Prey-Related Suffocation in Harbor Porpoises
- Behavior
- Foraging
Abstract
Harbor porpoise (Phocoena phocoena) diets are predominantly comprised of small fish species (<30 cm) and squid. However, predation on larger species (up to 63 cm) occurs, raising the question of increased risk of asphyxiation associated with this behavior. Literature was reviewed and stranding data from 1983 to 2020 from the U.S. West Coast (including California, Oregon and Washington) were searched for cases of prey-related asphyxiation of harbor porpoises and analyzed in relation to age, sex, reproductive status and prey species. Twenty-nine cases were documented. Twenty-seven cases involved large prey; non-native American shad caused the asphyxiation in 87% of the cases where the prey species was identified. The majority (92%) of harbor porpoises were females, and at least 83.3% were pregnant or recently post-partum. Reproductively active females may be more likely to attempt potentially risky behavior in order to compensate for their increased energetic needs. Increasing numbers of non-native American shad may pose a unique danger in this region for harbor porpoises not adapted to deal with the challenges of that prey. This may be a cause for concern, as there is likely an interaction between location, age and reproductive status on the diet composition and foraging strategies of harbor porpoises.
Elliser, C.R., Calambokidis, J., D’Alessandro, D.N., Duffield, D.A., Huggins, J.L., Rice, J., Szczepaniak, I. and Webber, M., 2020, September. Prey-Related Asphyxiation in Harbor Porpoises (Phocoena phocoena) along the US West Coast: Importance of American Shad (Alosa sapidissima) on Adult Female Harbor Porpoise Mortality. In Oceans (Vol. 1, No. 3, pp. 94-113). Multidisciplinary Digital Publishing Institute.
foraging
Marc Webber
Meet The Experts
{"image":"\/People\/Portrait\/cropped-images\/marc-webber-0-196-1204-940-1618436847.jpg","alt":"Marc Webber","title":"Marc Webber","text":"Cetacean Field Research Associate","link_url":"https:\/\/www.marinemammalcenter.org\/person\/marc-webber","link_text":"Read Bio"}
Related Publications
{"image":"\/Animals\/Patients\/Harbor seals\/hs-by-bill-hunnewell-c-the-marine-mammal-center.jpg","alt":"harbor seal in a life preserver enrichment item","title":"Enrichment as a Tool for Rehabilitating Harbor Seals","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/enrichment-as-a-tool-for-rehabilitating-harbor-seals","label":"Research Paper"}
Recent News
{"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":"Top Eco Friendly Father\u2019s Day Gifts that Give Back","link_url":"https:\/\/www.marinemammalcenter.org\/news\/eco-friendly-fathers-day-gifts-that-give-back","label":"News Update","date":"2023-05-17 02:00:00"}
{"image":"\/Animals\/Wild\/Gray whale\/cropped-images\/gray-whale-golden-gate-bridge-by-darrin-allen-c-the-marine-mammal-center-noaa-permit-26532-470-3-2853-2229-1683822339.jpg","alt":"gray whale tail seen above the water with the Golden Gate Bridge in the background","title":"Experts Suspect Record-Setting Gray Whale Struck Multiple Times in San Francisco Bay","link_url":"https:\/\/www.marinemammalcenter.org\/news\/experts-suspect-record-setting-gray-whale-struck-multiple-times-in-san-francisco-bay","label":"Press Release","date":"2023-05-11 02:00:00"}
Experts Suspect Record-Setting Gray Whale Struck Multiple Times in San Francisco Bay
May 11, 2023
Read More{"image":"\/Animals\/Patients\/Hawaiian monk seals\/2023\/cropped-images\/hms-rl68-photo-c-the-marine-mammal-center-210-866-2232-1743-1682023516.jpg","alt":"Hawaiian monk seal RL68","title":"Endangered Hawaiian Monk Seal Receiving Life-Saving Care at The Marine Mammal Center","link_url":"https:\/\/www.marinemammalcenter.org\/news\/endangered-hawaiian-monk-seal-receiving-life-saving-care-at-the-marine-mammal-center","label":"Press Release","date":"2023-05-03 02:59:00"}
Endangered Hawaiian Monk Seal Receiving Life-Saving Care at The Marine Mammal Center
May 3, 2023
Read More{"image":"\/Animals\/Wild\/Gray whale\/cropped-images\/gray-whale-fluke-shutterstock-186-2-2129-1663-1659123185.jpg","alt":"gray whale tail seen above water as animal dives","title":"San Francisco Chronicle: Gray Whale Busts Record for Most Time Spent in San Francisco Bay","link_url":"https:\/\/www.marinemammalcenter.org\/news\/san-francisco-chronicle-gray-whale-busts-record-for-most-time-spent-in-san-francisco-bay","label":"In the News","date":"2023-04-21 02:00:00"}
San Francisco Chronicle: Gray Whale Busts Record for Most Time Spent in San Francisco Bay
April 21, 2023
Read More