Sionnachan-mara

Milky seas effect

Milky seas is a condition on the open ocean where large areas of seawater are filled with bioluminescent bacteria, causing the ocean to glow an eerie blue at night.

While monochromatic photos make this effect appear white, Monterey Bay Aquarium Research Institute scientist Steve Haddock (one of the authors on the milky seas study) has commented, "the light produced by the bacteria is actually blue, not white. It is white in the graphic because of the monochromatic sensor we used, and it can appear white to the eye because the rods in our eye (used for night vision) don't discriminate color." [1]

The condition has been the stuff of mariner's tales for centuries, but until recently it has not been scientifically documented.

In 2005, Steven D. Miller of the Naval Research Laboratory in Monterey, Calif. Began research into the phenomenon. His team found only one well-documented occurrence, off the Somali coast on Jan. 25, 1995. Satellite images collected at the same time and location by the U.S. Defense Meteorological Satellite Program also showed a milky white area aprox. 15,400-km2 (roughly the size of the US state of Connecticut), lending truth to the stories.

The luminescent field was observed to glow over 3 consecutive nights.

It should be noted that no in-field observation of the phenomenon has been made, so the assertion of bioluminescence is conjectural.

References and further reading:

• Miller, S.D., et al. In press. Detection of a bioluminescent milky sea from space. Proceedings of the National Academy of Sciences.
• abstract
• Booth, C. K. & Nealson, K. H. (1975) Biophys. J. 15, 56 (abstr.).