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17 <br />8 <br /> <br />E <br /> <br />9 <br />T <br />H <br /> <br />S <br />T <br />R <br />E <br />E <br />T <br /> <br /> | <br /> <br /> <br />SU <br />I <br />T <br />E <br /> <br />2 <br />0 <br />0 <br /> <br /> <br />| <br /> <br />SA <br />I <br />N <br />T <br /> <br />P <br />A <br />U <br />L <br />, <br /> <br />M <br />N <br /> <br /> <br />| <br /> <br />55 <br />1 <br />0 <br />1 <br /> <br /> | <br /> <br /> <br />65 <br />1 <br />. <br />2 <br />8 <br />6 <br />. <br />8 <br />4 <br />5 <br />0 <br /> <br /> | <br /> <br /> <br />WS <br />B <br />E <br />N <br />G <br />. <br />C <br />O <br />M <br />Memorandum <br />To: Long Lake Creek Watershed Partnership <br />City of Orono <br />City of Medina <br />City of Long Lake <br />Long Lake Waters Association <br />Minnehaha Creek Watershed District <br />From: Tony Havranek, WSB <br />Date: January 22, 2019 <br />Re: Long Lake Creek Subwatershed Carp Management <br />WSB Project No. 011933-00 <br />The purpose of this memo is to provide an update on the Long Lake Creek Subwatershed <br />Common Carp Management Project-Phase 1. This project was initiated in 2018, as part of a <br />larger effort by the Long Lake Creek Subwatershed partnership as one of several strategies to <br />improve water quality and ecological integrity of lakes and streams within the subwatershed. <br />Phase 1 had two objectives; implant 10 high frequency radio transmitters to document carp <br />movement within the subwatershed and the Long Lake basin to identify migration routes and <br />winter aggregations for carp removal and develop a carp population and biomass estimate. <br />Six (6) high frequency radio tags were implanted during electrofishing surveys on May 23, 2018; <br />the remaining four (4) were implanted during a subsequent electrofishing survey on October 24, <br />2018. Subsequent telemetry surveys completed between June and October, showed some <br />indication that a portion of carp were swimming upstream of Long Lake to access Wolsfeld. No <br />radio tagged carp were documented in Wolsfeld, but one radio tagged carp died in the rock <br />spillway that acts as the outlet for Wolsfeld. The remaining radio tags have remained within the <br />Long Lake basin. Telemetry surveys planned or late December 2018 and 2019 will document <br />aggregations within Long Lake and used to target those aggregations for removal. <br />Carp population and biomass estimates were completed using an electrofishing catch per unit <br />effort (CPUE) model. This model uses the number of carp caught in a specific period of time <br />while electrofishing and calculates the number of individual carp per acre. Using weight data <br />obtained in 2018 during electrofishing surveys, we could calculate a population and biomass <br />estimate. Two (2) electrofishing surveys were employed to calculate this estimate. <br />The estimated number of individual number of carp in Long Lake based on this methodology <br />ranges from 9,367 to 24,518 with an average value of 17,316 individual carp. The total biomass <br />using this estimate ranges from 90,056 pounds to 232,262 pounds of carp biomass in Long Lake; <br />the average estimate is 166,477. We can compare this to published threshold values for carp <br />biomass density. The identified threshold is 100 kg/ha or 89 lbs./acre. Ecological damage can <br />occur below this value. The average stated carp biomass density for Long Lake is 570.6 ±209 <br />lbs./acre, well above the threshold value. <br />K:\011933-000\Admin\Docs\Report\MEMO_CityCouncilUpdate_LLCarp_121018.docx