Nicktoons: Island of the Blue Dolphins is the sequel to Nicktoons Unite!, Nicktoons: Battle for Volcano Island, Nicktoons: Attack of the Toybots and Nicktoons: Globs of Doom. Characters from SpongeBob SquarePants, Danny Phantom, The Adventures of Jimmy Neutron: Boy Genius, Tak and the Power of Juju and The Fairly OddParents appear.
While whale watching on a magic ship, SpongeBob, Patrick, Danny, Sam, Timmy (with Cosmo, Wanda and Baby Poof), Jimmy and Tak discover that there are some blue enchanted dolphins are being captured by the fish hunters and also their enemies, the Evil Syndicate. They realize that the Evil Syndicate has join forces with those evil fishermen. So, it's up to the heroes to stop them and rescue the dolphins from being captured.