March 09, 2017
By Dan Small
A generation ago, northern pike were a big part of the fishery in the bay of Green Bay.
The Packers might be the biggest attraction here, but the Bay of Green Bay also supports a multi-million-dollar sportfishing industry, including northern pike.
Anglers caught them through the ice and in open water, and they often ran big. It is fair to say northerns were the dominant game fish species there.
Then, slowly, things began to change. Anglers reported catching fewer pike every year. Survey and creel census data collected by the Wisconsin Department of Natural Resources confirmed what anglers were saying — — pike numbers just were not what they had been not that long ago.
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Cleanup efforts have improved water quality in the Fox River and Green Bay, and muskie, walleye and smallmouth bass populations have thrived, but pike numbers continue to decline.
Anglers would like to catch more pike, but northerns are also an important predator in the Bay's fish community. Without them, populations of prey species, like shad and white perch, could easily spiral out of control.
Pike are important to the local economy, too. The Packers might be the biggest attraction here, but the Bay of Green Bay also supports a multi-million-dollar sportfishing industry. Bait and tackle shops, restaurants, motels and other businesses benefit from a strong fishery, and they suffer when one element of that fishery is in decline.
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"Each adult northern pike is worth about $156 in terms of its economic impact on local businesses in the community," said Brown County Conservationist Mike Mushinski. "The more fish we can produce in the Bay, the greater the economic boost to the community."
The cause of the pike decline, it turns out, is the loss of spawning habitat. More than 50 percent of the remaining wetlands surrounding all of Lake Michigan are located along the west shore of Green Bay, much of it in the Suamico and Little Suamico River watersheds. And these remaining wetlands are disappearing at an alarming rate.
Shortly after ice-out each spring, adult pike move upstream from Green Bay into tributaries, including major rivers, small streams and even roadside ditches, and eventually into shallow wetlands, where they spawn. Female pike deposit their eggs in thick vegetation, often in flooded fields and ditches. Pike eggs cling to the vegetation and hatch in about two weeks, depending on water temperatures. The fry remain in the wetlands, feeding on zooplankton, small fish, and insects for another six weeks or so before swimming out into the Bay. Many of these wetlands are temporary, holding water for only a few weeks in early spring.
A lot of factors must line up for pike to pull off a successful hatch. Adult pike must be able to reach the shallow spawning areas. Water levels in the wetlands must remain high enough to allow young pike to grow to about 4 inches in length. And there must be sufficient flow later in spring in waterways connecting the wetlands and the Bay to flush out the pike fry. Unfortunately, all those elements don't always fall into place.
If there were enough spawning areas, the failure of a few to produce a hatch in any given year would not have a significant impact on the pike population. Habitat assessments done in the early 1990s, however, showed that some 70 percent of pike-spawning habitat in the Green Bay area had been lost. Farming, road construction and urban sprawl all contributed to the degradation of wetlands.
Poorly designed culverts blocked the upstream movement of adult pike. Runoff from farm fields carried silt into spawning marshes, smothering pike eggs before they could hatch. Roadside ditches drained water from shallow wetlands too quickly, stranding young pike before they were mature enough to leave them.
To counter these problems, in 2007 a coalition of agencies and conservation groups, led by the Brown County Land and Water Conservation Department, the DNR and the U.S. Environmental Protection Agency, launched the West Shore Northern Pike Habitat Restoration Project to restore wetlands along the west shore of Green Bay. Much of this work is being done on private land.
"Without the cooperation of private landowners, we couldn't have done much at all," said Mushinski. "Local residents have noticed the decline in pike numbers over the years and want to help."
From 2010 to 2014, a four-year $400,000 EPA grant under the Great Lakes Restoration Initiative gave the project a big boost. Brown County leveraged an additional $600,000, much of it provided by the Fox River/Green Bay Natural Resources Damage Assessment (NRDA) Trustee Council and the U.S. Fish & Wildlife Service, to cover out-of-pocket costs and incentive payments to landowners of restored wetlands. Other donors include Ducks Unlimited, Trout Unlimited, The Nature Conservancy, Great Lakes Sport Fishermen, Izaak Walton League, U.S. Environmental Protection Agency, a local Lions Club, area communities, Oneida Tribe and even the Green Bay Packers.
"The project has two goals," Mushinski said. "To remove impediments to fish travel and to restore or construct new wetlands."
When hooked by an angler, northerns often turn acrobatic, tail-walking and jumping like bass or steelhead. But unlike steelhead and salmon, pike won't jump over even low obstacles to migrate upstream, and so low rock dams and high culverts effectively keep them out of some areas.
In the past, road-building and other construction projects installed riprap and culverts without concern for their impact on pike migration. Similarly, farmers dug ditches to drain low spots in farm fields to put a few more acres into production. Collectively these efforts have destroyed most of the original pike-spawning habitat.
