For instance, Asian carp were introduced by U.S. fish farmers in the southern states during the 1960s and 70s to help control weeds and algae problems in fish farm ponds. Some of these fish have escaped to the wild and are now in many rivers and streams of the Mississippi Basin. Because they are living in the rivers, they are becoming hazardous to native fish populations. They have a large appetite and eat the food that native fish need.
