Blue Pike Workshop Minutes July, 1997............ A lot of questions answered
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List of attendees at the end of this report
1. Why revisit the blue pike issue?
listed several reasons to this question. There has been continued interest and
questions by the fishing public about blue colored suspects caught in other
lakes, especially in northern Ontario. A new tool, DNA analysis, that may be
able to better differentiate blue pike from walleye. A guild approach analysis
by our office found that blue pike fit into the offshore, coldwater community. A
search of suspects should focus on lakes with coldwater habitat. He showed a
graph of the historic commercial catch of blue pike indicating their economic
Issues in identification
Stepien reviewed research on the mitochondrial DNA (mtDNA) analysis of walleye
and a few blue pike suspects from Lake Erie and Canadian lakes. The blue pike
suspect samples were not significantly different than the Lake Erie yellow
walleye. However, she cautioned that mtDNA follows only the maternal line. The
mtDNA of one sample provided through Dieter's office from a source in Canada did
fit within that found in Lake Erie's walleye but it also had a few differences.
She has not completed the analysis of mucus from blue pike scale samples. She
will be using nuclear DNA analysis as a second method of testing genetic
differences of populations and species. This process provides more complete
data. She is also currently looking for museum specimens not fixed in forinalin.
Some recent research on extracting DNA from specimens fixed in formalin, has
been reported in the literature but she has not been able to get complete DNA
from formalin preserved samples. The preferred material/tissue for new/fresh
samples is liver or a piece of muscle tissue from fresh blue pike suspects for
DNA analysis. The samples should be wrapped in foil and frozen. If the sample
cannot be sent frozen, it can be preserved in 95% ethanol and shipped to her
lab. Information on location fish was caught, and morphological characteristics
such as length and weight should be sent with the sample.
Burnham‑Curtis has scale samples of blue pike and walleye, including
samples collected by John Parsons from the 1920's through the 1950's. She has
found DNA, but there is contamination from chemicals in the paper used in the
envelopes to hold the scales. She is working on separating the chemical
contaminants and DNA fragments.
Halyk mentioned a researcher at the University of Guelph, Dr. Moira Ferguson and
a graduate student who will be analyzing scale sa:mples collected by OMNR in the
central basin during the 1950's.
mentioned another researcher, Dr. Neil Billington, who analyzed three suspects
sent by our office. He also found no difference in the mtDNA of the blue pike
suspects and walleye.
continued on the need for funding to continue these efforts. There was a promise
of support for any grant proposals. Other suggested sources of funding are
non‑profit groups and sport fishing clubs.
Trometer passed out a table listing physical and habitat differences between the
sauger, walleye and blue pike based on a literature search. If there are any
suggestions or changes, please forward them to Betsy.
Ed Crossman, Royal Ontario Museum, Toronto, has been reviewing their blue pike
and walleye collection and measuring morphological characteristics and has been
unable to separate the two subspecies. It is unclear whether he was looking at
the traditional characteristics such as eye size, or was looking for other
differing characteristics. He has also compared blue pike suspects with the
museum collection, and has not found any
to be blue pike.
Daniels, New York State Museum, Albany, also has a reference collection that he
has compared blue pike suspects with and found none of the suspects to be blue
Jorgensen gave a short presentation on the history of the blue walleye in Lake
Nipissing. Historically there may have only been blue pike in the lake, but has
since been replaced by numerous stockings of walleye. The average depth of the
lake is approximately 14', but there are places in the French River near the
mouth as deep as 300’, which could have been the summer refuge for blue pike.
In the 1970's, blue walleye were examined morphologically and only one was
identified as a blue pike.
How could blue pike be located (if they survived)?
of historic agency transfers
office has received several documents that indicate there were transfers of Lake
Erie blue pike to lakes in Tennessee and Minnesota. Ontario Ministry of Natural
Resources has an electronic database of fish transfers that go back to the
1970's. Earlier records are in files. There is a code for blue pike that
indicates it may have been transferred. Larry Halyk will search this data for
for inland lakes with "blue pike" habitat
effort is needed to identify bodies of water that provide the correct habitats
needed to support blue pike and to identify the historic and current population
Larry Halyk will also try to review the morphology of Ontario lakes and identify
those that have coldwater habitat.
guide for screening suspects
office will be working on producing a field guide to help the fishing pubic
screen suspects based on morphologic and habitat characteristics. Those that
they identify as potential blue pike can be saved for more rigorous screening
and DNA analysis.
Potential hindrance to restoration if stock were found
are concerns that the present environmental conditions and fish community may be
a hindrance to efforts to restoration. Of particular interest is the impact of
rainbow smelt if they are a major part of the diet of blue pike. Smelt were
becoming very abundant at the same time the Lake Erie blue pike population
crashed. Smelt have high levels of the enzyme thyaminase, which causes thiamine
deficiency in some of the fish species that feed on them. Thiamine deficiency
has been linked to reproductive failure in lake trout, coho and Atlantic salmon.
Dr. Ketola has been heading a project examining the impacts of thiaminase on
Lake Erie walleye. Walleye in Lake Erie feed heavily on smelt. Preliminary
research indicates the levels of thiamine in walleye eggs collected in the
eastern basin of Lake Erie are significantly lower than in walleye eggs
collected from Oneida Lake. Next he will be measuring thiamine levels in walleye
eggs collected from several sites around Lake Erie. He will also be comparing
concern is to find funding to continue DNA research.
· Search databases for blue pike transfers
· Search databases for lakes that provide "blue pike" habitats.
· Prepare a “field guide” and get this information out to the fishing public so that they can use for field screening to provide samples of potential blue pike for DNA analysis.
· Continue efforts to restore native forage fish diversity and to limit negative impacts caused by exocitc forage fish such as smelt.
· Keep public informed as to progress in the search for blue pike.
Great Lakes Fishery Resources Office
U.S. Fish and Wildlife Service
405 N. French road, Suite 120A
Amherst NY 14228-2008
Biological Resources Div.Great Lakes Science Center
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