I came back from Maui last week. Bought 1/4lbs of fresh ogo seaweed (Gracilaria pacifica) from Safeway and declared it at Canada customs on the way back. They checked with the guy from Agriculture and then told me there was no restriction on it and let me through. Most of the algae was for someone else and I kept 5% of it for my sump. It is still alive.
Here's an interesting link in case you are collecting it instead of buying it.
http://www.iyor-hawaii.org/wp-conten...klet_final.pdf
"Limu (ogo): bag limit of one pound per day for personal consumption; prohibited to take with the holdfast (the part attaching to a rock or other surface), or to take when covered with reproductive nodes or bumps."
I'm not saying go ahead and do it. I'm just reporting what happened to me at customs with my purchased seaweed.