Population growth and colonization of Steller sea lions in the Glacier Bay region of southeastern Alaska: 1970s–2009

Steller sea lions in the Glacier Bay region of southeastern Alaska exhibited rapid population growth from the 1970s to 2009, increasing at a rate of 8.2% annually (95% CI = 6.4%–10.0%), with the most significant growth observed at South Marble Island (16.6%/yr) and in Cross Sound. This study documented the colonization of new haul-outs and the transition of Graves Rocks to a rookery, suggesting potential reversal of reproductive isolation between eastern and western populations. Seasonal distribution patterns were linked to new breeding opportunities and prey availability. The research combined multiple observation platforms to assess trends, highlighting factors such as habitat expansion due to deglaciation, immigration, reduced mortality, and ecosystem changes contributing to this growth.

Mathews, E. A., Womble, J. N., Pendleton, G. W., Jemison, L. A., Maniscalco, J. M., & Streveler, G. (2011). Population growth and colonization of Steller sea lions in the Glacier Bay region of southeastern Alaska: 1970s–2009. Marine Mammal Science, 27(4), 852–880. Portico. https://doi.org/10.1111/j.1748-7692.2010.00455.x