Keynote speakers

We are honoured to present the following keynote speakers:

Opening session
	Opening of the conference and introductory keynote Jeffrey Polovina NOAA Fisheries
Dr. Polovina described the origins of Ecopath which date back to 1979 when he was hired by NOAA and assigned the task of building an ecosystem model. The research context which contributed to Ecopath's development was discussed, as well as some of the history about its creation including a walk along Kailua beach with Daniel Pauly. Some thoughts about future directions for Ecopath concluded the opening of the Ecopath 25 years conference.
	Ecopath from the French Frigate Shoals to the Philippines to UBC Daniel Pauly UBC Fisheries Centre
This contribution highlighted efforts, starting in the late 1970s at the International Centre for Living Aquatic Resource Management (ICLARM, Philippines), to complement the single-species methodological toolkits then available to understand tropical fisheries with an ecosystem-based perspective. After various other approaches proved inadequate, the Ecopath approach, developed in the early to mid-1980s by J.J. Polovina, was identified as a solution to the challenge of ecosystem modeling in data-sparse situations. Thus, their software was reprogrammed at ICLARM to increase its versatility and scope, and applications were developed for ecosystems in a number of countries, notably Malaysia, Kuwait and Peru. These activities intensified when, in 1990, a position was created at ICLARM, using Danish funding, for Villy Christensen to devote himself fully to the further development of Ecopath. This presentation concluded with our gradual transition to the UBC Fisheries Centre, starting in the mid-1990s, and the adoption of Ecopath by a number of its faculty, notably Carl Walters, which contributed to making the FC a world center of aquatic ecosystem modeling excellence.
Session 1: Fisheries Applications
	When do trophic interactions matter in Ecosim population dynamics mModels? Carl Walters UBC Fisheries Centre
Frequently Ecosim gives dynamic predictions essentially identical to models that do not include trophic interactions. This happens when natural mortality rates of older fish are relatively low, and when predation mortality on younger fish is severely limited through foraging arena behaviors. In such cases, a key issue is whether the Ecopath diet matrix carries sufficient information to predict changes in predation risk for juvenile fish. In contrast, Ecosim frequently predicts very different behaviour for small “forage” fishes (e.g. small planktivores) than single species assessment models, and is often able to capture strong top-down impacts of changes in predation mortality rates for such species. Shrimp are a special and interesting case where strong predation impacts are expected but are not typically found in model fitting.
Session 2: Spatial analysis
	Ecospace: has its time come? Steve Mackinson Cefas
Born in 2000, amidst rapidly growing international political and scientific interest on the use of Marine Protected Areas as fisheries management tools, Ecospace enabled users to probe the what if questions of spatial management. Thanks to Alistair Beattie (and colleagues), Ecoseed provided the means to investigate trade-offs between the number, size and location of MPAs. Although applications of Ecospace are not as prevalent or as well developed as those of Ecosim, with spatial management plans becoming increasingly popular, the issues that need to be addressed are equally pressing. This session showcased applications of Ecospace, sought to identify the type of problems for which this tool is well suited, and promoted future development on validation and linking with spatial planning tools.
Session 3: Ecosystem comparisons / Network Analysis
	Comparing indicators of ecosystem change using ecological Network Analysis Sheila Heymans SAMS
Long term changes in ecosystems as diverse as the northern Benguela upwelling system in the South Atlantic, the Chesapeake Bay estuarine system and the Baltic Sea has been studied using food web models in Ecopath with Ecosim. Indices of ecosystem change were calculated using ecological network analysis and decadal regime shifts were estimated for these systems and indices using STARS, PCA and chronological cluster analysis. Results show that in most systems at least 2 regime shifts have occurred over the past 40 years. For instance, in the northern Benguela shifts occurred 1963 and 1984 while in the Chesapeake shifts occurred in 1971 and 1986. These shifts in physical drivers did not always cause regime shifts in the ecosystems, but ecological regime shifts mostly occurred when anthropogenic stressors such as fishing were analysed in addition to large scale environmental drivers such as SST.
Session 4: Climate change applications
	Ecoworld: EwE one link in global systems model Beth Fulton CSIRO CMAR
Climate change is a challenge that is capturing the attention of science, media, politicians and public alike. It has been the focus of some of the greatest acts of collaborative science the world has seen to date (e.g. the IPCC reports and model comparisons). There have been physical, predictions of shifts in species distributions and models of economic impacts. The work on ecosystems has largely been through the use of the output of global climate models as drivers for multispecies or trophic models. While these studies have all produced insights into potential effects of climate change one significant facet that has typically been lacking is feedback. Ecosystems involve links, direct and indirect pathways between their many ecological, physical, chemical and human (social and economic) components. Feedback and change are at the core of ecosystems. While this has always been true (and is one of the major drivers for using ecosystem models to explore fisheries issues), global climate change has made it clear that the non-stationary nature ecosystems, and their dynamics, needs to be addressed explicitly. An obvious first step is to couple EwE with biogeochemical (nutrient-phytoplankton) models, and through them global climate models (GCMs), to begin to build truly end-to-end models that have dynamic feedback connections at every step in the chain. By intelligently using each model in the role it plays best and coupling at points that “cut-out” the weakest representations in each model type (e.g. replacing static environmental forcing and production with a link to dynamic production and climate models) the set of coupled models can avoid the biggest limitations of each of the models in isolation. There are significant scientific challenges involved in successfully and seamlessly coupling models with different temporal, spatial, ecological, anthropogenic and process resolutions. Nevertheless early examples already exist (e.g in the Southeast of Australia) and are being used to give insight into potential ecosystem-level effects of climate change and the implications of these affects for the sustainability of fisheries.
