To deny humanity and Earth the right to explore new water resources not only on Mars but any other planet in the Universe and move closer to those new sources of water is denying humanity the right to survive.
What if humanity's contact with those sources of water contaminates them and leads to the death of other species?
Is that not denying those species the right to survive?
Why are you supporting another species over the survival of the human species?
If there were in fact any species of life other than human and the rest of animal kingdom similar to that of Earth on any other planet in the Sol System independent astronomers would have that life on the planet. But since life similar to that on Earth has not been found anywhere else and that the only other life in the Sol System other than Earth based life would only be microbes then such life does not represent any sentient life that would be effected by humanities presence.
When humanity came into contact with new sources of water on Earth it is obvious that we discovered new species outside of the human species itself where our survival lead to the death of those species.
The argument is invalid regarding other life on planets that does not the ability to leave the planet and explore other planets and colonize them using innovation.