Icon for Current HLI Categories webpageThe Coordinated Assessments Partnership (CAP) supports the sharing of standardized high-level indicators (HLIs) and supporting metrics to inform regional fish monitoring priorities. Guidance for which types of information will be shared are described in the Five-Year Plan for the Coordinated Assessments Partnership. The plan also provides guidance related to possible additional HLIs of interest; which are summarized on the Upcoming HLI Categories page.

Current HLIs

CAP currently provides six HLIs of the health of naturally spawning salmonid populations. The formal descriptions of the current HLIs are maintained in the Coordinated Assessments Data Exchange Standard document; abbreviated descriptions are provided below.

NOSA is the number of natural-origin fish that actually spawn, not necessarily the number of fish returning to a spawning area. Escapement estimates are provided when calculating NOSA is not feasible.

Spawner escapement is the number of natural-origin fish returning to spawn that pass upstream of a specified location during a specified time period. Spawner escapement estimates may include prespawn mortality due to harvest or other causes that occurred after passing the specified location.

Number of natural-origin juvenile fish in a population. Usually late-summer parr but may be any time of year and any life stage earlier than smolts.

Number of natural-origin juvenile fish passing a defined location as they migrate downstream toward the ocean.

The point estimate of the number of returning natural-origin adults divided by the point estimate of the number of smolts that produced those returning adults, multiplied by 100 and expressed as a percentage.

R/S is the ratio of recruits from a specified brood year to the number of parent spawners that contributed to that brood year.

R/S ratios are specific to the locations and seasons described in each record of data. The number of “recruits” can be defined at any life stage.

PNI is an estimate of the relative selection pressure of the natural environment in an integrated natural/hatchery population.
PNI is calculated as:

PNI = pNOB/(pNOB + pHOS)

where:

pNOB is the proportion of natural-origin fish spawned in a hatchery;
pHOS is the proportion of fish spawning naturally that are hatchery-origin fish.
Current Fish HLIs Data
CAP FISH HLIs SUMMARY FOR
NATURAL-ORIGIN SALMON AND STEELHEAD
250
Populations and
other fish
groupings
6
HLI
Categories
198
ESA
Listed
Populations
84
Year Range
Spanned
by HLIs
7375
Records of Natural-Origin Spawner Abundance HLI
3892
Records of
Recruits per
Spawner HLI
1405
Records of
Smolts to
Adult Return HLI
2332
Records for PNI, Outmigrant & Presmolt
HLIs combined

Data updated March 2023
Photo credit A. W. (Tony) Grover

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Current Species and Population Names

The list of species and populations provided by the fish HLIs query can be viewed and downloaded here.

CAP Fish HLIs Queries and Data Summary

Data are accessible in two ways: from a map-based query, or from a tabular query. Both query systems provide the ability to view and download the available HLI estimates. You can find them on the CAP Fish HLIs (CAX) Query webpage.

The graphic above provides an overview of the data currently available from the queries.