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Posted

There is no fully characterised jellyfish season in Thailand as yet as the species may not be the same as the Australian one. It may also be affected by the fact that Samui and the archipelago have a double wet season.

 

Box Jellies have a lifespan of about a year. Elsewhere they are known to spawn in fresh water... so this would also suggest on an island they require a river/stream with an estuary, which may only flow in wetter months.

 

There is also a myth that box jellies drift with wind and tide. This is not the case. They are good swimmers up to 4 knots,  and they have "eyes" and actually hunt their prey. In fact they aren't even true jellyfish.

 

There are several species of box jellies and new ones are being identified quite often.

It is likely that the identification of box involved in incidents in Thailand is not yet fully accurate.

 

As for vinegar being a "cure" for the sting, this is untrue. Vinegar is believed to paralyse the envenomation cells and so slows or prevents further envenomation and the allows removal of the tentacles. Doing so without first dousing with vinegar increases the chances of death.

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Posted
46 minutes ago, kwilco said:

Elsewhere they are known to spawn in fresh water... so this would also suggest on an island they require a river/stream with an estuary, which may only flow in wetter months.

Since there are no rivers on Koh Tao are there also no box jellyfish around Koh Tao?

Posted

From below linked article of today...

 

Various kinds of jellyfish including boy jellyfish that can kill are particularly prevalent in the area from July to October, said Krissana Phromkoh the owner of Lamai Wantha Hotel as the net was installed outside her property.

 

[...]

 

Daily News also published figures from Koh Samui Hospital for the number of stings from all kinds of jellyfish that were treated there:

 

2016 42 cases

2017 47 cases

2018 17 cases

2019 and 2020 8 cases each

2021 9 cases so far.

 

 

Posted
7 hours ago, kwilco said:

There is no fully characterised jellyfish season in Thailand as yet as the species may not be the same as the Australian one. It may also be affected by the fact that Samui and the archipelago have a double wet season.

(My bold in quote)

July till October is normally mentioned as Box Jellyfish-season for Samui and her sisters, and especially calm sea after rain is said to be the most dangerous conditions, due to the fresh water from rain.

Posted
10 hours ago, ExpatOilWorker said:

Since there are no rivers on Koh Tao are there also no box jellyfish around Koh Tao?

Bit of a false conclusion. You need to look at the life cycle...and where there is freshwater on Koh Tao.

 

As Said there is little research done into species of Box Jelly indigenous to the area and their life cycle is only hypothesized based on similar species elsewhere.

 

The jellies in Oz breed sexually and asexually – they use fresh water to spawn. The resulting eggs hatch into lava which turn into stationary polyps which cling to rocks etc they then either split asexually or turn into mini medusa - i.e. jelly fish- These small creatures could then float on wind and tide. Once the medusa form is large enough it can swim up to 3 or 4 knots, have vision and can hunt. 

 

So I’d say there are various possibilities

It is  quite possible that the jellyfish around Koh Tao could come from the mainland or islands with rivers. They like to hunt in shallow waters and the beaches on Koh Tao might be suitable for them.

 

They may still come from the island itself.

 I don't know Koh Tao but I take it there are no waterfalls on the island? However the island is definitely not a desert, therefore there is fresh water on the island which in some way drains into the sea – this may well provide suitable places with enough fresh water to allow  jellies to mate and leave their eggs.

 

It seems to me that there needs to be a lot more research into the life cycle of Box Jellies around Thailand. If more were known about their life cycle then more could be done to predict their presence and discover the size of the populations. They’ve had nearly 30 years to do this but it seems they only think about it when someone dies,

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Posted
3 hours ago, khunPer said:

(My bold in quote)

July till October is normally mentioned as Box Jellyfish-season for Samui and her sisters, and especially calm sea after rain is said to be the most dangerous conditions, due to the fresh water from rain.

Yea a lot of the media say this but it's not scientifically confirmed especially as the wettest season on Samui and surrounding islands is also November and December. There is also usually a delay between the mating in the wet and the emergence of the medusa.

 

There are many species of box jellies, some are jot even poisonous so without detailed research it is difficult to come to conclusions about when and where there orence should be.

It is known that they can appear all year round and it is known that box jelly populations rise and fall. In Oz they have extended the "official" box jelly season from May until July. (It starts in October there). They put this down to changes in water temperatures due to climate change .

There is no way in Thailand they have enough information for detail like this.

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Posted
1 hour ago, kwilco said:

Yea a lot of the media say this but it's not scientifically confirmed especially as the wettest season on Samui and surrounding islands is also November and December.

It's monsoon season in November-December, not as much calm sea as from July till October. The Box Jellyfish season is likely based on observations of accidents, there are a number of cases reported on Samui, if you see my above post and link to article...????

