SACRAMENTO, Calif. - The Puyallup tribe is trying to unravel the mystery
behind a federally listed threatened species. In the coming months the
tribe will take a high-tech approach to learn more about the elusive bull
The fish will be tagged with devices that emit a low frequency signal that
will be relayed to Puyallup tribal staff, who will monitor several patterns
of the bull trout. The devices are estimated to emit signals for up to a
year and will be monitored throughout that entire period.
"One of the main questions we have is where are they [bull trout] going,"
asked Puyallup Resource Protection Manager Russ Ladley.
Since bull trout do not migrate in nearly-solid schools as do other fish
such as salmon, the amount of information on the species is somewhat
limited. Like salmon, bull trout are anadromous, meaning they migrate from
salt water to fresh water. However, Ladley said it is apparent that some
bull trout stay within river systems and do not migrate out to sea.
It is these differences with other species in the salmon family, to which
bull trout belong, that led to the radio tracking system. Since most of the
information on bull trout is fragmentary, the tribe is hoping that more
detailed information can lead to their ultimate restoration.
Though the fish are found in a large portion of the Puget Sound region,
populations of bull trout are found as far south as the Columbia River and
as far north as Alaska. Another population also exists in the mountains of
western Montana. However, the study will concentrate mainly on bull trout
in the White River, one of the tributaries of the larger Puyallup River.
Tribal data on the fish already shows that a main population of bull trout
stays close to the "glacial source of the White River in the western
Cascade Mountain Range. Bull trout seem to need very cold water in which to
spawn. However, another population migrates downstream to the lower part of
the Puyallup system.
From this a much smaller group then migrates out to the Puget Sound, a
saltwater inlet of the Pacific Ocean, and stays out for up to four years
before returning to the river's icy upper reaches to spawn. Ladley said
that fish going into the Puget Sound will not be the focus of this study.
Ladley said there is no population estimate on the total number of bull
trout. However, at one fish trap only 40 bull trout were caught. This pales
in comparison to the tens of thousands of salmon that routinely traverse
the same river path.
Bull trout are not commercially harvested anywhere and are considered a
"sport" fish to be taken in only by individual anglers.
The bull trout used in the study will be caught in one of the oldest fish
traps in the Puget Sound, dating to 1941, and operated by the Army Corps of
Ladley said the effort is important since the bull trout are one of many
species important to the Puyallup river system.
"Bull trout, chinook, coho and all of the other fish in the river don't
live in isolation of each other. The more we understand about how one fish
species lives, the better we understand all species."