A night at the beach

Fred,
I'm a late-comer to this fascinating thread. You managed to capture some lovely images of this magic looking effect.
The thing that I'm most surprised about is that it occurs at all in the North Sea!
I've seen movies and images of it in tropical and sub-tropical latitudes including The Maldives, The Caribbean, Australia and various South East Asian and Pacific island nations, so I'd naturally assumed it needs quite warm ocean temperatures to live in. So either Global Warming is really cranking up off the coast of Holland, or the bio-luminescent algae have adapted to cooler temperatures in that part of the world.
As for Neil's story, I can just imaging the consternation of locals seeing the eerie glow not far from a nuclear reactor. I'd think as well that the discharge from the cooling tanks would warm up the ocean in that location thereby making it a suitable site.
Perhaps there's also some warm water discharge near that part of your coast from a power station?
TFS.

@Joe- you are addressing Fred and I take the liberty to answer i.e. to vent my side of the story?
the answer is NO. and yes, it does occur in the North sea, as it always has.
(in my case 'always' means for the last 60 years -eh barely, i.e. since last week ;-)- ). but -as mentioned before- only under xtreme weather conditions, meaning HEAT. also in this country heat waves occur occasionally, they have been recorded since 1901.
but true, in general temperatures have risen over the last decade(s).   
while we live in the southern part of Holland and Fred lives up north, chances are that this phenomena has occured here more frequently, since this is the sunniest part of the country (it's official! ;-)) and temperatures are usually slightly higher. but Fred can tell us about simular happenings up north?

we do have a nuclear power plant -since 1973- and did (! ) have some serious industry nearby, german (!) chemical Hoechst and french (!) alu factory Pechiney, that started their build in 1968-1969. as a kid, living directly by the seaside, I clearly noticed the FX after they became operational. 'wildlife' seemed to have vanished from 'our' beach. gone were the sea anemones, the star fish, the baby crabs, ......... (at that time. at least, I couldn't find them anymore, all of a sudden. but numbers seem to have decreased big time).
but the sea has always 'lighted', for as long as I can remember.

warmth is what makes the numbers of algae explode, and therefore they in particular occur in shallower waters.
seen them in the Atlantic ocean though, by no means shallow, but we must have been in the 'warm' gulf stream then, since we came from Ireland. and again, it was H☼T.

THANKS for your THANKS, Joe!
PS? I said that temperatures are usually slightly higher here, but meant in comparison with parts of the country with a sea climate of course.
a friend, who lives in the east, land climate, once said that the difference between 'us' is always 5 degrees Celsius. 5 more in summer there and 5 less in winter.
how warm it becomes, always depends on the sea. even in (INLAND! ) Middelburg, about 10 kilometers away from sea, trees are in bloom, in early spring, long before the flowering trees of Vlissingen-at-sea.
but in summer, the more the seawater is warming up, the more all changes around. and then we have the wind at sea, cooling down the air. and therefore sea sparkle will usually only spread it's magic when the wind is absent or calm.
these algae do have a lot of conditions before they are willing to make their appearance.

owenn01 wrote: "Nowadays you just search the web and find it's just innocent algue." - Fred; this was so long ago that it was before the Web!! Best regards, Neil.

That's exactly what I assumed

Apologies, missed that ..

Up north, even to the islands (Texel etc.), the sparkle can bee seen now and then. There are no power plants over there, but it's only seen at warm and calm nights, in the undeep parts of the see.