The brook trout has a red elastomer tag, indicating a Tobin Strain hatchery fish. - FWS photo

Staff from various agencies conduct the Whittlesy Creek fish surveys. - FWS photo

Staff from the Ashland FRO, Whittlesey Creek National Wildlife Refuge, Wisconsin DNR and Wild Rivers Chapter of Trout Unlimited conducted fish population surveys on three index stations, September 11-14, 2006. 

Four days of backpack and barge shocking electrofishing surveys were conducted to obtain population estimates for salmon and trout species, using a mark-recapture population estimate.  In addition to these population estimates the crews also evaluated survival of previous stocking efforts, including December 2005 and January 2006 egg stocking and May 2006 yearling stocking. 

These surveys are a part of a long-term data set the Wisconsin DNR has been collecting on Whittlesey Creek, and part of the experiment to establish a self-sustaining coaster brook trout population in Whittlesey Creek.

The crews focused on capturing brook, brown and rainbow trout and coho salmon.  On the marking run, fish collected were measured and fin clipped before they were returned to the creek.  All brook trout captured were checked for previous fin clips, to determine if they were from a previous stocking. 

The yearlings that were stocked in May were adipose clipped and marked with an elastomer tag under the jaw (green tag for Siscowet strain and red tags for Tobin strain).  Some fish captured were adipose clipped indicating a hatchery fish but had lost their elastomer tag.  A genetic sample (fin clip) was taken from fish captured that were either unmarked or missing their elastomer tag to determine their origin. 

During the recapture run, any fish collected were checked for an identifying fin clip.  A formula is then used to estimate the population size of the trout/salmon species based on the number of fish marked in the first run and the number recaptured in the second run.  Population estimates will be conducted annually through 2012. 

Contact:  Jonathan Pyatskowit