Are these sentences correct? A couple of times ago, I read an article on the negative impact of the transplantation, or introduction of new species to new environments. One of them was about a kind of frog, I do not remember the exact name, which was introduced to some parts of Australia in order to eliminate the effect of an intrusive species. At first, this species worked well, but after a while it itself became a new problem for the area. To further elaborate on this, introducing new species to an area might cause severe damages to the native species in terms of available food, prey, territory, or other things. So, human should take care of these issues.