In a video that recently went viral, thousands upon thousands of fish fly out of a plane over a lake:
The video, published by the Utah Division of Wildlife Resources, shows “air fish stocking,” the practice of dropping fish from airplanes into high-lying lakes far below. That month, the state used the method to populate over 200 lakes in hard-to-reach areas with species such as rainbow trout and cutthroat trout.
Slate spoke to Phil Tuttle, outreach manager for the Utah Division of Wildlife Resources, about why the fish need to be in these lakes and how they are likely to fare in their new homes. This conversation has been compressed and edited for reasons of clarity.
Sofia Andrade: I had never seen anything like it. Is air fish population … normal?
Phil Tuttle: Absolutely normal. I think Utah was one of the first to do this, but it was done back in the mid-1950s. It has been a common practice for more than half a century. And it was mainly done by plane because these lakes are actually not accessible by vehicles or other means of occupation, because they are really remote and they are really lakes at high altitudes. There aren’t any roads or anything, so we can’t really take a tanker to these waters and stock them up.
Many of these lakes have historically been fishless. They had no fish in them and otherwise they would not have any fish in them. But we offer anglers a unique opportunity to fish in these really remote and beautiful high mountain lakes. So we kind of do it.
Is that the main reason for the “fish stocking”? Offer fishing opportunities?
This is one of the main reasons for giving anglers the opportunity to fish. There are other reasons as well. We are stocking some fish because they are native fish and we are simply trying to increase their populations and ensure the conservation of certain species by also stocking them in certain bodies of water.
Are there any ways to store fish that don’t involve an airplane?
By far the most common method is by tank truck – a truck with a large tank of water. We raise the fish in a fish hatchery, and then they put them in the truck, and then they take them from the truck to the water and then just dump them from the truck. But there are also some areas where historically [ish have been stocked by either horseback or on mules carrying big water tanks. But that’s not done as often anymore, partly because we just do by plane for most of those hard to reach places.
Is there a difference in fish survival rates when fish stocking is done by truck versus by plane?
Believe it or not, they’re actually really, really comparable survival rates. Anytime you’re, taking fish and sloshing them around in water and trying to get them from point A to point B, there is a level of stress on the fish. If you were like putting them in a water tank, and then putting them on a mule, and then sloshing them back and forth for hours while taking them up a trail and dumping them into a high elevation lake? That actually is a lot more stressful, believe it or not than dumping them out of an airplane. Because you know they’re just put on the plane, and the plane in just a matter of minutes flies to the lake and gets as low as they can down to the water.
We also make it a point to stock fish that are really small, one to three inches. Since the fish are so small, they literally are almost like leaves. They kind of catch the air and they just slowly flutter down. We estimate the survival as high as 90, 95 percent.
How are survival rates measured?
We’ve done studies where we’ve had people at the reservoir basically counting dead fish after stocking to see how many are dead. But also, we do netting surveys on the lakes in subsequent years to see what’s there. We’ve found [stocking by plane] to be highly effective and with really great survival. Otherwise we wouldn’t do it if it were like, “Oh, you know, tons of fish are dying.”
On social media, a lot of people were worried that the fish were being dropped from very high heights. Could the planes have flown lower?
One of the really important things is that we naturally value our pilots and want them to be safe. So when they populate the lake, it really just depends on the lake. Some of the lakes have lots of rocks and cliffs and mountains right around the lakes or there are trees. Some lakes don’t have very many trees. And so, depending on the trees and the surrounding cliffs and rocks and the like, the pilots can get a lot closer.
You’d like to drop them from a distance of 50 feet or less, and that happens most of the time, but depending on the trees and things and the obstacles, the safety of the pilots is an important consideration. If you have to drop the fish a little higher – again, the fish only flutter downwards – the survival rate is still very, very high.
Are there any special requirements to be a pilot who stores fish?
No training or certification is required for these pilots. However, they have been doing this for a long time. There is a timing component, right? The pilots need to know when to press the button that opens the valve that releases the fish because the fish will not live on land. It is important that these pilots are good pilots, that they are safe, and that they have the right timing to get these fish into the water.