(lives here on the beaches) - I documented the metota crab for the first time on the shores of Israel in 2006, it was right after the first feeding of sand that was carried out on the shores of the Kiryat.
This invasive species has acclimatized nicely in areas with fine sand suitable for the burrowing of the crab, which in this way camouflages itself and waits for its prey.
And here, during the last two weeks, we are witnessing a new phenomenon: hundreds of metota crabs are ejected from the sea on the beaches of Kiryat, scattered at different points over hundreds of meters, some of the crabs are dead, some were still alive, but when I tried to return them to the sea, it was clear that they would not survive.
Cancer of the stomach is not harmful to humans at all. Although there may be cases where bathers accidentally step on it and get stung, this could certainly be an unpleasant experience, but also harmless.
The local ecology, on the other hand, is fairly harmed by the presence of the metota, as it kills crabs larger than itself and a variety of other sea creatures, which it does with its powerful pincers.
Local fishermen usually use the metota as bait for bream fish, after finding the method to be very effective.
At this stage it is already clear that in the Haifa Bay alone, the number of crabs reaches tens of thousands at certain points.
did not survive the change
We do not have sufficient tests regarding the outflow of runoff water in Kiryat Yam, but the very fact that this is the first time we have encountered this phenomenon, allows us to assume that its cause is a radical and rapid change in water temperature.
From the heat of the summer and autumn, the temperatures dropped suddenly and quickly, which caused the water to cool (both according to measurements and complaints from swimmers), this in combination with particularly strong easterly winds in the area, and the fact that the water is shallow - all of these led to an accelerated cooling of the water, and it seems that the metota crabs were harmed by Thus, until many of them did not manage to survive.
Skydiving
According to the data of the meteorological service, last October opened with high temperatures - 28 degrees. Such a value is measured once every two decades, with the last time being in 2005
Then, around Sukkot, the temperature suddenly dropped drastically, and in the last week it dropped by another 4 to 5 degrees. The powerful easterly winds that arrived immediately afterwards resulted in another drop of another five degrees.
Eastern winds
At the Kiryat Yam beach, the temperature was measured using the underwater camera and reached 19 degrees, and at the place where the mass death occurred - 20 degrees Celsius.
About 200 m from the shore, the water was unusually shallow, this as a result of the easterly winds which flattened the small waves and tore up the water, especially during the nights. Every morning more and more dead crabs were added while they were still fresh.
Since this is a very exposed beach and with urban drainage, it seems that the cold that hit it killed these spider crabs. This hypothesis, as mentioned, is based on the temperature data indicated, and since the methota came from the Red Sea, which is characterized by constant temperatures, some of the crabs did not survive the extreme change.
From this it can be understood that not every invader is able to establish himself here and prosper, far from his natural environment. This is despite the fact that the metota has replaced the wandering shayton - which, like him, preys on the remains of jellyfish.
Invaders that succeeded in moving to our shores and the frequent changes are the urchins, as well as the haharon fish.
Nature is under our feet if we only choose to see and treat it as Moti does for us.
Question: If the Suez Canal was opened in 1869, why did it take so many years to arrive?
Good week Zohar.
The invasion is a long process.
The more sea transport you use, the more the invasions will increase
Dear Motti, as usual you publish another amazing and fascinating article with spectacular photos from the seas:) I am very interested in the fact that there is a type of cancer that even if encountered in the sea it does not harm humans. You have definitely enriched me and my knowledge! strength
Hello Jordan. Indeed, cancer is quite avoided by humans...and as in nature...only the adapted survive.
good week
Very interesting article. Keep bringing such interesting materials.
Thanks for the abundant added information you always post. Interesting and waiting.
A wise and interesting article, thanks Motti
Amazing article!
And maybe the fed sand has toxic substances
But they die in the sea, as if dhahaha
Hello Rochester
In this case there is no connection to the contamination of sand. Mortality is at points not only in Haifa but anywhere with a similar topographical structure.
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