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Nehalem

Nehalem (Independent Population)

Analyses of viability criteria (adult abundance, persistence, productivity, distribution, diversity and habitat) are presented for each independent population. Trends in adult abundance and habitat condition are presented for dependent populations.

Oncorhynchus kisutch

Abundance

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

Spawning Year	Nat. Origin Spawners × Nat. Origin Spawners The point estimate for natural origin spawner abundance, excluding jacks. Close	95% Confidence Interval × 95% Confidence Interval 95% confidence interval for wild abundance estimate Close	Broad Sense Goal × Broad Sense Goal Abundance goal for wild fish specific to the marine survival category as stipulated in the Oregon Coastal Coho Conservation Plan (Appendix 2). Populations of naturally produced fish comprising the ESU are sufficiently abundant, productive, and diverse (in terms of life histories and geographic distribution) that the ESU as a whole will: a) be self-sustaining, and b) provide environmental, cultural, and economic benefits. This goal represents a condition of the ESU that is significantly higher than a level where it could be considered a potential candidate for listing under federal ESA. Close	Proportion of Goal × Proportion of Goal Observed abundance/ abundance goal Close
2021
2020
2019	12,383	5,363	37,800	33.0%
2018	4,190	2,041	72,900	6.0%
2017	5,486	2,011	72,900	8.0%
2016	7,549	3,668	72,900	10.0%
2015	3,079	1,376	37,800	8.0%
2014	30,577	11,643	83,300	37.0%
2013	4,539	2,303	72,900	6.0%
2012	2,963	1,267	72,900	4.0%
2011	15,322	3,864	83,300	18.0%
2010	32,215	8,426	83,300	39.0%
2009	21,753	7,732	83,300	26.0%
2008	17,205	11,909	72,900	24.0%
2007	14,033	7,548	37,800	37.0%
2006	11,614	3,551
2005	10,451	3,048
2004	18,736	4,231
2003	32,517
2002	17,164
2001	21,928
2000	14,462
1999	3,555
1998	1,206
1997	1,187
1996	527
1995	1,700
1994	2,844
1993	3,049
1992	1,392
1991	6,837
1990	1,158

Evaluation Thresholds

Pass -the observed spawner abundance is > the marine survival-specific escapement target at least six times in any 12-year period.

Fail - the observed spawner abundance is > the marine survival-specific escapement target 5 times or less in any 12-year period.

Distribution

The manner in which adults (spawners) are distributed within the freshwater portion of a population's home range.

Metrics

1. The percentage of random, spatially balanced surveys that have more than 4 wild adult spawners/mile (percent occupancy)

2. Comparison of the spatial pattern of potential spawning distribution to that observed using SVB or other spatial statistics.

Spawning Year	Total Sites Visited × Total Sites Visited Number of sites sampled Close	Occupied Sites × Occupied Sites Number of sites sampled that passed the criterion for occupancy (>= 4 naturally produced adult coho per mile) Close	Percent Total Occupied Sites × Percent Total Occupied Sites Percent of sampled sites that met the occupancy criterion for total fish (= occupied sites / total sites) Close	Percent Wild Occupied Sites × Percent Wild Occupied Sites Percent of sampled sites that met the occupancy criterion for wild fish (= occupied sites / total sites) Close	Proportion of Goal Wild Sites × Proportion of Goal Wild Sites Percent of the delisting goal for wild occupied sites Close	Broad Sense Goal × Broad Sense Goal Goal for percent of surveyed streams occupied under specified marine survival conditions. Goals could not be determined for Beaver, Floras, and Sixes populations due to inadequate data for a regression between spawners and occupancy. Populations of naturally produced fish comprising the ESU are sufficiently abundant, productive, and diverse (in terms of life histories and geographic distribution) that the ESU as a whole will: a) be self-sustaining, and b) provide environmental, cultural, and economic benefits. This goal represents a condition of the ESU that is significantly higher than a level where it could be considered a potential candidate for listing under federal ESA. Close
2021	5					77%
2020	13					77%
2019	24	14	58%	58%	76%	77%
2018	21	13	62%	62%	80%	77%
2017	23	15	65%	65%	85%	77%
2016	19	11	58%	58%	75%	77%
2015	15	9	60%	60%	78%	77%
2014	13	12	92%	92%	120%	77%
2013	27	14	52%	52%	67%	77%
2012	21	8	38%	29%	37%	77%
2011	34	25	74%	68%	88%	77%
2010	33	31	94%	94%	122%	77%
2009	13	11	85%	85%	110%	77%
2008	6	5	83%	83%	108%	77%
2007	15	12	80%	80%	104%	77%
2006	22	19	86%
2005	30	24	80%
2004	61	44	72%
2003	56	51	91%
2002	65	51	78%
2001	56	41	73%
2000	58	39	67%
1999	43	17	40%
1998	62	16	26%

