DOI: 10.57830/2312752
title: Harbor Seal (Phoca vitulina richardii) Aerial Photographic Survey Data from Glacier Bay National Park & Preserve, Alaska, 2004-2023

description: Population monitoring studies of harbor seals in Glacier Bay National Park, Alaska, have spanned five decades from the 1970’s to the present (Streveler 1979; Calambokidis et al. 1987; Mathews & Pendleton 2006; Womble al. 2010; Womble et al. 2020; Womble et al. 2021), representing one of just a few sites in in Alaska where such long-term monitoring effort exists. Monitoring methods for harbor seals at terrestrial sites have remained consistent since 1992 allowing for quantifying distribution, abundance, and trend of harbor seals in Glacier Bay National Park.

This file includes data includes count data of harbor seals from digital photographs collected during aerial photographic surveys conducted in Glacier Bay National Park & Preserve in southeastern Alaska to assess the distribution, abundance, and trend of harbor seals at terrestrial and glacier ice sites (McBride Inlet and Tarr Inlet) from 2004 to 2023. Aerial photographic surveys were conducted from May-September, with most surveys occurring during May-June (pupping period) and July-September (molting period). Replicate aerial surveys (2-4 surveys during pupping and molting period) were conducted to increase precision in the trend estimates of harbor seals. If it was not possible to complete at least 4 replicate surveys on different days during one tidal cycle, then surveys were attempted during the second low tidal cycle of the month, weather permitting.

From 2004-2025 this project was led by Jamie N. Womble (National Park Service), please contact Jamie if you have questions regarding these data, at jamienwombleak@gmail.com.

Please see associated publications for more details.

Womble, J.N., Williams, P.J., McNabb, R., Prakash, A., Gens, R., Sedinger, B. and Acevedo, C. (2021). Harbor Seals as Sentinels of Ice Dynamics in Tidewater Glacier Fjords. Frontiers in Marine Science, 8, pp.1-16.  https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2021.634541/full

Blanchet, M.A., Vincent, C., Womble, J., Steingass, S. and Desportes, G., (2021). Harbour Seals: Population Structure, Status, and Threats in a Rapidly Changing Environment. In Oceans (Vol. 2, No. 1, pp. 41-63).https://www.mdpi.com/2673-1924/2/1/3

Womble, J.N., Ver Hoef, J.M, Mathews, E.A., Gende, S.M. (2020). Calibrating and adjusting counts of harbor seals in a tidewater glacier fjord to estimate abundance and trends 1992-2017. Ecosphere 11(4), p.e03111.  https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2.3111

Womble, J.N. 2012.  Foraging ecology, diving behavior, and migration patterns of harbor seals (Phoca vitulina richardii) from a glacial fjord in Alaska in relation to prey availability and oceanographic features.  Ph.D. Dissertation.  Oregon State University, Corvallis, Oregon.

Blundell, G.M., Womble, J.N., Pendleton, G.W., Karpovich, S.A., Gende, S.M., Herreman, J.K. (2011) Use of glacial ice and terrestrial habitats by harbor seals in Glacier Bay, Alaska: costs and benefits. Marine Ecology Progress Series 429:277- 290.  https://www.int-res.com/articles/meps_oa/m429p277.pdf

Allen, S.G., Brown, E., Faulkner, K., Gende, S.M., Womble, J. N. (2011) Conserving pinnipeds in Pacific Ocean parks in response to climate change. Park Science 28:48-52.  https://www.researchgate.net/profile/Jamie-Womble/publication/258407609_Conserving_pinnipeds_in_Pacific_Ocean_parks_in_response_to_climate_chnage/links/0f3175372b3ec3667c000000/Conserving-pinnipeds-in-Pacific-Ocean-parks-in-response-to-climate-chnage.pdf

Womble, J.N., Pendleton, G.W., Mathews, E.A., Blundell, G.M., Bool, N.M., Gende, S.M. (2010) Harbor seal decline continues in the rapidly changing landscape of Glacier Bay National Park, Alaska, 1992-2008. Marine Mammal Science 26:686-697https://onlinelibrary.wiley.com/doi/10.1111/j.1748-7692.2009.00360.x?msockid=14da1e5b94b961b802740be595036098

Womble, J.N., Pendleton, G.W., Mathews, E.A., Gende S.M. (2015). Status and trend of harbor seals at terrestrial sites in Glacier Bay National Park from 1992-2013. Report to Glacier Bay National Park and Preserve, Gustavus, Alaska.

Womble, J.N., and Gende, S.M. (2013). Harbor seal population monitoring in Glacier Bay National Park, Progress Report to Glacier Bay National Park, Gustavus, Alaska.

Additional publications related to harbor seal ecology, movements, and diving behavior in Glacier Bay can also be found on Data Store or:

https://www.researchgate.net/profile/Jamie-Womble?ev=prf_overview

https://scholar.google.com/citations?user=4zSbT-gAAAAJ&hl=en