Lucy Smith
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Email
lucy.r.smith@essex.ac.uk -
Location
Colchester Campus
Profile
- Vaterite switching
- Atlantic salmon movement & migration
Biography
I am a marine ecologist with a particular interest in fish ecology and movement. I primarily use natural tags such as otoliths (ear stones), eye lenses and scales to reconstruct the life histories of salmon to better understand their migration and foraging pathways at sea, and the potential carryover effects from freshwater life stages.
Qualifications
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MSc Statistical Ecology University of St. Andrews (2022)
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BSc Marine Biology University of Essex (2021)
Research and professional activities
Thesis
Factors influencing salmon survival and marine migratory pathways in a changing world
Salmon have great cultural, economic, and ecological value, yet are experiencing unprecedented declines. We still have large gaps in our understanding about their migration pathways at sea and how the freshwater phase of the lifecycle affects marine survival. I use archival otoliths, eye lenses, and scales to understand the factors driving life history choices and mortality in salmon, and reconstruct patterns in habitat use, migration phenology, and growth.
Supervisor: Dr Anna Sturrock
Research interests
Is incidence of vaterite switching higher in hatchery vs. wild outmigrating juveniles?
Using the otoliths (ear stones) of outmigrating fall run chinook salmon juveniles we modelled incidence of vaterite replacement (deformed otoliths) against origin (hatchery vs. wild) and environmental factors over time (2014-18). We found that vaterite switching was significantly higher in hatchery origin fish compared to their wild counterparts. We will continue this work by assessing the role of genetics vs environment in vaterite formation through a common garden experiment.
What are the patterns in size at outmigration of Atlantic salmon in the North Atlantic?
We will identify point at outmigration in adult fish using change point analysis of otolith strontium and barium concentration profiles. The radius at which outmigration occurs is converted to fork length, to give us size at outmigration. We will then compare the size at outmigration among UK and Irish populations (returning 2020-24, outmigrating 2018-23), and for all populations contributing to the Greenland fishery 2007-24 (outmigrating 2004-23).
For cohort matched outmigrating post-smolts and returning adults is there a difference in the distribution of size and age at outmigration?
We will identify point at outmigration in outmigrating post-smolts from the east coast of Scotland, and in returning adults from the same cohort, and compare the variation in size (and maybe age) distribution between these life stages, and identify potential selection pressures encountered during the marine migration.
Do populations that are geographically distant in the UK undergo different migration trajectories?
For three geographically distant populations in England (Frome), Scotland (Deveron), & Ireland (Burrishoole), we will use d18O from otoliths and relate it to SST in the Atlantic Ocean. This will allow us to map likely migration routes using a hidden Markov model, after Hanson et al. 2019. We will then compare migratory routes among populations and years.
