Trout Raining From the Skies

Pilots use 1950s method of aerial fish stocking in remote areas of Maine

May 1, 2006

My wife, Lorraine, and I were enjoying a quiet day of fishing on a remote Maine trout pond last fall when my ears perked up at the sound of a light airplane. As a pilot, I couldn't resist craning around for a look. I turned just in time to see a low-flying Cessna floatplane approaching. At that instant, a gush of foaming water blossomed out and streamed back from each side of the pontoons, and several hundred slim, dark shapes came arcing down and splashed into the pond a couple of hundred feet from our canoe, as the pilot throttled up and roared away overhead.

Our small pond was receiving its annual stocking of brook trout — in spectacular fashion.

The technique of stocking fish by dropping them from the air was developed in Maine, by Maine Warden Service aircrews. Maine has hundreds of small ponds, many located in remote areas and inaccessible by road. Many are popular with anglers, who may reach them by hiking or — if the pond is large enough — flying in by bush planes. Increasing popularity meant that existing native fish populations often must be supplemented by stocking.

As early as the 1940s and 1950s, Maine warden pilots began stocking ponds from the air. Initially, an old Stinson Reliant was equipped with interior tanks, with chutes opening through the bottom of the fuselage. The pilot released the fish by reaching back and pulling hand levers. Later, as wardens began flying more modern aircraft, including Piper Super Cubs and Cessnas, they designed and perfected the current system of pontoon-mounted tanks.

Presently, the warden fleet comprises three Cessna 185s, mounted on floats in the summer and wheel skis during the winter months.

The torpedo-shape plastic tanks, mounted on each pontoon, are designed so that they are held upright by a heavy pin in a slot at the front. They are off balance, so when the pin is retracted by a solenoid controlled by a switch in the cockpit, the tanks tip outward and dump the fish and water. They are individually controlled, so the pilot can select to drop either tank, or both simultaneously. Each tank is equipped with an oxygen system, controlled from the cockpit, to keep the water well-oxygenated and the fish lively and healthy during the flight from stocking truck to pond.

Each tank holds 25 to 30 gallons of water and 90 pounds of trout. In the case of legal-size trout (from 8 to 12 inches long), as many as 350 trout occupy each tank.

The Maine warden pilots stock approximately a quarter-million fish (mainly brook trout, but also some landlocked salmon and splake, a hybrid of brook and lake trout) annually in 150 to 160 ponds in areas inaccessible to trucks. This is roughly 15 to 20 percent of the 1.5 million or so stocked each year, according to the hatcheries' superintendent Steve Wilson.

Funding for aerial fish stocking comes from revenue produced by the sale of hunting and fishing licenses. Recently a bond issue for $7 million was approved, earmarked for badly needed improvements to the hatcheries. Receiving the largest upgrade is the Embden Hatchery, which raises and supplies most of the trout stocked by air.

Aerial fish stocking occurs in the spring and fall, with the bulk of the drops made in late September through early October. This is close to the end of the fishing season. The trout then have all winter to become acquainted with their new home, and become acclimated to the wild and to foraging on their own before the next fishing season rolls around. The fall stocking usually coincides with the peak of the foliage season.

The normal drill is that early in the morning one or more tank trucks are loaded with thousands of fish at one of the department hatcheries and driven to a rendezvous point at a lake. The three airplanes (often supplemented by a Cessna 185 and pilot loaned by the Maine Department of Conservation to expedite the process) land at the lake and taxi to the shore, where a ground crew awaits. The crewmembers fill the seaplanes' fish tanks with fresh water from the lake and then dump in the squirming trout, which have been carefully weighed and counted. The pilots receive instructions as to the locations of ponds and quantities of fish that each pond is to receive.

And then comes the takeoff and the flight — sometimes exciting because the heavy load of water and aeration equipment can come close to the aircraft's maximum payload.

