red algae (gelidium sesquipedale ) on the beach

seaweed red algae reddish alga ocle gelidium sesquipedale agar washed gelidiaceae cantabrian sea atlantic ocean rhodophyta beach sand sandy plant botany spain northern cantabria great britain france portugal morocco antioxidant properties phycology algology mesoproterozoic ecology nature natural environment sustainability concept beautiful coastal marine litoral vivid color pink magenta pigment shore detail