Imperial College London
Division of Biology
Silwood Park Campus
Buckhurst Road
Ascot,
Berkshire, SL5 7PY

e: james.o.roberts @ imperial.ac.uk

Current Research

I am currently studying the population dynamics and fisheries management of deep water fish species in the Southern Ocean.

Toothfish species (Antarctic and Patagonian) are large finfish predators of deep water ecosystems in the Southern Ocean. Both are targeted by commercially important fisheries, which are generally thought to be well-managed according to the CCAMLR principals of marine resource exploitation. Toothfish are caught across a broad range of latitudes and, though regional differences in toothfish biology have been observed, the underlying mechanisms that cause variation in population dynamic parameters and which ultimately drive distribution patterns are not well understood.

From a management perspective, the poor understanding of range edge population dynamics is likely to compromise predictions of how fish populations will respond to large scale disturbances, such as those arising from fishing pressure or temporal climate change – a particular concern for Southern Ocean ecosystems.

At the South Sandwich Islands, Antarctic and Patagonian toothfish are on the edge of their distributional range. I am using data collected on-board commercial longline vessels to describe the demographics, source-sink dynamics, growth and recruitment variability of resident populations, with the aim of answer three main questions:

1. How to population dynamics at the range edge differ from those at the centre?
2. What are the factors that cause range limits in toothfish species?
3. How can we use this information to improve the management of fisheries on deep water and range edge populations?

I make use of a wide variety of analytical approaches, ranging from spatial modelling of fish populations to analysis of otolith microchemistry and other novel techniques.

Publications

Roberts, J., Xavier, J. C. & Agnew, D. J. 2011. The diet of toothfish species Dissostichus eleginoides and Dissostichus mawsoni with overlapping distributions. Journal of Fish Biology 79, 138-154.

Supervision

This project is supervised jointly by Prof. E.J. Milner-Gulland (Imperial College) and Dr D.J. Agnew

Brief CV

2008 – current     Ph.D. fisheries analysis, Imperial College London
2006 – 2008         Fisheries analyst, Marine Resources Assessment Group, London
2005 – 2006         M.Sc. Environmental Technology, Imperial College London
2002 – 2004         Phytoplankton Ecology Research Group, Queen Mary University London
1996 – 1999         B.Sc. Marine & Freshwater Biology, Queen Mary University of London