The correct answer is (a). The introduction of exotic fish species into Assam’s water bodies can sometimes disrupt native fish populations. This is because the exotic fish species may compete with native fish species for food and habitat, or they may prey on native fish species. As a result, native fish populations can decline or even become extinct.
Option (b) is incorrect because the introduction of exotic fish species can actually reduce biodiversity. This is because the exotic fish species may outcompete native fish species, leading to the decline or extinction of native species.
Option (c) is incorrect because the introduction of exotic fish species can actually decrease total fish production. This is because the exotic fish species may compete with native fish species for food and habitat, or they may prey on native fish species. As a result, the total amount of fish that can be caught in a water body may decline.
Option (d) is incorrect because the introduction of exotic fish species can actually degrade water quality. This is because the exotic fish species may introduce new diseases or parasites into a water body, or they may compete with native fish species for food and habitat. As a result, the water quality in a water body may decline.