I'm planning a month-long diving trip to Tahiti for my honeymoon and there is 1 thing that is worrying me....
Tahiti is known for its abundance of sharks. So, will I be in danger if I dive while on my period? Since we'll be there for a full month, there seems to be no way of avoiding female anatomy.
I've just gone off the pill for other personal reasons.
Anyone out there have any advice?
Walter
February 6th, 2003, 08:16 PM
If you do a search, you'll find this topic has been covered several times. Bottom line - you're at no greater risk from sharks while you are having your period.
GirlieDiver
February 6th, 2003, 09:16 PM
Looks like you're new to the board too, welcome! And although I haven't read the other threads about this topic, I can say that when you are in the water, I know that menstruating slows down, or maybe even stops. At least that's what I remember from Sex Ed, in High School.
Have fun on your honeymoon! Lucky you, a month long!
ratherbediving
February 7th, 2003, 02:40 PM
For the replies. I tried a couple of searches but only saw stuff about decompression illness risks. I'll try again.
Feeling relieved.
Thanks.:)
Walter
February 7th, 2003, 02:41 PM
I'll make a search tonight and post some links.
jbd
February 7th, 2003, 07:21 PM
to the search feature and type in menstruation and sharks.
You should get a couple threads to read.
As Walter mentioned in his first response its not a problem.
Actually, the menstrual blood does not attract sharks because it is kind of a dead blood, i.e. the shark can feel it's not someone bleeding from a wound.
Relax ;) and enjoy :)
jbd
February 9th, 2003, 09:15 AM
be weird or anything but I wonder if that has been tested?
Why would chumming work to attract sharks? It would seem to me that the blood etc used for chumming would be "dead".
I'm certainly no shark expert but I wonder if sharks are actually drawn to blood as we have been led to believe or is there something different that actually draws them to chum or injured animals.
Ladydiver
February 9th, 2003, 05:43 PM
You can find a very good article by Dr. Jacalyn McComb at Women in Scuba (http://www.womeninscuba.com/jacalyn/debated.html) which addresses a variety of women's issues in diving, including diving during menses.
Check it out.
DocVikingo
February 9th, 2003, 09:21 PM
.... to be entirely cursory & not compelling as written.
This is not to say that she is incorrect, only that she does not prove the case & that a more scholarly treatment appears warranted.
The scientific truth is that the smell & taste receptors of many carnivorous sharks routinely permit the recognition of one part of blood in 100 million parts of water. With some species under some conditions, e.g., food deprivation, this sensitivity can be very much higher. Those expert in the central nervous system of the shark have suggested that two-thirds or more of its brain may be devoted to smell. I, for one, believe that there is a sound evolutionary reason for this.
Unfortunately, no studies of which I am aware have specifically tested for menstrual blood. However, the extensive research findings on fresh human, animal & fish blood, other human bodily fluids, e.g., urine, and a wide variety of water-borne organic chemicals found in human fluids (e.g., amino acids, amines & small fatty acids) indicate to me that the carnivorous shark's exquisite sensory capabilities can in fact detect menstrual blood, and at a considerable distance.
Although the blood lost during menstruation typically is small & occurs over several days, there simply is no argument but that, most especially on the days of heaviest discharge, it is more than enough to be detected by a creature that not only can sense one part of blood in 100 million parts of water or better, but also often can tell which of its nostrils that part is closest to.
So much for detection, as "ratherbediving" is inquiring about any increased risk of shark attack during menses. Again, to the best of my knowledge there is no research on this, and for obvious reasons controlled studies would be difficult.
Dr. McComb's short paragraph on the subject includes the sentence, "The hemolytic blood associated with menses may instead act as a shark deterrent (Edmonds, et al., 1992, p. 65). " One will want to be aware that Dr. Edmonds arrived at this conjecture based solely on the statistical finding that women are attacked by sharks less often than men. Clearly there a many possible reasons for this statistic having nothing to do with menstruation.
There as well are several credible sources who opine that risk may be increased. These include George Burgess, Director of the International Shark Attack File, and Divers Alert Network (DAN). An article on shark attack in the Feb '02 issue of their "Alert Diver" magazine states: "Although there is no positive evidence that menstruation will increase risk, it is best not to tempt a predator that finds its prey via smell" (p.15). As with Dr. Edmonds' comment, this other position also is without direct research support.
In addition, in the thread cited above by "Walter," http://www.scubaboard.com/showthread.php?s=&threadid=340, you will find several anecdotal reports of menstruating divers being hassled by sharks, and I can provide others if you like. And while we are here, I'd like to expand upon a reference made by Walter within that thread concerning the work of H. David Baldridge & his colleagues back in the 1970s. To the best of my recall, this work in essence demonstrated that sharks prefer fish to mammalian blood, not that mammalian blood isn't of interest to them.
