Unusual amounts of dead cod in Inner Oslofjord this past December

codCod.Photo: SCANPIX

In December, more than 100 kilos of dead cod fish were trawled up in several places in the Inner Oslo Fjord. Scientists believe a lack of oxygen is the cause.

In connection with a monitoring program, between 100 and 200 kilos with dead cod fish was trawled in the Vestfjord in the Inner Oslofjord, the Norwegian Institute for Water Research (NIVA) states.

A trawl on December 5 took place in the deep water between Måsene and Sjøstrand, just northwest of Storegrunnen in the middle of the Vestfjord, while on December 19th, they trawled in the depths just southwest of Storegrunnen, between Steilene and Slemmestad.

  • “One likely explanation is that the fish were killed due to oxygen-poor water,” says André Staalstrøm, researcher and oceanographer in NIVA.

Also in October, high amounts of oxygen-depleted water was recorded in Lysakerfjord and at Steilene outside Nesodden.

“These oxygen-depleted water masses are most likely derived from Bunnefjord, where they have been formed by deep water having remained at rest so that all oxygen is exhausted,” says Staalstrøm.

As a rule, fish can escape from such toxic water masses, but this has not happened in these cases.

© NTB Scanpix / #Norway Today