Seaweed for my herbs?
Dried kelp, sold in stores as kelp meal is a good source of nutrients for plants. It's not really fertilizer, more like vitamins. I expect any seaweed would be good in that respect. However, I wouldn't just toss some wet seaweed onto my garden. Rinse it a bit to remove excess salt (probably not a big deal unless you plan to add a lot of seaweed to your garden year after year), and chop it up a bit and dry it for a few days so it doesn't form a solid mat over the soil. Maybe mix it with some other mulch material or compost?