Where have all the coasters gone?
Mark Brouder
Since 2003, the US Fish and Wildlife Service’s (FWS) Ashland, WI National Fish and Wildlife Conservation Office has been stocking various life stages (eggs, fry, fingerlings, & adults) of 2 strains of coaster brook trout (Tobin Harbor and Siskiwit Bay; Isle Royale) into Whittlesey Creek, WI as part of a long-term experiment to re-establish a migratory brook trout population in this Chequamegon Bay, Lake Superior tributary. To date, different life stages of coaster brook trout have been stocked into Whittlesey Creek, with varying degrees of post-stocking success based on annual fall assessments. Thus, we often times found ourselves asking, “Where have all the coasters gone?” Although a question not easily answered, the FWS has recently turned to PIT tag technology to help find an answer.
If you have taken your dog or cat to the vet lately, you are probably familiar with PIT (Passive Integrated Transponder) tag technology. PIT tags are similar to that little micro-chip your vet offers to place into your dog or cat in the unfortunate event he/she gets lost. If found, your vet can scan your pet with a wand-like PIT tag reader to confirm that, in fact, it belongs to you.
Throughout the month of May, PIT tags were inserted into approximately 2,100 5-6 inch coaster brook trout and the FWS installed a remote PIT tag reading station near the mouths of Whittlesey and Little Whittlesey creeks. The remote station is comprised of an antenna that loops across the stream and a PIT tag reader. As a PIT tagged fish swims through the antenna, the tag is activated, “releasing” its 10-digit unique id, which is then transmitted to, and ultimately read and recorded by, the PIT tag reader. Because this station is remote, we rely on a solar panel and 2 deep cycle 12V batteries to provide continuous power to the antenna and reader.
On May 18th, 2008, as part of the Chequamegon Bay Birding Festival’s Coaster Brook Trout field trip, the FWS and 2 dozen volunteers released 100 PIT tagged coaster brook trout into Whittlesey Creek, 23 of which have already been detected moving downstream from where originally released and through the antenna near the mouth of Whittlesey Creek. Another interesting observation is the apparent movement pattern of these fish, the majority of which has occurred between 11:00 PM and 2:00 AM. In just over 1 months time using PIT tag technology, we have begun to learn more about the fate of fingerling coaster brook trout stocked into Whittlesey Creek than we had in the previous 5 years without. We are anxious to see what the coming months and years of PIT tag data tell us about coaster brook and our ability to re-establish this migratory form to Whittlesey Creek.
On June 10, 2008 FWS, TU, and volunteers released the remaining 2,000 PIT tagged coaster brook trout fingerlings into Whittlesey and North Fork Whittlesey creeks. Stay tuned for updates as to their whereabouts!
Notes by Bill Heart: The Wild River chapter has been working with Mark and the Fish & Wildlife Service on Whittlesey Creek for many years. We applaud their interest and hard work for trying to make a successful re-introduction of coaster brook trout. This latest effort with using PIT tags has given them more information on the movement of the coasters in these past couple of months then has been received in the past five years. The Red Cliff Tribal Fisheries Department and The Bad River Tribal Fisheries are installing a PIT tagging reading stations on Raspberry Creek and Graveyard Creek on their reservations. Since we believe that these fish do move to different streams, I would like to see the Wisconsin DNR at least start looking at the possibility of install a few PIT stations on a few of the south shore tributaries of Lake Superior. Possibly Fish Creek, Bark River, and the Sioux River. It would be wonderful to monitor the movement of these tagged fish up and down the Bayfield Peninsula.
I have helped with population estimates and stocking of all life classes with the F&W Service and the WDNR for 5 or 6 years and the results are starting to get a little more exciting. Just being able to be out on Whittlesey Creek releasing these coaster brook trout, like last week, and seeing some of the results, makes all of my work for TU worth every minute of it.