Recently, a video from Utah, the U.S. went viral. It showed thousands of fish bursting out of a plane into a lake. The Utah Division of Wildlife Resources explained it was part of an annual stocking exercise that the State has been undertaking since 1956. The aerial dumping is done to repopulate the lakes across the State with certain species of fish.
Fish stocking is the practice of raising fish in a hatchery and releasing them into a river, lake, or ocean to supplement existing populations or to create a new population. Stocking is usually done to benefit commercial or recreational fishing. It is also done to restore an ecosystem or to increase a population of threatened or endangered fish in a body of water. Sometimes, prey fish are introduced into waterbodies to control the population of an invasive species.
Fish are transported in a large water tank or airplane to their respective locations.
At Utah
In Utah, the exercise is done every summer. Many lakes and streams in the State are found in mountains and aren’t reachable by road, so the State resorts to aerial stocking, where the plane is allowed to hover at around 150 feet above the waterbody to deposit the fish gently into their new homes. The fish – which are usually one to three-inch long and include rainbow trout, cutthroat trout, brook trout, tiger trout, splake and Arctic greyling – are specifically raised for recreational fishing.
About 35,000 fishes along with gallons of water are dropped at a time. The Utah Division of Wildlife Resources has claimed that since the fish are small, their survival rate is 95% and that the plane drops are much quicker, cost-effective, and less stressful for the fish. (Earlier, people and horses would carry the fish up to the remote mountain lakes on foot.) Biologists acclimatise the fish to the water temperature and pH level of the lakes before loading them onto the plane. While in the air, the fish tanks are pumped with oxygen so that the fish aren’t stressed in the water.
The fish are usually sterile so that they do not affect the native fish population. However, there is a dark side to the practice – if done without proper research, fish stocking can upset the balance in an ecosystem.
Picture Credit : Google
