There is no danger of a massive fish die-off just yet, but all the same, the deaths of the ten bream are remarkable. For one thing, because the father-and-son team of Henk, Jonathan and Matthias Erkelens of Erkelens Visserij from Alblasserwaard were supposed to have removed all the fish from the pond back in April. For another, because the fish all died at pretty much the same time, says Frans van der Kroef, who works at Erasmus Sports and is an extremely experienced sport angler.
According to Van der Kroef, the fact that all the fish died at the same time is due to acute aquatic hypoxia (oxygen depletion), possibly caused by a sewer that accidentally drained into the pond, or alternatively, by large quantities of rotting water plants.
