Ulvaria obscura is an intertidal and subtidal benthic marine algae found in temperate and Arctic ocean waters around the world.

[1][2] Ulvaria obscura is a common marine algae, typically identified in algal blooms referred to as "Green Tides".

[3][4] The species is distinct in its ability to produce the neurotransmitter dopamine as a herbivore defense mechanism.

[5][6] The species has a wide tolerance to various growth conditions, surviving temperatures between 5-29 °C, salinities from freshwater to complete saturation, and grows well under various light intensities.

[11] Thalli turn from green to dark brown upon desiccation due to the oxidation of dopamine within the tissues.