Answer:
16) overfishing means taking more than is regrowing so the population is decreasing.
17)
A) shark population decrease if tuna is one of the Main food sources available. No food, no reproduktion or even survival
B) if striped fish and tuna share the same food source and tuna is being overfished, there wil be more food available for the striped fish and therby the population increases. However, if they live in the same Area as tuna, striped fish could face also being fished by accident and the population could decrease.
C) the population of zooplankton increases if the population of tuna decreases, because zooplankton is a natural prey for young, small tunas. Because less tuna are going to eat them.