My personal opinion is that there may be a very small increased risk of shark attack related to menses. But, as the risk of shark attack on a diver is already so infinitesimally small, and even smaller on women, it would be extraordinarily difficult to prove the matter one way or the other even if controlled studies were easily done.
This having been said, if I were a woman & was otherwise feeling up to scuba I would not alter my dive plans due to menstruation.
Of course for you hardy ladies diving cold water in drysuits, the whole discussion lacks relevance.
Best regards.
DocVikingo
leadweight
February 15th, 2003, 12:34 PM
men must taste better :)
Thank you Doc V.
GTADiver
February 16th, 2003, 02:21 AM
I can look for the references if somebuddy really wants them but if memory serves me correctly the Royal Air Force did studies on this during the world wars. They tried to duplicate menstrual flow as their studies revealed it acted as a repellant. Its a cleansing process lots of mucus and other yucky stuff mixed in that the sharks dont want to eat.
In Richard Martin's book Shark Smart--The Divers Guide to Understanding Shark Behaviour page 132 "Most (96%) injuries sharks inflict on humans are single slashes, apparently made with the upper teeth only, suggesting that hunger in not the motivating force"
Bubble Boy
February 16th, 2003, 02:30 AM
Richard Martin states:
" It has been demonstrated that sharks are uninterested in menstrual fluids. This is not, as some dive physicians suggest, because the amount of fluid is small and discharged over a number of days. Sharks have an highly developed ability to detect chemicals dissolved in water, down to an infinitestimal 10 trillionth of a mole per litre of seawater for certain amino acids. If even the tiniest quantity of mensus is released into the water during an hour's dive, the incredible acuity of the shark olfactory system may welll be able to detect it. While certain types of blood are well-known to be hightly attractive to sharks, menstrual 'blood' is a complex fluid that is chemically very different from systemic blood. Menstrual fluid does include 'old' (hemolysed) blood, but it has been shown experimentally that sharks are simply not interested in it."
So if you feel good enough to dive then there is no reason not to.
DocVikingo
February 16th, 2003, 10:53 PM
Thanks.
DocVikingo
PS: If a major artery is severed and one bleeds to death, or lives but is permanently disfigured buy a single slash, apparently made with the upper teeth only, the motivating force is probably only of academic interest.
DocVikingo
February 16th, 2003, 10:56 PM
Would you please cite the studies he uses to support his statement that, "Menstrual fluid does include 'old' (hemolysed) blood, but it has been shown experimentally that sharks are simply not interested in it."
Thank you.
DocVikingo
Bubble Boy
February 17th, 2003, 01:24 AM
DocVikingo once bubbled...
Would you please cite the studies he uses to support his statement that, "Menstrual fluid does include 'old' (hemolysed) blood, but it has been shown experimentally that sharks are simply not interested in it."
Thank you.
DocVikingo
He has no reference in the text portion quoted but there are at least seven pages of references at the end of the book. The one that looks most promising is by:
Johnsen, PB., and J.H. Teeter. 1985. Behavioral responses of bonnethead sharks (sphyrna tiburo) to controlled olfactory stimulation. Mar.Behav.Physiol., 11:283-91.
or
Perrine, D. 1989. Reef shark attack! New clues raise new questions about why sharks bite people. Sea Front., 35(1):31-41.
DocVikingo
February 17th, 2003, 12:27 PM
Thanks for taking the time to look this up.
That Richard Martin does not provide references in the text portion to support his assertion that ""Menstrual fluid does include 'old' (hemolysed) blood, but it has been shown experimentally that sharks are simply not interested in it" is unfortunate, and not the way scholarly pieces are written.
I have read the Johnsen & Teeter article you cited, and it investigates olfactory directional sensitivity in bonnethead sharks & involves only non-human blood, so no help there.
Haven't been able to access the Sea Frontiers piece by Perine, but from what I know of that magazine it seems highly unlikely that it would include such content.
So to this point I would hold that, like Dr. McComb's piece referenced earlier in this thread, Mr. Martin's position is not compelling as written.
Best regards.
DocVikingo
jewie27
March 16th, 2003, 12:40 AM
i dont think fluids from body orfices attracts sharks..
Dot Wethington
November 13th, 2004, 01:01 AM
I think sharks fear p.m.s. over anything- nothing worse than cranky, bloated, junk food craving women giving them the "finger". They give them plenty of room. :goldfish:
Ber Rabbit
November 13th, 2004, 10:25 AM
These are two sets of statistics I like to point out to my students when they talk about being afraid of sharks:
International Shark Attack Files (http://shark-gallery.netfirms.com/attack/2003attacksummary.htm)
Personally I'd rather dive with sharks than ride a bicycle on the road. Like DocVikingo said the odds of getting attacked by a shark are small.
