Because orcas are the bizzomb.

If you're thinking, "Aww, how cute, a mom, dad, and their baby" you'd be wrong. Common place in orca society, the familial ties between mother and son are very strong. It's not often you see sons staying with their mothers their whole life with any other animal, but it's common place with orcas we know most about. Here, we see a mother and her two offspring.

Sadly, orca numbers are struggling to increase as contaminates in their habitat have reproductive and immuno-suppressive affects. The most contaminated animals are orcas, especially in the Northwestern region of the Pacific of the coast of the US where residential pods take up their home in the Pugent sound area. It's the price they pay for being top of the food chain in a world where humans' need to make profit inevitably collides with the balance of nature.

Here's a wonderful article to learn more about pollutants that affect whale populations, and resources to learn what other threats wild cetaceans face:
http://wildwhales.org/conservation/threats/toxins/