Evaluation Thresholds

Metric 1

Pass - the observed percent occupancy is greater than or equal to the marine survival-specific occupancy target at least six times in any 12-year period.

Fail - the observed percent occupancy is greater than or equal to the marine survival-specific occupancy target five times or less in any 12-year period.

Metric 2

Pass - the observed regularity ratio is not significantly different from a random distribution at least six times in any 12-year period.

Fail - the observed regularity ratio is significantly different from a random distribution at least six times in any 12-year period.

Diversity

Within-population diversity is the result of phenotypic differences among individuals. These differences provide the flexibility of the population as a whole to respond successfully to short-term environmental variations. They are also the basis by which populations are able to adapt and evolve as conditions within their home range go through changes that are more permanent.

Metric

The average of the 100-year harmonic mean of spawner abundance for each independent population, as forecast from a population viability model.

Analysis Year	Harmonic Mean × Harmonic Mean Harmonic mean population abundance as predicted by a Ricker simulation model Close	Broad Sense Goal × Broad Sense Goal A harmonic mean of spawner abundance greater than 1,200 (forecast from a population viability model) requires predicted maintenance of at least 97.5% of a population's heterozygosity over a 100-year period (Chilcote et al. 2005). Populations of naturally produced fish comprising the ESU are sufficiently abundant, productive, and diverse (in terms of life histories and geographic distribution) that the ESU as a whole will: a) be self-sustaining, and b) provide environmental, cultural, and economic benefits. This goal represents a condition of the ESU that is significantly higher than a level where it could be considered a potential candidate for listing under federal ESA. Close
2019	3,294	1,200
2007	2,926	1,200

Evaluation Thresholds

Pass - If 100-year harmonic mean of spawner abundance is greater than 1,200.

Fail - If 100-year harmonic mean of spawner abundance is less than or equal to 1,200.

Habitat

The amount of available high quality habitat for all freshwater life stages in each independent population, excluding the lakes populations.

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 Coast Coho ESU have been surveyed for habitat at this time therefore some populations will display no habitat data.

Survey Year	Miles Current × Miles Current Current miles of high quality habitat (capable of producing > 2,800 smolts/mile) available Close	95% Confidence Interval × 95% Confidence Interval 95% confidence interval for estimate of current miles of high quality habitat Close	Broad Sense Goal × Broad Sense Goal Miles of high quality habitat (capable of producing > 2,800 smolts/mile) needed to achieve the desired abundance status goals. Populations of naturally produced fish comprising the ESU are sufficiently abundant, productive, and diverse (in terms of life histories and geographic distribution) that the ESU as a whole will: a) be self-sustaining, and b) provide environmental, cultural, and economic benefits. This goal represents a condition of the ESU that is significantly higher than a level where it could be considered a potential candidate for listing under federal ESA. Close	Percent of Goal × Percent of Goal Current miles of high quality habitat/ goal *100 Close
2007	158.5	83.2	353	44.9%

Evaluation Thresholds

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

Persistence

The forecast probability of persistence for each independent population based on results from population viability analysis (PVA) models.

