BY DALE HANSON, GREEN BAY FWCO
Dale Hanson, biologist at the Green Bay Fish & Wildlife Conservation Office (FWCO), recently worked with the Great Lakes Fishery Commission's web developer, Jeff McAuley, to update the Great Lakes Fishery Commission’s fish stocking database with all reported fish stocking events that occurred in the Great Lakes during 2014. Hanson works with state, tribal, federal, and provincial agencies across the Great Lakes to report the number of fish stocked in a standard database. The database, available on-line at http://www.glfc.org/fishstocking/ enables fish managers, researchers and the general public to determine the number of fish stocked by species, location, and date for each of the five Great Lakes. Users can also find information on tagged fish; tag numbers can be entered on-line and users can get information such as the strain of the fish, its original stocking location and the age of the fish. The database is generally updated with the previous year’s stocking events by April 1st.
BY DALE HANSON, GREEN BAY FWCO
Green Bay FWCO biologist Dale Hanson and Chuck Madenjian (USGS Great Lakes Science Center) recently completed the annual report summarizing the progression of lake trout rehabilitation in Lake Michigan. This report is based on the consolidated data from spring and fall gillnet surveys completed by state, tribal, and federal agencies throughout Lake Michigan. Average catch rates, the proportion of wild origin lake trout, and the age structure of lake trout populations within each statistical district of Lake Michigan are highlighted in the report. Overall, lake trout abundance in spring surveys are below the benchmarks defined in the rehabilitation plan; however the fall spawner survey catch rates exceed the benchmarks in most locations of the lake with the exception of the Northern Refuge. Most importantly the surveys have shown consistent detection of unclipped "wild" lake trout in recent years. Wild fish accounted for up to 50% of the spawners caught in southern Lake Michigan waters and between 10-30% in the MidLake Refuge and waters along the western shore of Lake Michigan and Little Traverse Bay in northern Lake Michigan. This report was provided to the Great Lakes Fishery Commission’s Lake Michigan meeting on March 25th in Ypsilanti, Michigan.
BY BRANDON KESSLER, IRON RIVER NFH
This winter at the Iron River National Fish Hatchery we renovated one of our fish towers. The fish tower uses a pump to move fish from the raceways into the tanks on the truck. Fish leave the dewatering tower via a short or long pipe and gently slide into the tanks. We measure the amount of fish we are loading by using volumetric displacement. We currently raise about 1.3 million lake trout which are stocked into Lake Huron and Lake Michigan. The purpose of the renovation was to make fish loading safer, quicker and easier, and to reduce the stress on the fish. The first problem we sought to overcome was the need for a long loading pipe which can cause stress on the fish and is heavy for the staff to lift onto the trucks. Due to space limitations, the tower needed to be located between the raceways. In this position, the trucks can only back up to the tower instead of pulling up alongside it. We remedied this by creating a platform that bolts onto the tower. The tower can be lifted with a forklift and placed on top of the raceway, clearing space for a truck to park alongside it. The modification will eliminate the need for moving trucks during loading, and get trucks on the road faster. Second, we wanted to make attaching and handing of hoses easier, to speed up moving from one location to another. This was accomplished by making the water discharge tube permanent and free moving so when the tower is raised and lowered the hose does not need to be moved or detached. The loading tube was modified by attaching a permanent section of tube to the tower, creating a lower more manageable connection point for the pump hose. This improvement eliminated the need to have a 30 foot stiff hose to move from raceway to raceway. It will also increase safety because the old hose was heavy and cumbersome, and when flexed it could straighten and push people off raceway walls. These two renovations will make fish loading smoother, faster, and safer. All of this will lead to happier and healthier fish upon arrival at their stocking locations.