Ber :lilbunny:
Fatimah_Dive_Instructor
November 13th, 2004, 11:44 AM
Hi
My personel experiance with sharks leaves me with no fear of diving with my period, period. Anouther wanna be urban legend plugged up.... ;) Were do we come up as human beings with all these unreasonable worrys.
Fatimah
lemondiver
April 21st, 2010, 02:00 AM
chumming involves fish blood, fish blood is oil based. Human blood is water based. Has nothing to do with a wound or dead blood. If there is a HUGE amount of human blood in the water sharks have been known to check it out-they see the red color. Once they realized it's not oil based they are not interested and yes this had been documented. A nosebleed, cut ect will not be an issue.
diverdoug1
April 21st, 2010, 03:20 AM
I have an anecdotal story that relates to this topic. A couple of summers ago, I was on night call, and a young female was admitted to our ER. She was skinnydipping with some friends at night, and was bitten on the hip/torso by a shark (thought to be a bull about 8' in length). She was the only female, and was at the peak of her menses.
DCBC
April 21st, 2010, 08:34 AM
To the best of my recall, this work in essence demonstrated that sharks prefer fish to mammalian blood, not that mammalian blood isn't of interest to them.
I'm sure that the Seals in South Africa will be pleased to hear this. :)
lemondiver
April 26th, 2010, 11:25 PM
The reason she was bit is that she was swimming at night, no wetsuit on-white skin looks like fish at night especially. Most people splash around and that mimics wounded fish. The fact that she was the only female is irrelevant. She was probably the first person the shark came to or was off to the side of the others. Again sharks looks for oil based blood not water based which is what we are. The best advice to not get bitten is don't swim at dusk/night, stay off the surface, dont splash around, dont spearfish, wear a wetsuit in a dark color.
diverdoug1
April 27th, 2010, 08:41 AM
The reason she was bit is that she was swimming at night, no wetsuit on-white skin looks like fish at night especially. Most people splash around and that mimics wounded fish. The fact that she was the only female is irrelevant. She was probably the first person the shark came to or was off to the side of the others. Again sharks looks for oil based blood not water based which is what we are. The best advice to not get bitten is don't swim at dusk/night, stay off the surface, dont splash around, dont spearfish, wear a wetsuit in a dark color.
Lemondiver,what is this magical oil based blood of which you speak? OIL BASED BLOOD????:rofl3: An erythrocyte can't even function if bathed in an oil soultion. OK, sharks do home in on fish oil (which is why I have a DC garberator to grind up barracuda when I chum for sharks), but fish do not have "oil based blood". Armchair pontificating about a subject which you do not understand leads to the spread of your ignorance. The enemy of truth and scientific discovery is ignorance, magical thinking, and firmly held beliefs in mythology. Also, chumming for sharks with mammalian blood does work very well. I frequently have used pig blood to chum when fishing for sharks in the Gulf of Mexico (because I don't know where I can get 5 gallon buckets of fish blood), and they tear up the hams we hang over the side to keep them interested. As far as the comments about why the young woman was attacked instead of her male companions, how can you say that her sex or cycle of menses was irrelevant? This anecdotal story is only a potential data point in a study that has not been done yet. I think I will go along with the director of the IASF, who says that menstruation may increase the incidence of unprovoked shark attacks. Having said this, the risk is still so low for shark attack, I don't discourage my wife from diving while she is menstruating. I do tell her not to dive with me while I am spearfishing in certain areas (regardless of her cycle).
diverdoug1
April 28th, 2010, 10:51 AM
ISAF not IASF (oops).:D
baggysalls
April 28th, 2010, 03:22 PM
super interesting topic and i would agree with the above post that if chum works to attract fish and sharks then blood from menstruation should do the same. have a speargun on you just in case. (in my opinion)
Crowley
May 2nd, 2010, 02:28 PM
You go fishing for sharks? I hope you use circular hooks and put them back afterwards, cos just exactly what the world's very seriously depleted shark population needs is somebody to hoik another one out of the water for no particular reason. Forgive me, I don't know you, but if you're tagging and tracking all is well and good.
Bull sharks have attacked people for no good reason, men/women/bleeding or not. It may be defensive or territorial. They are potentially agressive animals and it has recently been postulated that female bulls will - unlike other sharks - defend their pups.
The general consensus from research referred to above is that menstruating women have no more chance of attracting sharks than a diver wearing yellow fins. Some people suggest that urinating in the water attracts sharks as well - for those that like to pee in their wetsuits. If menstruating women caused shark attacks I would not have as many female colleagues as I do.
So - if you are capable of diving during your period - do so. The only equipment you need to bring when you are diving with sharks is a camera.
