These sea lettuces where seen on the beach in Oahu. They where soft and I guess edible too!
Location found: This Sea Lettuce was found washed up on Canoe Beach, Nahant, MA.
Habitat types: Its range extends from the Arctic to Long Island, and it is found in tide pools, intertidally, and subtidally up to 24m.
Physical description: Chlorophyta. It looks like a large, flat, or rippled sheet of green resembling lettuce. It grows up to 50cm long, and has a rounded, oval, or elongated blade that is often undulated at the edges.
Fun fact: It's blades are just two cells thick.
Villalard-Bohnsack, Martine. Illustrated Key to the Seaweeds of New England. Kingston: The Rhode Island Natural History Survey, 2003.
Martinez, Andrew. Marine Life of the North Atlantic: Canada to Cape May. New York: Aqua Quest Publications, Inc. 1994.
Scientific Name: Ulva Lactuca
Common Name: sea lettuce
Location Found: subtidal 5-15 feet, Pumphouse Beach, Nahant MA
Habitat Types: subtidal, attached to rocks, shell, wood; common year round; varying salinities (open water to estuaries) (Villalard-Bohnsack, M. (2003) Illustrated Key to the Seaweeds of New England, Kingston, RI; The Rhode Island Natural History Survey)
Physical Description: large oval rounded blade, 2 cells thick, green (Villalard-Bohnsack, M. (2003) Illustrated Key to the Seaweeds of New England, Kingston, RI; The Rhode Island Natural History Survey)
Fun Fact: can bloom so big that it blocks sunlight and kills vegetation below http://www.edc.uri.edu/restoration/html/gallery/plants/sea.htm
I was attracted by a blue billet which I wanted to move off the riprap.