Tutorial 4: Spatial model of Anchovy Bay
Objectives:- Introduction to basic Ecospace operations
- Introduction to the habitat capacity model of Ecospace
Go to Ecospace scenarios tab: Under Capacity calculations select “Capacity and habitat”. If you loaded the time series then the Run time on the tab is likely to be 41 years, and number of time steps is 12. Notice that Ecospace can use variable time steps, but fine to leave this at 12 (monthly) time steps.
Next task is to create the spatial map that we will use for the tutorial: Click Ecospace – Input – Maps in the Navigator. At the top of the right side panel, click “Map”. Set number of rows to 20, and number of “cols” (columns) to 20. This gives us 20 x 20 = 400 cells to work with. More would give us prettier picture, take longer, and not necessarily give us different results. Advice: use a coarser map while testing model, if you have to you can always change to a finer map once you have the model behaving.
Set cell length to 20 km. Click OK. EwE will save and close the page. Select Input – Maps again, and click “Depth” in the right hand side panel. Now click the icon to the right of “Depth”. This will open a form that will allow you to: Edit Layer “Depth”. Click the data tab, and you will get a spreadsheet.
Now open the spreadsheet Spatial Anchovy Bay.xlsx (download from course website), and on the first tab (Depth), highlight the values (including row and col numbers), the press Ctrl + C (for copy). Go back to Ecospace, click the top left cell in the depth data spreadsheet, and press Ctrl + V (for paste). You should now have the depth map for Anchovy Bay.
Next we want to start parameterizing the habitat capacity model. Here, we’ll just illustrate this with a simple example (before loading a version of the model with more layers). Click Habitat based foraging on the Ecospace Input tab. Click Add on the lower center panel in order to add a response curve. For now, think of this shape as representing the depth distribution of a species, e.g., for cod. We can read in such shapes, but for now just get by with a sketched shape. So draw a shape, for instance with a low value at low X, then increasing to a max at 1/3 of the max X-value and then gradually declining to 0 again.
First we need to define what the X-axis is. For this, click “Set input values (X-axis)” in the lower right panel. In the middle panel here, “Map group assignments” click on Depth. This will bring a histogram of depth values up in the panel to the right. This histogram is just for your reference. Now we are to set X-min and X-max above the right hand side panel. OK to leave X-min at 0. Set X-max to, e.g., 400 m (just to try it). Move the cursor away from the X-max input box, and the shape below should update. Click OK to exit the form.
Now we have to assign the functional response above to cod. Go to Ecospace, Input, Habitat based foraging, Apply foraging response. In the spreadsheet, click the cell under Depth for Cod. In the left panel, click the shape you made, click the green arrow to the right, OK.
Now try to run Ecospace. Go to Ecospace, Output, Run Ecospace, and click the Run Ecospace button at the bottom-left of the center panel. On the small distribution maps, you should see that cod have a distribution that is impacted by the functional response you defined.
Explore the Ecospace model a bit.
Now, let’s read in a version of the model that has more data. Download the file Anchovy Bay Spatial.ewemdb.zip from the course website. It has a new version of the Anchovy Bay database. Unzip and open the database in EwE.
Go to Ecospace, Input, Habitat based foraging, and explore the additional shapes (see Figure 1).
Figure 1. Habitat capacity functional responses.
On the next tab, Apply foraging arena shapes, you can see an example of how to allocate shapes for the model groups (Table 1).
Table 1. Applied foraging arena shapes
Group no / Group name / Depth / Temperature / Distance from coast
1 / Whales / 3: Depth cod / 7: Distance whales
2 / Seals / 2: Depth whiting / 8: Distance seals
3 / Cod / 3: Depth cod / 5: Temp cold
4 / Whiting / 2: Depth whiting / 6: Temp warm
5 / Mackerel / 4: Depth pelagics / 5: Temp cold
6 / Anchovy / 4: Depth pelagics / 6: Temp warm
7 / Shrimp / 1: Depth shrimp-benthos
8 / Benthos / 1: Depth shrimp-benthos
9 / Zooplankton
10 / Phytoplankton
11 / Detritus
Explore these aspects of the model.
The habitat based foraging arena shapes are used to calculate how much foraging arena there is in each spatial cell for each functional group in the model. As such it replaces the "habitats" in previous versions of Ecospace – which either were good or bad for the individual groups.
The old type of "habitats" is still included in Ecospace. This is partly for compatibility with existing Ecospace models, and partly as they can be used to allocate effort for fishing fleets. This is illustrated in the present tutorial, see Ecospace, Input, Maps, where you under Habitats in the right hand side panel, can find four habitats, Coastal, Sand, Rocky, and Deep. These habitats are used on the Ecospace, Input, Ecospace Fishery tab to allocate fleets to habitats; e.g, the trawlers are not able (or allowed) to operate in cells with rocky bottom.
There is a major change with regards to habitats in Ecospace, the habitats now occupy a fraction of a cell. See for instance the Rocky habitat. Click on the Icon to the right of Rocky, which brings up the: Edit layers “Rocky”. (This is where you can change the map icon for the habitat).Here, click Data on the top left, and you can see that there are rocky reefs in fractions of some habitats.
Run and explore the model.