Chilean seaweed called cochayuyo. Good to eat, it's collected and sold in the markets and grocery stores.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/56796376@N00">McKay Savage</a> from London, UK
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/mckaysavage/6968021539/">Chile - Pichilemu 21 - cochayuyo seaweed dried for sale</a>