Which of the following has left less than half of the salmon in Puget Sound healthy?

Cleanup efforts have effectively ruined the salmon's habitat.

Dams have enabled gas and oil to reach Puget Sound.

Acid rain that drops on Puget Sound is poisoning the salmon.

Old fishing nets left in Puget Sound have trapped and killed the salmon.

The correct alternative is Cleanup efforts have effectively ruined the salmon's habitat.

Besides all threats such as climate change, predation and diseases, habitat loss is the worst problem for the salmon in Puget Sound. Being by loss of access, habitat destruction, pesticide use, aquaculture, urban development and rising water temperatures in streams, it is important to protect the habitat and species, both for the environment and for the local economy.

The correct answer is D. Old fishing nets left in Puget Sound have trapped and killed the salmon. I just took the quiz.