Prof. Edward A. Codling

 

Professor of Mathematical Biology

Department of Mathematical Sciences

University of Essex, UK

Back to Homepage
 

 

Research Topics and Interests

 

I currently have two main areas of research interest in the rapidly expanding fields of Mathematical Biology and Ecology:

I. Movement & Behavioural Ecology: modelling the behaviour, movement and dispersal of animals, micro-organisms and cells;

II. Population Ecology: mathematical analysis and simulation of the population dynamics and optimal management strategies of fisheries and marine ecosystems.

 

  I. Movement & Behavioural Ecology

∞  II. Population Ecology

 Animal movement: random walks, diffusion and dispersal

 

Modelling of marine populations: fisheries assessment and management

Correlated random walk

 

Correlations between SSB and an age-proportion indicator

The movement behaviour of animals and micro-organisms is an interesting and fast-developing field of study where results and observations can be highly relevant to our understanding of population dynamics, our understanding of general animal behaviour and interactions between species and environment, and also aid in developing and evaluating spatial conservation measures.

Movement behaviour can be studied at many spatial and temporal scales - from fine scale observations of micro-zooplankton over a few milliseconds, to annual tracking of global migration trends in bird flocks of thousands of individuals (and all scales in-between). Of particular interest is how behaviour at an individual-level can affect and influence the behaviour and dynamics at the population- or even species-level.

There are many different approaches for analysing movement at an individual and/or population level - from a simple random walk in a homogeneous environment to a highly complex interacting population in a diverse heterogeneous environment.

 

Global marine fisheries provide the vast majority of fish consumed by humans. However, over the last 20 years, annual catches have remained static (85-95 million tonnes) and many fisheries now appear to be in trouble.

It is still unclear whether these problems are due to poor data and inflexible stock assessment models used by scientists, political interference and watering down of scientific advice by managers, or illegal over-fishing and misreporting by fishermen, but all these factors are likely to have contributed.

Strategies such as using marine reserves or marine protected areas (MPAs) or long term management plans using decision-based harvest control rules based on multi-species interactions are still being discussed and debated with little consensus as to the best way forward.

It is certainly an exciting time to be studying fisheries science due to the widespread and sometimes controversial debate as to what is the best future direction for fisheries science and management! What remains clear is that something in the system needs to change before fish stocks are exhausted beyond the chance of recovery.

 Animal movement: behaviour of groups and crowds

 

Modelling of marine populations: plankton dynamics

Testing the 'many wrongs principle' in human crowds

(Picture provided courtesy of Jens Krause and Jolyon Faria)

 

Image by Glynn Gorick

In nature, many animals are observed in groups – bird flocks, fish schools, insect swarms, etc. Animals may form groups for various reasons: avoiding predation, navigational benefits, or simple social interactions.

Observations of the interactions between individuals in groups reveals that often only a few simple rules of behaviour can lead to complex emergent behaviour that is often difficult to predict. Recent advances in mathematical and computer modelling have allowed us to explore this problem from a theoretical stand point. Often this involves defining simple decision and interaction rules across individuals in the group and determining the outcome of a particular scenario at the group level.

However, testing theoretical models against real biological data is often difficult. Hence, we have developed experiments that use human crowds as a proxy for an animal group, so that theories about group decision making processes can be tested and validated. These human experiments are also relevant to studies in the fields of psychology and sociology.

The oceans contain only about 0.5% of total global biomass of primary producers. However, they provide a similar amount of total annual production to that on land and turnover times for organic matter is 1000-times faster in marine in comparison to terrestrial ecosystems. Therefore grazing by zooplankton is disproportionably important and competition among grazers is high.

All organisms release chemicals into the surrounding environment and at small spatial scales the high viscosity aqueous environment allows the persistence of chemical gradients and the reliable transmission of chemical cues. As a consequence chemosensory systems have evolved in a diverse range of marine taxa. in the vast 3D marine environment non-visual planktonic-grazers rely on infochemical (information conveying chemical) signals to locate prey or mates. Conversely, intense grazing pressure has lead to the evolution of defence mechanisms in phytoplankton.

 Microzooplankton and copepods are important grazers of phytoplankton primary productivity. The ability to detect and respond to infochemicals associated with rich prey patches may provide vital foraging cues.

 Further details:

 

Further details:

Click on the following headings for further description, background and web resources including pictures and links to relevant publications:

 

Click on the following headings for further description, background and web resources including pictures and links to relevant publications:

Random walks and mathematical analysis

Observation and analysis of movement paths

Simulating the 'many wrongs principle'

Behaviour of human crowds

Individual specific risk in evacuations: women and children first?

Assessment of dairy cow welfare through predictive modelling of individual and social behaviour

 

Simplifying the assessment & management of fisheries

Marine protected areas

Rebuilding fish stocks in Irish waters

Role of dimethyl sulphide (DMS) in pelagic tritrophic interactions

 

Page last updated December 2012