 channel catfish. |
to big river flows
Montana Fish, Wildlife and Parks
GLENDIVE – Spring rainstorms have been washing across the eastern part of the state, greening the prairie and filling the many streams that feed the Yellowstone River.
Although most Montanans are pleased to see this year’s spring rains few are happier than some of the radio tagged fish in our studies and Missouri-Yellowstone Adopt-A-Fish program.
Many fish species take advantage of the seasonal pulse of spring water to move out of the big rivers and ascend smaller tributaries to spawn and forage for prey. The positive effects of this year’s combination of rain and snowmelt on Yellowstone River fish populations have been most pronounced in the Tongue and Powder rivers, which are the lower Yellowstone’s two most important tributaries.
Fisheries data from the 1970’s documents major spawning migrations of sauger, channel catfish, and shovelnose sturgeon up the Tongue and Powder rivers coinciding with high flows in March, April, and May.
However, a combination of drought, fluctuating reservoir releases, and removal of water for irrigation have resulted in low Tongue River flows during critical spawning periods in the 1980’s and early 1990’s and again in recent years. Drought has also affected stream flows in the Powder River during this period. Recent sampling efforts indicate that fewer fish now ascend these tributaries and few, if any, of the radio tagged fish in our study have made tributary migrations.
However, this year has been an exception and the fish have responded. Flows in the Tongue and Powder rivers have been near or above average for most of the spring and both systems have had pulses of water move through in recent weeks that were more than 10 times the average flow for this period.
Coinciding with high flows radio tagged shovelnose sturgeon and channel catfish are beginning to make truly impressive migrations from throughout the Yellowstone River into the Tongue and Powder rivers.
In the last three weeks, one radio tagged channel catfish moved over 60 miles upstream from Fallon into the Tongue River. Over the same period, another catfish moved over 50 miles downstream from Forsyth into the Tongue. However, the award for biggest traveler among the catfish this spring goes to one originally tagged upstream of the Big Horn River that had not been relocated for a few weeks. Last week it reappeared up the Tongue River thereby completing a migration of over 100 miles to this important spawning tributary.
Not to be outdone, shovelnose sturgeon are also making swift migrations to these spawning tributaries. Last week our crews recaptured a particular radio tagged shovelnose sturgeon downstream of Forsyth to assess whether this fish was ready to spawn.
We found that she was full of black eggs, which indicates she will be spawning in the near future and would be an ideal candidate to help us determine critical spawning areas for this species. Six days later she was found about five miles up the Tongue River – a migration of over 55 miles.
Shovelnose sturgeon are also moving into the Powder River. No less than four radio tagged sturgeon have ascended the Powder River in recent weeks, one of which moved about 100 miles downstream from near Forsyth.
Although fish make huge movements within the Yellowstone River to access these spawning tributaries that may be just the start of their journey. Two of the radio tagged sturgeon that moved into the Powder River have migrated over 30 miles upstream so far and, because of how far and fast they are moving, will now need to be relocated by aircraft.
In fact these fish may be planning on visiting another state. It is not uncommon for Wyoming biologists to recover sturgeon, catfish, and sauger in the upper Powder River that were originally tagged over 220 miles downstream in the Yellowstone River.
Radio tagged spiny softshell turtles have been moving into many of the small prairie streams that feed the Yellowstone in recent weeks and our latest tracking run revealed two large radio tagged catfish a short distance up a tiny stream in the Miles City area.
This is the last update of the 2007 Missouri-Yellowstone Adopt-A-Fish program with classes who adopted fish and turtles getting out of school for the summer in the weeks ahead. Hopefully, they’ve learned along with us about the unique species that call these prairie rivers home. You can always learn more about the program at its Web site at www.pikemasters.com/adopt-fish/home.html
Matthew Jaeger is a fisheries biologist for Montana Fish, Wildlife and Parks at Glendive.