Edited by Paul Holtan
Wisconsin Department of Natural Resources
PO Box 7921
Madison WI 53707
(608) 267-7517
Fax: (608) 264-6293
E-mail address: paul.holtan@wisconsin.gov

Crews collecting fish eggs take steps to prevent spread of deadly fish virus

Low water flows also complicate Lake Michigan trout and salmon egg collection

STURGEON BAY - Fall trout and salmon runs up Lake Michigan tributaries are trophy time for anglers and a great time for everyone else to see these big fish up-close at the state egg collection facilities critical to continued fantastic fishing on the big pond.

Wisconsin’s Lake Michigan trout and salmon fisheries depend on stocked fish that start as eggs collected at the three Department of Natural Resources egg collection facilities -- C.D. Besadny Anadromous Fish Facility near Kewaunee, Strawberry Creek Spawning Facility near Sturgeon Bay, and the Root River Steelhead Facility in Racine.

Chinook and coho salmon and steelhead aren’t native to Lake Michigan but were stocked starting in the late 1960s to help control alewives and have since become a popular target for anglers. These Pacific Coast natives don’t reproduce in significant numbers in Wisconsin, so eggs collected during spring and fall spawning runs are needed to produce the next generation of fish.

Strawberry Creek is the primary chinook egg collection facility or “weir”; the other two provide back up on chinook and capture coho, steelhead and brown trout for spawning later in the year, according to Paul Peeters, DNR fish supervisor in Sturgeon Bay.

This fall, while the fish are starting to follow the same biological imperative that’s driven their species for millennia, state fish crews at the three weirs are preparing for a challenging year for several reasons. Foremost among those reasons is the detection last spring of a deadly fish disease, viral hemorrhagic septicemia, or VHS, in fish from Lake Michigan and the Lake Winnebago system.

No DNR hatchery fish, water supplies or brood stock have tested positive for VHS. The DNR, however, has instituted additional testing, disinfection and other requirements for its hatchery and stocking system to minimize the risk of accidentally spreading VHS to new waters, to DNR hatcheries, or to Lake Michigan tributaries beyond the first barrier impassable to fish.

In addition, low water levels on Lake Michigan and its tributaries will make the runs up the Kewaunee River to the weir more stressful for fish and fish handler alike, according to Mike Baumgartner, the Kewaunee facility supervisor.

The spawning runs are normally triggered by a change in stream flow; if the rain never comes this fall, or not in sufficient amounts, then daylight cues kick in and the fish start their spawning runs. They typically arrive all at once, making it more difficult for fish crews to process them. The low water levels make it more difficult for the fish to swim upstream, increasing their stress and consequently the potential for disease, Baumgartner says.

Fortunately, DNR’s construction several years ago of a pipeline to pump water into Strawberry Creek during low water years allow the chinook to get upstream. So on a misty Monday morning, the pump at Strawberry Creek was hard at work supplying water and the DNR crews readied their equipment to collect eggs and milt from the fish, as they’ve done for decades.

They set up for the first time a disinfection station at the weir where eggs are bathed in iodine before being packaged up. Normally, eggs collected at the weirs are disinfected before being brought into a hatchery to kill any viruses. This fall, the chinook eggs are being disinfected onsite at the weirs, and then again before they are brought inside a DNR hatchery.

In another change, DNR Fish Health Specialist Sue Marcquenski is collecting fish samples every week for VHS and other viral tests, instead of just once during the weeks-long spawning period. This way, DNR can assure that fish that reach the spawning weirs during all parts of the spawning run – not just those fast swimmers arriving in the early weeks – are healthy. DNR collects eggs from the early part of the spawning run, the middle, and the tail end to assure the greatest genetic variety.

Other changes made to reduce the risk of spreading VHS mean the DNR will limit where eggs collected from Lake Michigan fish can go. The chinook eggs, for instance, will be kept only at hatcheries within the Lake Michigan basin, and the fish stocked only into waters in the Lake Michigan basin, where VHS has been detected. In past years, some chinook eggs collected at Strawberry Creek have been sent up to the Bayfield hatchery for hatching and raising and the fish eventually stocked into Lake Superior.

In Kewaunee, the threat of VHS means that DNR fish crews will harvest all chinook that arrive at the weir – a task that could mean fish crews will handle thousands of fish in a short time span. “We’d normally pass the majority of the chinook run upstream before they get into our ponds, but this year, because we’re trying to control any potential spread of VHS, we’ll be harvesting any fish that come up to keep them from going farther upstream,” Baumgartner says.

And VHS means that the brown trout and steelhead also beginning their spawning runs will be kept at the Kewaunee weir until they are “ripe” for spawning. Normally, DNR collects a certain number of adult fish of these species and transfers them to a hatchery where the fish are kept until they’re ready for spawning -- in December for browns and a little later for steelhead, Baumgartner says. Because of the possibility of VHS, DNR will be keeping those adult fish at the Kewaunee and Root river facilities instead of sending them on to hatcheries until they ripen.

Once DNR has collected the browns and steelhead it needs for spawning, it will continue to capture browns and steelhead instead of letting them go upstream, again to contain fish that possibly might have VHS. Fish crews will likely load them on to a hatchery truck that will deliver them downstream so they’ll run the gauntlet of anglers again, Baumgartner says.

In Racine, the Root River Steelhead Facility was up and running as of Sept. 24, having successfully cleaned up a lot of woody debris left in the wake of heavy rains and high water in August. John Komassa, who supervises the facility, said fish crews had added the extra disinfection step for the eggs to prevent the spread of VHS. “We also are trying to incorporate Root River Facility specific equipment and enforcing the new disinfection protocols for all equipment on site,” he says.

Visitors will find more than ever to see at this facility. Volunteers from Salmon Unlimited are opening and closing the facility’s viewing window daily, and new educational signs were installed this past summer around the facility.

FOR MORE INFORMATION CONTACT: Mike Baumgartner, Kewaunee facility (920) 388-1025; Paul Peeters, Strawberry Creek (920) 746-2865; John Komassa, Root River facility (262)594-6218