UV and Perch Spawning
June 25, 2013
Yellow perch typically spawn when temperatures at spawning depth range from 45°F to 50°F, as females produce an accordion-like gelatinous egg mass, frequently draping them on vegetation or submerged wood. A team from Lehigh University studied the relationship of depth, temperature, and solar ultraviolet radiation (UVR) on perch spawning in two lakes in Pennsylvania.*
Lakes with high levels of dissolved organic carbon (DOC) tend to be darker in color than those with low levels of DOC as the organics filter out radiation that's known to be lethal to fish eggs. For example, at murky Lake Lacawac, 99 percent of UVR was filtered out at a depth of 1½ feet, while at clear Lake Giles, that level of shading wasn't reached until a depth of 16 feet.
But temperature also plays a role, as eggs develop faster in warmer water and survive at a higher rate. This suite of factors suggests that perch face conflicting selective pressures. Egg survival, in theory, should be higher at depths that balance the lethal effects of radiation with the benefits of solar heating.
The scientists found that at Lake Giles, with low DOC and high UVR, perch laid eggs in water from 7 to 33 feet deep, with most between 16 and 19 feet. At murky Lacawac, maximum spawning depth was just 5 feet and most were 2 feet deep. They note that dissolved oxygen can play a role, particularly in high DOC lakes, and perch may select objects to drape eggs on to prevent them from falling into low-oxygen zones.
*Huff, D., G. Grad, and C. E. Williamson. 2004. Environmental constraints on spawning depth of yellow perch: The roles of low temperature and high solar ultraviolet radiation. Trans. Am. Fish Soc. 133:718 — 726.
3 Devils Lake, North Dakota
This ever expanding perch mecca is again on the upswing for trophy-size perch. North Dakota Fish and Game reports that the lake's perch population is at the highest level since 2003. With strong year-classes from both 2006 and 2007, perch in the 10- to 14-inch range will make up a large percentage of the catch this year. Contact: Guide Jason Mitchell, 701/662-6560, fishdevilslake.net; The Perch Patrol, 701/351-3474, perchpatrol.com
9 Lake Michigan, Indiana
Big water means plenty of opportunities to intercept roving schools of jumbo perch that can number in the thousands. High winds in spring have reduced angling pressure during the last two spawning cycles, and 2013 should be a banner year for fish in the 12- to 15-inch range. The prespawn bite starts in deep water over clay bottom during early spring, with fish moving to shallower rock and weededges in summer and fall. Contact: Capt. Ralph Steiger, 219/688-3593, captainsteiger.com
7 Finger Lakes, New York
Perch thrive in these 11 glacier-formed, deep, clear waters. Multiple lakes in close proximity allow for lake-hopping for beautifully colored perch. Seneca Lake draws much of the attention, but perch over 12 inches are in all of the lakes. Contact: Capt. John Gaulke, 607/319-0450, fingerlakesanglingzone.com
4 Glacial Lakes, South Dakota
With more than 50 lakes near the town of Webster, each year sees different lakes peaking for perch in the 9- to 13-inch range. Fertile waters from recent flooding help to ensure consistent good year-classes of perch. Bonus fish include a nice mix of crappies, bluegills, walleyes, and pike. Contact: Guide Cory Ewing, 605/929-3894, waubaylakeguideservice.com
1 Interlake, Manitoba
Situated between the mammoth waters of lakes Winnipeg and Manitoba, local fisheries range from natural valley lakes of 30 square miles, to shallow inland lakes of modest size. Fantastic perch fishing runs from early December through ice-out. Plenty of perch hit the 12-inch mark in these fertile lakes, and there is a good shot at 14- to 15-inchers. Contact: Dino Branfield, 204/362-2945, nelsonvilleoutfitters.com
10 Lake Erie, Ontario
Along with its 'œwalleye factory' moniker, Lake Erie produces more perch than any other lake in North America. A hot bite exists in fall along Erie's north shore. Once fish are located, 50-fish daily bags are the norm. Manmade structures, including midlake gas wells and underground pipelines, concentrate massive schools, making the fishing reminiscent of the Gulf of Mexico. Contact: Capt. Frank DiMarcantonio, 905/933-4834, niagarasportfishing.ca
8 Lake Gogebic, Michigan
Despite being the largest inland lake in the Upper Peninsula and producing more state angler award fish than any other fishery in the area, this trophy perch fishery somehow remains under the national radar. While not a numbers fishery, perch surpassing 2 pounds are caught each year, both during the open-water and hard-water seasons. Contact: Barry Drews, 906/842-3361, ninepinesresort.com
; Gogebic Lodge, 906/842-3321, gogebiclodge.com
5 Lake Simcoe, Ontario
Abundant freshwater shrimp and other small invertebrates allow this heavily fished lake in southern Ontario to continually produce good numbers and sizes of perch. While ice fishing generates the most angling pressure, some of the biggest fish are taken shortly after ice-out in shallow bays around Beaverton. Schools of big perch roam deeper water throughout summer. Contact: Guide Greg Klatt, 416/580-2541, profishntanglingservices.com
6 Lake St. Clair, Michigan
Lake St. Clair provides incredible summer and fall fishing for numbers of 8- to 12-inch perch. Target them just outside thick vegetation in 6 to 18 feet of water. By fishing shallower water, deep-water mortality among sorted fish isn't an issue. One hundred- to 200-fish days are common. Contact: Capt. Steve Jones, 586/463-3474, fishpredator.com
2 Mille Lacs Lake, Minnesota
A big-water favorite in central Minnesota, this year-round fishery puts out jumbos averaging 12 inches, if you know where to hunt them, and fish in the 15-inch range aren't out of the question. For those willing to put in the work to locate a mess of jumbos, the rewards can be huge. Contact: Guide Tony Roach, 763/226-6656, roachsguideservice.com