CC PACKET 03262013 - Laserfiche WebLink

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31 Silver Lake Carp Removal Scope of Services This scope of services has been prepared to accomplish the following goals for Silver Lake: 1. Assess common carp spatial usage of Silver Lake with respect to habitat types, water depths, activity levels, etc. to delineate areas of intense carp usage and locations where carp may be vulnerable for removal operations 2. Develop population/biomass estimate of common carp in Silver Lake to determine removal effectiveness as a percentage of carp removal. 3. Reduce common carp densities in Silver Lake to a level that will protect critical habitat and improve water quality conditions. 4. Assess age structure of carp population on Silver Lake to determine how effective a removal may be. To assess the common carp population in Silver Lake a mark and recapture study will be employed. Due to the late start in 2012, the marking period will not commence until the spring of 2013. To initiate the study roughly 250 adult carp will be targeted for marking. The mark will consist of a simple fin clip; most likely the front right pectoral fin. The hope is that we are able to mark approximately 5 % of the adult population. Marking can begin at ice out and continue through the spawning period in late May/early June. Fish may be captured by a variety of techniques (hoop netting, open water seine, and electrofishing). In addition to fin clips, 5 fish will be implanted with low frequency (48-50 mhz) radio transmitters. The fish will be monitored or "tracked" to determine their spatial usage of the lake during the spawning period. Marked and radio tagged fish will be allowed to mix for the remainder of the summer/early fall. Fish will then be tracked again in late fall 2013 to determine if they have aggregated enough for a removal. At this time, a recapture effort may commence to develop a population estimate. If recapture rates are too low (<5%) these efforts will be discontinued. However; fish captured during this period may receive marks to increase the recapture rate. Fish will then be tracked in early winter 2013/2014 until they are aggregated enough for a removal operation. When the fish have become schooled or aggregated, they will be removed through commercial fishing operations (underwater seining). A population estimate will be developed from the number of recaptured fish. A subsample of fish (-50) will be analyzed for weight, length, and an age structure will be removed for aging.