The West Shore Pike Project has established vegetative riparian buffers along streams, restored and created wetlands and migratory routes, replaced culverts and improved pike access to streams. Most of this work has been done in the Suamico River watershed, but there is much more work ahead.
"We've just scratched the surface," Mushinski said. "There's a lot more to be done, especially in more urban settings on the Fox and East rivers."
Under Mushinski and now Chuck Larscheid, who succeeded Mushinski as project manager, Brown County staff have been monitoring pike movement and spawning at 20 to 30 sites to look for young-of-the-year pike as evidence the restoration efforts are doing what they are designed to accomplish. In addition, research projects have been conducted by UW-Green Bay graduate students, under the direction of professor Patrick Forsythe, and by Solomon David, a fish ecologist at the Shedd Aquarium in Chicago.
UW-Green Bay graduate student Rachel Van Dam conducted a two-year research project in 2014 and 2015 to measure the effectiveness of these restoration efforts and to learn more about pike spawning habits. Van Dam set fyke nets at three restored wetland sites on the west shore of Green Bay to capture adult pike moving into and out of the wetlands. She then conducted spawning surveys at each site to document daily spawning activity and habitat selection.
Van Dam's research spanned two years in order to measure the variations in environmental conditions and pike behavior from year to year.
"In 2014, we had high water and a late spring," she said. "And in 2015, there wasn't as much precipitation and spring came early, so water levels were lower."
Across the three sites, Van Dam captured, measured and tagged 111 females and 154 males in 2014 and 58 females and 352 males in 2015. At these sites, she recorded a total of 33 spawning events in 2014 and 29 in 2015. She noted that many adult pike moved in and out of the spawning wetlands as many as four times and stayed in the wetlands for periods ranging from four to 17 days. She also monitored water levels, water temperatures and the type of vegetation used by spawning pike.
Van Dam found that several fish tagged the first year at one site showed up the second year at another. The first site attracted more adult pike and produced more fry than the other two, but pike spawned at all three sites, and fry were found at all sites both years.
"Rachel's research has been very valuable because we didn't really know how many pike were using these wetlands and how many young fish they were producing," Mushinski said. "Her work with water temperature and levels all plays into how we design these wetlands in the future. We need to maximize flooded conditions, but we also need to retain water so the eggs don't dry out. There just isn't much information on northern pike spawning."
Pike are not the only species to benefit from these improvements. Waterfowl use the shallow wetlands during their spring migration. Muskrats and mink make their homes along their banks, and other fish species move into the wetlands in spring to spawn or feed.
"We've also seen other native species, such as bowfin and short-nosed gar, using these same areas," Solomon David said. "These systems are much more dynamic than anyone ever knew. They serve as aquatic corridors connecting the Great Lakes with inland aquatic systems. They may look like agricultural fields, but they are very important for native species to move back and forth."
This research may also have far-reaching implications, according to Forsythe.
"There aren't too many places in the entire world where you can gather this kind of information," Forsythe said. "Rachel's thesis is going to feed into pike ecology globally, not just here in Green Bay. We call these areas 'living laboratories' because we can gain information here that no one else can get their hands on. They are a great place to educate ourselves on pike ecology and the importance of wetlands to other species, as well."
There is an educational component to the West Shore Pike Project. Project staff have invited elementary and high school classes to observe the pike monitoring efforts, held public meetings to inform citizens of the project, erected informational signs explaining the importance of temporary wetlands to pike spawning success and even produced a 15-minute video on the project. That video can be seen at youtube.com/watch?v=SeIwQL4cvXM&feature=youtube .
To date, the project has completed more than 50 wetland restorations and impediment removals on the west shore, but not every effort has been successful. After several early wetland restorations dried up too quickly, the team learned to mimic a natural wetland that maintains a flat, gentle flow throughout the spawning and egg-development period. In some instances, they installed water-control structures to retain falling water levels long enough to let eggs develop.
"The accomplishments of (the project partners) over the last several years will continue to benefit northern pike and other wetland-associated species for many decades to come, and ultimately make the area a better place to live and recreate in," said Tammie Paoli, the DNR's Green Bay fisheries biologist.
The West Shore Pike Project does not have an expiration date. The project is off to a great start, but this work must continue well into the future in order to achieve and maintain a balance between northern pike and Green Bay's abundant forage species and restore the excellent pike fishery that once existed here.
Fired by a passion every bit as great as that of the most avid of Packers fans, the staff and volunteers of the pike project are determined to succeed. With so many elements of the community pulling for them, I'd put my money on the northern pike as the next wearers of green to make a comeback here in Titletown.
