OCEAN 320 Lecture Notes - Lecture 1: Blubber, Killer Whale, Bioaccumulation
Unit 1C: Chemical Pollution in the Ocean
PCBs in Whales (Video)
• Puget Sound
o Orcas in Puget Sound are monitored as an indicator of the overall health of the
area
o Orcas are the top of the food chain, therefore they accumulate the most of these
chemicals
o In one year, 7 orcas died; there are only 86 left in Puget Sound, making them
officially endangered in the area
o Scientists extract and analyze blubber, looking for contaminates such as PCBs;
shows that Puget Sound orcas are some of the most PCB-contaminated animals in
the world
o PCBs bioaccumulate throughout the food chain; do not break down
• Orcas are not the only organisms impacted by these chemicals; their health indicates the
nature of the fish humans are consuming, and what we absorb from eating those fish
populations
• Puget Sound orca population expected to die off entirely within 20 years; so few left, that
we can track them from birth to death
• Proof in mortality patterns
o Young whales are dying before they even become sexually matured
o Caused by absorption of PCBs through mother’s milk
• Arctic communities most highly affected; PCBs break up less than in warmer climates
• Salmon in Puget Sound areas are also most highly contaminated in pacific region
find more resources at oneclass.com
find more resources at oneclass.com
