Seven gill nets were set suspended 10-15-feet from the water's surface to see if Walleye and Sauger catch increased while chasing bait fish. However, the number of fish/lift could be misleading because of the poor suspended gill net catch. A total of 64 Walleye and 155 Sauger were sampled. The number/lift for both species was within the range of past surveys, but the increased number of Walleye and Sauger collected was much higher than past surveys because of the increased number of nets. The mean number of Sauger sampled/lift in the five previous surveys was 3.23. The mean number of Walleye sampled/lift in the five previous surveys was 1.04.
Walleye catch/gill net lift (1.83) was the highest observed since 1973 and Sauger was within the range of historical surveys (4.43/lift). Much of the remaining non-game fish sampled in this survey were Gizzard Shad, Mooneye, Gar species, and Redhorse species.Ĭatch rates for Walleye and Sauger were above the average from the previous five surveys. Freshwater Drum were also the most caught and released fish in the 2013 open water creel survey. Croix in 2013 estimated Freshwater Drum harvest almost tripled the Channel Catfish harvest during the open water season. In fact, the most recent creel survey conducted on Lake St.
Croix River and are commonly the most harvested non-game fish. Although Freshwater Drum are considered a non-game species, they are frequently harvested from the St. Of the 362 non-game fish species sampled, over 56% were Freshwater Drum. The top five game fish species sampled were Sauger (155), Walleye (64), Channel Catfish (64), Yellow Perch (59), and White Bass (24). Over 54% of the fish sampled were considered game fish species. A total of 793 fish were sampled represented by 23 different species and one hybrid (Sauger/Walleye hybrid).
It was determined the 15 nets set in Segment 4 were sufficient. Five fewer nets were set in Segment 4 as a large number of fish were being sampled and the remaining locations to set nets were high traffic boat areas. Twenty gill nets were set in Segment 2 and 15 were set in Segment 4. Fall turnover had already occurred as dissolved oxygen was above 6 parts per million as deep as 50-feet and the temperature difference between the surface and 50-feet was less than two degrees Fahrenheit for both segments. Prior to setting nets, temperature and dissolved oxygen profiles were taken for each segment to ensure that nets were not set in areas of low dissolved oxygen, which would reduce the catch of Walleye and Sauger.
Segment 2 and Segment 4 were chosen for the first year of sampling, which began on September 22, 2014. Another experiment was conducted by suspending a small number of gill nets to determine if Walleye and Sauger may be sampled higher in the water column, presumably while chasing bait fish such as Gizzard Shad. At the end of the two year sampling period, net catches were to be evaluated to determine if certain locations could yield a higher catch of Walleye and Sauger to develop new standard nets sites with higher catch rates of targeted species that would require less effort to duplicate in future sampling years. Twenty gill nets were to be set in each segment, and two segments were to be netted in September each year, with all four segments being completed in two years. The segments were defined as follows: Segment 1, the Stillwater Lift Bridge to the Railroad Bridge near Hudson, WI Segment 2, the Hudson Railroad Bridge to Catfish Bar Segment 3, Catfish Bar to the Kinnickinnic River Narrows Segment 4, the Kinnickinnic River Narrows to the mouth of the St. The Lake was divided into four segments with increased gill net sets in each segment. An experimental survey design was developed to target Walleye and Sauger to learn more about their respective populations in Lake St. Our goal in the 2014 survey was to determine if increased gill net effort would catch more Walleye and Sauger for a more detailed analysis of their respective populations and to determine if better locations could be selected for new standard sites to increase sampling efficiency of these popular sport fish.