Meet the team
Theoretical Ecology team at QUB, as it was in 2010: from left to right
- Dr Tak Fung (PhD graduated 2013), Dr Olga Lyashevska (PhD graduated
2011), Dr Jennifer Houle (PhD graduated 2013), Dr Axel
Rossberg (was Senior Research Fellow), Dr Deirdre Duggan (PhD graduated
2014) and Dr Keith Farnsworth (team leader).
The team is developing theoretical understanding for applied science,
mainly in fisheries management ecology and biodiversity conservation.
In 2016 Dr Hannes Höffle joined us to work on a radically new kind of
fisheries management (see below). Between 2012 and 2016 we had Senior
Research Fellow Dr Francisco De Castro and Research Fellow Dr Sam
Shephard (see below for both) working on other aspects of fisheries
management. Francisco still works in QUB (now studying soil foodwebs)
and Sam is a science leader for Inland Fisheries Ireland. Tak
research scientist at the National University of Singapore, Jen is an
insurance actuary, Deirdre is working with fisheries sustainability on
Bali and Olga, having completed a post-doc stint with the Royal
Netherlands Institute for Sea Research, is now post-doc researching
(using biostatistics) at Galway Mayo Institute of Technology. Axel
is now a Reader in Aquatic Biology at
Queen Mary College, London University.
If you would like to join in, please identify
a source of funding
and drop us a line.
Present Team Members
Hannes says: My research interests broadly cover three areas. Firstly,
in the spatial distribution of marine organism and what factors are
limiting the range of species or communities. Secondly, I am interested
in the effects of disturbances, whether natural or anthropogenic, on
biota, ranging in scale from individual populations up to entire
ecosystems. Thirdly, on a more theoretical side, I am interested in the
evaluation of uncertainty of survey results as well as model
predictions. As it touches all three of these interests, I have worked
in fisheries ecology since 2008, mostly working on spatial
distributions of early life stages and how they are affected by
As part of the project "Creating
the knowledge for precision fisheries management
" I am
responsible for the creation of an operating model, representing the
Celtic Sea fishery and it’s interactions with the marine
environment. Pulling together components from a range of existing fish
community and fisheries models, the operating system shall strike a
balance between capturing the processes of interactions in the
community, and ease of parameterization as well as stakeholder
acceptance. The model shall serve as a basis for a management strategy
evaluation (MSE) of a real time incentive (RTI
management system. The RTI is a modern 'nudge' policy, which provides
fishermen with an annual contingent of credits and a, periodically
updated, map showing how much credits it costs to fish in a given area.
It allows fishermen to fish, where and when they want until they run
out of credits, thus devolving responsibility to the industry. MSE is a
quantitative approach of evaluating harvest control rules, initially
developed for the International Whaling Commission (IWC 1993).
Essentially, it is a statistical modeling exercise, simulating
management scenarios and evaluating the extent to which a management
strategy is affected by uncertainty from various sources of error.
My first research project, addressed the influence of introduced
species on growth and survival of sea grasses in the Baltic Sea and the
western Indian Ocean. The study came to the main conclusion that
effects of algal mats largely depend on the morphological structure of
the algae and their longevity (Höffle et al. 2011,
Höffle et al. 2012).
In fisheries ecology I mostly worked on early, planktonic, life stages
of demersal fish, which play a major role in establishing year-class
strength. These studies, on populations in the North and Barents Seas,
led to three main conclusions (Höffle 2012, Höffle et
al. 2014). Firstly, that, regardless of the stock and its demographic
structure, some environmental variables will have a consistent
influence on the spawning distribution. Secondly, that on large
temporal and spatial scales, even for fish which do not depend on a
certain substrate, spawning grounds are in recurrent locations, while
centers of abundance vary between the years. Thirdly, that the
importance of environmental factors controlling the population may vary
between life stages (Höffle & Kjesbu 2014).
(2012) Spatial patterns in the distribution and early life
characteristics of North Sea cod - influence from environmental factors
and climate change, Ph.D. thesis, Technical University of Denmark,
Kongens Lyngby, DK.
Höffle H and
Kjesbu OS (2014) Some like it cold - consequence of warming seas for
the distribution of large bodied fish, oral presentation, ICES ASC
2014, A Corua, ES
Thomsen MS, Holmer M (2011) High mortality of Zostera marina under high
temperature regimes but minor effects of the invasive macroalgae
Gracilaria vermiculophylla. Estuarine Coastal and Shelf Science 92:35-46
Höffle H, Solemdal P, Korsbrekke K, Johannessen M,
Bakkeplass K, Kjesbu OS (2014) Variability of northeast arctic cod
(Gadus morhua) distribution on the main spawning grounds in relation to
biophysical factors. ICES J Mar Sci 71:1317-1331
Wernberg T, Thomsen MS, Holmer M (2012) Drift algae, an invasive snail
and elevated temperature reduce ecological performance of a
warm-temperate seagrass, through additive effects. Mar Ecol Prog Ser
International Whaling Commission (1993) Report of the scientific
committee, annex I. report of the working group on implementation
trials. Rep.Int.Whal.Commn 43:153-196.
