Post #13817

King crab: It has already destroyed the Barents Sea. Now this horde is coming to devastate the Scandinavians Kamchatka crab is in a kind of superposition. On the one hand, this is a vulnerable species, the numbers of which already have to be maintained artificially. And on the other hand, there is a multimillion-strong horde that effortlessly broke the ecosystem of the Barents Sea and continues to seize new territories. And, characteristically, in both situations the person is to blame. Let's figure out how we brought the poor crab to a bipolar life. When the Russians reached Kamchatka and the British reached Eastern Alaska, they discovered hundreds of millions of arthropods in the local waters. Very large and tasty arthropods! The leg span of the Kamchatka crab can reach 180 centimeters, and its weight can reach 12 kilograms. Moreover, more than 60% of this mass is tasty, healthy and easily digestible meat. Without thinking twice, both ours and the English settlers quickly launched an industrial crab catch, the volume of which gradually increased over the centuries. However, in the 20s of the last century, the Soviet authorities discovered that it would no longer be possible to increase production: the number of crabs began to decline. In search of a solution to the problem, they came up with an idea that no environmental organization on the planet would approve of today. They decided to move the Kamchatka crabs to the Barents Sea (Let me remind you that the Barents Sea is located next to Murmansk, that is, almost half the world from Kamchatka). The crabs themselves, by the way, desperately did not want to move. Attempts to acclimatize arthropods to new conditions failed for more than 30 years! It was only in the 60s that crabs introduced into the Barents Sea gave birth to offspring for the first time. And the population of arthropods became stable and stable only in 1992. And then the real nightmare began. As soon as the crabs adapted to new conditions, their reproduction rate became even higher than in their homeland. Even though the females still laid 40-80 thousand eggs at a time, the larvae grew and matured noticeably faster - this was due to the warmer summer. And the shorter the time a crab spends in the planktonic larval stage, the lower the chances that it will be eaten. Mortality in the early stages of development has dropped sharply. It has also become lower in older arthropods: there are no specialized predators here, and predatory fish attack only young crabs with thin shells. While the crabs themselves eat everything: carrion, bottom fish, algae and other arthropods. In regions with high numbers of king crabs, small and medium-sized invertebrates completely disappear, after which they switch to larger prey, such as sea urchins and bivalves. And they also suffer great damage. In 2000, king crabs already consumed approximately 90 million sea urchins per year - 15% of the entire population. But their numbers only co