These blades of macrocystis kelp were floating near the surface just west of Bluebanks, on the south side of Santa Cruz within sight of the radar towers above Yellowbanks. The water's surface divides sunlight onto the blades. I'm not sure of the role of the jagged edges of the blades, but evolution must have decided that this is the best shape for a kelp leaf! A field of macrocystis can absorb nearly as much carbon dioxide as a field of alfalfa in Puerto Rico. Perhaps that alfalfa field holds the record; it seems to be the standard. Stop global warming, go kelp!