A group of state and federal
agencies, The Nature Conservancy, and the Lower Yellowstone Irrigation
District are partnering to develop fish passage around the 100-year-old
Intake Diversion Dam on the Yellowstone River in Montana. The primary
reason for this unique effort is to help the endangered pallid sturgeon
(Scaphirhynchus albus) access spawning habitat upstream from the
dam.
A hatchery-raised
pallid sturgeon is released into a wild environment.
Photo courtesy of U.S. Geological Survey.
The pallid sturgeon is a living
representative from the dinosaur age. Their oldest known ancestors are
from the Cretaceous period. This large cartilaginous fish has survived
ice ages, but now it is threatened with extinction. Pallid sturgeon are
larger than the related shovelnose sturgeon (Scaphirhynchus
platorhynchus). Adult pallid sturgeon weigh15-80 pounds and can live
for more than 50 years, with some individuals surviving for 100 years
(see sidebar below). The pallid is highly migrational, with seasonal movements
of hundreds of miles when not impeded by man-made structures. The
construction of major dams along the Missouri River in the 1940s and 50s
segmented the population, impeding migration and successful spawning and
recruitment of young pallids. Other impediments include the locks and
dams on the Mississippi River and irrigation diversion dams on the
Yellowstone River. In addition to blocked migration routes, this large
fish was also commercially harvested in the past.
When the pallid sturgeon was
listed as endangered in 1990, federal agencies were required under the
Endangered Species Act to consult with the U.S. Fish and Wildlife
Service (Service) about ongoing operations of projects under their
jurisdiction. As a result of ongoing consultation, two federal agencies
have identified responsibilities to aid in the recovery of pallid
sturgeon. The U.S. Army Corps of Engineers (Corps) operates the Missouri
River main stem dams, and the Bureau of Reclamation (Reclamation) owns
the Intake Diversion Dam on the Yellowstone River—both important
migration routes for pallid sturgeon. The Corps and Reclamation, along
with the Service, Montana state agencies, The Nature Conservancy, and
the Lower Yellowstone Irrigation District signed a Memorandum of
Agreement to work together on development of fish passage around the
100-year-old Intake Diversion Dam.
Passage around Intake Diversion
Dam is a high priority task in the Service’s 1993 Recovery Plan for
pallid sturgeon, and is also recommended by the Upper Basin Pallid
Sturgeon Recovery Workgroup (see sidebar left). This fall, a team consisting of Corps and
Reclamation staff began the National Environmental Policy Act (NEPA)
process to evaluate alternative ways to get pallid sturgeon and other
native fish past the dam so they can access another 165 miles of the
Yellowstone River and its tributaries upriver from the dam. Public
scoping meetings were held in Montana in order to gather comments and to
solicit other ideas on providing fish passage. A key local issue is
maintenance of irrigation, valued at $25-30 million annually. The NEPA
document will be available for public, agency, and Tribal review when
released in late 2009. After finalization of the NEPA process, the Corps
intends to fund the construction of the selected alternative.
Time is running out for the
pallid sturgeon, since some biologists anticipate that the wild pallids
may be extirpated from Montana by 2017. After the wild pallids are
gone, only hatchery-raised pallid sturgeon will reside in the
Yellowstone. Although other recovery actions are ongoing in other river
reaches, the recovery of the upper basin pallid sturgeon is especially
important since few of these fish have hybridized with the related
shovelnose sturgeon, as is the case in the lower Missouri and
Mississippi Rivers. The lack of hybridization is thought to be an
indicator of high-level habitat quality within the Yellowstone River.
Unlike the Missouri River, the Yellowstone River has a relatively
natural hydrograph (river discharge over time) and temperature profile,
and offers the best locale for conservation of wild pallid sturgeon.
Although fish passage projects
have been constructed elsewhere for lake sturgeon and have been
incidentally used by green sturgeon and white sturgeon, this will be the
first fish passage project specifically for the endangered pallid
sturgeon.
The Nepa team after a
public scoping meeting.
The author is front
and center of the group, in a white shirt.
The NEPA team will work
together over the next two years, along with other partners, to ensure
that the selected management alternative meets the needs of the pallid
sturgeon and other river resource users, including irrigators. For more
information on this project, visit
http://www.usbr.gov/gp/mtao and click on “Lower Yellowstone River.”
Becky Latka has worked as an Environmental
Resource Specialist for the Omaha District Corps of Engineers, Planning
Branch, since 1991. She works on projects in the Missouri River and
Yellowstone River drainages, specializing in Endangered Species, NEPA
compliance, fisheries biology, and fish passage.