Seaweed and Beer?

How can seaweed and beer coexist in a bottle? I've been staring at this bottle of Kelpie Seaweed Ale from Scotland for a while and finally decided to try it.

The idea of seaweed in my beer did sound strange to me, but then I read the bottle. "Prior to the 1850s...[in coastal areas of Scotland] ales were made from local malted barley which was grown on fields fertilised with seaweed." This beer doesn't follow the tradition of fertilizing the barley, but rather mixes the seaweed with the malted and roasted barley. Kelpie also describes itself as a "rich chocolate ale."

Kelpie is a dark beer that tastes more like a porter than an ale, and there's no trace of seaweed flavor that I detected. I didn't notice what they call "an aroma of fresh seabreeze," but it could be that I didn't smell anything because of the frigid temperatures. This was a very nice beer for a winter night, but I don't think I'll be willing to spend $3 for a bottle too often.