Old Hyatt Lake fish kill
This is in regard to your story in Thursday's Mail Tribune about the low water in Hyatt Lake and why the Oregon Department of Fish and Wildlife is not interested in upping the fish limits, or removing them entirely, at Hyatt Lake so people can catch the trout before they might die due to low water. The biologist said there isn't a history of fish kills in Hyatt Lake, but I recall at least one 10 or 12 years ago. Who's right?
— J.S., Ashland
Well, J.S., as much as us at Since You Asked Central like triggering spats between readers and sources, we gotta say this time that you're both right.
Dan VanDyke, the ODFW's Rogue District fish biologist, said in Thursday's Mail Tribune that Hyatt does not have a history of fish kills triggered by low water in drought years, particularly similarly low-water years like 1992 and '94. That's why he's not planning on any emergency regulation changes to increase or remove the current five-trout daily limit.
And you also have good recall about the lake's history.
In mid-July 2002 a significant fish-kill event occurred at this reservoir east of Ashland.
Lake conditions turned lethal a week ago when as many as 2,000 rainbow trout, some more than 20 inches long, began turning up dead along the shoreline. Hundreds more were seen finning listlessly atop the lake's surface and an unknown number of dead fish whose carcasses had sunk to the bottom.
ODFW biologists measured the lake's temperature and dissolved oxygen levels at just 2.6 parts per million, leading biologists at the time to suspect that the trout suffocated.Dissolved oxygen levels of at least 4 parts per million are considered the minimum for trout survival.
That crash in dissolved oxygen likely occurred when the lake's mid-summer bloom of algae died en masse, and the decaying organisms sucked the lake's water of oxygen.
The previously recorded fish-kill at Hyatt Lake was an intentional one, when biologists in 1989 poisoned the lake with rotenone to kill off millions of illegally stocked brown bullhead trout and restocked it with rainbow trout the following spring.
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