We are proudly presenting the following keynotes at the Ecopath 30 years conference:

Marta CollDr. Marta Coll
Institute of Research for the Development – Exploited Marine Ecosystems Unit (UMR 212)
Sète cedex, France
WebsiteSheila HeymansDr. Sheila Heymans
The Scottish Association for Marine Science, Ecology Department
Oban, Scotland, UK

Dr. Villy Christensen Dr. Villy Christensen
University of British Columbia Fisheries Centre
Vancouver, Canada

Modeling marine ecosystems: Lessons learned and the road ahead

We’ve learned from numerous studies that ecosystem models can now replicate historic changes in ecosystems and be used to evaluate the relative impact of fisheries, food web dynamics, and environmental change, and notably use this to evaluate trade-offs. With models that behave well enough to replicate the past, we can start thinking of using them to predict the future, to ask “what-if” questions.

While ecosystem models now offer some predictive capabilities for evaluating major human impacts and making predictions, we cannot make detailed predictions, and we will never be able to do that for complex ecosystems. We must expect the unexpected; there will be events we cannot predict. Invasive species is a case in point, and more generally, behavioral responses in ecosystems are no more predictive than they are for human systems.

There is also considerable uncertainty about how ecosystems will react to many management interventions, especially where our knowledge about drivers and impact is very incomplete. Our best option wherever this is the case is represented by adaptive management with carefully planned monitoring, experimentation, and adaptation. Modeling is an integral part of this, needed to guide the entire process and limit the risk of making bad, preventable mistakes. So, though we cannot make detailed predictions for how ecosystems will develop, we as a society need to carefully choose what direction to take and we need to avoid the preventable mistakes. For this, it is crucial that fisheries policy makers and managers set clear objectives for management, and that fishery scientists in turn define and evaluate alternative policy options. We need to manage our ecosystems with a strong commitment to moving in a sustainable direction if there indeed is to be seafood and healthy oceans for future generations to enjoy.

Session 1 – Scientific advice for management
Dr. Steve Mackinson Dr. Steve Mackinson
Centre for Environment, Fisheries and Aquaculture Science – Lowestoft Laboratory
Lowestoft, Suffolk, UK

A European perspective on modelling to support an ecosystem approach to management

Recent EU legislation makes explicit the need to take trophic interactions and marine environmental impacts in to account in management. Policy requirements are echoed in the ICES strategic plan, where an integrated and ecosystem approach will form the basis for delivering scientific advice. Together, these commitments signal a clear need for ecosystem modelling tools to prove themselves worthy of providing evidence on the effects of trophic interactions that can be used with confidence in advice. It’s a daunting but welcome challenge. Achieving this requires having a strategy to guide the development and use of models for advice, and convincing demonstrations of their utility.

Various tools will be required to meet the needs for supporting stock assessments and assessing ecosystem and fishery impacts. Bringing their results together to generate an integrated understanding and communicate it clearly is an important challenge. The shift in the skill sets being required for generating advice requires investment in training and development.

Session 2 – Informing and planning marine conservation
Dr. Tony Pitcher Dr. Tony Pitcher
University of British Columbia Fisheries Centre
Vancouver, Canada

Marine protected areas in the Haida Gwaii ecosystem (Canada): modelling and policy issues

An Ecospace model of the marine ecosystem around Haida Gwaii, Canada, employs detailed habitat and fisheries maps on a 4km grid deriving from extensive GIS material that is part of an official regional spatial planning process by the Haida Nation and the Canadian government. MPAs are designated by Marxan modeling and by the output of a 3-year marine spatial planning process performed by the local community. In addition to the usual biomass conservation from protected areas, results suggest considerable benefits to some fisheries from spillover around MPAs, even for quite modest amounts of protected area in the order of 10%.

Although Ecospace modeling can be very helpful in indicating likely benefits once MPAs are established, the work raises many issues in its practical application to real situations. Choice of boundaries for MPAS that are yet to be gazetted can be controversial and unfortunately many results are dependent on small local difference. Marxan output is often not usable directly for both ecological and human reasons, and similar issues apply to MPAs set by collaborative marine spatial planning. Spill-over benefits are very sensitive to values for dispersal parameters in Ecospace. This type of work not only raises fundamental issues in the governance of marine protected areas but also highlights the uncertainties inherent in even the best spatial modeling, which may be seen in public policy fora as weaknesses to question to the method or even be exploited to the advantage of some stakeholders.

