I mean, Mark Trail WROTE THE BOOK (or at least a number of articles) on respecting and preserving nature… And Marlin, what has given you the impression that Mark wants to HURT anything? This is so stupid.
In the second Panel we see that Mark has a few inches of height on Marlin, and it also appears that he has filled his chest cavity with air so as to appear larger than life. This is the natural response of any number of species when confronted by a threat- puff up and out and make yourself appear large and scary…