January 25, 2011
MILWAUKEE -- The last mission of the state research vessel Barney Devine was a melancholy one: its annual search for yellow perch turned up low numbers of the fish fry favorite, heavy ice cover in Sturgeon Bay resulted in a small hole in the vessel's hull that let on water, and the crew was having a hard time saying goodbye.
The Department of Natural Resources plans to retire the 74-year-old boat from active duty when its replacement, the Coregonus, is delivered later this spring. Burger Boat Company in Manitowoc is building the 60-foot RV Coregonus to replace the Barney Devine, which has become technologically obsolete and is facing increased maintenance costs.
"For the crew here in Sturgeon Bay, the boat isn't gone yet but when it disappears it will be like a part of everyone's life is gone," said Brandon Bastar, who captains the Barney Devine.
The vessel steamed out of Milwaukee Harbor on Dec. 8 and 9 and again on Dec. 15, 16, 17, for one last netting survey aimed at looking for yellow perch of all ages.
"This is the time of year where we don't see the fish segregate by size or sex. We think it's the best time to get an idea of number, size, sex ratio and age composition of the perch population," says Brad Eggold, fisheries supervisor for southern Lake Michigan, who was on the vessel. "Unfortunately, we caught a lot fewer fish than previous years."
Over the past five years, DNR's December yellow perch surveys had netted about 1,000 or more fish per survey; in December 2010, that number was only in the high 200s, Eggold says.
"So we were quite a bit down," he says. "We were in the same spot, same location, same time as past years, so there's nothing to explain the numbers drop in terms of our sampling."
More worrisome than a one-year drop in numbers is that the nets were virtually devoid of any small fish from the last few years of natural reproduction, even though some of those years saw bumper crops of young fish hatched.
"We didn't really see any small fish from the last couple of year classes," Eggold says. "We're seeing fish from the 2005 year-class and some from 2002."
For some reason, while other DNR surveys show that yellow perch seem to be reproducing in good numbers, the young fish aren't surviving to their second or third year. For example, beach seine and micromesh gill net surveys in August and September 2005 of fish born earlier that spring found the largest number of yellow perch ever. But that hasn't translated into the largest year-class ever. Likewise, August 2009 surveys saw pretty good numbers in the nets, "but we're not seeing them in this assessment," Eggold says.
"We updated all the yellow perch models and data, and looked at it all over the course of several meetings in 2010 and came to the conclusion that we were not going to make any changes to bag limits or to the closed commercial season," Eggold says. "Population is lower than it had been historically, and while the adult population still seems to be relatively stable, there is a lack of young fish coming up, certainly not enough to have a higher bag."
Eggold says there's a lot of speculation that the failure of perch hatched in the spring to survive to the next spring and beyond is tied to fishes' difficulty in finding enough food. "Food availability is nowhere near what it was back in the 1980s when you saw large year classes being produced over a 10-year span."
Quagga mussels, an invasive aquatic species that now carpets the bottom of Lake Michigan, are believed to be a huge factor in yellow perch sustainability. "It is number one on the list" of why food availability for these young fish has decreased, he says.
Quagga mussels, which feed on plankton at the base of the food chain, are closely related to another invader, the zebra mussel. Both are native to the Caspian Sea in Eurasia and both most likely arrived as stowaways in the ballast water of ocean going ships. Zebra mussels were first found in Wisconsin's Lake Michigan waters in the late 1980s, and quaggas within the last decade.
Quagga mussels are considered even more damaging than zebra mussels because they can live in a wider range of water temperatures, water depths, and they feed all year, even in winter when zebra mussels lie dormant. In fact, in Lake Michigan, quagga mussels have essentially outcompeted and displaced zebra mussels in the last few years.
DNR and counterpart agencies around Lake Michigan started detecting very few small fish nearly 20 years ago. And while the number of adult female yellow perch has been recovering and there have been some years with good, even great natural reproduction, the number of fish surviving to catchable size is not improving.
FOR MORE INFORMATION ON YELLOW PERCH SURVEYS CONTACT: Brad Eggold (414) 382-7921
FOR MORE INFORMATION ON THE REPLACEMENT VESSEL CONTACT: Brandon Bastar (920) 746-2881
The 74-year-old RV Barney Devine steamed out of Milwaukee Harbor in December for one last netting survey aimed at looking for yellow perch of all ages.
RV Barney Devine breaking through ice in Sturgeon Bay
A view from the pilot house
Cheryl Peterson, fisheries technician from Milwaukee tries her hand at piloting the boat
Dave Schindelholz, Brad Eggold, Pradeep Hirethota, and Cheryl Peterson pose for one last picture on the Barney Devine
A look at sea conditions off Milwaukee during Barney's last yellow perch assessment
"Pancake ice" two miles offshore
Staff buoy showing the location of yellow perch nets
Dick Pagel, retired captain of the RV Barney Devine holds down the fort
Fisheries technician, Dave Schindelholz, boxes yellow perch nets under the watchful eye of Captain Dick Pagel
Dick Pagel and Dave Schindelholz stop to pose for a picture
Tim Kroeff, fisheries technician, monitors the setting of the yellow perch gill net
The crew picks out fish from the net as it comes out of the water
Research Vessel Captain, Brandon Bastar, holds a trophy-sized yellow perch
Dick Pagel, Brad Eggold, Cheryl Peterson, Tim Kroeff, Brandon Bastar and Pradeep Hirethota take some time for a group photo during one of the last surveys
The RV Barney Devine makes its way through the ice
Ken Royseck, fisheries technician; Scott Hansen, fisheries biologist; and Pat McKee, fisheries technician, gather round to bring in the RV Barney Devine from its last mission.
The RV Barney Devine gets tied up at the WATER Institute in Milwaukee
Crew for one of the last trips onboard the RV Barney Devine after the cruise: Pradeep Hirethota, Brad Eggold, Dave Schindelholz, Brandon Bastar, Dick Pagel, Cheryl Peterson and Tim Kroeff