I looked into this a while ago when I wanted to setup a temperate (chilling would have been to expensive). Technically it is legal to collect and possible more importantly most Marine macro algae although not kelp. That was 2013 anyways and I'm sure theirs not much of a difference between last year and this year. Are you using it in a tropical reef tank or a temperate tank? I would love to be able to put some in my refugium.