Project Title: The effects of proximate factors on alternative migratory tactics in brown trout.
Brown trout show dramatic differences in life history tactics, in particular, the phenomenon of partial migration. Populations can be comprised of solely anadromous individuals (that move to sea and grow to a large size, returning to spawn in freshwater), purely freshwater residents or a mixture of the two ecotypes. If a physiological condition cue exceeds an inherited threshold, a resident life history is triggered, alternatively, anadromy occurs.
I aim to analyse how genes and environment interactively determine anadromous life histories. Experimental families created from one anadromous and one freshwater resident population have been reared in a controlled laboratory setting, where environmental conditions are manipulated: food and temperature. Smolting rates will be measured within each treatment. If energy requirements exceed energy acquisition (through increased temperatures or reduced food), higher rates of anadromy are expected as individuals are energy constrained and move to more productive feeding areas at sea. Life history will be related back to metabolism to determine if differences in energy usage underpin life history decisions. This “common-garden” experiment will help establish whether differences in energy usage (and resulting life history tactics) have a genetic basis, and whether genes and environment interactively determine life history.
PhD Completed 2019
Project Title: Genetic basis of alternative migratory tactics in brown trout.
My research aims to gain further insight into how and why sympatric individuals of the same species can develop strikingly different life histories. Although many alternative life history (ALH) traits have been well documented and described in a physiological and behavioural sense, the genomic basis of this phenotypic variation remains poorly understood, despite advances in genomic technology.
My PhD project will focus on understanding the relative roles of genes and environment in shaping facultative anadromy in brown trout (Salmo trutta). One goal of the study is to establish whether phenotypic differences among trout populations, with ALH traits, reflect genetic divergence. To do this we will conduct a common garden experiment involving two populations of S. trutta (one that naturally exhibits high rates of anadromy, the other low). Offspring of pure and hybrid crosses will be reared under fully wild conditions, the environment is equipped with downstream traps to capture migrants. Furthermore, two complimentary genomic approaches will be applied to investigate the genomic basis of ALH tactics and their plasticity: (1) a genome wide association study (GWAS) to identify single nucleotide polymorphisms statistically associated with discrete phenotypic variation within populations, and (2) gene expression profiling to quantify “genomic reaction norms”. Gene expression differences among cross types within a single common environment should provide information on genetic variation in reaction norm elevations, while cross-specific expression differences among environments provides information on reaction norm slopes (i.e. genetic variation in plasticity).
Project Title: Adaptive capacity and resilience of hybridised populations in a changing world: interactions between wild and domesticated Atlantic salmon.
Farming of Atlantic Salmon, Salmo salar, occurs throughout the species’ natural range and escapes from fish farms are an annual occurrence. Farmed strains of salmon have been bred for traits such as increased growth rate and size relative to their wild conspecifics, with all strains of farmed Irish salmon coming from limited Norwegian founding stock. Previous work has shown that the F1 and F2 hybrids between wild and farm salmon have reduced lifetime fitness compared to pure wild salmon stock.
My research shall focus on developing an eco-genetic model to predict what specific adaptive phenotypes are divergent between wild and farmed salmon and how such divergence depresses the overall fitness of hybrid progeny. The model will utilise quantitative traits to examine the phenology mismatch and will also incorporate various predicted future climate scenarios, in order to quantify how climate change is likely to impact upon hybrid populations’ fitness and persistence.
Project Title: The biology of farmed Atlantic salmon (Salmo salar) in the wild.
My core interests are marine conservation, genomics and microbiome. I am a passionate advocate for the sustainable exploitation of marine resources and for biodiversity conservation with a special interest in endangered species.
The focus of my PhD will be the difference in microbiome and host-parasite interaction between the two different yellow eels ecomorph: broad and narrow head. I will try to understand if ecomorph diversity have stable and predictable consequences on energetics including maximal metabolic rate, standard metabolic rate and lipid content and rate of lipid accumulation. How the diet and the ecomorph diversity predicts gut microbial complement and biochemistry more robustly than salinity preference. I will try to characterise the immune genes and immune gene expression involved in the differentiation of the ecomorph and the difference between eels parasitise with A. crassus or not. I will try to define declining A. crassus abundance in infected catchments using adaptive immunity and clearance rather than swim bladder destruction with a definition of a new vaccine targets. To understand the parasite dynamic, A. crassus, I will conduct also a second host survey to understand the epidemiology and the principal vector taxa.
Project Title: SalmoSim: Exploring the microbial basis of Atlantic Salmon energetics via a synthetic intestinal system.
Currently my PhD focuses on the gut microbiota of Atlantic salmon and its link with host metabolism, physiology and behaviour via microbiological methods. By amplifying bacterial 16S rRNA, I aim to explore the Atlantic salmon gut microbiota in the hope of improving aquaculture sustainability. I am interested in links between the gut microbiota and host behaviour and the mechanisms behind this and is therefore hoping to explore this further.
My PhD focuses on the microbiota in the gut of Atlantic salmon.
Currently I am working with three different cohorts of salmon; wild, farmed and hybrid. My research aims to disentangle the genetic and environmental effects on host microbiomes and also to monitor bacterial impacts on phenotypic traits (e.g. metabolism, immune response).