Diving During Red Tide

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Otter

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Are there any health issues posed by diving during Red Tide?

TIA

Otter
 
Scuba diving itself is not likely to put the diver into the kind of contact that can be problematic.

However, when the toxin produced by the red tide becomes aerosolized by such actions as boat propellers/exhaust churning the water and the wind blowing across masses of the algae that have washed ashore & dried, it can cause irritation of the eyes, nose & throat, and tingling of the lips & tongue. A choking cough is common, and the clinical picture may appear much like that seen with upper respiratory infections. These signs & symptoms typically pass within a day after exposure ceases. Of course, the development of these signs & symptoms could interfere with enjoyable & safe scuba.

Also, one does need to be careful of eating filter feeders such as local bivalves during a red tide bloom.

This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual, and should not be construed as such. If you have concerns, consult with your physician.

Best regards.

DocVikingo
 
DocVikingo,
Thanks for your response. So (in general), possible ear infections from Red Tide are unlikely and a 'old wives tales'?

Otter
 
Hello Otter:

Red tide is caused by Pfiesteria piscicida - which literally means "fish killer". It's effects on humans are no less dramatic - as described in Steven Barsky's book, "Diving in High Risk Environments", 8-10.

"While Pfiesteria kills fish and other marine creatures, in humans exposure causes skin lesions, eye burning, shortness of breath, loss of memory, loss of reasoning ability, and symptoms that resemble dementia. "

It is considered a Class III biohazard, which is one step below such deadly organisms as Ebola. As explained by DocV, it poses a hazard when it becomes aerosolized and is inhaled via your regulator or riding in an open boat in choppy water.

Working divers in North Carolina were exposed to Pfiesteria while diving in the Neuse River in 1995. They suffered from open sores, vertigo, disorientation and mood changes that were persistent for months.

One should think twice before diving in waters containing this dinoflagellate.

References to above in Steve Barsky's book - or I can provide them to you if need be.
 
To the best of my knowledge, the term "red tide" refers to an algae bloom caused by varying dynoflagellates dependent upon location. Organisms which cause theses blooms around the United States are: Gonyaulax tamarenis, along the Atlantic Northeast coast, ranging from the Canadian Maritimes to Southern New England; Gonyaulax catenella, on the Pacific West Coast from California to Alaska; and Karenia brevis (formerly called Gymnodinium breve/Ptychdiscus breve), in the Gulf of Mexico along the West Florida coast.

It is my understanding that the episodic proliferations of the dynoflagellate Pfiesteria piscicida (AKA "fish killer") neither cause a visible red tide---> http://www.acnatsci.org/research/anserc/pfiesteria.html, nor do the scientific & medical communities typically refer to P. piscicida as a cause of "red tide." For example, this CDC site appears to draw a distinction---> http://www.cdc.gov/nceh/hsb/algal.htm And, P. piscicida blooms are most likely to occur in estuarine & very near coastal waters rather than farther offshore.

The remarks that I made in initial post refer to red tides caused by the most commonly involved algal organism, Karenia brevis (formerly called Gymnodinium breve/Ptychdiscus breve), as well as by G. tamarenis & catenella.

Of course, if you are diving waters undergoing a known or suspected proliferation of P. piscicida, you certainly will want to pay close heed to Scubadoc's cautions.

My apologies if this has gotten complicated, but the distinction is necessary for a proper answer to Otter's general inquiry.

To answer your last specific question, Otter, I am not aware of any mechanism by which the organisms involved in conventionally termed "red tides" would dispose to ear infections. My other cautions, however, continue to apply.

This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual, and should not be construed as such. If you have concerns, consult with your physician.

Best regards.

DocVikingo
 
Of course, DocVikingo is correct in pointing out that Pfiesteria piscicida does not cause what is known as 'red tide', but is a more deadly relative of those organisms. (dinoflagellates)

Other relatives of the organism are now suspected in the fish kills in Mobile Bay, South Carolina and in Florida.

I appreciate the correction!

scubadoc
 
The P. piscicida info remains most useful. As you well know, it was a serious worry in my greater Chesapeake Bay neck of the woods a while back. Some of our watermen were badly affected.

Best regards.

DocVikingo
 
Wow. As usual, you guys have covered the subject very thoroughly. My original question was in response to our local newspaper forecase that there was a Red Tide at Santa Catalina Island, CA today. As it turned out, there was no such Red Tide (I believe about 1/10 of our newspaper's SCUBA forecast) and diving was quite good -- it was nice to dive for fun vs. instruction -- with the highlight being 1" away from a Bat Ray with a 4 1/2" wingspan.

Sounds like for all the obvious reasons (viz, etc..) and possible medical issues, avoiding Red Tide remains a prudent measure.

Thanks again

Otter
 
Otter reports:

My original question was in response to our local newspaper forecast that there was a Red Tide at Santa Catalina Island, CA today. As it turned out, there was no such Red Tide (I believe about 1/10 of our newspaper's SCUBA forecast) and diving was quite good -- it was nice to dive for fun vs. instruction -- with the highlight being 1" away from a Bat Ray with a 4 1/2" wingspan.

Hi Otter, I was also at Catalina on Sunday 5/25 (that's when you went?), and I think red tide depended on exactly where you were. Of three dive spots we visited, all had material of various kinds in the water (lots of jellies), but only one had what I would call red tide -- Eel Cove just northwest of Two Harbors -- and the red tide was only in the last few yards right up against the shore. It drew in enormous schools of sardines and mackerels feeding on it -- quite cool to swim through them. We also heard reports of red tide at Santa Barbara Island the previous day, and there's been a lot of it along mainland beaches this week.
 

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