Ph. D. Ecology. 1993. University of Seville. Spain.
Thesis: Simulation model of plant structure.
PROFESSIONAL CERTIFICATIONS & ASSOCIATIONS
Member of the International Society of Ecological Modeling (ISEM)
Ecological Society of America (ESA) Member: 110042
Certified Senior Ecologist by the Ecological Society
of America (2002 – 2007)
Francisco joined us in 2012 from Potzdam University.
Here is what he says: "I am mainly a theoretical ecologist/modeler.
Currently, I am working on spatial aspects of food web dynamics. Also
on how individual body size, metabolism and efficiency in energy
transfer affects community structure. Previously I worked on
host-parasite dynamics and its effects on the community and a variety
of other subjects: dune movement, tree shape, canopy structure, etc.
always trying to extrapolate interactions at small scale to the
dynamics of the large-scale system". Francisco worked as a Senior
Research Fellow on the
Beaufort Marine Award, helping to expand our models and
theories into spatial domains. He is still working at Queen's
University Belfast, now on soil foodweb structure.
A few of his publications:
Riede, J. O., Brose, U., de Castro, F., Rall, B. C., Binzer,
A., Curtsdotter, A., Eklo¨f, A. 2011. Food web
characteristics and robustness to secondary extinctions. Basic &
Applied Ecology 12(7): 1-9.
de Castro, F., Gaedke, U., Boenigk, J. 2009. Reverse evolution: Driving
forces behind the loss of acquired
photosynthetic traits. PloS ONE 4(12):1-6.
de Castro, F., Gaedke, U. 2008. The metabolism of lake plankton does
not support the Metabolic Theory of
Ecology. Oikos 117(8): 1218-1226.
de Castro, F., Bolker, B. M. 2005. Mechanisms of disease-induced
extinction. Ecology Letters 8(1):117-
de Castro, F., Bolker, B. M. 2005. Parasite establishment and host
extinction in model communities. Oikos
111: 501 -513
Jennifer Houle - Research Fellow (size-spectrum marine
BA (2006) Mathematics, University of Maine; MSc (2007) Music
Technology, University of Limerick
PhD (2009-2013) QUB: "Structure and dynamics of marine-community
Funded by a Beaufort Marine Research Award from the Republic of
My research aims to support the
ecosystems approach to fisheries management by studying how fishing
affects marine ecological communities. I am examining this using
dynamic numerical models of the marine ecosystem which consist of a
network of size-structured populations connected by community
interactions. I am jointly supervised by Dr. Axel Rossberg and Dr
David Reid of the Irish Marine Institute.
- Mathematical ecology
- Physiologically structured population models
- Ecosystem-based fisheries modelling
Tak completed his PhD with us in
BSc Mathematics with Management, First
Class Hons. (2003), Imperial College London; PhD modelling
biological complexity, University College London (2009). Previous
work involved applying mathematics to a range of biological areas, such
as visual perception, population genetics and the dynamics of coral
PhD Queen’s University
My PhD focused on using
techniques to investigate the mechanisms behind key ecosystem phenomena
such as biodiversity and stability. These include complex systems
theory, network theory and size-structured community theory. New
insights were gained that can be translated into effective biodiversity
policy for fisheries operating around the Irish coast and generalised
for the Ecosystem Approach to Fisheries Management. My PhD was funded
by the Irish Government under the Beaufort Marine Award Scheme and
jointly supervised in conjunction with Dr Axel Rossberg and Dr David
Reid of the Irish
completed her PhD with us in 2014. She now works for Masyarakat dan Perikanan, Indonesia (MDPI) in
fisheries management development and sustainability in Bali, Indonesia .
BSc (2004-2008): Marine Science,
MSc (2009-2010): Applied Marine Science, University of Plymouth,
PhD (2010-present): "Modelling the Ecosystem Approach to
management is moving
maximising the sustainable yield of a single stock towards a community
perspective. This ecosystem approach requires far more complex models
of multi-species interactions and community structure than previously
encountered by fisheries managers and other stakeholders. My PhD
aims to bridge the gaps between scientists and fishermen caused by this
expansion of complexity. I am investigating and selecting
appropriate indicators of community health which can summarise
ecological complexity in a 'dash-board' describing the system's state
to managers. I am incorporating size-structured multi-species
models into fisheries simulation tools to enable rapid scenario
exploration and conceptual learning. I work in close
collaboration with fisheries management professionals at the Irish
Marine Institute to ensure the practical applicability of the decision
support tools that I am building. The ultimate aim of my work is
to enable fishers to take greater responsibility for the sustainability
of the resources they exploit by providing accurate, comprehensive and
understandable information on the behaviour of the marine community
Here are two relevant publications from the work:
D.E. Duggan, K.D. Farnsworth, S.B.M. Kraak, D.G. Reid. (2015).