Cheers,
C.
diverdoug1
May 2nd, 2010, 02:48 PM
You go fishing for sharks? I hope you use circular hooks and put them back afterwards, cos just exactly what the world's very seriously depleted shark population needs is somebody to hoik another one out of the water for no particular reason. Forgive me, I don't know you, but if you're tagging and tracking all is well and good.
Bull sharks have attacked people for no good reason, men/women/bleeding or not. It may be defensive or territorial. They are potentially agressive animals and it has recently been postulated that female bulls will - unlike other sharks - defend their pups.
The general consensus from research referred to above is that menstruating women have no more chance of attracting sharks than a diver wearing yellow fins. Some people suggest that urinating in the water attracts sharks as well - for those that like to pee in their wetsuits. If menstruating women caused shark attacks I would not have as many female colleagues as I do.
So - if you are capable of diving during your period - do so. The only equipment you need to bring when you are diving with sharks is a camera.
Cheers,
C.
I do use circle, hooks, but I practice filet and release.:D Blacktip is one of my favorites to eat (one about 3'-4' in length, steaked out, and blackened on the BBQ is best). Our shark fishery in south Florida is healthy and well regulated. I release the other shark species I catch, but my target species is Blacktip (YUM YUM).
lemondiver
May 3rd, 2010, 02:18 AM
ok, I think the men answering the post may be a bit confused........when you menstrate you are not "gushing" blood, it usually stops in water and you would be using a tampon. Oh and on the fin color there's a reason it's called yum yum yellow and most shark dive trips require you not wear bright neon colors, the light glints on it and does attrack attention. Blues tend to like to nip bright colors too.
TechBlue
May 3rd, 2010, 06:06 AM
Actually, the menstrual blood does not attract sharks because it is kind of a dead blood, i.e. the shark can feel it's not someone bleeding from a wound.
Relax ;) and enjoy :)
:confused:
be weird or anything but I wonder if that has been tested?
Why would chumming work to attract sharks? It would seem to me that the blood etc used for chumming would be "dead".
I'm certainly no shark expert but I wonder if sharks are actually drawn to blood as we have been led to believe or is there something different that actually draws them to chum or injured animals.
Good point chumming uses fish blood, human blood does not mean anything to a shark.
ratherbediving,
Relax and enjoy your honeymoon and your diving :)
Chris
aku321
May 3rd, 2010, 08:33 AM
I cut my finger on a wreck dive once and it was gushing blood. Back on the boat I tried to patch it up but they olny had cheap bandaids and I needed stiches. The second dive was on a reef and there was a shark there. I looked at my finger, which continued to bleed, then at the shark wondering if I was going to get eaten. The shark didn't care. Now if I was on a actual shark dive where they get the sharks in by chuming and they are excited I think it might be different.
diverdoug1
May 4th, 2010, 01:34 PM
ok, I think the men answering the post may be a bit confused........when you menstrate you are not "gushing" blood, it usually stops in water and you would be using a tampon. Oh and on the fin color there's a reason it's called yum yum yellow and most shark dive trips require you not wear bright neon colors, the light glints on it and does attrack attention. Blues tend to like to nip bright colors too.
Lemondiver, would that non-gushing blood be "oil-based" "dead" blood?:rofl3:
sailingk8
May 8th, 2010, 01:21 AM
I do use circle, hooks, but I practice filet and release.:D Blacktip is one of my favorites to eat (one about 3'-4' in length, steaked out, and blackened on the BBQ is best). Our shark fishery in south Florida is healthy and well regulated. I release the other shark species I catch, but my target species is Blacktip (YUM YUM).
As a Marine scientist maybe you can tell me how many parts per million of methylmercury Blacktip Shark filets contain?
ShakaZulu
May 8th, 2010, 02:02 AM
Pretty interesting, looks like a lot of BS responses to me...go dive, and let us know what happens :)
PS. Dead blood, can you explain that to me again :)
diverdoug1
May 14th, 2010, 09:39 PM
As a Marine scientist maybe you can tell me how many parts per million of methylmercury Blacktip Shark filets contain?
Sorry Sailingk8, I don't have a source for mercury tissue levels in the smaller sharks we eat, but it is supposed to be close to the levels found in other slower growing predators of similar size (such as Wahoo, or Swordfish). We usually try to limit our consumption to 2 servings per month of shark/mackeral/wahoo/swordfish. One of the highest levels of methylmercury in comonly consumed seafood in the US is sushi grade tuna. Everything in moderation. Bon Apetit. P.S. please pass along your favorite Blacktip recipe (I sear mine with louisanne cajun seasoning, and sprinkle on montreal seasoning and lemon pepper).
Belmont
May 14th, 2010, 10:47 PM
According to statistics Ratherbediving has 47% chances of being divorced because she was married 7 years ago when she posted.:D
Now I'm kidding, maybe she can tell us what happened during her honeymoon (divewise I mean);)
