Dinosaurs among us

Scientists estimate the sturgeon family has been around for more than 60 million years. That makes them contemporaries of T. rex and other creatures from the Age of Dinosaurs.
There are nine species of the sturgeon family across North America, and most are threatened, endangered, extirpated, or “of concern.”
In most of its original habitat, the lake sturgeon has been decimated or eliminated.
In the Rainy River basin, we are fortunate to have one of the few recovering and healthy populations of Acipensir fulvescens, or the lake sturgeon—the only species native to our watershed.
But it hasn’t always been that way. At the beginning of the 20th century, in less than 10 years, wanton over-harvesting of the resource by European settlers nearly wiped out the massive numbers of lake sturgeon that had provided a staple food supply for native peoples for centuries.
Further degradation of the waterways by clearing, erosion, and indiscriminate dumping of industrial and municipal waste continued beyond 1950.
“In the 1970s we began to see a rebound in lake sturgeon populations,” noted biologist Dennis Topp, Assistant Area Supervisor, Fisheries with the Minnesota Department of Natural Resources in Baudette.
Today, these fisheries are managed by a model of inter-agency co-operation.
On Rainy Lake, the Rainy River, and Lake of the Woods, the Ontario-Minnesota Fisheries Committee, and other stakeholders such as the Rainy River First Nations, conduct joint and independent studies as part of the overall management of this and other shared fisheries resources.
The Minnesota DNR continues to carry out tagging studies on the lake sturgeon populations in the Rainy River and Lake of the Woods. More than 5,000 have been tagged to date.
The tag placed near the caudal fin has a unique number. If you catch a tagged fish and intend to release it, do not remove the tag. Rather, record the number on the tag, date caught, location, approximate length, and if you kept it.
Then report this information to the Baudette Area Fisheries office at 1-218-634-2522.
From tagging studies, it is estimated that the Rainy River has an estimated population of around 60,000 lake sturgeon over 40 inches, around 14 plus years of age, said Topp.
“The sturgeon sport fishery is very important to our area, both socially and as a economic activity,” noted Mike Larson, Area Supervisor, Fisheries at the DNR in Baudette, stressing their determination to further enhance the population and habitat by further reducing harvest to very conservative levels and encouraging catch and release.
Minnesota has very strict regulations and slot sizes for sturgeon, including a single annual harvest tag.
On a recent trip on the Rainy River to the mouth of the Rapid River, where the DNR was netting sturgeon during the spring spawn, Topp said they were continuously evaluating their sampling techniques, including larger mesh nets with heavier line, to see if they could capture and tag some of the larger sturgeon.
Put simply, “they break stuff,” said Nick ‘Tiny’ Schlesser, Area Fisheries Specialist. At 6’8”, Schlesser is the designated wrangler for handling the monster sturgeon in this tagging program.
Minnesota’s largest recorded angling catch of a lake sturgeon is 94 pounds, four oz. in the Kettle River in 1997 while the largest netted was recorded on Lake of the Woods in 1911 at 236 pounds.
But the DNR’s website shows an old photo from 1905 (before the days of PhotoShop) of a 15-foot specimen caught in the Roseau River, purported to weigh roughly 400 pounds.
This DNR website also has a wealth of other fishery information, including a length-girth-weight chart for estimating the age and weight of your catch.
This is an important tool as there is no other practical method of determining weight of a large catch and release sturgeon without injuring it.
Schlesser, extending his massive hand, displayed a tiny stone fly he had scooped from the Rainy.
“This critter grazes on algae growing on stones in the bottom of a stream. It is a good indicator of good water quality,” he explained, noting the steady water quality improvement of the Rainy over the past few decades.
Since European settlement of this watershed, numerous water control structures on the Red River and Winnipeg River systems have prevented the movement of adult sturgeon migrations—effectively segmenting remaining populations and restricting spawning patterns.
Although Topp works primarily out of the DNR office in Baudette, he also works on the lake sturgeon programs in the adjoining Red River watershed.
“There were over 300 water control structures on the Red River system in the U.S.,” he said, noting the eight on the U.S. portion of the Red would all have been eliminated or modified by the end of this year to facilitate free movement of spawning fish.
“We have been re-introducing lake sturgeon populations into the Red system,” Topp added, explaining they have been purchasing eggs and stock produced by the Rainy River First Nations sturgeon hatchery near Emo.
The DNR thinks the material from the Rainy River basin is the best genetic match to the remaining and previous Red River populations.
Although female sturgeon can produce from 50,000 to more than one million eggs in a single year, they only may spawn once every four-nine years and generally don’t start spawning until they are more than 25 years of age.
They continue to produce over their lifespan, which has been documented at more than 80 years and likely exceeds 100, noted Topp.
Males, Topp added, generally spawn every other year beginning at around 15 years of age. Males and females are externally indistinguishable, and are identified by DNR staff by expelling either eggs or milt during handling.
More invasive identification techniques are avoided.
“We are not sure of all the factors, but we are certain the Rainy River itself is the key to the health of this lake sturgeon population,” said Larson, alluding to continued and expanding research activities.
Although lake sturgeon migrate and spawn up the Rainy and many of its tributaries, the population appears to be spreading across Lake of the Woods and there are indications of some successful spawning in the lake itself, he added.
The dam at Fort Frances effectively has prevented the Rainy River population from mingling with that of Rainy Lake.
There are differences in the fishing seasons and catch limits between Ontario and Minnesota—reflecting the different goals and objectives of each jurisdiction on this shared resource.
They will be dealt with in detail in an upcoming article, along with an Ontario perspective by John Vandenbroeck, a biologist with the Ministry of Natural Resources in Fort Frances.
Larson stated, however, that in Minnesota, the importance and scope of the lake sturgeon as a tourist attraction was expanding beyond a record catch, adding catch and release does not seem to overly stress the fish as the same tagged fish have been caught twice in a single day, without observable ill effect.
“And we have people that come from Wisconsin just to watch them spawn in the Littlefork,” he said, explaining the fascination many have with seeing the huge creatures up close or watching them frolic in the Rainy as they leap and roll.
Look, there goes another dinosaur!