Tracking Pike and Muskies
May 07, 2014
Kinkaid Lake in southern Illinois experiences mild winters and long, hot summers, comparable to the climate of central Arkansas. Surface temperatures can reach 86°F during extended periods in summer. This 2,300-acre reservoir supports a popular muskie fishery, and is an excellent venue to study muskies at the southern edge of their range.
Researchers at the Fisheries and Illinois Aquaculture Center at Southern Illinois University tagged muskies with temperature-sensing transmitters to determine seasonal movements and habitat use of adult muskies and to examine behavior during the potentially stressful summer period.* Fish were located every several days, and at each location, depth profiles of temperature and dissolved oxygen were taken and used to estimate fish depth, based on fish transmitter temperature. Habitat type also was recorded as open water, standing timber, vegetation, or a combination of vegetation and standing timber.
Thermal stratification occurred from mid-May through mid-November at depths from 14 to 21 feet. Summer surface temperatures ranged from 81°F to 86°F. Dissolved oxygen was limiting (less than 3 ppm) below the thermocline from June through September and increased through October until the lake was mixed by November.
From October to December, body temperatures of muskies generally matched the surface temperature, as the lake was mixed during that time. In winter, body temperatures, from 39°F to 52°F, were slightly cooler than surface temperatures. From June through September, muskies maintained body temperatures of around 77°F, inhabiting depths associated with the thermocline where dissolved oxygen was suitable.
In July and August, muskies often inhabited temperatures that are considered stressful for coolwater fish, or were located at depths with low dissolved oxygen, presumably to avoid warm water. Fifty percent of muskies were located in dissolved oxygen levels less that 3 ppm in summer. Some were found in depth zones where oxygen levels would occasionally drop to 1 ppm. Twenty percent of the fish occupied water at or above 82°F. Muskies in water that warm typically returned to cooler, deeper water after short periods.
Some muskies established seasonal home ranges, often overlapping with other muskies. Other muskies wandered throughout the lake most of the year. Wanderers seemed to temporarily linger in areas frequented by other muskies before moving to other high-use areas.
In late February and early March, all tagged muskies moved to a shallow creek arm area. Some fish moved farther up into the creek and remained there for several weeks to as late as June. Movements overall tended to be highest in February and lowest in July.
In fall, muskies had a preference for combined (timber and vegetation) habitat, and preferred timber areas in winter and spring. Vegetation and combined cover were selected by muskies in summer. When the lake was stratified, muskies most often suspended at depths of around 11 to 12 feet.
*Beck, P. A., and R. C. Brooks. Seasonal movement and habitat use of muskellunge in a southern Illinois reservoir. Fisheries and Illinois Aquaculture Center Research Report, Southern Illinois University.
Pike Habitat Use
Outside of the Far North, big pike in lakes can be difficult to locate in summer. They seem to disappear from shallow environs and move to deeper water, either along deep weededges where they feed on perch, sunfish, and minnows, or open water where they hunt for pelagic baitfish like whitefish and ciscoes. Location appears to be affected by water temperature, dissolved oxygen, and prey preferences and availability.
To help solve the summer location puzzle, Minnesota DNR fishery biologists tracked pike to determine selected depths and temperatures.* Pike were divided into large (greater than 28 inches) and small fish groups. Water temperatures were continuously measured throughout the water column at the deepest part of each lake, and depth profiles of dissolved oxygen were made weekly.
Individual pike were flexible in depths used within seasons and between years, although significant patterns emerged. Pike had the deepest movements and more fully used all available depths during the spring and fall turnover periods when dissolved oxygen in deep water increased. In summer and winter, depth selection was affected by low dissolved oxygen in deeper water.
As upper layers warmed during summer, large pike tended to follow the thermocline to cooler water. Models predicted that pike preferred water temperatures between 61°F and 70°F in August when temperatures up to 82°F were available. Small pike were found in warmer, shallower water in two lakes that had dense water lilies. In the third lake without similar vegetation coverage, smaller pike were often in deeper, cooler water. The researchers suggest that temperature is secondary to shallow vegetation in affecting habitat use of small pike.
One of the test lakes had numerous cold groundwater inflows near the shoreline in water less than about 3 feet deep. The researchers found no evidence that large pike took advantage of these shallow pockets of cold water.
*Pierce, R. B., A. J. Carlson, B. M. Carlson, D. Hudson, and D. F. Staples. 2013. Depths and thermal habitat used by large versus small northern pike in three Minnesota lakes. Trans. Am. Fish. Soc. 142:1629-1639.
Tiger Muskie Movements
Fishery biologists of the Washington Department of Fish and Wildlife implanted transmitters into tiger muskies to track their long- and short-term movements in Newman Lake, Washington.* This reservoir near Spokane is 1,200 acres and has an average depth of 19 feet and maximum depth of 30 feet. Thirty muskies between 22 and 45 inches were outfitted with ultrasonic transmitters and tracked over two years.
Tiger muskies tracked bi-weekly had greater movements during the winter-spring (November-June) period than in summer-fall (July to October). About 90 percent of bi-weekly movements were greater than 100 yards. While movements followed a similar seasonal pattern as found at Mayfield Reservoir in a previous study, Newman Lake fish moved about twice as far between observations, suggesting that behavior of tiger muskies can be lake-specific.
Short-term movements were determined from hourly observations over 24-hour periods. A range of behavior was observed among individual fish. Some tiger muskies occupied short stretches of shoreline or stayed in a certain bay, while others traveled long distances. One fish moved just under 10 miles in 24 hours. The same fish traveled almost 1,000 yards in 15 minutes — an average speed of 2.9 mph.
Seventy percent of muskies were found in water greater than 7 feet deep in summer and fall. In spring, 43 percent of the fish occupied depths less than 7 feet.
*Osborne, R., M. Divens., W. Baker, and Y. W. Lee. 2012. Behavior of tiger muskellunge in Newman Lake, Washington determined by ultrasonic telemetry. Washington Department of Fish and Wildlife Report FPT 12-01.
Tracking Pike and Muskies