Question

1. what did the decline of porpoise (e.g. dolphin) bones in garbage piles indicate?

Explanation:

The decline of porpoise bones in garbage piles could indicate a reduction in the porpoise population, perhaps due to over - hunting, habitat loss, or other environmental changes that made them less available as a food source or less present in the area where the garbage piles were formed.

Answer:

A decline in the porpoise population or changes in their availability in the area.