Yellowstone River shuts down after emerging parasite kill tens of thousands of fish
By Molly O’Neill “Go Fish” – only not in the Yellowstone River. September 1, Montana Fish, Wildlife and Parks reopened sections of a 183 mile stretch of the river that was previously closed after officials discovered a number of dead, native Mountain Whitefish, numbering in the tens of thousands. In addition, approximately 4,000 Rainbow Trout, Yellowstone Cutthroat, Longnose Suckers, Sculpin, and Longnose Dace were found dead. |
The river was shut down after discovering a parasite, Tetracapsuloides bryosalmonae, on August 19. The parasite causes Proliferative Kidney Disease (PKD) to species in the family Salmonidae. The repercussions of the parasite affect the ecosystem, recreation, and economy.
There are two contributing factors to this parasite –– evolution and environment.
Evolutionarily, millions of years ago a jellyfish-like animal changed into a parasite. How did the parasite evolve? Due to the increase in aquaculture that bring new species into contact with myxosporeans, microscopic parasites, between the cultivation of saltwater and freshwater leads to susceptibility to disease. The myxosporeans are accountable for important pathogens of fish largely in part of the cultivated waters (aquaculture) that bring new species into contact with myxosporeans. The most significant diseases worldwide caused by myxosporeas in cultured fishes is Proliferative Kidney Disease (PKD), caused by a Malacopsporea member, Tetracuapsuloides byrosalmonae.
“Unfortunately, the Tetracapsuloides bryosalmonae parasite is much more difficult than cleaning up debris,” Cody Richardson, a Tech biology graduate student, said.
He emphasized that cleaning up the parasite is more challenging than cleaning up the oil spill.
“Efforts to clean up the parasite will mostly be reducing the spread to other bodies of water. Over time the fish in the isolated infected areas may build up greater immunity to the parasite and populations of fish may begin to increase.”
Environmentally, the hot summers contribute to the growth of the parasite. The high water temperatures and low water levels are not helpful. If our winters continue with low winter snowpack and dry, hot summers an epidemic such as the Tetracapsuloides bryosalmonae may potentially affect larger areas.
Mark Mariano, a graduate student in restoration ecology and instructor of fish biology at Montana Tech, added,
“Increased flow and lower water temperature is the only way that the parasite will slow down. Until we get some precipitation and fall temperatures begin, there is no way to clean it out of the Yellowstone or other rivers.”
Whitefish are a native species, unlike the brown and rainbow trout that fisherman chase. Whitefish are a major food source for osprey, eagles, trout, and other wildlife. Economically, recreation is prevalent is sustaining businesses; fly shops, restaurants, and retail in the Upper Yellowstone Valley.
“They are also a large part of the trophic system in that river. Ecosystems are complex and have a lot of moving parts; the whitefish die-off will affect every other organism in that system in so many ways that we will not fully understand the consequences until it happens,” stated Mariano.
Whitefish are accredited for their adaptability, providing substantial population growths, and maintaing clean and clear river water. Female whitefish propagate up to 100,000 eggs and in turn provide an abundance of forage for game and predatory species in the surrounding ecosystem.
“Whitefish are bottom feeders meaning they ingest bottom dwelling invertebrates, algae, and debris,” stated Richardson.
Although this parasite is harmless to humans, we assist in disseminating the parasite to other bodies of water. Cleaning river gear, boots, and your pets are preemptive measures.
“Montana has an outstanding reputation for having some of the top blue-ribbon fly-fishing streams in the nation. If the fish killing parasite were to continue to spread, decreasing the populations of fish in other areas, those areas may suffer the same or greater amount of ecological change, damage revenue, and reputation in the Yellowstone Valley,” concluded Richardson.
There are two contributing factors to this parasite –– evolution and environment.
Evolutionarily, millions of years ago a jellyfish-like animal changed into a parasite. How did the parasite evolve? Due to the increase in aquaculture that bring new species into contact with myxosporeans, microscopic parasites, between the cultivation of saltwater and freshwater leads to susceptibility to disease. The myxosporeans are accountable for important pathogens of fish largely in part of the cultivated waters (aquaculture) that bring new species into contact with myxosporeans. The most significant diseases worldwide caused by myxosporeas in cultured fishes is Proliferative Kidney Disease (PKD), caused by a Malacopsporea member, Tetracuapsuloides byrosalmonae.
“Unfortunately, the Tetracapsuloides bryosalmonae parasite is much more difficult than cleaning up debris,” Cody Richardson, a Tech biology graduate student, said.
He emphasized that cleaning up the parasite is more challenging than cleaning up the oil spill.
“Efforts to clean up the parasite will mostly be reducing the spread to other bodies of water. Over time the fish in the isolated infected areas may build up greater immunity to the parasite and populations of fish may begin to increase.”
Environmentally, the hot summers contribute to the growth of the parasite. The high water temperatures and low water levels are not helpful. If our winters continue with low winter snowpack and dry, hot summers an epidemic such as the Tetracapsuloides bryosalmonae may potentially affect larger areas.
Mark Mariano, a graduate student in restoration ecology and instructor of fish biology at Montana Tech, added,
“Increased flow and lower water temperature is the only way that the parasite will slow down. Until we get some precipitation and fall temperatures begin, there is no way to clean it out of the Yellowstone or other rivers.”
Whitefish are a native species, unlike the brown and rainbow trout that fisherman chase. Whitefish are a major food source for osprey, eagles, trout, and other wildlife. Economically, recreation is prevalent is sustaining businesses; fly shops, restaurants, and retail in the Upper Yellowstone Valley.
“They are also a large part of the trophic system in that river. Ecosystems are complex and have a lot of moving parts; the whitefish die-off will affect every other organism in that system in so many ways that we will not fully understand the consequences until it happens,” stated Mariano.
Whitefish are accredited for their adaptability, providing substantial population growths, and maintaing clean and clear river water. Female whitefish propagate up to 100,000 eggs and in turn provide an abundance of forage for game and predatory species in the surrounding ecosystem.
“Whitefish are bottom feeders meaning they ingest bottom dwelling invertebrates, algae, and debris,” stated Richardson.
Although this parasite is harmless to humans, we assist in disseminating the parasite to other bodies of water. Cleaning river gear, boots, and your pets are preemptive measures.
“Montana has an outstanding reputation for having some of the top blue-ribbon fly-fishing streams in the nation. If the fish killing parasite were to continue to spread, decreasing the populations of fish in other areas, those areas may suffer the same or greater amount of ecological change, damage revenue, and reputation in the Yellowstone Valley,” concluded Richardson.