I'm not really sure how I got onto the shark theme with some older classes (6th grade, middle school), but I think it started when I saw this news item:
http://www.smh.com.au/travel/travel-news/shark-follows-kayaker-as-jaws-fears-hit-us-20120710-21svg.html
Then, a class had to learn vocab about kayaking, so I searched and found this:
http://www.thomaspeschak.com/kayak-great-white-sharks-/
And then I happened upon this video, which I tied into a lesson on "Success and Happiness", in this case an example of the negative:
http://www.youtube.com/watch?v=ZcuYjDR2tSg
There's so much more out there . . .