Answer:
The correct answer is - declining in animals of all ages .
Explanation:
Puget Sound is experiencing a change in the climate from a very long period of time. The salinity went up, hypoxia is also persisting as a new threat in this area and many other changes like adding chemical compounds affecting the ecosystem of Puget Sound.
Due to this change, there is the killer whale population is declining in animals of all ages due to the chemical compound which leads to the condition in killer whales which are similar to AIDS.
Thus, the correct answer is - declining in animals of all ages.