Exploring Ocean Futures – Ecopath with Ecosim

By Sherman Lai (s.lai@fisheries.ubc.ca)

 

Overview

Ecopath with Ecosim (EwE) is a modeling tool that predicts trends in an ecosystem.  It is a scientific modeling tool based in UBC Fisheries centre that is used by over 3000 scientist worldwide.  EwE is a tool that is scientifically recognized through the world.  It is used for management in real world policy decision.  The next goal for the UBC Fisheries Centre is to create summits where all stake holders for a certain ecosystems come convene to explore these scenarios and come up with a common decision where all parties are satisfied. 

I have been personally involved in the development of EwE and proposing these summits for stakeholders.  I will be doing my thesis on in Collaborative Decision Support Systems (CDSS) which explores the difference between a shared environment where they users debate the best scenario and can only run one simulation at a time or individual users anonymously submit scenarios into a pool and they make decisions from the pool. 

There are several modes this available in my thesis study.  One mode will be the input mode where users can manipulate input variables.  Another mode will be an exploring mode where the users can visualize the output.  The last mode will be a evaluation mode where the users will compare different scenarios that will inform to their final decision.

 

Design Goals

                This Information visualization project will extend the current scientific interface which currently targeted to for scientist as seen in (FIGURE 1).  I will make a visualization/interaction that will be understandable to the laymen.  Since these summits consist of users from various backgrounds within fisheries and various computer skill levels, it is imperative for this tool to be simple and straight forward to extent to all participants. 

                The first goal is to create  an visualization tool for users to easily understand and input parameters for each simulation.  Users will be able to 1) control fishing effort over time for each fishing fleet.  2) control Marine Protected Areas (MPA’s) for different fleets in different regions.  Proper intuitive control mechanisms such as affordance will be important.  Information that display proper output is imperative for proper use. 

                Since there will be various modes, clear use of modes will be critical for smooth development of this project.  There will be 3 modes for this project.  The first mode will be “exploration” mode where users will attempt to find solutions a common solution.  The second mode will be “run” mode where users cannot modify the values.  This is where the model is running and users will view where their ecosystem is heading towards with live drawing of the graphs.  The last mode will be “discussion” mode where user(s) will be able to compare solutions to one another.   

                 

Figure 1 - Current spatial exploration tool used by scientist.  On the far left shows the amout of fishing effort each fishing fleet will fish over time.  The middle spreadsheet tells the quanatative values of each fleet.  Below this spreadsheet is a graph of the biomass at that paticular time.  On the right displays the biomass density in each cell (not shown).(Villy Christensen, 2005)

 

Solution

In the exploration mode where users view their outcome, the need for layering will be important.  Since layering several layers of quantitative values can be cognitively more difficult to understand.  Thus we combine quantitative values and layer it with categorical layers in a single map.  Layered values could be information such as depth information, habitat information, marine protected areas, and biomass information.  Redundant visual cues such as color, texture and transparency will be used to distinguish various layers.

                Since layering can comfortably support various up to a small number of layers, the rest of the quantitative values will be displayed as small multiples.   Small maps will be used for each group.

                Users will be able to select any small multiple map to get an overview plus detail system which will help further evaluate the group.  Once selected, users can view statistics for the species, and modify the values pertaining to that species.  When users modify the old graph, the old graph will be plotted behind the current graph to minimize cognitive load on  comparing current and different.  A difference plot will not work because of the requirement of the quantitative value. 

                Proper use of colors, alignment and other perceptual tools will be used throughout the program. 

A tool developed to compare multiple scenarios using difference plots.  Techniques such as  Blink Comparator will be used to compare special difference in biomass.  For example in the small multiple graph, the users can click on a small multiple graph, and will draw the same graph throughout the scene.  This way users can compare the differences in the two graphs. 

Biomass over time plot will be used for each species.  Techniques such as banking to 45 degrees (Jeffrey Heer, 2006)will be used in hopes to aid analysis of biomass over time.

Figure 4 - Exploration mode where users will "plan" the strategy

 

Figure 3 - Run mode where users will watch the model change through the timeseries.

 

Figure 2 - Exploration mode where the users will compare one run to another.

 

Usage Scenario

                A participant Joe in a user study will enter a user study of a summit session.  His task is to play a roll of a CEO of a fishing flee.  His objective is to develop a fishing strategy that will be acceptable for all participants including himself.  All other participants in a workshop will have respective goals with possible conflicts of interest. 

                Joe will now edit the fishing effort graph for each species and set marine protected areas.  Joe will now run the simulation and see the ecosystem change over time.   He will be interested in seeing the catches, values and profit of the catches go up or down.  He will also be interested in the biomass of each species.  Other things Joe will look at is the diversity of the ecosystem. 

Implementation

                EwE 5 (current version) is written in Visual Basic (VB) 6.  Currently it is being overhauled to VB .Net2.  It will be ambitious write this project in .Net when the core computation is not currently available.  Therefore the platform I will be writing this project in will be VB 6. 

                This project will utilize the 2D graphics library of VB6.  Other infovis toolkits will not be used because of the inability to potentially port this functionality over to the next version of EwE.

 

Milestones

Nov 11th – Gather variables required for simulation runs.  Create more variables if required.
Nov 18th – Develop class framework for drawing maps,  fishing effort graph,  biomass plots, biodiversity plots.
Nov 20th – Completion of exploration mode.
Nov 25th – Completion of run mode.
Dec 2nd – Completion of discussion mode.
Dec 9th – Completion

Works Cited

Jeffrey Heer, M. A. (2006). Multi-Scale Banking to 45 Degrees. InfoVis.

Villy Christensen, S. L. (2005). Ecopath with Ecosim 5.1 (non-release version).