LONG LAKE, Wash. -- Hundreds of dead fish are floating in Long Lake in Stevens County and neighbors want to know what's killing them.

Marcie and Paul Norstadt live along the lake and first noticed the dead fish as they washed up on their beach on Friday.

"It's the smell of death, it's a stench with all the hot sun we've been having and the fish float right on the surface it's just baking them," said Paul Norstadt.

Paul and Marcie cleaned up their beach, but the fish continue to wash up. Paul and Maurice went out in their boat to investigate, and discovered the problem extended beyond their shore.

"Something happened to cause this many fish to die," said Marcie Norstadt.

Most of the dead fish are large carps, known to be bottom feeders. Officer Bob Weaver with the Washington Department of Fish and Wildlife met up with the Norstadt's to get a first hand look at the fish.

Officer Weaver believes the fish are dying from a lack of oxygen, as most of the dead fish are found tangled in large pockets of vegetation.

"Because as these mats of vegetation decay, takes the dissolve oxygen out of the water which causes any fish in that area to have a hypoxia problem or lack of oxygen," said Officer Weaver.

Weaver doesn't believe the fish were poisoned because birds and other wildlife don't appear to be affected.

Weaver says he will pass along his report to a fish biologist and the Department of Ecology. Those two agencies will then decide what to do next and if any tests need to be completed. The entire process could take a long time and its waiting game that many neighbors don't want to stomach.

"It makes you wonder if you want to get in the water and go swimming or not," said Paul.

Weaver says people should avoid swimming around the decaying fish because they can carry bacteria.