Session 3 – Ecosystem evolution and challenges for management
Dr. Ken H. Andersen Dr. Ken H. Andersen
Center for Ocean Life, Technical University of Denmark
National Institute of Aquatic Resources
Charlottenlund, Denmark

Conflicting objectives for ecosystem based fisheries management

Current fisheries management is oriented towards management of single fish stocks, considered largely as independent, isolated units. However, management actions directed towards one stock, or one fishery, has implications for other parts of the ecosystem. Accounting for such indirect effects in an ecosystem approach to fisheries management requires food-web models that can quantify how perturbations on one part of the ecosystem influences the entire ecosystem. I will show how food-web models can be used to as tools to guide strategic fisheries management decisions through examples of trophic cascades and the effect forage fishery. In particular I will show how, due to the intrinsic dynamics of a ecosystems, a management action may lead to an unfavourable outcome in the short time, while a favourable outcome will only happen after a certain time has elapsed. Finally I will discuss fundamental challenges and obstacles that models need to overcome to provide a successful operational implementation of ecosystem-based advice.

Session 4 – Modelling cumulative ecosystem dynamics

Modelling cumulative ecosystem dynamics: progress and challenges

The need to consider changes in natural resources as well as human activities when analysing and managing marine ecosystems highlights the necessity to adopt an integrated view. Since the productivity of marine resources depends on the ecological state of communities and ecosystems, and on external drivers, not only the dynamics of target species, but also the dynamics of non-target organisms, trophic relationships and energy flows, environmental factors and human impacts have to be considered to manage our seas properly. In the last decade, the scientific community made substantial progress in the identification and quantification of multiple human threats that impact marine diversity, habitats, and ecosystems.

Currently there is increasing knowledge on the identification and quantification of these multiple drivers. However, the way these drivers may interact and combine to impact productivity patterns of marine ecosystems is not well known. Multiple drivers may interact and their effects may cause impacts that accumulate in an additive way or may act synergistically or antagonistically at different ecological levels. A comprehensive understanding of these impacts and their interactions is mostly lacking. In addition, multiple impacts are distributed in a heterogeneous way spatially and temporally, and their interactions do not occur the same way everywhere, affecting productivity differently. Moreover, future changes of current human activities (such as climate change, fishing or the invasion of new species), and the appearance and spread of new activities (such as deep sea exploitation), will likely challenge our current understanding.

To tackle some of these scientific challenges there is a growing need to develop and use novel methodologies of data integration, assimilation and modelling at different scales, taking into account uncertainties in data and processes. Here we provide an overview of the challenges the scientific community is currently facing to model these cumulative dynamics, on the progress achieved in the last decade and on how novel modelling approaches within the Ecopath with Ecosim approach can contribute to this progress.

Session 5 – End-to-end modeling
Dr. Kerim Aydin Dr. Kerim Aydin
NOAA Fisheries
Alaska Fisheries Science Center

Ecopath and Ecosim in fisheries management: notes from two decades on the front lines

In the Alaska region, Ecopath and Ecosim models have had nearly 20 years of use in the science of fisheries management. They have been used to address issues including fisheries bycatch, gear tradeoffs, endangered species concerns, and the development of broad environmental indices for determining ecosystem-level reference points. Food web results have been presented to the North Pacific Fisheries Management Council as part of their annual Status of Stocks review for 10 years, with a direct and specific impact on management decisions. However, Ecopath and Ecosim are at their best when used as the core of an operational suite of models, which may include spatial lower trophic level models, multispecies stock assessment models, bioenergetics models, individual-based models, and/or high-resolution climate-earth modeling.

In this talk, I’ll discuss the evolution of Ecopath and Ecosim in the fisheries management of Alaska, with particular emphasis on how its development and incarnations have spurred a range of multi-model development in the region, and how the different types of models have interfaced (whether directly or indirectly) to influence ongoing management policy.