Alternative to seaweed?

I enjoyed the film "Groundhog Day" but didn't realise that it was based on fact. There is indeed a groundhog day (February 2nd) when traditionally the groundhog - a North American rodent distantly related to the squirrel - comes out of its burrow where it has been hibernating. If it stays out, this is seen as a sign that Spring is on its way, whereas if it returns to its burrow, that indicates that we still have some cold weather to come. This year it stayed out apparently, but I'm not sure if that has any relevance to our weather over here, although it was certainly right last year, when it went back in, and you may remember February was really cold. So here's hoping!