RIVERDALE - A few years ago the Garrison Dam National Fish Hatchery took on a project that they believed had never been tried before. If it had been tried, it certainly wasn't successful.
"We started in 2006 when there was no propagation efforts that we were aware of," said Rob Holm, hatchery manager. "Burbot are declining or threatened throughout their range, worldwide, so we had a lot of interest from other countries when we started the spawning. They wanted to develop burbot stocks in their own historic range."
Burbot, sometimes better known as ling or eelpout, are more snake-like than fish in appearance. They are often shunned, even feared, by fishermen who catch them but they are a very good eating fish. In fact, so tasty are they, that burbot are often referred to as "poor man's lobster."
This young burbot, or ling, was hatched at the Garrison Dam National Fish Hatchery. The tail of another burbot can be seen extending outside a small piece of PVC pipe used to simulate a natural hiding place.
Not much is know about the snake-like fish, other than that their populations have declined considerably in much of their home range. How many exist in the Missouri River today is uncertain, but the occasional catch by a fisherman is proof that burbot have not disappeared from the system. That's not the case elsewhere.
Along the Wind River in Wyoming, burbot have been fished extensively for years, perhaps too much. Populations of burbot in that river are believed to be in peril. Without a way to replace them, they are in danger of disappearing entirely. However, as biologists soon discovered, no one knew how to raise burbot in a hatchery environment. A new technique would have to be developed. That's when research work began at the Garrison hatchery.
Burbot are basically a bottom-dwelling fish, certainly not the kind of fish that lends itself to easy capture in nets. Additionally, they like to hide in caverns and deep within rocks. Finding them gathered together, such as during the spawn, was virtually impossible because burbot spawn underneath the ice as early as January. Netting them was simply not a viable option.
The hatchery staff let it be known to fishermen who frequent the Garrison Dam Tailrace that they would like to obtain some burbot for an experimental propagation program. In time a few adult burbot, caught on hook and line, were turned in by helpful fishermen. That handful of fish was the beginning of the burbot experiment. Even though hatchery personnel were familiar with rearing multiple species of fish, burbot proved to be a difficult challenge.
"We still haven't got it knocked down," said Holm. "I know the first couple of years we tried to raise them it just didn't work out at all. Now though, it seems like we've gotten past the spawning issues. Now it's just a matter of refining what we can do with the feed part of it."
Biological technician Carmen Sheldon was assigned the task of discovering a working formula for raising burbot from eggs to fingerlings. Burbot eggs are so small - tinier than a grain of salt - that it takes a microscope to count and observe them. Newly hatched burbot appear as little more than flecks of lint suspended in the water.
What the burbot would eat, or accept as food, in a hatchery environment was unknown. Several food sources were tried, most of them without success. Sometimes burbot would accept micro-organisms but, when it became apparent larger feed was necessary, the transition failed. For a time it seemed as though raising burbot in a hatchery might not be possible. Each year the numbers of tiny fish would diminish until only a few remained.
"What we found was that two or three cannibalistic fish in the group would eat the rest of them," explained Holm. "Last year Carmen was able to get them on a diet. We have some confidence. I think we are moving along."
Today three different life stages of burbot are alive and well in hatchery tanks - adults, fingerlings and those recently hatched. Encouraged by recent results, it may not be long before research conducted at the Garrison Hatchery will lead to restoration of the burbot population at Wind River.
"The idea would be to collect fish from the Wind River, spawn them there and then ship the eggs over here," said Holm. "There's some importing issues with the state, but that's the idea."
Although the Wind River connects with the Yellowstone River, and the Yellowstone to the Missouri River and Lake Sakakawea, Holm says precautions will have to be taken to prevent the possibility of a Wind River strain of burbot from entering the Missouri. One of the precautions would be that Wind River eggs and resulting fry would never leave indoor tanks at the hatchery.
"We want to get all the techniques down," said Holm. "They have three different populations over they that they are wanting to restore. Their numbers are way down in that fishery."