Stinging Sensation from Plankton ?

[Phil_C]

Has anyone got any thoughts on this ? - I was diving in the eastern meditteranean on a dive to 40 metres yesterday and below the first 2-3 metres the visibility was very poor with what I can only descibe as hanging white filaments, 3 or 4 cm long, of some sort of plankton.

Not just in one spot, but all the way to the bottom and across the whole water column.

It looked as if there had been some sort of spawning/release of planktonic spores. I have seen these on a couple of dives over the last week or so.

The dive site was about 2-3 miles from the shore so it was unlikely to be any form of pollution from the land.

Other than visibility I didn't notice anything unusual during descent or the dive, but whilst waiting at the safety stop I noticed that all my exposed skin (I was diving a shorty) felt like it was 'stinging' as if I had small droplets of something corrosive being splashed over me, or like I was rubbing against stinging nettles. I first thought of some sort of skin DCI, but after surfacing others reported the same thing so I have ruled that out. I have dived through similar planktonic blooms before but never had the stinging sensation - I shall wear a full wetsuit not a shorty tonight - has anyone come across this before ? - P

 

[farsidefan1]

Sorry I have never been diving in the Med but I have been stung by floating hydrids drifting in the current. Floating stinging jellies are pretty common in other parts of the world. Most often all you have to deal with is skin irritation which usually doesn't last too long.
It is almost enough to make me wear a full wetsuit. Almost, I prefer my wet suit shirt. But after getting nailed twice on one trip I started wearing a rash guard- full length.

 

[drbill]

The hanging white filaments MAY have been "sea snot" which is frequently found in the Med during warm water periods. It is formed during warm water/low nutrient episodes which cause phytoplankton and seaweeds to release carbon in the form of mucilage. See my column on its presence here in California waters this summer: Sea Snot. The mucilage is stringy and white and traps various things which could include the stinging cells of various cnidarians. Of course it is also possible you encountered the remnants of planktonic cnidarians (jellyfish and their relatives) and the stinging cells (nematocysts) were still active.

 

[supergaijin]

Diving in the Maldives we get a bit of plankton and in certain areas where it pools there can be a massive concentration. Luckily we get a few mantas to clean it up or a whale shark.

But diving in these areas, I often feel small stinging sensations especially around the sensitive areas like wrists and ears. Many species of zooplankton are herbivores, feeding on the phytoplankton at the surface. But there are still tons of 'meat-eater' planktonic species which prey on the herbivores and they use stinging cells for the most part.

Then a manta comes along and swallows the lot.

 

[koozemani]

The hanging white filaments MAY have been "sea snot" which is frequently found in the Med during warm water periods. It is formed during warm water/low nutrient episodes which cause phytoplankton and seaweeds to release carbon in the form of mucilage. See my column on its presence here in California waters this summer: Sea Snot. The mucilage is stringy and white and traps various things which could include the stinging cells of various cnidarians. Of course it is also possible you encountered the remnants of planktonic cnidarians (jellyfish and their relatives) and the stinging cells (nematocysts) were still active.

I was going to suggest the same thing only not nearly as eloquently.

 

[Phil_C]

The hanging white filaments MAY have been "sea snot" which is frequently found in the Med during warm water periods. It is formed during warm water/low nutrient episodes which cause phytoplankton and seaweeds to release carbon in the form of mucilage. See my column on its presence here in California waters this summer: Sea Snot. The mucilage is stringy and white and traps various things which could include the stinging cells of various cnidarians. Of course it is also possible you encountered the remnants of planktonic cnidarians (jellyfish and their relatives) and the stinging cells (nematocysts) were still active.

Yep - that about describes what it looked like, but I was being polite. That was all I could see in the water, and no jelly fish or other organisms, but I had not considered that something may have even trapped in the "snot".

The snot first appeared around ten days ago on the night of a full moon - two consecutive night dives - first day clear, second snot everywhere. I didn't have any stinging sensations on any of the other dives and was not linking it to the snot until you mentioned it.

i suspect you have the answer there - thanks P

 

[wedivebc]

I spent a 40 minute deco stop in Thailand being stung by those things. I wore a full length wetsuit for the rest of the trip.

 

[Phil_C]

Cheers - full wetsuit now out of summer retirement !

P

 

[shoredivr]

This is reinforcing why on the few times I dive the tropics, I wear a full length 3ml.

 

[Frosty]

This is reinforcing why on the few times I dive the tropics, I wear a full length 3ml.

Yup I wear a 3.0mm steamer no matter what