If they didn't adapt, they couldn't survive in the changed environment.
Because abiotic factors determine the kind of organisms that are able to live in certain conditions.
I think if the whale population decreased the surface fish populations would decline due to reduced populations of algae. This can be simply explained by the fact that, if the whale population is decreased, it means that the nitrogen rich feces that is supply nutrients to the algae would also decrease and therefore decrease the population of the algae and as a result the population of of the surface fish would also decline.
I would go with false, Being life has a lively look, Non-life is well lifeless lol