What might happen to the fisheries if upwelling stopped

If upwelling stopped then the food chain would break thus causing the fisheries to collapse

Destruction of fish habitats

Explanation:

As up-welling is the phenomenon that involves the wind movement of the waves and that drives the nutrient-rich waters towards the surface. And this forms a great place for the breeding of the fishing population and hence this water is essential for the growth and the reproduction of the primary producers and as a fact, about 25 % of the fish caught in the world comes from the marine fresh warm waters.

D. coal i hope that

When a lake, river or other aquatic  system  becomes  eutrophic, it can have serious negative effects on other organisms like fish, birds and even people.if an algal bloom is so bad that it causes wide-spread death  in  the  water, the organisms that die will all sink to the bottom and start to decompose.