THE STELLER SEA LION
(Eumetopias jubatus)
by Liam Lautze
He’s the big one
Description and Ecology
The Steller sea lion is pretty huge. The largest of the seals and sea lions and fourth largest pinniped, the Steller is rightfully known for its size. Males can grow up to eleven feet long and weigh more than a ton, and while still outclassing all their fellow pinnipeds, female Steller sea lions are much smaller than their male counterparts at up to nine feet long and weigh up to 800 pounds. Though still not so huge as the mighty Elephant Seal, this pinniped is remarkable for its size, especially when you consider that these monsters grow up from just 32 pound, three-foot-long pups.
It can be easy to mistake female or younger male Steller sea lions for your standard California sea lion because of their relatively similar body shape. The telltale differences are that the Steller has a much lighter coat and is said to have a boxier, short, more bear-ish head instead of that classic pointy nose that sea lions like to balance beach balls on.
The Steller sea lion is a social animal and will frequently gather in big groups on beaches and rocks near where food is plentiful, however, despite being social animals they usually travel in smaller groups of 1 to 10. Stellers aren’t migratory, however they do cover a lot of ground. Following the food, large groups can come and go as the seasons change.
When mating season rolls around in late Spring and Summer, the rookeries come to life. Established long ago by some ancient league of sea lions, rookeries are permanent haul outs where Stellers go to breed and raise their pups. Males usually arrive first and compete for control of territory and thus breeding rights with any female who hauls out onto their part of the beach. Younger males usually can’t compete and so until the age of eight or nine most young guys are left out of the ritual. Pups are usually born in May through July and the mothers will stay with them for around a week before they have to go back to the sea for a short foraging trip.
Geographic and Population Changes
There are two subspecies of Steller sea lion: The Western Steller sea lion and the Loughlin’s Steller sea lion. The Loughlin’s Steller sea lion has experienced steady growth in population since 1973 and is thriving along the coast of the western United States and Canada. The Western Steller is another story entirely. That subspecies has been in steep decline since 1960’s and reached its lowest population in the year 2000. The number of Western Stellers declined by 69% from 1977 to 2007 and only recently has been experiencing mixed population growth. The western populations are still firmly considered endangered.
"Recovery Plan for the Steller Sea Lion." (2008): n. pag. National Marine Fisheries Service National Oceanic and Atmospheric Administration, Mar. 2008. Web. 27 Nov. 2016.
Listing Date and Type of Listing
Though the western subspecies has been in decline, the success and steady growth of the Laughlin’s Steller sea lion made the species only considered at first “Vulnerable” when first classified in 1994. This was later revised to “Endangered” in 1996 and this classification remains for the Western Steller, however the Laughlin’s Steller has been removed from the list entirely.
Cause of listing and Main threats
to its
continued existence
But just what is causing this decline? Scientists aren’t really sure. Overfishing reducing food supply, hunting by Alaska Natives, disease, all definitely contributing factors but not sufficient explanation for why some populations of Western Steller continue to dwindle in size while the Loughlin has never been better. A lot of research remains to be done on the effects of fisheries, killer whale predation. All are considered potentially significant threats, but too little is known to say for sure.
Description of Recovery Plan
The currents recovery plan in place involves undertaking a survey to understand the status of the Western Steller and see exactly what is going on in terms of population and mortality rates, better understanding and assessment of the threats to the sea lions, and what it will take to get this endangered species off that dreaded list.
What can you do?
The currents recovery plan in place involves undertaking a survey to understand the status of the Western Steller and see exactly what is going on in terms of population and mortality rates, better understanding and assessment of the threats to the sea lions, and what it will take to get this endangered species off that dreaded list.
What can you do?
All of this might seem far off might even make you feel a little helpless, so I want to point you in the depiction of some resources that can help you help the Steller sea lions. First is the Marine Mammal Center, these guys actually go out and rescue injured or sick baby seals and a donation or even just going to one of their locations for a tour can help them do their job and save out seals. Next up is the Seafood Watch app which will tell you if that tasty fillet o’ fish is contributing to the overfishing that is hurting everyone’s favorite giant see lion.
"Recovery Plan for the Steller Sea Lion." (2008): n. pag. National Marine Fisheries Service National Oceanic and Atmospheric Administration, Mar. 2008. Web. 27 Nov. 2016.
"The Marine Mammal Center." The Marine Mammal Center. N.p., n.d. Web. 27 Nov. 2016.
"Steller Sea Lions." National Geographic. National Geographic, n.d. Web. 28 Nov. 2016.
"Eumetopias Jubatus." ICUN. ICUN Red List of Threatened Species, n.d. Web. 27 Nov. 2016.
Fernando Astiazaran, BIO227Fall2016
ReplyDeleteHey, mentee. Awesome blog! Great info. Even though these might not be prevalent in our area, I definitely feel that this applies to us here at Cal Poly since I've seen some sea lions wash up on the shore that need some help. Thanks for sharing, bro.