approach: Detection of a fish near the base of
a dam; records are 'coded' for the first and any subsequent approaches
to a dam. Efficiencies are not calculated for approaches as they are
not associated with a specific route at the dam.
channel: set frequency of radio signal emitted by a transmitter; portion of data used to identify individual tagged fish.
code: digital pattern of signal
emission that uniquely identifies a transmitter within a given Channel
or radio frequency; necessary to identify individual radiotagged fish.
corr: A label assigned to an
individual record - used to summarize the movements/behaviors of tagged
fish (for example, the last record in the ladder at a dam = LT).
Records with corrs are termed "coded" records. See the data description
for more info and fish records for specific examples.
efficiency: the number of unique fish
performing an action divided by the number having the chance to perform
that action. Efficiencies are defined separately for each action and
are provided on each web page where efficiency values are reported.
entrance: a location in a dam
structure where there is access to the fish ladder system for migrating
adult salmonids. Fish entrances are noted and tallied at entrances with
event: one of the following actions: approach, entrance, exit, fallback, or passage.
exit: the action of a fish
leaving a fishway through a downstream path after it has entered a dam
fishway; denoted with a corr beginning with either 'X' or 'UX'.
fallback: an event in which a fish is detected
at a location downstream of a dam after having been above that dam.
These are determined either by records showing the fish's actual
passage route back over a dam, or assumed when a fish is recorded
downstream of a dam after it has originally passed. Fallbacks are one
source of delay in a fish's migration, or can occur if a fish overshot
its natal stream.
fishway: a specifically named passage route (i.e. ladder) at a dam (varies for each structure).
forebay: the upstream area immediately adjacent to a dam structure.
natal stream: the waterway in which an anadromous fish was spawned and to which it returns to reproduce.
PIT-tag ID: a unique code associated with an individual PIT-tagged fish.
passage: the act of traversing a
dam as part of the upstream spawning migration. Passage times are
calculated based on the time of a fish's first approach to a dam and
the last detection of that fish at the top of a fish ladder.
power: signal strength; power can be influenced by distance from the reciever, battery strength, and other environmental noise.
radiotelemetry: a powerful technology used to
monitor animal movements. It utilizes tags that transmit a radio signal
which is picked up by stationary or mobile receivers. Data indicate a
unique code to identify individuals as well as a time stamp.
river kilometer (rkm): distance
upstream from the system's river mouth. For this project, rkm is
measured from the mouth of the Columbia River and indicates where a
signal was recorded or a receiver located.
route: the fishways and passages
by which a fish navigates a dam; often based on/named for the side of
the river on which a receiver resides.
site: location of a radiotelemetry receiver,
either aerial or underwater, for tracking fish locations; see maps for
location of receivers.
species code: a number in the
database assigned to quickly identify each species or run under
investigation (see species code table for full information).
study year: the annual tagging
period defined for this project, generally beginning in mid-April of a
given calendar year (for specific dates refer to the study year table).
tag ID: a random number assigned to radiotagged
fish for unique identification of that fish and its associated records
in the database.
tailrace: a fast-moving area of
the river from the base of a dam downstream to where the water flow is
no longer imminently affected by spill at the dam.
transition pool: a section of
dam fishways that begins at the convergence of collection channels into
a single ladder area or at the entrance if there is only one collection
channel, and terminates at a variable point determined by the lowermost
emerged weir in the ladder proper.
weir: a concrete structure placed in fish ladders to regulate and direct water flow.