr Ross Finlay defended his PhD in 2020. 

Investigating the effects of fish protein hydrolysate supplementation of plant protein-based diets in juvenile freshwater Atlantic salmon (Salmo salar)

IRC’s Enterprise Partnership Fund with Biomarine Ingredients Ltd

APC Microbiome Institute

There are two major challenges that the aquaculture industry is currently facing; 1.) how to reduce disease among farmed fish, and 2.) the manufacture of nutritionally balanced and sustainable compound diets that will produce healthy, high quality fish. These challenges are not mutually exclusive, and it is expected that optimum feed formulation will play a role in the reduction of infectious disease through improving animal health and immunity.

This project aims to address these industry challenges by developing a high-quality natural supplemental nutritional ingredient (fish protein hydrolysate) that can be added to a high plant protein diet to enhance the health, nutrition, growth and stress-tolerance of Atlantic salmon (Salmo salar).  Reducing the amount of fishmeal used in aquafeeds and replacing it with plant-protein is currently being researched. One proposed method by which this is achievable is the use of smaller quantities of appropriately balanced, highly absorbable and convertible protein. With the aim of reducing the consumption of valuable fish sources, while meeting the nutritional needs of aquaculture stock, fish by-products and low-value fish sources can be converted into high-quality protein sources such as protein hydrolysates. This study will investigate the effect of dietary protein hydrolysates on the immune levels, growth rates and body composition to juvenile Atlantic salmon in the freshwater developmental stage.

Dr Sian Egerton defended her PhD in 2019 and is now a Research Support Officer with the Aquatic Animal Health Group (UCC).