yes it gases them
In some circumstance, yes.
it can kill fish and hrm humans but it does a good job in cleaning
They are important because, black bears kill lots of fish. Some of the fish can't be catched by any human. And we can get the fish and enjoy meals.
Some people do believe fish are attracted to urine. It is not recommended though, for some fish may be killed from the chemicals that are found in urine.
only some fish are poisonous to humans
they kill humans by squeezing them tight and some use venom (which is poisin)
Sometimes.most of the time some sharks will attack for no reason .they like to feed on blood by other organisms.other times sharks will mistake us for fish and kill or eat people.
There is no required amount of fish that humans should eat in a day. Many humans go days without fish, and some people never eat fish.
Some can, yes.
some poisans fish have elvoved to non poisnas fish eg cod Also humans can eat it i guess
Sand is not alive, so urine cannot kill it. However, some creatures like small crustaceans burrow under the sand. It would take a LOT of urine to kill one.
fish, crabs, humans if they get in the way.