Session 5: Ecosystem approach to fisheries
	How can EwE assist us in implementing ecosystem-based fisheries management? Drawing from the South African experience. Lynne Shannon MA-RE
By constructing suites of trophic flow budgets of the southern Benguela, and taking them further into simulations of the past 25 years, we have summarized and enhanced our understanding of the ways in which several species interact, and what their respective roles are. In this process, gaps were identified, and have been at least partly addressed in subsequent iterations of our model-building process. EwE has provided a means for exploring possible combined impacts of environmental and fishing drivers of ecosystem changes, and has shed light on how these drivers may interact. Comparison with similar EwE models from other upwelling systems and with another ecosystem modelling approach has led us to further examine our models, to identify unique characteristics of the southern Benguela that need careful management consideration and further investigation, to revisit gaps and improve confidence in our understanding of the ecosystem and how it is affected by fishing. Indicators derived from EwE models have been helpful in assessing trophic-driven impacts of fishing and, together with data-based ecosystem indicators, will form an important contribution to monitoring future progress with EAF in South Africa.
Session 6: Ecopath and beyond
	Introduction to the session Francisco (Paco) Arreguín-Sánchez CICIMAR-IPN
"Ecopath with Ecosim" has been used for the construction of over 300 trophic models of aquatic ecosystems around the world and has been described as a development with one of the greatest scientific impacts in recent years, for its contribution to the knowledge of ecosystems. Most applications have been based on the use of its own analytical tools, some making emphasis on exploited species, while others to test some hypotheses, especially on the role of species in the ecosystem. However, one highly relevant scientific attribute of EWE is still little explored, and it refers to the outputs it offers and it can offer, beyond its own possibilities. Some aspects are being explored with a certain intensity, as are the ecosystem indicators which are mostly aimed to the impact of fishing. But especially, from a holistic perspective, EwE offers major opportunities for testing hypotheses and explore answers to questions scientific, or even more, to explore scenarios searching new hypotheses. The existence of a large number of models built for different types of ecosystems, environments also different, with diverse objectives and criteria for the definition of functional groups, with also different levels of use and disturbance, provides a fertile platform to confront new ideas. In this context one of the aspects of great importance concerns the possibility to identify, from a holistic perspective; global patterns of behavior which, through the understanding of natural processes, clarify or define basic laws and principles that serve as a platform for the conservation and sustainable use of ecosystems. Among the most evocative aspects, we can make mention of the topology of food webs, thermodynamic aspects of its or his organization; as examples, the fragmentation of a food web, the role of species and species groups (subnets ) in maintaining the cohesion of the network and thus on its function and organization. Also, the understanding of the processes that govern the propagation of a signal (any disturbance) through the ecosystem and the ecological and homeostatic processes (such as ecosystem metabolism), which in turn allows to explain observed changes in their structure and function. Some of these processes are of great current relevance and significance, particularly those relating to the vulnerability of ecosystems and their capacity to respond to disturbance (resilience). ). Of course, the depth with which these topics are addressed, will give answers that serve to generate knowledge that offers theoretical frameworks for management policies.
Closing session
	The future of Ecopath Villy Christensen UBC Fisheries Centre
When a child is 25 year old it is about time to start thinking about its future. Though, when you’re 25, you’re no longer a child, but an independent existence that may listen to its parents (biological (right Jeff?) or adoptive), but really needs to get a life of its own. We would like to see that happen to Ecopath. To foster this, we have redesigned the Ecopath with Ecosim (EwE, once more) software completely over the last few years. Emphasis has been on modularizing, i.e. breaking it up into small, rather independent building blocks that can communicate with each other, but which does not interfere with the internal workings of each other. This opens several avenues. One is that we make it simple and straightforward for modelers to use the EwE framework to develop their own models, modules, or analysis. Knowing a bit of programming and using freely-available software tools it is possible in a few hours to develop a ‘plug-in’ that can communicate with the core EwE, thus allowing exploration of the wide data source made available through Ecopath models. Another avenue is that it opens for using different interfaces. We are no longer tied to the complex scientific interface (with ‘Villy-buttons’ according to Carl), but can use alternative interfaces, not just the slick new EwE6 scientific interface, but also simpler interfaces for decision-support systems, and, notably, the gaming interfaces we’ve developed linking to a 3D gaming engine. A third avenue is represented by the ability to couple to other models. We can and should not create one Frankenstein Model that does everything, a much better strategy is to get models representing different aspects of the world we live in to talk together, and to do so in real time, not just linking them through files. Let each model do what it is good at, and get the complete picture by using a variety of coupled models. Finally, I reflected on what I’d heard in the earlier presentations at the conference, and felt absolutely free to pontificate on what we ought to do.

"Ecopath 25 years": conference and workshops

Menu

Downloads

Conclusion