Study shows sluggish Sandusky walleye run

By Mike
Moore Editor

Sandusky, Ohio — Ohio fisheries biologists have a theory on the
spring walleye spawning run on the Sandusky River in northwest
Ohio.

“We’ve long suspected that some large number are not making that
run,” said Roger Knight, the DNR Division of Wildlife’s fisheries
administrator on Lake Erie. “We don’t see the numbers of fish up
the river that we see in the commercial seining operations in the
(Sandusky Bay) in the spring. We’ve often seen fairly decent
numbers of walleye in Sandusky Bay and we often wondered why they
were not running the river. The thought is that either they’re
spawning in the bay or their not spawning at all.”

To test the theory, biologists this spring implanted radio
transmitters in 50 Sandusky Bay walleyes to see where they were
going. The results were good in that 44 of the 50 were tracked.
However, only three of them made the spawning run up the river just
as the division biologists, and undoubtedly more than a few
anglers, suspected.

“We think it’s a habitat issue more than anything,” said Knight.
“The spawning area below the Ballville Dam (in Fremont) is not very
large in terms of the nice riffle, cobble habitat that (walleye)
like.”

The spring walleye run up the Maumee River is much more
successful and anglers know that too as evidenced by them lining up
elbow to elbow to catch large females each spring. The favorable,
rocky bottom structure of the Maumee, Knight said, is a big reason
for its success.

“In a river like the Maumee, you have fairly broad areas of
cobble habitat and the river constantly renourishing those,” he
said. “When you put a dam up, that stops the renourishing process.
That’s what we think is one of the big problems in the (Sandusky
River) system.”

The barrier is the Ballville dam, which was built in the 1920s.
In 1973, the area below the dam was channelized for better water
flow to prevent flooding events.

“In the process, they took out a lot of the gravel habitat,”
Knight said. “Four years later that we started seeing a decline in
the fishery, which is about how long it takes a walleye to reach
sexual maturity.”

The Sandusky, one of the biggest river systems in the Lake Erie
basin, hasn’t always taken a back seat to the Maumee. Things were
much different 30 years ago.

“In the early 70s, there were years where the Sandusky fishery
exceeded the Maumee fishery in terms of harvest,” said Knight. “It
hasn’t been that way in a long time. We think it was that
channelization exercise that caused a habitat constraint and that’s
what we think is the real problem.”

If the Ballville dam were removed, it would open up 14 miles of
good gravel bottom habitat above the dam that is now inaccessible
to spawning fish. And, they wouldn’t be all walleyes, according to
Knight. White bass would likely make the run in greater numbers and
it is suspected that Lake Erie sturgeon use the Sandusky River as a
nursery.

“The whole Ballville dam issue presents a win-win possibility,”
said Knight. “The city has some water supply issues; the quantity
and the quality of the water isn’t where it needs to be…. There are
things that need to be done to rectify a water issue, a dam safety
issue, and an ecology issue in that area.”

It’s not just a local issue, Knight said, but one that could
affect the bigger Lake Erie picture for generations to come not
only in Ohio but for the entire lake.

“It’s one of those rare opportunities ecologically on the Great
Lakes, particularly for a spawning stock of fish like the walleye,
which is our most important species across Lake Erie economically,”
he said. “We know from tagging studies that those Sandusky Bay fish
move east. So, if that stock could be rebuilt to larger numbers,
that could only help the fishery near Cleveland and moving on
east.”