Ticket #540 (assigned: open) — at Initial Version
Network Analysis: MTI
| Reported by: | carieh | Owned by: | carieh |
|---|---|---|---|
| Priority: | normal | Milestone: | Ecopath 5: build 5.2 |
| Component: | Network Analysis plug-in | Version: | |
| Severity: | minor | Keywords: | |
| Cc: |
Description
From ecopath.org user:Alberto Barausse
This is not precisely a bug according to the standard meaning, but in the MTI analysis discarded groups are positively impacting the fleet that discards them, i.e. I believe they are treated as landings making up the fleet diet matrix. If I am right (this is what clearly appears from my model) I think the routine should be corrected.
Hi guys,
I tried to test this by opening the generic model
-copying the Mixed Trophic Index for the model
-adding discards to small reeffish (they currently do not affect the fishery)
(I added 0.1 t/km2 discards)
-recalculating the MTI
The MTI for reeffish small (xaxis) to fleet 1 (yaxis) changed from 0.0046 to 0.021 so in my opinion the reeffish is having a positive effect on the reeffish?
The MTI for fleet 1 (xaxis) to reeffish small (yaxis)changed from 0.2473
to 0.2473 so no change.
I am not sure why the fish are having a positive effect on the fishery when they are ONLY inserted as discards, perhaps some interactions that are not direct between the two. I am struggling with how to answer this for the user, and I am not sure it is actually a bug, so I will assign to Villy. (sorry Villy)
