Tony,
While you are there, look for red mangrove seedlings. (long pods)
The name they may go by is rhizophora mangle.
If you find them, wrap them in damp newspaper, put them in a plastic bag and mail them to yourself regular US mail.
You should be able to easily find them and cheap too. .50 each
While you'll never realize the filtration benifit, they do grow well (not fast) with little care and look cool.
I bet you can mail 30 or so for less than 10 bucks.
Nice pic, thanks for thinking of us poor slobs back here