Posted
35 minutes ago, khunPer said:

It's monsoon season in November-December, not as much calm sea as from July till October. The Box Jellyfish season is likely based on observations of accidents, there are a number of cases reported on Samui, if you see my above post and link to article...????

We simply dont have significant numbers, even over 30 years to draw conclusion about a season.

As said earlier they also dint know enough about their life cycle and behaviour in these seas. Whereas rough water might drive them away, the general opinion of other populations is they spawn in the wet and appear a few weeks later. This would mean Janyary would be the start of that season.

I also lounted out that Samui archipelago has a double wet season. So storms might drive them away but it doesn't suggest it kills them. 

Then there is the lifespan and  even that  seems to be in doubt with estimates ranging from 9 months to 2.years. Either way they would be hanging around long after any rain.

Posted
3 minutes ago, kwilco said:

I also lounted out that Samui archipelago has a double wet season. So storms might drive them away but it doesn't suggest it kills them.

Where did you get "double wet season" from?

 

5 minutes ago, kwilco said:

We simply dont have significant numbers, even over 30 years to draw conclusion about a season.

Have you checked what observations the authorities already have, i.e. for example the cases registered by Samui hospital?

Posted
2 hours ago, khunPer said:

Where did you get "double wet season" from?

 

Have you checked what observations the authorities already have, i.e. for example the cases registered by Samui hospital?

I've tried to get records from a couple of the 5 or more hospitals on Samui....the answer is "no record".

The correct people to approach would probably be the zMariitume Deot of Delt Wildliife.

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Posted

Seasons and Stats

There are many reasons why we need to view the concept of “season” with scepticism and also look critically at the stats.

 

If we cling to the idea of a “season” it means we may not be vigilant at other times of year – yet we know that Box jelly presence in Thai waters is year round.

 

We still can’t say with any confidence the relationship between  this jelly and seasons – they don’t even know or (haven’t been told) where they spawn.

 

Double wet season - Monsoon is not strictly speaking just the wet, it is a total seasonal cycle, thoughnoeople often refer to the monsoon rains as just "the moonsoon".

Samui has a double wet season. Like the rest of Thailand, it is subject to both the Indian (southwest) and Chinese (northeast) monsoons.

The wet season throughout most of Thailand is heralded by the onset of the Southeast monsoon, normally around May ,,,,, the brunt of this is born by the west coast but it carries over the rest of the country including Samui. At this point, Koh Chang is the wettest island in Thailand  as it picks up moisture from the winds over the Gulf.

When the monsoon changes to the Northeast around November, it heralds the dry season for most of Thailand, but unfortunately it’s then Samui’s turn; the fresh winds pick up moisture over the Gulf and drop it on the Samui archipelago. The wettest 2 months of the year on the island being November and December

 

This will then increase fresh water flows again on the islands and is likely if the science is correct, to facilitate the mating of Box Jellies that appear to need fresh water for this. They should then drift out a few weeks later into the balmy waters of the short dry season. They may even be washed out by the estuary flows here they were hatched. So distribution may rely on how much flow there is in any particular year. Streams and rivers on islands are of course much less reliable than the rivers on the mainland.

 

 

 

Deaths as a statistic - There is a problem using just one set of figures for Statistics. It only gives a tiny part of the whole picture. The best you say is “research suggests” - but that is insufficient to lower your guard - just relying on deaths or even reported incidents.

The numbers involved are too small to be used for valid statistics.

There is also a problem with reporting incidents as often the attacks are not accurately reported - e.g. may or may not be Box Jellies.

 

To get a proper idea these stats need to be used with other available information - one of these would be sightings - they do however need to be educated and confirmed sightings  - yet another problem with dealing with this animal is that information is clouded with a lot of dubious misinformation.As seen on the threads here. People are far too ready to jump to conclusions. The government in the past has even actively tried to cover up box jelly incidents, presumably fearing any impact they might have on tourism. THere always seems an effort to distort the evidence with a bias towards reducing the impact it may have on tourism. One has to observe this is almost a default position with Thai authorities when confronted with any controversial situation involving deaths of tourists.

 

A report in 2017 found that the public in general were unaware that Box jellies could kill and called for more information from local people in order to get a better overall picture …. This doesn’t really seem to have happened. In fact the sporadic installation of vinegar stations and poor maintenance thereof seems to indicate a general disinterest in the matter on a local level.

 

Between 2008 and 2015 there were 15 box jelly incidents in Thailand - not all fatal, Although nearly half were round Samui archipelago but this is hardly sufficient to claim a season of even a cluster- Samui is of course a part of the country where  very large numbers of tourists enter the water. In Thailand records weren’t kept until 1997, rthis because the animals weren't even officially identified. Researchers have interviewed local fishermen etc and have received accounts dating back long before this date that can reasonably be assumed to have been box jellies even though the species wasn’t recognised. 

