AP News: Banned Decades Ago, PCBs Still Posing Threat to Wildlife
- Cancer
- Pollution
AP News: Banned decades ago, PCBs still posing threat to wildlife
Published by AP News: December 13, 2021
The Marine Mammal Center responds to 800 stranded marine mammals yearly along 600 miles (965 kilometers) of California coast. A 2020 study of stranded adult sea lions concluded that PCBs and DDT, which also was banned decades ago, are contributing to cancer rates as high as 23%.
“That rate of cancer is mostly unprecedented in wildlife,” said Cara Field, medical director of the center, adding that the disease caused a “complete systemic breakdown” in the animals and their blubber had much higher levels of PCBs than those without cancer.
Cancer Research at The Marine Mammal Center
Cancer was first diagnosed in California sea lions at The Marine Mammal Center in 1979. Since then, our veterinarians and scientists have contributed to a number of scientific papers on cancer in marine mammal populations.
{"image":"\/Animals\/Patients\/California sea lions\/2018\/cropped-images\/csl-leadbelly-by-bill-hunnewell-c-the-marine-mammal-center-664-0-2502-1954-1607626905.jpg","alt":"California sea lion","title":"Contaminant Exposure and Herpesvirus Associated with Cancer in Wild Sea Lions","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/contaminant-exposure-and-herpesvirus-associated-with-cancer-in-wild-sea-lions","label":"Research Paper","type":"publication"}
Contaminant Exposure and Herpesvirus Associated with Cancer in Wild Sea Lions
Read More{"image":"\/Animals\/Wild\/California sea lion\/cropped-images\/csl-on-a-rock-shutterstock-191-0-3072-2400-1617060454.jpg","alt":"California sea lion on a rock","title":"Unlocking the Role of a Genital Herpesvirus in California Sea Lion Cervical Cancer","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/unlocking-the-role-of-a-genital-herpesvirus-in-california-sea-lion-cervical-cancer","label":"Research Paper","type":"publication"}
Unlocking the Role of a Genital Herpesvirus in California Sea Lion Cervical Cancer
Read More{"image":"\/Animals\/Wild\/California sea lion\/cropped-images\/sea-lion-mom-pup-shutterstock-338-0-3131-2446-1603926801.jpg","alt":"California sea lion mom and pup","title":"Effects of In Vitro Exposure to PCBs on California Sea Lions","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/effects-of-in-vitro-exposure-to-pcbs-on-california-sea-lions","label":"Research Paper","type":"publication"}
{"image":"\/Animals\/Patients\/California sea lions\/cropped-images\/csl-resting-c-the-marine-mammal-center-605-0-3523-2751-1603927376.jpg","alt":"California sea lion resting on the pen floor with a young sea lion in the background","title":"Prevalence of Cancer in Stranded California Sea Lions (2005-2015)","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/prevalence-of-cancer-in-stranded-california-sea-lions","label":"Research Paper","type":"publication"}
{"image":"\/Animals\/Wild\/California sea lion\/cropped-images\/csl-monterey-photo-c-bill-hunnewell-1984-1534-1582-1236-1603927643.jpg","alt":"Group of sea lions on a rock","title":"No Evidence that Cancer in Sea Lions Is Spread Through Clonal Transmission","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/no-evidence-that-cancer-in-sea-lions-is-spread-through-clonal-transmission","label":"Research Paper","type":"publication"}
{"image":"\/Animals\/Patients\/California sea lions\/2020\/cropped-images\/csl-boycrus-by-bill-hunnewell-c-the-marine-mammal-center-0-0-3110-2429-1603927870.jpg","alt":"California sea lion","title":"California Sea Lions as a Model for Studying a Common Cancer","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/california-sea-lions-as-a-model-for-studying-a-common-cancer","label":"Research Paper","type":"publication"}
Yes, I want to save a life!
You’ll be giving sick and injured animals the best possible care at the Center’s state-of-the-art hospital. With your gift today, you are giving a patient a second chance at life in the wild.
See Our Latest News
{"image":"\/Animals\/Wild\/Gray whale\/gray-whale-angle-by-josie-slaathaug-c-the-marine-mammal-center.jpg","alt":"A gray whale in San Francisco Bay","title":"The Wall Street Journal: Huge, Hungry Whales Are San Francisco\u2019s Latest Traffic Headache","link_url":"https:\/\/www.marinemammalcenter.org\/news\/wall-street-journal-huge-hungry-whales-are-san-franciscos-latest-traffic-headache","label":"In the News","date":"2026-05-19 15:32:00"}
The Wall Street Journal: Huge, Hungry Whales Are San Francisco’s Latest Traffic Headache
May 19, 2026
Read More{"image":"\/Animals\/Wild\/Other species\/cropped-images\/two-seals-playing-shutterstock-250-0-3211-2510-1602631793.jpg","alt":"two seals playing on a beach","title":"Meaningful Father\u2019s Day Gifts for Ocean Lovers","link_url":"https:\/\/www.marinemammalcenter.org\/news\/eco-friendly-fathers-day-gifts-that-give-back","label":"News Update","date":"2026-05-15 12:37:00"}
{"image":"\/Animals\/Patients\/Harbor seals\/2021\/cropped-images\/hs-meringue-photo-by-bill-hunnewell-c-the-marine-mammal-center-2-117-0-1270-992-1744225251.jpg","alt":"Animal care volunteers gently position a feeding tube into a harbor seal pup\u2019s mouth.","title":"How Seal Milk and \u201cFish Smoothies\u201d Help Pups Grow Strong","link_url":"https:\/\/www.marinemammalcenter.org\/news\/how-seal-milk-and-fish-smoothies-help-pups-grow-strong","label":"Patient Update","date":"2026-04-29 09:41:00"}
{"image":"\/Animals\/Patients\/California sea lions\/2026\/csl-irving-pre-rescue-in-san-francisco-photo-by-katie-young-c-the-marine-mammal-center.jpg","alt":"A California sea lion pup is stranded on a sidewalk in front of a car.","title":"Sea Lion Irving Rescued on a San Francisco Street","link_url":"https:\/\/www.marinemammalcenter.org\/news\/sea-lion-irving-rescued-on-a-san-francisco-street","label":"Patient Update","date":"2026-04-17 14:50:00"}
