The beginning of the end for the Invincible Armada and the harbinger of the end of Spain's golden age was a sudden, violent storm in the Atlantic. At the end of May 1588 130 ships left Lisbon in the direction of the Channel to destroy the English fleet, but were forced to stand for a long repair in La Coruña in the north-west of the Pirine Peninsula.
The Spaniards began restoring masts and sails, patching up holes, and discovered that the bottoms had been significantly damaged by the shipworm (Teredo), a menace to wooden ships. The repairs were not completed until two months after the start of the voyage. The English had time to prepare, and the morale of Philip II's fleet was undermined.
140 years later, the same worm helped England weaken its other rival, Holland. The trigger was again a weather force majeure. One by one, several dry years then passed, and the Söidersee River grew shallow. The water of the bay of the same name consequently became much more brackish. In the harbor of Amsterdam, the very same shipworm or piling worm (in the Dutch version) suddenly became active.
Half a year of the worm's destructive work was enough to make the 70 kilometers of the system of dikes and piers made of the strongest moraine wood look like an apple, corroded by a moth. More than two-thirds of the structures could not be saved. The world's first country of victorious capitalism faced the threat of flooding.
It was necessary to import huge quantities of stone in order to build a new dam. For this project, the government of the Dutch Republic was forced to sharply increase already burdensome taxes. Popular unrest ensued. Problems with the port infrastructure hampered foreign trade, the main source of the country's wealth. England took advantage of the unexpected disruption to its new main competitor and once again consolidated its power.
The salinity of the North Sea reaches 35 ppm. In coastal waters it is lower; at the mouths of large rivers, like the Söiderse, it usually fluctuates at about 10 ppm. This is the salt concentration that is the threshold concentration for the spread of the shipworm. In more fresh water, this bivalve is not active. The higher the salinity, the greater their number and their voracity. The small, jagged shell of Teredo, like a helmet, covers only the front end of the worm-like body of the sea animal. With this "helmet" it can drill holes in wood up to 5 centimeters in diameter and up to 2 meters long.
The "living drill" was feared by the seafarers of antiquity. But the Ancient Russia, on the contrary, benefited from it. On the Baltic, in contrast to all other navigable seas, the Teredo factor is virtually absent. The water salinity in its central part is about 6 ppm, and in the Gulf of Finland does not exceed 3.
Ships from Lubeck or other handicraft centers of Northern Europe from X to XII century, despite the need to pass a considerable distance by drag, preferred the route "from the Varangians to the Greeks" for trade with Constantinople. By the Baltic Sea to the Neva, Ladoga, Volkhov, Dnieper to the Black Sea. The alternative route passes through Atlantic and Mediterranean Sea to Rome and further by Aegean and Marmara Seas. Well tarred boards and bottoms saved ships on the relatively short Black Sea section. Around Europe on the salty waters was much more dangerous.
Since Peter's time the absence of the worm has been an additional argument in favor of developing St. Petersburg's port communications. Fragments of wood affected by the mollusk had to be brought for the Mining Museum from "warm countries". Today several such exhibits are on display as part of the Paleoecology collection.