This strong principle supports Lopez’s argument. Since the mysis shrimp is non-native and threatens the native kokanee population, it implies removing the shrimp is the best way to protect the kokanee.

Without more information, this doesn’t strengthen or weaken Lopez’s argument. It’s not suggested that allowing trout fishing would protect the kokanee’s food supply, nor is it indicated which would work faster—removing the shrimp or removing the trout.

This weakens Lopez’s argument. It implies other ways of helping the kokanee population—allowing trout fishing, for example—are preferable to removing a whole species, which Lopez advocates.

This supports not introducing mysis shrimp in the first place, but it says nothing about removing species that are already present. Since the mysis shrimp have already been introduced, this principle doesn’t apply.

If anything, this weakens Lopez’s argument. It implies mature kokanee should be prioritized, suggesting it would be better to allow trout fishing than to remove mysis shrimp.