As the airplane lifts from the water, there is the thrill of flight. The shore-side trees dip below the nose and pass underneath. The world opens up — a world of vast forests, blue lakes dotted with toylike boats, and distant blue mountains. And in this fall season the leaves are turning color and the hillsides form a tapestry of orange and gold and scarlet.

In the intensity of takeoff, the pilot may have forgotten all about the "passengers" sharing this airplane ride with him.

A glance down through the airplane's side window shows the large red, rocket-shape tank fastened to the top of the pontoon. The wind blast from the slipstream lashes the surface of the water in the tank, mixing a good supply of oxygen into the water. Under the ruffled surface the pilot can make out the dim forms of swimming fish. They swim agilely about the tank, unaware that they are now being flown 1,000 feet above the ground. And they don't know that in a few minutes they face the most exciting adventure of their lives.

As the airplane approaches the designated pond, the pilot throttles back and sets up his approach by adjusting engine power and flaps for a gradual descent. Ideal drop speed is approximately 70 knots, at treetop level (50 to 70 feet agl). This dissipates the forward motion of the fish and ensures that they fall straight down into the water to minimize the shock, rather than skipping along the surface.

The trout hit the water with a splash. Instantly, they dive and disappear.

Department biologists using scuba gear have had trout dropped around them and observed as the fish hit the water and swam away. The biologists report that most of the trout easily survive their aerial drop without injury or harm.

The warden pilots have racked up a remarkable record of success and safety over the decades, while hauling millions of fish on thousands of fish-dropping missions. Often, this is flying under tough conditions. Many of the smaller ponds are tucked up in the mountains, sometimes almost completely surrounded by granite peaks. Pilots must sometimes thread their way up narrow, twisting valleys, dodging tall trees and craggy cliffs. Then there's always the weather to contend with — mountain squalls, scud, gusty winds — while delicately maneuvering a heavily loaded and aerodynamically "dirty" aircraft at low airspeed.

There have been misses and mis-haps. One pilot once found himself in a fuel-starved situation while engrossed in a long, tiring day and was forced to land in a rough clearing. The floats were damaged, but the airplane and pilot survived to fly again. Another pilot, landing in rough conditions on Rangeley Lake, had his airplane hit by a powerful wind gust, which forced the floats under and flipped the airplane over onto its back. He was rescued by a passing boater, and the aircraft was subsequently hauled ashore and restored to airworthy condition. And there have been a few "misses," when fish inadvertently have dropped on land instead of hitting the water. This usually occurs at the smallest, trickiest ponds in the mountains, when unpredictable wind gusts can blow the falling fish off course.

One day a pilot had a problem at a tiny pond in eastern Maine, when one of his tanks delayed tripping when he flipped the switch. A couple of fishermen approaching the pond through the woods heard an airplane roar overhead, and seconds later trout began falling down through the tree branches around them, flopping at their feet. The fishermen failed to make the connection between airplane and fish. Later that day when they encountered a crew stocking fish in a brook, they approached the men and said, "You guys ain't gonna believe this, but...."

Brook trout are among nature's most beautiful and admired creatures. They provide beauty and pleasure (and excellent eating!) to many. But trout are extremely vulnerable. They can't tolerate competition for food and space from more aggressive fish species. They do best when they alone occupy a body of water. They can live only in water that is very pure, clean, and cold. They cannot survive in warmer, dirty waters. Also, trout are slow to reproduce. So even where the environmental conditions are good, their numbers are rapidly depleted by heavy fishing. Even at best, trout are very short-lived. A 3-year-old trout is old; few trout live to the age of 4 or 5 years.

All of which adds up to the need for stocking these waters to maintain fish population. Aerial stocking of trout is exciting and colorful. It's also less expensive and faster than stocking by truck or backpack. It makes possible the stocking of remote ponds, which could not be reached any other way. Best of all, it ensures that trout fishing remains available to many present-day anglers who would otherwise be deprived of the pleasure of seeing and fishing for these beautiful rare gems of nature.


Paul J. Fournier, of Palm Bay, Florida, began flying in 1948. He is a commercial pilot.