Foreword

Ecopath with Ecosim (EwE) has been a constant in my life for nearly 30 years. I first became aware of it as a PhD student in South Africa, where I was in the depths of building a model using the labour- and data-intensive software, NETWRK, an ecological network analysis (ENA) tool written in FORTRAN by Bob Ulanowicz. I was working on a model of the northern Benguela current, and my PhD supervisor, Dan Baird, came back from the USA with this new software, Ecopath – on two discs with no manual. Luckily NETWRK had been included into the Ecopath software by Villy Christensen. Long story short, I spent quite some time trying to get the same results from Ecopath as we got in NETWRK, and in that process realized that Ecopath is much more forgiving of data gaps. It is also much more logical to an ecologist, which is why it has been so successful over the past four decades.

The theories behind network analysis and Ecopath has influenced my view of the world in everything from understanding the behaviour of seagulls on garbage day, to politics: human systems become brittle when you reduce diversity, just like ecosystems do, so reduced redundancy in political viewpoints creates two party systems that flip-flops from one extreme to the other, or in the worse-case one party systems that become dictatorships – just like lack of predators changes the dynamics of coral reefs.  Similarly, the foraging arena theory explains why the seagulls in Oostende will always peck at my garbage bags until the municipality starts using garbage cans, reducing the vulnerability of the garbage to the predation by seagulls, similar to the small fish under Carl’s boat in Figure 6 of the On Modelling chapter were not predated on by the larger fish, or how the planktivores that stay closer to the corals avoid predation in Figure 7, and explained more mathematically by Figure 4 in the Density Dependence chapter. So, if you study the networks of fisheries, or the networks of fishers, as you will be able to do after reading this book and following the tutorials, you too will be able to understand some of the crazy things happening in the world.

Seriously though, to address the very real problems that we face both in the Ocean and on land, we need all the scientists and tools we can get, and EwE is one of the few tools that translate easily to people with limited programming skills. The software has been taken up by policy makers in the USA, Australia and South Africa more quickly than in Europe, but even this bastion of academic conservatism is realizing that we need all the tools we can get to help with the large problems we have created. In the past decade EwE has been used in at least 15 large scale projects in Europe, through both National, Regional and European funding. This has created a suite of models that is ready to be plugged into the EU new Destination Earth architecture: the European Digital Twin of the Ocean (EDITO). As part of the EU’s Mission to Restore our Ocean and Waters, EDITO must make Ocean knowledge available to all and be usable to address what-if questions asked by policy makers not just in the Ocean but also on land, where most of the problems originate. EwE is the most comprehensive and understandable tool to achieve those aims, and these models will be critical to ensure that EDITO achieve those aims.

The EU is also currently reviewing its Marine Strategy Framework Directive, which needs better indicators for food web descriptors, and under the EU’s Biodiversity Strategy for 2030 should dovetail more closely with other legislation such as the Water Framework Directive, Nitrates Directive, the Maritime Spatial Planning Directive and the Common Fisheries Policy. I do not know of any other tool that will be able to address this better than an EwE-enabled EDITO.

Sheila JJ Heymans

Executive Director, European Marine Board