Plums and peaches are examples of drupes?

Yes

Explanation:

A drupe is a fruit with a hard stony covering enclosing the seed (like a peach or plum).

Yes

Explanation:

The killer whales eat large fish. The large fish eat smaller fish and shrimp. Lastly, the smaller fish and shrimp eat the algae-eating krill. When the sea ice melts, there is less food for the krill. There is less krill for other fish to eat. Lastly, since there is less krill, there will be less killer whales because there isn't enough food.