green Algae

common sea lettuce

Scientific name: Ulva lactuca

Family: Ulvaceae

Phylum: Chlorophyta

Typical size: Up to 30 centimeters wide

Depth range: Intertidal to 25 meters

Description: It is light green in color and has rough edges. The lettuce is very thin and often has several holes.

Habitat and behavior: Sea Lettuce can be found attached to rocks, but it is not uncommon to find it free floating. Sea Lettuce is able to withstand nutrient loading that other species cannot which allows it to thrive in areas of moderate nutrient pollution.

maiden hair sea lettuce

Scientific name: Ulva intestinalis

Family: Ulvaceae

Phylum: Chlorophyta

Typical size: 10 to 30 centimeters in length and 6 to 18 millimeters in diameter.

Depth range: 0 to 7 meters

Description: The thin algae is light or dark green in color. The shape of individual strands is cylindrical but the lettuce itself grows in colonies that look like hair.

Habitat and behavior: Maiden Hair Sea Lettuce is found world-wide. The seaweed prefers to grow in/ on sand, rocks, mud, and rock pools but if it becomes detached from its base it will rise to the surface and continue to grow.