No. 105: May-Jun 1996
January 25, 1995. Indian Ocean. Aboard the s.s. Lima, Juaymah to Rotterdam.
Third officer, S.M.F. Masud, and others of the ship's company observed another instance of one of the sea's great unex plained phenomena.
"At 1800 UTC on a clear moonless night while 150 n.mile east of the Somalian coast a whitish glow was observed on the horizon and, after 15 minutes of steaming, the ship was completely surrounded by a sea of milky-white colour with a fairly uniform luminescence. The bioluminescence appeared to cover the entire sea area, from horizon to horizon but above the surface, and it appeared as though the ship was sailing over a field of snow or gliding over the clouds.
"There was no damping effect on capillary waves or reduction of visibility at all and there was no mist at deck level although at a distance it seemed as if there was either lowlying mist or the upwelling of the luminescence itself. The bow waves and the wake appeared blackish in colour and thick black patches of oil were passing by. Later, the Aldis lamp revealed that the 'oil patches' were actually light-green kelp, amazingly black against the white water."
A water sample contained many singlecelled microorganisms, but they displayed no luminescence. After 6 hours, the luminescence disappeared.
Commenting on this report, P.J. Herring, of the Southhampton Oceanography Centre, said that milky seas are most often associated with the Southwest Monsoon. This one was was rare in that the Northeast Monsoon prevailed. His final remark was: "The mystery of its cause remains unsolved."
(Briand, J.P.; "Bioluminescence," Marine Observer, 66:12, 1996)
Reference. The various types of anomalous bioluminescence are cataloged in GLW in our Lightning, Auroras. To order, visit: here.