Evaluating Sense of Smell in California Sea Lions and Relevance to Domoic Acid
- Domoic acid
Abstract
Domoic acid is an algal toxin that has caused neurologic disease and reproductive failure in California sea lions (Zalophus californianus). In affected sea lions, necrotic neurons have been observed in the olfactory bulb and pyriform lobe of the brain, indicating potential for disrupted olfactory capability in addition to other documented neurological effects. Sea lions use olfaction in social interactions, and deficits could lead to maladaptive interactions, including between mothers and pups. Here, to assess olfactory capability in wild California sea lions, we developed a behavioral assay for use in a clinical context. We tested 24 stranded sea lions with no apparent neurological symptoms and 22 sea lions with a clinical diagnosis of chronic domoic acid toxicosis, probing differential responses to a scented and unscented object. The neurologically healthy animals spent significantly more time with the scented object than with the unscented object, establishing this method as effective in demonstrating olfactory discrimination in California sea lions. The domoic acid toxicosis group showed a nonsignificant reduction in response to the scented stimulus. However, variability in responses suggests that olfactory sensitivity is impaired in at least some sea lions with domoic acid toxicosis.
De Maio, L.M., Cook, P.F., Reichmuth, C., Gulland, F.M.D. 2018. The evaluation of olfaction in stranded California sea lions (Zalophus californianus) and its relevance to domoic acid toxicosis. Aquatic Mammals. 44(3): 231-238.
Related Publications
{"image":"\/Animals\/Patients\/California sea lions\/2020\/csl-oso-by-bill-hunnewell-c-the-marine-mammal-center-1.jpg","alt":"California sea lion","title":"Loss of Neuron Connectors in the Brains of Sea Lions with Epilepsy","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/loss-of-neuron-connectors-in-the-brains-of-sea-lions-with-epilepsy","label":"Research Paper"}
{"image":"\/Animals\/Wild\/California sea lion\/cropped-images\/sea-lion-pup-shutterstock-451-142-3018-2358-1603915228.jpg","alt":"California sea lion pup","title":"Domoic Acid in Fetal Fluids of California Sea Lions","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/domoic-acid-in-fetal-fluids-of-california-sea-lions","label":"Research Paper"}
{"image":"\/Animals\/Wild\/Steller sea lion\/cropped-images\/steller-sea-lion-harem-shutterstock-648-0-4424-3456-1603916879.jpg","alt":"Group of Steller sea lions","title":"Algal Toxins in Alaskan Marine Mammals Foraging in a Changing Environment","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/algal-toxins-in-alaskan-marine-mammals-foraging-in-a-changing-environment","label":"Research Paper"}
{"image":"\/Places\/Coastal landscapes\/cropped-images\/algal-bloom-washington-state-shutterstock-159-0-3840-3000-1603917390.jpg","alt":"algal bloom off the coast of Washington state","title":"Unprecedented Toxic Algal Bloom Linked to Unusual Ocean Conditions","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/unprecedented-toxic-algal-bloom-linked-to-unusual-ocean-conditions","label":"Research Paper"}
Related News
{"image":"\/Animals\/Wild\/California sea lion\/cropped-images\/csl-release-4-5-24photo-by-chris-deimler-c-the-marine-mammal-center-138-0-1270-992-1745348188.jpg","alt":"Four young California sea lions walk on the beach toward the ocean.","title":"Achievements in Ocean Health","link_url":"https:\/\/www.marinemammalcenter.org\/news\/achievements-in-ocean-health","label":"News Update","date":"2025-04-23 10:20:00"}
{"image":"\/Animals\/Patients\/California sea lions\/cropped-images\/LA Times Front Page 8.13.24-340-15-1270-992-1723588213.png","alt":"LA Times Front Page Domoic Acid Sea Lions","title":"LA Times: Neurotoxin is Poisoning Large Numbers of Sea Lions","link_url":"https:\/\/www.marinemammalcenter.org\/news\/la-times-neurotoxin-is-poisoning-large-numbers-of-sea-lions","label":"In the News","date":"2024-08-13 02:00:00"}
{"image":"\/Animals\/Patients\/California sea lions\/2024\/cropped-images\/musty - csl - bill hunnewell-180-0-1270-992-1723649438.jpg","alt":"California sea lion being treated for domoic acid poisoning","title":"NBC Nightly News: Researchers Investigate Dozens of Sick Sea Lions Along California Coast","link_url":"https:\/\/www.marinemammalcenter.org\/news\/nbc-nightly-news-researchers-investigate-dozens-of-sick-sea-lions-along-california-coast","label":"In the News","date":"2024-08-13 02:00:00"}
NBC Nightly News: Researchers Investigate Dozens of Sick Sea Lions Along California Coast
August 13, 2024
Read More{"image":"\/Animals\/Patients\/Releases\/cropped-images\/csl-quly-left-and-togozees-release-by-bill-hunnewell-c-the-marine-mammal-center-90-0-3996-3122-1693421090.jpg","alt":"two California sea lions are released in front of a crowd of people","title":"NPR Morning Edition: Hundreds of Seals and Sea Lions Are Treated Each Year at The Marine Mammal Center","link_url":"https:\/\/www.marinemammalcenter.org\/news\/npr-morning-edition-hundreds-of-seals-and-sea-lions-are-treated-each-year-at-the-marine-mammal-center","label":"In the News","date":"2023-08-18 02:00:00"}
NPR Morning Edition: Hundreds of Seals and Sea Lions Are Treated Each Year at The Marine Mammal Center
August 18, 2023
Read More