Effects of Mercury Exposure in Harbor Seal Pups
- Behavior
- Pollution
Abstract
Monomethyl mercury (MeHg+) from the diet can cause mild to severe neurotoxicosis in fish-eating mammals. Chronic and low-level in utero exposure also can be neurotoxic, as documented in laboratory animal studies and epidemiologic investigations. In free-ranging animals, it is challenging to study low-level exposure related neurotoxicosis, and few studies have investigated the relationship between mercury (Hg) and adverse outcomes in wild populations. Relative to Hg concentrations on admission we evaluated different types of behaviors for 267 Pacific harbor seal (HS; Phoca vitulina richardii) pups at The Marine Mammal Center from 2015 to 2019 during rehabilitation after stranding and maternal separation. Admitted HS pups underwent a clinical exam; including sex and weight determination, and hair (partly lanugo grown in utero) and blood samples were collected for total Hg concentration ([THg]) determination. All pups were monitored weekly (behavior assessments included response to tactile stimulation, movement, swimming, interactions with other seals, hand feeding, and feeding independently), and days in rehabilitation and survival were recorded. There was a significant negative correlation between [THg] and responses to tactile stimulation and movements, measured in both hair and whole blood (p < 0.05). This relationship was found both during the intensive care unit (ICU) stage, and during the pool stage of rehabilitation. Additionally, there was a significant association between greater [THg] and number of days spent in rehabilitation, although there was no relationship between [THg] and survival. There was a significant sex difference, with greater [THg] in female pups, which contrasts with previously published findings in juvenile and adult harbor seals. Our findings support small, but significant associations between gestational THg exposure and clinical effects for tactile sensory response and movement, and longer rehabilitation durations for HS pups, although there was considerable variability amongst animals.
Lian, M., Field, C.L., van Wijngaarden, E., Rios, C., Castellini, J.M., Greig, D.J., Rea, L.D., Coleman, D.J., Thomson, C.E., Gulland, F.M. and O’Hara, T.M., 2020. Assessment of clinical outcomes associated with mercury concentrations in harbor seal pups (Phoca vitulina richardii) in central California. Science of The Total Environment, p.143686.
pollution
Cara Field
Carlos Rios
Meet The Experts
{"image":"\/People\/Portrait\/cara-field.jpg","alt":"Cara Field","title":"Cara Field","text":"Medical Director","link_url":"https:\/\/www.marinemammalcenter.org\/person\/cara-field","link_text":"Read Bio"}
{"image":"\/People\/Portrait\/cropped-images\/carlos-rios-0-180-1160-906-1605722153.jpg","alt":"Carlos Rios","title":"Carlos Rios","text":"Clinical Laboratory Scientist and Manager","link_url":"https:\/\/www.marinemammalcenter.org\/person\/carlos-rios","link_text":"Read Bio"}
Related Publications
{"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"}
Contaminant Exposure and Herpesvirus Associated with Cancer in Wild Sea Lions
Read More{"image":"\/Animals\/Wild\/Harbor seal\/cropped-images\/harbor-seals-shutterstock-307-0-4076-3184-1645666025.jpg","alt":"harbor seal moms and pups on a beach","title":"Fetal Mercury Concentrations in Harbor Seals: Associated Drivers and Outcomes","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/fetal-mercury-concentrations-in-harbor-seals-associated-drivers-and-outcomes","label":"Research Paper"}
Fetal Mercury Concentrations in Harbor Seals: Associated Drivers and Outcomes
Read More{"image":"\/Animals\/Wild\/Humpback whale\/cropped-images\/humpback-whale-sea-lions-photo-c-bill-hunnewell-190-2-2774-2167-1659123832.jpg","alt":"humpback whales and California sea lions feeding","title":"Aquatic Mammals","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/aquatic-mammals","label":"Research Paper"}
{"image":"\/Animals\/Wild\/Hawaiian monk seal\/cropped-images\/hawaiian-monk-seal-in-fishing-gear-shutterstock-103-0-4424-3455-1714076342.jpg","alt":"Hawaiian monk seal in the middle of a large plastic fishing net and buoys","title":"Marine Mammals and Plastics in the Ocean","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/marine-mammals-and-plastics-in-the-ocean","label":"Research Paper"}
Related News
{"image":"\/Places\/Coastal landscapes\/cropped-images\/underwater-barrel-shutterstock-328-0-4424-3456-1651790853.jpg","alt":"rusty barrel underwater and covered with algae","title":"The Hill: 'Under the Sea, Out of Mind' Has Turned Into a Ticking Time Bomb","link_url":"https:\/\/www.marinemammalcenter.org\/news\/the-hill-under-the-sea-out-of-mind-has-turned-into-a-ticking-time-bomb","label":"In the News","date":"2022-05-03 02:00:00"}
The Hill: 'Under the Sea, Out of Mind' Has Turned Into a Ticking Time Bomb
May 3, 2022
Read More{"image":"\/Animals\/Patients\/California sea lions\/cropped-images\/csl-by-bill-hunnewell-c-the-marine-mammal-center-2-0-1031-1794-1401-1603916128.jpg","alt":"California sea lion","title":"Spectrum News 1: California Sea Lions Dying from Cancer at Alarming Rates, Researchers Demand Action","link_url":"https:\/\/www.marinemammalcenter.org\/news\/spectrum-news-california-sea-lions-dying-from-cancer-at-alarming-rates-researchers-demand-action","label":"In the News","date":"2022-01-24 01:00:00"}
Spectrum News 1: California Sea Lions Dying from Cancer at Alarming Rates, Researchers Demand Action
January 24, 2022
Read More{"image":"\/Animals\/Patients\/California sea lions\/cropped-images\/csl-by-bill-hunnewell-c-the-marine-mammal-center-0-0-3110-2430-1639515407.jpg","alt":"California sea lion","title":"AP News: Banned Decades Ago, PCBs Still Posing Threat to Wildlife","link_url":"https:\/\/www.marinemammalcenter.org\/news\/ap-news-banned-decades-ago-pcbs-still-posing-threat-to-wildlife","label":"In the News","date":"2021-12-13 01:00:00"}
AP News: Banned Decades Ago, PCBs Still Posing Threat to Wildlife
December 13, 2021
Read More{"image":"\/People\/Action\/Misc\/cropped-images\/coastal-caucus-roundtable-photo-c-the-marine-mammal-center-282-0-2949-2303-1630353219.jpg","alt":"","title":"The Marine Mammal Center Hosts Roundtable Discussion to Launch California Coastal Caucus","link_url":"https:\/\/www.marinemammalcenter.org\/news\/the-marine-mammal-center-hosts-roundtable-discussion-to-launch-california-coastal-caucus","label":"Press Release","date":"2021-08-30 02:00:00"}
The Marine Mammal Center Hosts Roundtable Discussion to Launch California Coastal Caucus
August 30, 2021
Read More