Conservation physiology of marine fishes: linking individual movement with populations and community dynamics in a changing climate

Christopher Griffiths


Start Year: 2014, 1st cohort

Host University: The University of Sheffield

Department: Animal & Plant Sciences / School of Mathematics and Statistics

Supervisors: Prof. Paul Blackwell, Dr. Julia Blanchard, University of Tasmania; Dr. David Righton, CEFAS,  Dr. Jon Pitchford, University of York, Prof. Richard Law

Twitter: @christophgriff5 


Academic profile


MRes in Applied Marine & Fisheries Ecology – University of Aberdeen (Scotland, UK), Sept 2013 – August 2014;

BSc in Biology – University of Sheffield (England, UK), Sept 2009 – June 2012.

Work experience

Head Researcher at SOS Tartarugas (Turtle Conservation Programme), Cape Verde, Africa – May 2013 – Sept 2013;

Researcher at Cardigan Bay Marine Wildlife Centre, Wales, UK – June 2011 – Sept 2011 and March 2013- May 2013.

Volunteer at Cheshire Wildlife Trust, England, UK – Sept 2013 to Present.

Volunteer at Chobe National Park, Botswana, Africa – June 2008 – September 2008.

Skills and relevant qualifications

Code programming in R and C++;

Built an individual based growth model for juvenile sandeels in the Northern North Sea in both R and C++;

Currently working on size-spectrum models of marine communities;

Currently analysing individual tagging data using Hidden Markov Modelling.

ACCE PhD Research topic

Conservation physiology of marine fishes: linking individual movement with populations and community dynamics in a changing climate

Marine ecosystems are highly size-structured. Fish grow several orders of magnitude in their lifetime, feeding on organisms that are a fraction of their own size. As fish grow larger, their environmental tolerances and movement rates also change influencing the spatial distributions we observe. The environment individual fish experience is also undergoing rapid climatic driven change. The aim of this project is to develop and test new mathematical and statistical approaches to understanding the complex interplay between size-structure and environmental change. Currently, our work focuses on using telemetry data (both tagging and mark-recapture) from a variety of species, most notably cod and porbeagle to test the allometric movement assumptions of these size-structured models. Further work will aim to build on my background of individual based modelling to produce stochastic individual based frameworks that correctly incorporate explicit movement. The results of which will allow us to incorporate more biological realistic movement into size-structure community models. Application will then capture the importance of spatial movement in both past and future change and ultimately evaluate management implications under climate and fishing scenarios.

This project will address the following key questions:
1. Can individual-movement data validate the theoretical assumptions of marine size-structured modelling?
2. Can individual-level processes of movement give rise to patterns in abundance-size-distribution that are consistent with those observed in nature?
3. Does integrating individual-level movement data with dynamic size-structured models help to improve predictions of abundance and distribution for fish assemblages and changes that have occurred at regional and local scales?
4. Does environment-mediated spatial movement affect the coexistence of species and sizes of organisms in local marine communities?