NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Glowing Sea Surface
From: Trevor Kenchington
Date: 2003 Nov 11, 00:22 -0400
From: Trevor Kenchington
Date: 2003 Nov 11, 00:22 -0400
Jared, You wrote: > But in answer to your direct question as to whether sea water itself > emits light...The general answer we learned in oceanography is "no". > Seawater does not glow at all, by itself. Thank you. That was the answer I was looking for. (If my undergrad oceanography courses mentioned this at all, nobody stressed it enough for the detail to have remained in my memory over the past quarter century.) I guess that means that what I saw during the hurricane was almost certainly bioluminescence. It is widespread, of course, and I too have played with "living sparks" during night dives, seen them over the side of boats, watched bow waves and wakes glow and all the rest. I can remember one night, in the Tasman Sea I think, when we stopped for an oceanographic station and saw a large glowing blob, beyond the reach of the deck lights. On closer inspection, it proved to be a mass of colonial gelatinous plankton -- salps I think, though my memory of that detail may be faulty. What was different in the hurricane (though close to George's observations in his cooling-water inlet pipe) was that the glow in the water was not visible as isolated sparks but rather as if it was continuous. If it was biological, then there must have been a very large number of very small organisms -- which implies that they were blooming in Musquodoboit Harbour at the end of September. As I noted in my last, that seems a bit improbable, though it clearly isn't impossible. Just perhaps, it was neither the water itself nor anything living but rather something non-living suspended or dissolved in the water (other than the sodium chloride). I don't know what might glow but I also don't know what flows into the Harbour, down the river, off the road, out of faulty septic systems or even with leaves blowing off the trees. Harbour water certainly isn't pure seawater and I'll not rule out a physico-chemical explanation. As of this afternoon, I did manage to add another species to the Harbour's fauna: Got into trouble trying to work off a lee shore in water too shallow to get the centreplate down and had to resort to kedging. On one particularly energetic attempt to throw the anchor to windward, I lost my balance and followed it over the side! The water was only waist deep but it was not a dignified mode of navigation. Trevor Kenchington -- Trevor J. Kenchington PhD Gadus@iStar.ca Gadus Associates, Office(902) 889-9250 R.R.#1, Musquodoboit Harbour, Fax (902) 889-9251 Nova Scotia B0J 2L0, CANADA Home (902) 889-3555 Science Serving the Fisheries http://home.istar.ca/~gadus