Orca Whale

Noise from shipping, drilling, and other human activities is a significant concern in some key killer whale habitats, including Johnstone Strait and Haro Strait. In the mid-1990s, loud underwater noises from salmon farms were used to deter seals. Killer whales also avoided the surrounding waters. High-intensity sonar used by the Navy disturbs killer whales along with other marine mammals. Killer whales are popular with whale watchers, which may stress the whales and alter their behavior, particularly if boats approach too closely or block their line of travel.
The Exxon Valdez oil spill adversely affected killer whales in Prince William Sound and Alaska's Kenai Fjords region. Eleven members (about half) of one resident pod disappeared in the following year. The spill damaged salmon and other prey populations, which in turn damaged local killer whales. By 2009, scientists estimated the AT1 transient population (considered part of a larger population of 346 transients), numbered only 7 individuals and had not reproduced since the spill. This population is expected to die out.