DNR Stocking Effort Features Flying Fish

Humans have been "stocking" fish for a couple millennia. Chinese palaces often featured ponds inhabited by ornamental fish and archaeological evidence suggests several Mediterranean civilizations were in the business of enhancing their fisheries before the Roman Empire took them over.

In the United States the practice of "planting" fish goes back to the colonial period. Early attempts were focused on sport fishing and involved mostly trout.

The bad news was hatchery raised fish were being released with little planning or consideration for ecology.

In 1871 the government recognized the need for a more scientific approach and the "United States Fish Commission" was established. Later the Commission morphed into the "Fish and Wildlife Service." They developed the scientific foundation for establishing and maintaining fish populations.

Today the management of freshwater sport and commercial fisheries is largely the responsibility of the states which, in Minnesota, means the Department of Natural Resources or DNR.

Fish hatcheries are operated by the DNR's Section of Fisheries. They do excellent work. Lots of fish are raised and released annually, mostly transported by truck. Land vehicles are equipped with a 125-gallon tank that can hold up to 8,000 fish. Every effort is made to keep the passengers comfortable including adding oxygen. Ceramic stones are used for diffusing air in the tank, much like a sophisticated home aquarium.

Not all the lakes that would benefit from stocking are accessible by road. Fortunately, the DNR has aircraft and pilots. Better yet, they have Brad Maas, who was a fishery technician for 31 years before transferring to aviation and is also an expert helicopter pilot. In April, Brad flew over 2,800 trout to a remote lake in Voyagers National Park. Flying fish is a regular part of his job.

Before Maas started working with DNR Aviation, fixed-wing aircraft were used to stock fish. Helicopters offer several advantages, including a more comfortable ride and the ability to carry more fish. They can also fly in weather conditions when floatplanes would be grounded, and best of all they deposit the fish without touching the water.

Floatplanes have the same issue with transporting invasive species as boats. The U.S. Park Service likes the helicopter for that reason.

DNR Aviation's MD-500 is almost the perfect aircraft for flying fish, but tanks that would fit the cabin were not available.

So, Maas put on his inventor hat and made one. After some careful measuring, he used cardboard to build a mockup and fitted it to the helicopter's cabin. Then he took the cardboard pieces to a fabricator and ended up with a four-compartment aluminum unit that weighs only 128 pounds.

Brad's tank has been in use for three years and most of the bugs are now worked out.

Maas is a full-time DNR pilot and does all the helicopter fish flying. That takes about 20% of his time, but it seems to be his favorite activity.

He learned to fly in the U.S. Army's "High School to Flight School Program" during the Vietnam war and flew the legendary "Huey" for five years before transferring to the Minnesota National Guard. Maas manages the helicopter fleet and is responsible for training helicopter pilots.

The DNR entrusts fish only to their most experienced aviator. However, Maas is currently writing a manual about using the helicopter and tank to stock fish so in the future other pilots will not be scratching their heads and saying, "How the heck did he do that?"