A Polish honey producers’ association, Polska Izba Miodu (PIM), said on Wednesday the flooding devastated much beekeeping infrastructure, and that would affect future honey harvests and local ecosystems.

A low-pressure system named Boris triggered downpours in Central and Eastern Europe in September, leading to some of the worst flooding in nearly three decades in some areas of Poland.

The flood hit four regions—Opole, Silesia, Lower Silesia, and Lubuskie—the most and had disastrous consequences for beekeepers, PIM reported. The four provinces were home to nearly 430,000 bee colonies and a significant portion of Poland’s bee population.

“As a result of the floods, up to 25% of the bee colonies in these regions may have been destroyed, which means we have lost more than 100,000 bee colonies,” a PIM representative said.

According to PIM, more than 7,000 beekeepers in the four provinces incurred huge losses due to the floods.

The loss of the bees could have a huge impact on local ecosystems, as the insects play an invaluable role in crop pollination, which is crucial for agriculture.

Beekeepers are also concerned that rotting crops will negatively affect the condition of bees.