Send this article to Promobot

Abundance of algae found on dead salmon

August 29th, 2014 | By Jillian Rogers Print this article   Email this article  

Hundreds of dead salmon washing up along the Kobuk River appear to be healthy, according to the Alaska Department of Fish and Game's pathology lab.

A carcass collected by a U.S. Fish and Wildlife Service employee last week was sent to the lab for testing and a necropsy. Lab officials ran tests for viruses and bacteria, though those results are still unavailable, according to an update from the USFWS.

In the dissection of the fish, scientists noted that the salmon appeared healthy and was close to spawning before it died.

"The one interesting thing they found was algae (diatoms) on the gills and skin," said Susan Georgette with the USFWS in a statement. "They said there would have to be a lot of algae in the water to stick to fish."

According to the lab, the excess of algae backs up the indication that the hundreds of salmon died from low dissolved oxygen, or Low DO.

"Algae blooms consume lots of oxygen in the water, and combining that with a huge return of salmon could have led to enough oxygen depletion to kill salmon," read the statement from Georgette.

Several types of algae were found, she added, and with the warm, sunny days, the chance of increased algae growth in the river increases.

Fish and Wildlife is now looking into getting the algae tested.

Georgette noted that on a boat trip upriver last week, she and a colleague counted 284 salmon carcasses on a sandbar above Kiana.

"The number of salmon returning to the Kobuk River this year is indeed impressive," Georgette said.

The test fishery in Kiana showed numbers one and a half times higher than last year, which was the second highest, and three times higher than most years since 1993.


Copyright 2018 The Arctic Sounder is a publication of Alaska Media, LLC. This article is © 2018 and limited reproduction rights for personal use are granted for this printing only. This article, in any form, may not be further reproduced without written permission of the publisher and owner, including duplication for not-for-profit purposes. Portions of this article may belong to other agencies; those sections are reproduced here with permission and Alaska Media, LLC makes no provisions for further distribution.