what can a 15 year oldin southern california do for whales?
Pick up trash off off the beach, raise awareness, make sure you cut the rings that hold soda cans together.
You could raise money for organizations.
Only eat sustainable seafood, information available at http://apps.edf.org/page.cfm?tagID=1540 You could also create or find pamphlets to educate people. (If you don't want to hand them out, you could just make a pile somewhere so people who are interested can pick one up if they want to)
Marine mammal rescue is a rescue facility in el segundo. You can contact them, website http://whalerescueteam.org , and ask if there is anything you can do. You probably won't be able to work with the animals but you may be able to do other things like clean around the facility or help build something.
If anyone has any other ideas please send them to my ask so I can publish them, I would love to hear about it!