Service biologist Dale Hanson of the Green Bay NFWCO has been collaborating with Craig Stafford (University of MT) to investigate the relationships between lake trout length, otolith weight, and age.  As fish get older their body growth slows.  Fish otoliths, or ear bones, are different and continue to grow over the fish's entire lifespan.  Hanson and Stafford have been manipulating these structural growth differences to develop a new method based on the ratio of fish otolith weight to fish length.  It is hoped that this new approach will offer an objective method for evaluating growth rates and ages among different populations of fish.  Hanson presented preliminary results of this work to Lake Michigan managers at the 2009 winter Lake Michigan Technical Committee meeting and also presented the work to the American Fisheries Society WI\MN\Ontario joint annual chapter meeting on February 2nd, 2009.