Salmon & Steelhead Recovery Tracker

Scappoose (Independent Population)

Oncorhynchus kisutch

Abundance

Annual estimates of the abundance of naturally-produced spawners for each population.

Spawning Year Nat. Origin Spawners 95% Confidence Interval Abundance Goal
2016 1,200 662 1,671
2015 487 213 1,047
2014 1,587 790 1,739
2013 979 428 2,687
2012 210 94 2,372
2011 298 114 1,282
2010 1,960 1,033 1,737
2009 778 371
2008 292 110
2007 375 293
2006 719 210
2005 348 152
2004 755 284
2003 336 170
2002 502 206

Analysis

A population with a non-negative growth rate and an average abundance approximately equivalent to estimated historical average abundance should be considered to be in the highest persistence category. The estimate of historical abundance should be credible, the estimate of current abundance should be averaged over several generations, and the growth rate should be estimated with an adequate level of statistical confidence.

Evaluation Thresholds

Delisting

Pass - The observed spawner abundance is greater than or equal to the abundance modeled for delisting at least six times in any 12-year period and the average observed spawner abundance is greater than or equal to the average modeled abundance for delisting over that same time period.

Fail - The observed spawner abundance is greater than or equal to the abundance modeled for delisting less than six times in any 12-year period or the average observed spawner abundance is less than the average modeled abundance for delisting over that same time period.

Broadsense

Pass - The observed spawner abundance is greater than or equal to the abundance modeled for delisting at least six times in any 12-year period and the average observed spawner abundance is greater than or equal to the average modeled abundance for broad sense recovery over that same time period.

Fail - The observed spawner abundance is greater than or equal to the abundance modeled for delisting less than six times in any 12-year period or the average observed spawner abundance is less than the average modeled abundance for broad sense recovery over that same time period.

Average Abundance

Twelve years of data are necessary to evaluate this metric. Data will become available after a suitable number of years of monitoring have occurred.

Spawning Year Average Abundance Avg. of Ab.Goal
2016 769
2015 732
2014 720
2013 629

Evaluation Thresholds

Twelve years of data are necessary to evaluate this metric. Data will become available after a suitable number of years of monitoring have occurred

Delisting

Pass - The observed spawner abundance is greater than or equal to the abundance modeled for delisting at least six times in any 12-year period and the average observed spawner abundance is greater than or equal to the average modeled abundance for delisting over that same time period.

Fail - The observed spawner abundance is greater than or equal to the abundance modeled for delisting less than six times in any 12-year period or the average observed spawner abundance is less than the average modeled abundance for delisting over that same time period.

Broadsense

Pass - The observed spawner abundance is greater than or equal to the abundance modeled for delisting at least six times in any 12-year period and the average observed spawner abundance is greater than or equal to the average modeled abundance for broad sense recovery over that same time period.

Fail - The observed spawner abundance is greater than or equal to the abundance modeled for delisting less than six times in any 12-year period or the average observed spawner abundance is less than the average modeled abundance for broad sense recovery over that same time period.

Occupancy

The occupancy of spawning adults or juveniles at spatially balanced, random survey sites.

Spawning Year Total Sites Visited Occupied Sites Percent Occupied Delisting Goal Broadsense Goal
2016 18 10 56% 90% 90%
2015 13 5 38% 90% 90%
2014 16 11 69% 90% 90%
2013 16 9 56% 90% 90%
2012 19 5 26% 90% 90%
2011 24 9 38% 90% 90%
2010 15 9 60% 90% 90%
2009 17 8 47%
2008 19 9 47%
2007 16 8 50%
2006 15 12 80%
2005 12 4 33%
2004 18 8 44%
2003 16 4 25%
2002 18 8 44%

Evaluation Thresholds

Pass - The percentage of sites not occupied by spawning adults or rearing juvenile salmon is less than or equal to the threshold at least six times during a 12-year period and the overall average percentage of sites not occupied during that same time period is less than or equal to to threshold.

Fail- The percentage of sites not occupied by spawning adults or rearing juvenile salmon is greater than the threshold at least six times during a 12-year period and the overall average percentage of sites not occupied during that same time period is greater than the threshold.

Habitat
  • 2013
    pass

The amount of available high quality habitat for all freshwater life stages in each population. Habitat condition is evaluated using population specific winter habitat surveys in the range of coho salmon. These surveys began in 2007 with the goal of surveying each independent population or dependent population group once every 5 years. Not all populations in the Lower Columbia Coho ESU have been surveyed for habitat at this time therefore some populations will display no habitat data.

Survey Year Sites Sampled Mi. HQ Hab 95% C.I. Delisting Goal Broadsense Goal
2013 44 18.7 10.4 10.0 24.0

Evaluation Thresholds

For a population to pass this criterion, the miles of high quality habitat (i.e. capable of producing > 2,800 smolts/mile) for independent populations (excluding lakes populations) equals or exceeds the population-specific goals.

Time Period Category Comment
2013 pass Goal met 1 of 1 years

Hatchery Proportion

The proportion of spawning fish that are of hatchery origin in each lower Columbia River population.

Spawning Year H proportion (whole basin) H proportion (above dam) Proportion Hatchery
2016 0.03 0.03
2015 0.00 0.00
2014 0.00 0.00
2013 0.00 0.00
2012 0.00 0.00
2011 0.00 0.00
2010 0.00 0.00
2009 0.00 0.00
2008 0.00 0.00
2007 0.00 0.00
2006 0.05 0.05
2005 0.00 0.00
2004 0.08 0.08
2003 0.10 0.10
2002 0.00 0.00

Average Hatchery Proportion

Average over a nine-year period of the percentage of the total number of natural spawners that are of hatchery origin.

Spawning Year Proportion Hatchery 9-yr. pHOS Avg. pHOS Limit
2016 0.00 0.00 0.05
2015 0.00 0.00 0.05
2014 0.00 0.01 0.05
2013 0.00 0.01 0.05
2012 0.00 0.01 0.05
2011 0.00 0.03 0.05
2010 0.00 0.03 0.05

Evaluation Thresholds

Nine years of data are necessary to evaluate this metric. Data will become available once a suitable number of years of monitoring have occurred

Delisting

Pass – Over a nine-year period, the average percentage of the total number of natural spawners that are of hatchery origin is on average less than or equal to the population specific hatchery stray rate target.

Fail – Over a nine-year period, the average percentage of the total number of natural spawners that are of hatchery origin is on average greater than the population specific hatchery stray rate target.

Broadsense

Pass – Over a nine-year period, the average percentage of the total number of natural spawners that are of hatchery origin is on average less than or equal to 10 percent.

Fail – Over a nine-year period, the average percentage of the total number of natural spawners that are of hatchery origin is on average greater than 10 percent.