Last November 1998 the Ministry of Natural Resource's Glenora Fisheries
Station (GFS) announced a "Walleye Tagging Study" (to read the press release click here). The GFS is
conducting the study to gather data which will be used to aid in understanding walleye
abundance and movements in the face of a dramatically changing ecosystem.
To help make this study successful the GFS is seeking your assistance. If you catch a
tagged walleye please remove the tag and mail it to the address shown below, please report
the date, location and size of the fish. For your efforts the MNR will send you a hat and
some specific information about the fish you caught.
The picture at the top is a close up of the actual tag and as you can
see the tag is only 4cm in length and
orange in color. Knowing this should save any heartbreak come the season opener this
spring and
mistakenly assume you just caught the tagged fish of the big derby.
The original press release stated that 12,000 fish were marked and just to clarify
marked is not tagged. Only 1000 walleye were tagged with the orange tags. The remaining
11,000 fish were marked in away that the untrained eye of the average angler would not
detect. The marks are created by cutting specific rays of the dorsal fin. When the ray
heals a tiny knot is formed. Some of the fish recently marked had the 3rd and 5th rays
counting back from the first ray cut.
One might question at this point "How does " marking" help the ministry
to understand walleye populations?"
The MNR has developed this coding system from many years of experience. The length
distribution of the marked fish is recorded at the time of marking and this is used to
estimate the age of the marked fish. The MNR recaptures walleye in trapnets a year after
marking at various locations in the bay of Quinte and eastern lake Ontario.
The ratio of marked to un-marked fish recaptured is used to estimate the population
size at the time of marking. As I mentioned earlier, the size of the fish is recorded at
marking and at recapture and this can be used to estimate the fish's age. This information
is then used in the calculations to determine the number of fish in each year class. The
GFS uses other data in their calculations and the whole process of population projections
is quite complicated and theoretical. However this technique has been used to estimate the
size of fish populations around the world for many years - it does involve some
assumptions but is a widely accepted technique.
The whole point of all this work is to manage the walleye fishery so that it continues
to provide benefits to all it's users, and thats us. So when you catch a tagged fish take
the time to help the GFS so they in turn can help us, continue to enjoy this great
fishery! That's all for now-tightlines and great fishing! P.S. See the poster below for
the mailing address should you catch a tagged walleye.
FOR MORE INFORMATION CALL THE GLENORA FISHERIES STATION AT 613 476-3255.
