Ulvaria obscura explained

Ulvaria obscura is an intertidal and subtidal benthic marine algae found in temperate and Arctic ocean waters around the world.^{[1] [2]}

Ecology

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.^[7] The species growth rate responds to increased dissolved inorganic nitrogen availability, making the species a possible indicator of anthropogenic pollution leading to eutrophication.^{[8] [9] [10]}

Identification

The thalli of Ulvaria obscura are bladelike, usually less than 5 cm tall and 8 cm thick, consisting of a single cell layer, and typically have between 2 and 6 pyrenoids per cell.^[11] Thalli turn from green to dark brown upon desiccation due to the oxidation of dopamine within the tissues.

Notes and References

1. Web site: Lindeberg. Mandy. Lindstrom. Sandra. Ulvaria obscura var. blyttii. Seaweed of Alaska. Cook Inlet Regional Citizens Advisory Council. 21 June 2014.
2. Latala. Adam. Photosynthesis and respiration of some marine benthic algae from Spitsbergen. Polar Research. 1990. 8. 2. 303–307. 10.1111/j.1751-8369.1990.tb00394.x.
3. Lee. Dejah J.. Nelson. Timothy A.. Are "Green Tides" harmful algal blooms? Toxic properties of water-soluble extracts from two bloom-forming macroalgae, Ulva Fenestrata and Ulvaria Obscura (Ulvophyceae). Journal of Phycology. 2003. 39. 5. 874–879. 10.1046/j.1529-8817.2003.02157.x. 42744177 . free.
4. Raven. J.A.. Fletcher. R.L.. Taylor. R.. Preliminary Studies on the Growth of Selected 'Green Tide' Algae in Laboratory Culture: Effects of Irradiance, Temperature, Salinity and Nutrients on Growth Rate. Botanica Marina. 2001. 44. 4. 327–336. 10.1515/BOT.2001.042.
5. Cancilla. DA.. Van Alstyne. KL.. Vyvyan. JR.. Nelson. AV.. Dopamine functions as an antiherbivore defense in the temperate green alga Ulvaria obscura. Oecologia. 2006. 148. 2. 304–311. 10.1007/s00442-006-0378-3. 16489461.
6. Gifford. Sue-Ann. Winans. Amanda K.. Anderson. Katie J.. Van Alstyne. Kathryn L.. Dopamine release by the green alga Ulvaria obscura after simulated immersion by incoming tides. Marine Biology. 2011. 158. 9. 2087–2094. 10.1007/s00227-011-1716-5 .
7. Mathieson. A.C.. Guo. Z.. Physiological Ecology of Four Ulvoid Green Algae. Botanica Marina. 1992. 35. 6. 523–534. 10.1515/botm.1992.35.6.523.
8. Tjoelker. M.. Nelson. A.V.. Tjoelker. M.. Seasonal and Spatial Patterns of "Green Tides" (Ulvoid Algal Blooms) and Related Water Quality Parameters in the Coastal Waters of Washington State, USA. Botanica Marina. 2003. 46. 3. 263–275. 10.1515/BOT.2003.024.
9. Nelson. T. A.. Van Alstyne. K. L.. Ribarich. H.. The Effects of Nitrogen Regime on Growth, [CHN], [DMSP], [Chlorophyll], [Protein] and Nitrogen Uptake Rate in Ulvaria Obscura and Ulva Fenestrata. Journal of Phycology. 2003. 38. 1. 29. 10.1046/j.1529-8817.38.s1.83.x.
10. Nelson. TA. Haberlin. K.. Fredrickson. K.. Simunds. DJ. Buckingham. L. Van Alstyne. KL. Ecological and physiological controls of species composition in green macroalgal blooms. Ecology. 2008. 89. 5. 1287–1298. 10.1890/07-0494.1. 18543622.
11. Book: Gabrielson. Paul. Widdowson. Thomas. Sandra. Lindstrom. Hawkes. Micheal. Scagel. Robert. Keys to Benthic Marine Algae and Seagrasses of British Columbia, Southeast Alaska, Washington and Oregon. 2000. University of British Columbia. Vancouver, British Columbia. 0888654669. 80 & 97.