Legal defense for animals?

Going to law school this Fall. I will be attending a university that has a very high ranking natural resources and environmental law program. I am still deciding what type of law to practice. I am seriously considering a focus on animal defense/protection. Animals in our society are so unprotected and vulnerable. Hearing stories about the dolphin macres in Japan and the bruatlity against seal pups in Canada makes me want to do something for them- perhaps a way to protect them from a legal standpoint. Does anybody out there work in this field from a legal view how available is a career in this area? Many thanks.