"PIT" tagging article

Pennsylvania Fish & Boat Commission
PIT Tagging Muskies
by Brian C. Niewinski, Fisheries Biologist
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Muskies have earned the title “the fish of 10,000 casts”. The Pennsylvania Fish & Boat
Commission (PFBC) is working to reduce the number of casts it takes to hook into one of these
great fish by improving their Musky Culture Program. The muskellunge Esox masquinongy is a
coolwater fish that is long-lived (up to 30 years old) and can reach 60-70 inches in length. In
recent years, the PFBC has made great strides in improving the overall success of the Musky
Culture Program. To learn more about the PFBC’s Musky Culture Program, you can read the
article written by Larry Hines in the November/December 2009 issue of the Pennsylvania Angler
& Boater. One of the recent advances in the Musky Culture Program is the use of Passive Integrated
Transponder (PIT) tags. Beginning in 2007, all of the broodstock muskies spawned at the
PFBC’s Linesville State Fish Hatchery have been implanted with a 12 mm (½ in) PIT tag. A PIT
tag is a glass-encapsulated microchip that sends a unique, numeric code to a reading device. The
major advantages to using PIT tags are that the data can be retrieved without harm to the fish and
each fish has a unique identifying code. When using other tags, like Coded Wire Tags, the fish
normally has to be killed in order to recover the tag. PIT tag technology allows the researcher to
individually tag and track fish throughout their life.

When adult muskies are spawned at the Linesville Hatchery, they are first collected with trapnets
from the Pymatuning Reservoir and Sanctuary. The fish are measured and weighed, and
then the eggs and milt are collected. The fish are also scanned with a PIT tag reader to determine
if they already have a PIT tag. If a tag is not detected, the fish is implanted with a PIT tag in the
abdominal area. Some of the data collected include the date and location the fish was caught, the
date the fish was spawned, fish length, weight and sex. If a PIT tag is detected, the current data
can be compared with previously collected data. With this technology, we can track growth
rates, estimate age, determine egg production and quality based on female length and weight, and
observe movement patterns. For example, a 50 inch, 39 ½ pound female musky was trap-netted
in the Pymatuning Reservoir and brought to the Linesville Hatchery to be spawned. Because that
fish was PIT tagged, we were able to determine that the female musky had grown an average of
5 ¾ inches and 12.8 pounds per year. After the fish are spawned, the muskies are returned alive
to the waters of Pymatuning.

The Musky PIT Tagging Project allows us to follow individual fish being handled and spawned
repeatedly over many years to determine if their egg/milt production and quality have changed
over time and if the act of spawning these fish was detrimental to their growth and survival.
Another objective of the Project is to determine if muskies released into the Pymatuning
Sanctuary remain in the Sanctuary or whether they move back into the Pymatuning Reservoir.
This information on musky movement patterns could provide insights into the best locations for
setting trap-nets. This has been a great opportunity to work with a non-lethal, fish marking
technique and to better understand the capabilities and limitations of this state of the art
technology.

Recently, Biomark, Inc. introduced a smaller, 8.5 mm (0.33 in) PIT tag. In 2010, we
experimented with tagging yearling musky at Linesville that were approximately 300 mm (12 in)
in length. The fish survived well with the smaller tag and were released into the Pymatuning
Sanctuary. With this yearling group of muskies now at large, there are now known-age, PIT
tagged muskies in the population. Each recaptured, PIT tagged musky will provide researchers
and managers with valuable data.

During 1997-2000, the Ohio Department of Natural Resources (ODNR) released yearling
muskies into the Pymatuning Reservoir that were given unique fin clips corresponding to the
year they were released. We’ve been catching these fin clipped muskies (now 11-14 yrs old) in
our trap-nets in the Pymatuning Reservoir and implanting them with a PIT tag allowing us to
now track their age and growth over time as they are recaptured.

In 2011, the Three Rivers Chapter of Muskies Inc. presented the PFBC’s Executive Director, John Arway, with a check for $500 to support the Musky PIT Tagging Project. These funds are greatly appreciated and will be used to buy additional equipment like PIT tags, injectors, and
readers.

The plan is to continue PIT tagging all of the broodstock muskies that are spawned at Linesville
and to continue to collect valuable data on age, growth and performance. The PFBC’s Fisheries
Management Division is currently evaluating the efficacy of using PIT tags in wild musky
populations in Pennsylvania. The PFBC will continue to look for ways to adapt emerging
technologies into our fish culture and fisheries management programs.