Did you know that stones are commonly found in the stomachs of Steller sea lions?
These stomach stones or “gastroliths” are as big as 12 cm!
Share your theories about why you think this might be after viewing the video below. It provides you with information to help with this Marine Detective case.
Happy sleuthing to you!
Click here for SeaDoc footage of Steller Sea Lions playing with California Sea Cucumbers.
Research into gastroliths in Steller Sea Lion
C. R. Shuert and J. E. Mellish “Size, mass, and occurrence of gastroliths in juvenile Steller sea lions (Eumetopias jubatus),” Journal of Mammalogy 97(2), 639-643, (11 January 2016).
Includes: “In summary, our opportunistic assessment of gastroliths in temporarily captive Steller sea lions showed that a large proportion of juvenile animals (e.g., one-third or more) may haveone or more stones at any given time. The regurgitation of gastroliths correlated best with leaner, but not poorer body conditions, and during the summer months, possibly indicating a weak association as a digestion aid. We found little evidence to suggest that they assist in buoyancy and satiation; it is even more unclear as to what drives an individual to regurgitate them. With a lack of strong conclusions relating to a particular use, we can only conclude that they appear to serve a function in sea lions and are not ingested accidentally. A combined assessment of regurgitated and in vivo gastrolith measurements may shed more light on the subject and allow for direct evaluation and conclusions as to their functionality in sea lions.”