Question

dangers faced by fishes in seas and rivers

Answer 1

pollution causes death of the fish ;plastic in oceans;growth of waste algae in sea ;

Answer 2

hi mate,

according to news the National Academy of Sciences estimated that ocean-based sources, such as cargo ships and cruise liners had dumped 14 billion pounds of garbage into the ocean.

Over 1 million seabirds and 100,000 sea mammals are killed by pollution every year.

Water pollution harms fish populations in various ways.

... Algal blooms can be harmful to fish as they feed upon algae, toxins accumulate within the fish,

and when a predator fish consumes that fish,

they too are consuming higher toxin levels. Pesticides and heavy metals that enter waterways can also harm or kill fish.

I hope it helps you.