My son and I recently completed a 155 page unit study on Dolphins.
I thought I'd share the link here to the unit study.
It had about 42 pages of printable worksheets to accompany the study.Approx. Grade 3-5 level.
We also visited the http://www.scholastic.com/winterstail/ website to watch the little video they have there about "Winter" a bottlenose dolphin who at age 3 months was caught in a crab trab and lost her tail...she is now 4 years old and resides at the Clearwater, FL. Marine Aquarium.A very inspiring little video about success despite the odds.
I think you and your child/children will enjoy both the unit study and the little video.
Have fun and Happy Homeschooling!
~The Garden Goose~