This number will now have risen but still will only be in low double figures - not enough on their own for statistics. What is needed are other inputs - sightings, fishermen’s catches, scuba divers etc., all who need to be reliable in identifying the animals.

 

Protection: - It is also worth noting that until tourists arrived in Thailand there were very few people who entered the sea voluntarily and those who did were usually fully clothed. It is well established that a thick denier pair of ladies tights is sufficient to protect against the sting of these jellies and people in areas known to be inhabited by them often wear rash suits these days.


 

Irukandji Syndrome is another example of the lck of hard evidence…….

This is even less recognised and subsequently reported in Thailand. However it has been identified in Pattaya and West coast This is a tiny animal (5 cm) and one of the most legal of all Box Jellies - nets for this are useless.

 

There is an app available from Dr Lisa Geshwin, one of the world’s leading experts on Jellyfish - .https://thejellyfishapp.com/

 

 This hopes to gather and collate information on all forms of jellyfish. It also has an identification setting and updates on sightings.- although sadly these are not much updated in Thailand since covid.

In short the statistics of Box Jelly incidents are very thin on the ground and far too narrow to draw any solid conclusions.

If scientists find out more about the lifestyle of species in this region and there is more efficient gathering of information then we will all be in a position to take precautions against what is in effect the most venomous animal to humans on the planet. Until then we need to be wary of jumping to wrong conclusions.

 

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Posted

Just for the records, downpour on Koh Samui...
The wet months are October till December, there are some downpour from May till September; the rainy season on Samui is May to December...

 

Climate data for Ko Samui (1981–2010)

Month

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Year

Average rainfall mm (inches)

86.2
(3.39)

54.4
(2.14)

80.8
(3.18)

83.1
(3.27)

155.9
(6.14)

124.1
(4.89)

116.3
(4.58)

110.9
(4.37)

121.7
(4.79)

309.8
(12.20)

506.6
(19.94)

210.3
(8.28)

1,960.1
(77.17)

Average rainy days

11.0

5.6

5.9

8.6

15.6

13.7

14.4

15.2

16.2

19.6

19.2

13.7

158.7

Average relative humidity (%)

83

82

82

81

80

78

78

78

80

85

85

82

81

Source 1: Thai Meteorological Department[16]

Source 2: Office of Water Management and Hydrology, Royal Irrigation Department (sun and humidity)[17]

 

Number of Box Jellyfish incidents registered by Samui Hospital the later years, according to Daily News...

According to data, July, August, September and October are the periods when many types of venomous jellyfish, including box jellyfish, enter the area around Koh Samui.

[...]

For statistics since 2021 of Koh Samui Hospital Found that there are people who have been poisoned by various types of jellyfish. Including box jellyfish attacking and releasing venom into the body until injured, divided into: 2016, 42 cases, 2017, 47 cases, 2018, 17 cases, 2019, 8 Year 2563, 8 cases and 2021, 9 cases, so be warned for those who will swim in the sea during this period.

Posted

Personally, I wouldn't say from experience that Samui has a 'double wet season'. I've never heard that expression and we all know it hammers down between Oct to Dec some years which is Samui's wet season. Living in the tropics, it's gonna rain hard at any time throughout the year ('99, it rained all Songkran), it's just random, but not necessarily a 'second season' per se.....................................................................................I've been stung 3 times by jellyfish, all at Choeng Mon bay. Twice by mushroom shaped ones/mild sting for an hour maybe and in '06 by a box swimming back over from Tongsai Bay.............I don't know for sure that it was a box, but I've never known pain like it. Vinegar defo doesn't work by the way, nor the local bushes that the jet ski boys insisted would cure me, nor does urine!!..................I was stung across my torso and arms by long tentacles that I know, I didn't see the main body of it.................................... Heart went crazy for ages and I spent 2 hours stomping up and down the beach like a madman trying to offset the pain assuming that going to hospital would just be a waste of time. 4 Nurofens later, the pain eased slightly and I then self medicated with 10 small singhas and other local herbs which finally send me on my way. Still woke up in the middle of the night in pain........................................... Never again and I haven't swam since in the sea in Thailand and I used to swim at least a kilometre at a time twice a day without fail..................................

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Posted

Great information.

 

I'm going to stick to wear the nets are for now on.

 

Hopefully the nets don't trap one inside.

 

I hope they have these nets at some locations in Hua Hin.  

Posted

Look guys just stay out of the water. Sharks, jellyfish and wasp spitting manta rays with laser eyes its just not worth it.

There is a reason our ancestors dragged themselves out of the ocean.

Its just too dodgy in there.

