Multiple years of sampling to mark and recapture individuals completed between 2006 and 2008 Despite significant effort, population estimates were not as precise as hoped - Peterson and Jolly-Seber estimates showed significant differences for the same time periods A small number of marked fish recaptured, insufficient mixing of tags between samples for Peterson estimates, and potential trap avoidance for Jolly-Seber estimates were potential problems Given the constraints noted above, we evaluated all the data and established a population estimate that reflected the most likely compromise. Population assessments suggest a population size of ~ in both basins of Moyie Lake combined. North Moyie – 1500 to 2500 adult burbot South Moyie – 1000 to 1200 adult burbot Moyie Lake Stock Status
Moyie Lake Angler Use fishery almost entirely through ice used trail cameras and angler interviews to track effort in 2007 and 2008 Significant change in timing and location of angler effort in 2008 Fishery was “discovered” in 2008, with effort on spawning concentrations during the daylight hours with significantly higher catch rates
Moyie Lake – Creel Survey and Fishery Management Fishery impacts could be a concern in this developing fishery and are being tracked. – caught 515, harvested 168 –2008 – caught 1089, harvested 360 (may be an under-estimate of both effort and catch) –Based on population estimates, this represents an annual exploitation rate of 14-24% –Modeling of the historic Balfour burbot population suggests exploitation rates of 20% may have been sustainable for that population New regulations are being implemented this winter (time period closure) to allow some recreational opportunity, reduce the possibility for over-harvest, and limit the exposure of spawning congregations to recreational angling
Moyie Lake spawning locations identified in 2008 (creel info suggests spawning as early as the last week of January, and as late as the last week of February) KTOI and MoE staff completed two trips to Moyie, the first we identified spawning sites, while the second was targeted on collecting gametes for fish culture activities We were successful in collecting sperm (50+ samples in one day) and KTOI staff established high motility using extender after 1 week. Although one ripe female was collected on the first trip, none were collected when we attempted to collect gametes on the second trip New capture methods will be employed in 2009 when we again attempt to provide gametes and should improve our catch of females Moyie Lake Burbot Biology
Spawning congregation observed on Moyie Lake – Spring 2008 Moyie Lake Burbot Biology
Next steps: –monitoring donor population (ongoing assessments of angling effort and population strength) –refining methods for providing broodstock while minimize impact to donor stock (ie. capture, spawning and release at spawning location instead of removal and captive stock) –provide up to 3 million fertilized eggs to U of I for fish culture experiments Turning the Tides - Burbot Recovery Efforts Funding for this work provided by: Kootenai Tribe of Idaho and Idaho Dept of Fish and Game through the Bonneville Power Administration (Northwest Power and Conservation Council’s Fish And Wildlife Program)Kootenai Tribe of Idaho and Idaho Dept of Fish and Game through the Bonneville Power Administration (Northwest Power and Conservation Council’s Fish And Wildlife Program) BC Mountain Pine Beetle FundBC Mountain Pine Beetle Fund BC Ministry of EnvironmentBC Ministry of Environment