Passage Summary: A salmon farmer claims that eating farmed fish is the green choice because it reduces the pressure on wild fish, letting their populations bounce back.

Conclusion: Farmed salmon is ecologically superior to wild salmon because its consumption helps wild populations grow.

Reasoning: As demand for farmed salmon rises, the market for wild salmon decreases, which allows more wild fish to survive and reproduce.

Analysis: The farmer's logic rests on a 'zero-sum' market assumption: that farmed salmon only replaces wild salmon without causing its own environmental damage. To weaken this, we should look for an answer that introduces a hidden ecological cost of fish farming that directly harms wild populations. For instance, if farmed salmon require large amounts of wild-caught fish for feed, or if they spread diseases to wild populations, the 'ecological' benefit vanishes. The argument is vulnerable because it ignores the biological interconnectedness of the two groups.