Ticket #540 (closed assessed: wontfix)
Network Analysis: MTI
Reported by: | carieh | Owned by: | villyc |
---|---|---|---|
Priority: | normal | Milestone: | Ecopath 5: build 5.2 |
Component: | Network Analysis plug-in | Version: | |
Severity: | minor | Keywords: | |
Cc: |
Description (last modified by jeroens) (diff)
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)
Change History
comment:2 Changed 13 years ago by jeroens
- Component changed from Contaminant tracing to Plug-ins
- Description modified (diff)
comment:3 Changed 13 years ago by jeroens
- Status changed from assigned to closed
- Resolution changed from open to fixed
comment:4 Changed 13 years ago by jeroens
- Status changed from closed to reopened
- Resolution fixed deleted
- Milestone changed from Ecopath 6 to Ecopath 5
This bug has not been addressed in EwE5. Needs fixing too?
comment:5 Changed 13 years ago by jeroens
- Owner changed from carieh to villyc
- Status changed from reopened to assigned
comment:8 Changed 13 years ago by shermanl
- Milestone changed from Ecopath 5: build 5.1 to Ecopath 5: build 5.2
comment:10 Changed 10 years ago by jeroens
- Status changed from assigned to closed
- Resolution set to wontfix
I've fixed this, Alberto is right. DCCnoDiscard added. A fleet will still have a negative impact on its discards, but the discarded group will not have a positive impact on the fleet