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Posted
30 minutes ago, bojo said:

Personally, I wouldn't say from experience that Samui has a 'double wet season'. I've never heard that expression and we all know it hammers down between Oct to Dec some years which is Samui's wet season. Living in the tropics, it's gonna rain hard at any time throughout the year ('99, it rained all Songkran), it's just random, but not necessarily a 'second season' per se.....................................................................................I've been stung 3 times by jellyfish, all at Choeng Mon bay. Twice by mushroom shaped ones/mild sting for an hour maybe and in '06 by a box swimming back over from Tongsai Bay.............I don't know for sure that it was a box, but I've never known pain like it. Vinegar defo doesn't work by the way, nor the local bushes that the jet ski boys insisted would cure me, nor does urine!!..................I was stung across my torso and arms by long tentacles that I know, I didn't see the main body of it.................................... Heart went crazy for ages and I spent 2 hours stomping up and down the beach like a madman trying to offset the pain assuming that going to hospital would just be a waste of time. 4 Nurofens later, the pain eased slightly and I then self medicated with 10 small singhas and other local herbs which finally send me on my way. Still woke up in the middle of the night in pain........................................... Never again and I haven't swam since in the sea in Thailand and I used to swim at least a kilometre at a time twice a day without fail..................................

It's quite simple...its to do with the switch between the Southwest and Northeast monsoons 

Posted
1 hour ago, khunPer said:

Just for the records, downpour on Koh Samui...
The wet months are October till December, there are some downpour from May till September; the rainy season on Samui is May to December...

 

Climate data for Ko Samui (1981–2010)

Month

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Year

Average rainfall mm (inches)

86.2
(3.39)

54.4
(2.14)

80.8
(3.18)

83.1
(3.27)

155.9
(6.14)

124.1
(4.89)

116.3
(4.58)

110.9
(4.37)

121.7
(4.79)

309.8
(12.20)

506.6
(19.94)

210.3
(8.28)

1,960.1
(77.17)

Average rainy days

11.0

5.6

5.9

8.6

15.6

13.7

14.4

15.2

16.2

19.6

19.2

13.7

158.7

Average relative humidity (%)

83

82

82

81

80

78

78

78

80

85

85

82

81

Source 1: Thai Meteorological Department[16]

Source 2: Office of Water Management and Hydrology, Royal Irrigation Department (sun and humidity)[17]

 

Number of Box Jellyfish incidents registered by Samui Hospital the later years, according to Daily News...

According to data, July, August, September and October are the periods when many types of venomous jellyfish, including box jellyfish, enter the area around Koh Samui.

[...]

For statistics since 2021 of Koh Samui Hospital Found that there are people who have been poisoned by various types of jellyfish. Including box jellyfish attacking and releasing venom into the body until injured, divided into: 2016, 42 cases, 2017, 47 cases, 2018, 17 cases, 2019, 8 Year 2563, 8 cases and 2021, 9 cases, so be warned for those who will swim in the sea during this period.

And this is precisely why you cant rely on these statistics...they dont even ID the jellies with any authority.. 

Posted
5 minutes ago, kwilco said:

It's quite simple...its to do with the switch between the Southwest and Northeast monsoons 

I wouldn't call it 'simple', rather more subjective and one's interpretation of the word 'season'......................................

Posted
1 hour ago, bojo said:

Vinegar defo doesn't work by the way,

You dint seem to understand what the vinegar is for. It doesn't reduce the pain, it reduces continued envenomation from the tentacles  that are stuck to the victim.

It has been shown quite convincingly that the application of vinegar to victims has reduced the chances of mortality 

BTW The venom primarily affects the heart and usually within 5 minutes.

 

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Posted
12 minutes ago, kwilco said:

You dint seem to understand what the vinegar is for. It doesn't reduce the pain, it reduces continued envenomation from the tentacles  that are stuck to the victim.

It has been shown quite convincingly that the application of vinegar to victims has reduced the chances of mortality 

BTW The venom primarily affects the heart and usually within 5 minut

I din understand, but prefer to keep it all simple for story telling purposes....................

Posted
2 hours ago, kwilco said:

And this is precisely why you cant rely on these statistics...they dont even ID the jellies with any authority.. 

People are more busy saving a life than trying to ID a jellyfish, as poster @bojotold, you might not know what it is, but you feel the pain; the jellyfish can have several meters long tentacles, so might not be next to you, waiting to be IDed for the stats.

  • 2 years later...
Posted
On 9/1/2021 at 6:25 AM, khunPer said:

(My bold in quote)

July till October is normally mentioned as Box Jellyfish-season for Samui and her sisters, and especially calm sea after rain is said to be the most dangerous conditions, due to the fresh water from rain.

And this is not substantiated by any significant evidence

Posted
On 9/1/2021 at 5:12 PM, bojo said:

I wouldn't call it 'simple', rather more subjective and one's interpretation of the word 'season'......................................

Nothing subjective about the turnaround in monsoons 

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