637 | Minnesota Musky Research with Kamden Glade: What These Predators Really Eat

Show Notes:  https://wetflyswing.com/637 

Presented By: Skwala, Togiak River Lodge, Togens Fly Shop, Visit Helena, MT

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Kamden Glade, fisheries specialist from the Minnesota Department of Natural Resources, joins us to discuss his groundbreaking research on the Minnesota musky diet. In some regions, these formidable fish have earned a dubious reputation for preying on prized sport fish like walleye and bass. However, Kamden's research provides a different perspective, revealing that musky in Minnesota seldom consume these highly valued species.

Throughout the episode, Kamden shares intriguing insights from his comprehensive study, including the innovative techniques used to examine the stomach contents of these apex predators without causing them harm. Listeners will gain a deeper understanding of what musky feed on, the average sizes of their prey, and how this knowledge can enhance their chances of a successful catch during the fishing season.

Episode Chapters with Kamden Glade on Minnesota Musky Research

3:45 - Kamden shares his lifelong passion for fishing, which started at a young age with his family, and later evolved into a professional career in fisheries biology. He explains that his interest in the ecology and biology of fish was sparked during his undergraduate studies, where a professor with a background in fisheries biology inspired him to pursue this path.

5:03 - His work in fisheries biology became more specialized during his graduate studies at Bemidji State University, where he led a research project analyzing the diets of muskies, walleye, northern pike, and largemouth bass in various lakes across Minnesota. This project aimed to address the negative perception of muskies, which are often thought to indiscriminately eat other fish species.

8:50 - Kamden discusses the diet of muskies, focusing on why walleye are not a significant part of their diet. Kamden explains that research, including studies in Minnesota and Wisconsin, shows that muskies primarily consume yellow perch and suckers. Other notable components of their diet include Northern pike, insects, aquatic invertebrates, and bullheads, depending on the region.

Despite the presence of healthy walleye populations in the lakes studied, walleye were found in only four out of 650 muskie stomachs analyzed. This scarcity is not due to habitat differences, as both species often occupy the same areas in the lakes. Instead, it appears that walleye have effective defenses against predation. They have large tails for quick escapes, a heightened awareness of their surroundings, and sharp dorsal spines that deter muskies.

12:11 - We delve into the status, native range, and life history of muskies. Kamden explains that muskies are originally native to the Mississippi River and Ohio River basin, the Great Lakes drainage, and parts of Eastern and Central Canada. Despite remaining naturally reproducing in many systems, habitat changes caused by human activities like building dams and docks, and removing aquatic vegetation have led to a decline in natural reproduction.

14:27 - On the musky life history, he details that muskies typically spawn in spring when water temperatures range from the high 40s to low 60s, with peak spawning activity around the mid-50s. Unlike some fish, muskies do not build nests or defend their eggs. Instead, they spawn in shallow vegetation, and the eggs are left to fend for themselves.

16:25 - We talk about the conservation efforts surrounding musky fishing, particularly in Minnesota. Kamden explains that in Minnesota, muskies are generally not eaten, partly due to a statewide minimum size limit of 54 inches, which promotes their status as a trophy fish. This size limit means that by the time muskies reach 54 inches, they are usually quite old and less critical to the population, allowing for occasional harvesting without significant impact.

19:23 - I ask how their project has impacted public perception and regulations on musky fishing. Kamden explains that the project aimed to provide robust data on musky diets and their impact on other fish populations in Minnesota lakes. This data would help address any future disagreements or questions regarding musky management strategies.

22:09 - He describes how they got samples from the muskies' stomachs. What they did was catch them through electro-fishing. They had a generator that created an electrical field in the water. That temporarily stunned the fish enabling them to net and bring them on board. They put them in a live well to let them recover. They worked on these fish and then released them back into the lake.

To get the food out from the fish, they used a regular bilge pump, hooked that up to a garden hose nozzle with a little piece of tubing and copper pipe on the end, and then they were able to put that pipe into the fish's mouth through their throat and into their stomach and then fill their stomach with water. That created pressure in their stomach and forced anything they'd eaten recently back out through their throat. They caught whatever was in their stomach and brought it back to the lab, identified it, and measured it.

28:16 - I ask about the long-term success of musky populations, particularly in light of climate change and other environmental factors. Kamden explains that in his region, climate change is not currently a major threat to musky populations because there are musky populations further south that suggest resilience to changes in water temperature. However, he acknowledges that climate change could affect the food sources for these fish, specifically citing the cold-water species Cisco, which are vulnerable to temperature changes.

31:03 - He says that in Minnesota, muskies are primarily found in larger lake ecosystems where natural reproduction is more prevalent. He speculates that the sheer size of these lakes might help protect the habitat better than smaller, more developed lakes.

36:34 - Kamden explains that the Cisco is a cold-water pelagic bait fish related to lake whitefish which inhabits deeper waters and has specific temperature and oxygen needs, making it a sensitive species. Due to its habitat, the Cisco has a unique isotopic signature compared to other prey fish.

37:37 - On the appropriate size of lures or flies for musky fishing, Kamden explains that their analysis shows a wide variation in prey size, but on average, predators tend to eat prey that is about 25 to 30% of their length. He mentions that while some large muskies have been observed eating very small aquatic insects and small yellow perch, others have consumed prey up to 60% of their length.

38:36 - We discuss fishing tips, particularly focusing on muskies and their feeding habits. Kamden challenges a common belief among anglers that smaller baits are necessary in the spring due to colder temperatures and fish not eating large meals. He notes that, contrary to this belief, many large fish are caught early in spring between the ice-out and the spawning period.

44:11 - Kamden mentions having recent interactions with Muskies Inc. Specifically, they helped purchase gear to trap minnows, which are essential for feeding the muskies during the summer before they are stocked in the fall.

46:28 - Kamden shares that he still enjoys fishing whenever he has time, particularly highlighting his enthusiasm for musky fishing. He notes that while working with fish professionally can sometimes diminish the desire to fish recreationally, especially with challenging species like muskies, he has rekindled his interest in musky fishing since completing graduate school.

Show Notes:  https://wetflyswing.com/637