Analysis Year	Average Probability × Average Probability Average of all previous QET-1/QET50 fields Close	Broad Sense Goal × Broad Sense Goal A persistence criterion of a 99% or greater probability of persistence significantly increases the likelihood that the ESU is will remain viable under extreme marine survival conditions. Populations of naturally produced fish comprising the ESU are sufficiently abundant, productive, and diverse (in terms of life histories and geographic distribution) that the ESU as a whole will: a) be self-sustaining, and b) provide environmental, cultural, and economic benefits. This goal represents a condition of the ESU that is significantly higher than a level where it could be considered a potential candidate for listing under federal ESA. Close

Discussion and Rationale

A persistence criterion of a 99% or greater probability of persistence significantly increases the likelihood that the ESU will remain viable under extreme marine survival conditions while providing substantial environmental, cultural, and economic benefits. Future analyses will be based on an average persistence value from the four PVA models developed by the TRT (Wainwright et al. 2008;Wainwright et al. 2006 poster).

Analysis

Because of the uncertainty of demographic effects at low population size, the TRT used two levels of "quasi-extinction" (1 and 50) to model persistence of the populations.

Evaluation Thresholds

For a population to pass this criterion it must have an average probability of persistence of 0.99 or greater as estimated by the four PVA models used by the TRT (Wainwright et al. 2008;Wainwright et al. 2006 poster).

Productivity

Annual estimates of the number of naturally produced recruits (progeny) per spawner (parent) (R/S) in the population.

Spawning Year	R/S × R/S The point estimate for the ratio of recruits from the designated brood year and RperStype, divided by the number of parent spawners responsible for that brood year. Straight ratio calculation, not a log/natural log transformation. Close	Broad Sense Goal × Broad Sense Goal If abundance goal is not met, goal R/S is >= 1. Otherwise, R/S values, standardized to a spawner density equal to the spawner abundance goal for each marine survival category, must be statistically greater than or equal to 1.0. Populations of naturally produced fish comprising the ESU are sufficiently abundant, productive, and diverse (in terms of life histories and geographic distribution) that the ESU as a whole will: a) be self-sustaining, and b) provide environmental, cultural, and economic benefits. This goal represents a condition of the ESU that is significantly higher than a level where it could be considered a potential candidate for listing under federal ESA. Close
2020		1.0
2019	1.86	1.0
2018	1.55	1.0
2017	0.20	1.0
2016	1.80	1.0
2015	1.23	1.0
2014	2.33	1.0
2013	0.17	1.0
2012	0.16	1.0
2011	0.98	1.0
2010	2.31	1.0
2009	1.87	1.0
2008	1.67	1.0
2007	0.84	1.0
2006	0.38
2005	0.61
2004	0.91
2003	2.42
2002	4.34
2001	18.08
2000	5.95
1999	0.89
1998	0.34
1997	0.24

Evaluation Thresholds

Pass - Over a 12-year period, R/S values, standardized to a spawner density equal to the spawner abundance goal for each marine survival category, are statistically greater than or equal to 1.0.

Fail - Over a 12-year period R/S values, standardized to a spawner density equal to the spawner abundance goal for each marine survival category, are statistically less than 1.0.

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Nehalem

Nehalem (Independent Population)

Abundance

Nat. Origin Spawners

95% Confidence Interval

Broad Sense Goal

Proportion of Goal

Evaluation Thresholds

Distribution

Total Sites Visited

Occupied Sites

Percent Total Occupied Sites

Percent Wild Occupied Sites

Proportion of Goal Wild Sites

Broad Sense Goal

Evaluation Thresholds

Diversity

Harmonic Mean

Broad Sense Goal

Evaluation Thresholds

Habitat

Miles Current

95% Confidence Interval

Broad Sense Goal

Percent of Goal

Evaluation Thresholds

Persistence

Average Probability

Broad Sense Goal

Discussion and Rationale

Analysis

Evaluation Thresholds

Productivity

R/S

Broad Sense Goal

Evaluation Thresholds