For example, the brittle stars that are echinoderms experience decreased muscle movement, although it may not seem like much, this can be deadly to this species. Brittle stars need muscle movement for arm movement, breathing and feeding, without these the brittle star can die. (Doney, 2008) On the other hand, some species actually benefit from excess carbon dioxide. The temperate starfish fed more and grew faster than the brittle star. (Kleypas, 2009) Having organisms that continue to live in an unbalanced way can have a serious impact on corals