A couple of weeks ago I highlighted a status report
featured on the North Dakota Game and Fish Department’s weekly webcast,
Outdoors Online, relating to the Missouri River- Lake Oahe walleye fishery.
This week, I’ll summarize the webcast’s recent
Devils Lake walleye population update
featuring biologist Todd
Caspers.
Todd Caspers:
The overall walleye numbers
are pretty close to average, just a little bit above average. In terms of size
distribution, right now most of the size groups of walleyes are right around
their long-term averages, except for 15- to 20-inch size group, which is the
ones anglers really like to keep. Those are a little bit below average, and the
reason for that is that from 2013 to 2015, we had lower reproduction each of
those three years, which is not typical on Devils Lake.
The good news moving
forward is that from 2016 to 2018 we had pretty good walleye reproduction, and
coupled with stocking efforts in 2016 and 2017, we should again see more
“keeper” size walleye for anglers in the next couple of years.
Our overall walleye mortality rates on Devils Lake are
on the low end of what is considered average, meaning anglers are not
harvesting too many fish. So additional regulations (size restrictions) really
would have no impact in improving size structure of the fishery.
Game and Fish also gets questions on protecting
walleyes running up the coulees (Channel A, Mauvais Coulee) in the spring.
Caspers:
At current (harvest) levels
we do not believe it is really impacting the population really at all. A good
example of that would be in 2009 when we had good coulee fishing that spring,
but we also saw a really good natural reproduction that year, our highest
reproduction event we have ever seen on Devils Lake. If the anglers were really
tough on those spawning fish you obviously would not have observed a huge
year-class in a year like that. And walleyes are a species that have a high
reproductive capacity. It does not take
a lot of females to be able to produce a good year-class if environmental
conditions are favorable for those eggs to hatch and then the young fish to
survive well.
Additionally, the majority of walleye that are caught
in the coulees north of Lake Irvine and Lake Alice are probably residents of
those two lakes, not Devils Lake itself.
Springtime walleye harvest from these coulees is not likely to harm the
walleye population since Lake Irvine and Lake Alice are relatively lightly-fished
lakes since access conditions are currently poor on Lake Irvine, and Lake Alice
is a national wildlife refuge where no open-water fishing is allowed. The most
serious threat to the walleye population in these two lakes is probably
declining water levels, which may lead to winterkill if dry conditions
continue.
There is a full section of questions and answers on
various versions of walleye size restrictions and the year-round open fishing
season on the Game and Fish website at
https://gf.nd.gov/fishing/faq
.