Integration of indicator alarm signals for ecosystem-based fishery
management. Conservation Letters. (on line)
Duggan, D.E., Farnsworth, K.D., Kraak, S.B.M. (2013). Identifying
functional stakeholder clusters to maximise communication for the
ecosystem approach to fisheries management. Marine Policy. 42:
56-67. (on line).
PhD Fisheries Ecology, Department of Wildlife and Fisheries,
University, U.S.A. 2003.
MSc Fisheries Management, Development and Conservation, University
College Cork, Ireland. 2000.
BSc Environmental Science, University of Westminster, London, UK. 1994.
I first became involved in fishing as a commercial deckhand, which
introduced me to the fascinating and troubling complexity of fisheries
systems. My current research is in the development of flexible
indicators for the Ecosystem Approach to Fisheries Management,
especially in the context of the Marine Strategy Framework Directive.
This work comprises empirical modelling and collaboration with
mathematical modellers, and includes connections with ICES WGECO and
STECF. A related focus is analytical and sea-going experimental work on
the ecosystem effects of fishing. In particular, bottom-up trophic
effects on demersal fishes caused by trawling-induced change in benthic
communities. Using high-resolution Vessel Monitoring System (VMS) data,
I am currently extending these analyses to incorporate the real spatial
scale of fisheries / fish community interactions and the application of
I have recently joined the FP7 project MYFISH , where
I will be working on Irish Sea elasmobranch and western waters pelagic
fisheries case studies.
Beaufort Senior Research Fellow here during 2008-2011. He moved on to
work as a Senior Scientist at the CEFAS (English marine biology /
fisheries institute) before taking a prestigious position as Reader in
Aquatic Biology at Queen Mary College, University of London.
Axel is the author of the Population Dynamic
featured in many of the team's important publications, for example:
Fung, T. Farnsworth, K.D. Reid, D.G., Rossberg A.G. (2015).
Impact of biodiversity loss on production in complex marine food webs
mitigated by prey-release. Nature Comms. 6.
is also author of the book:
Rossberg, A. G. (2013). Food Webs and Biodiversity: Foundations, Models, Data.
Wiley. ISBN 9-780470973-55-4
completed her PhD at Queen's University Belfast in 2011. With it she
showed that biodiversity was essentially a three-dimensional property
of ecological systems (and samples of them). Using worked examples
derived from large marine ecosystem databases, Olga demonstrated that
all the popular measures of biodiversity could be reduced to the three
major axes: phylogenetic relationships, ecological functions and
community structure. The work provided the basis for an empirically
based definition of what biodiveristy is. This definition is compatible
with the axiom-based definition: that biodiversity is a quantitative
summary of the total difference among biological systems (usually
organisms), which in turn matches the definition of information based
on Floridi's concept of well formed data. These definitions apply
equally well at any ontological level of description.
She is now working at GMIT, Ireland as a Quantitative Ecologist (see
2015 - present Postdoc Quanitative Ecology, MFRC, GMIT, Ierland
2012 - 2015 Postdoc Ecological Statistics, NIOZ, The Netherlands
2007 - 2011 PhD Ecology, Queens University Belfast, UK
2005 - 2007 MSc Environmental Sciences, Wageningen University, The
O.Lyashevska. The use of beached bird surveys for marine litter
monitoring in Ireland. In preparation.
O.Lyashevska, C.Harma, D.Brophy,
C.Minto, M.Clarke. Identifying drivers of change in size of Atlantic
herring populations using gradient boosting regression trees. In
O.Lyashevska, D.Brus and J.van der
Meer. Grid-spacing and the quality of
abundance maps for species that show
spatial autocorrelation and zero-inflation. Submitted to Spatial
Statistics (Impact Factor 1.605)
O.Lyashevska, D.Brus and J.van der
Meer. Mapping species abundance by a
spatial zero- inflated Poisson
model: a case study in the Wadden Sea, The Netherlands (2016). Ecology
and Evolution (Impact Factor: 2.32), 6(2): 532–543
O.Lyashevska and K.D.Farnsworth. How
many dimensions of biodiversity do
we need? (2012). Ecological
Indicators (Impact factor: 3.44), 18:485–492
K.D.Farnsworth, O.Lyashevska, and
T.Fung. Functional complexity: the
source of value in biodiversity?
(2012). Ecological Complexity (Impact factor: 1.931) 11:46–52