{"id":3013,"date":"2020-01-22T19:11:57","date_gmt":"2020-01-23T03:11:57","guid":{"rendered":"http:\/\/calsport.org\/fisheriesblog\/?p=3013"},"modified":"2020-01-22T19:11:57","modified_gmt":"2020-01-23T03:11:57","slug":"scott-river-coho-salmon-run-status-fall-2019","status":"publish","type":"post","link":"https:\/\/calsport.org\/fisheriesblog\/?p=3013","title":{"rendered":"Scott River Coho Salmon Run \u2013 Status Fall 2019"},"content":{"rendered":"

The Scott River Coho salmon population is one of the last remaining self-sustaining wild Coho salmon runs in California and in the Southern Oregon Northern California Coho (SONCC) Evolutionarily Significant Unit (ESU).\u00a0 The SONCC ESU is listed as \u201cthreatened\u201d under the federal and California endangered species acts.\u00a0 The ESU includes the Rogue River in Oregon and the Klamath River in California.<\/p>\n

The Scott Coho run is the major wild Coho population in the Klamath River system.\u00a0 Scott Coho spawn and rear in Scott Valley, once called \u201cBeaver Valley,\u201d located near Fort Jones.\u00a0 The run has numbered over 1,000 adult Coho spawners as recently as 2013, but numbered less than 100 as recently as the 2008-09 drought years (Figure 1).<\/p>\n

Scott Coho include three distinct sub-populations that have developed because the vast majority of spawners are three years old.\u00a0 One subgroup, the 2007-2010-2013 sub-group, dominated the population in the recent past, but declined sharply in 2016.\u00a0 The other two sub-groups have increased slightly since 2008 and 2009 lows.<\/p>\n

The spawner-recruit relationship (Figure 2) shows a generally positive relationship between the number of spawners and recruits three years later for each sub-group and the overall population with one distinct outlier (the sharply lower 2016 run).\u00a0 So why was the 2013 run so high and the brood-year 2013 run in 2016 so poor?<\/p>\n

1.\u00a0\u00a0\u00a0\u00a0\u00a0 2013\u2019s Good Run<\/h2>\n

The 2013 run (brood year 2010) got off to a great start in wet water year 2011.\u00a0 Flows for the fall 2010 spawning run were good from November through January [Figure 3), which ensured spawner access and good spawning conditions throughout Scott Valley.\u00a0 Flows were also good through the spring and fall of 2011 (Figure 4), ensuring good smolt production and a subsequent strong run in 2013.<\/p>\n

2.\u00a0\u00a0\u00a0\u00a0\u00a0 2016\u2019s Poor Run<\/h2>\n

The strong run in 2013 spawned in brood year 2013, which got off to a rocky start in dry water year 2013-14.\u00a0 Flows in fall-winter 2013-14 encountered by the strong 2013 run were very low through the early winter spawning season (Figure 5), leading to an unusually protracted run of adult spawners (Figure 6) and poor accessibility to good spawning areas.\u00a0 Spawning habitat quality and quantity likely also suffered from low flows.\u00a0 Flows were then very low from spring through fall of 2014 (Figure 7), likely resulting in poor over-summer survival and low smolt production for brood year 2013.<\/p>\n

In conclusion, the Scott Coho salmon population continues to suffer from low seasonal streamflow, especially in drought years like water year 2013-14.\u00a0 The population would benefit from improved summer-through-fall streamflows.\u00a0 It will also benefit from the watershed habitat restoration actions being implemented by landowners, CalTrout<\/a>,\u00a0 the Scott River Watershed Council<\/a>, Siskiyou RCD<\/a>, Scott River Water Trust<\/a>, California Department of Fish and Wildlife<\/a>, Quartz Valley Indian Reservation<\/a>, and other stakeholders<\/a>.<\/p>\n

\"Figure

Figure 1. Escapement of adult Coho salmon to the Scott River from 2007 to 2019. Data source: CDFW, Yreka, CA.<\/p><\/div>\n

\"\"

Figure 2. Spawner-recruit relationship for Scott River Coho salmon. The number represents recruits (spawner counts) for that year versus spawners counts from three years earlier. For example: \u201c13\u201d represents spawner counts (recruits) in fall 2013 versus spawner numbers three years earlier in 2010. Number color represents different spawner subgroups (blue=subgroup 10-13-16-19). The Red circle highlights significant outlier in 2016. The Yellow line is trend-line for years other than 2016.<\/p><\/div>\n

\"\"

Figure 3. USGS gaged daily average flow (log scale) in lower Scott River, Klamath River tributary, 9\/1\/2010-2\/1\/2011, with 78 year average daily median flow for that date.<\/p><\/div>\n

\"\"

Figure 4. USGS gaged daily average flow (log scale) in lower Scott River, Klamath River tributary, 4\/1\/2011-11\/1\/2011, with 78 year average daily median flow for that date.<\/p><\/div>\n

\"Figure

Figure 5. USGS gaged daily average flow (log scale) in lower Scott River, Klamath River tributary, 9\/1\/2013-2\/1\/2014, with 78 year average daily median flow for that date.<\/p><\/div>\n

\"\"

Figure 6. Scott River adult salmon collection weir counts of Coho salmon for fall-winter 2013-14. Data source: CDFW Yreka, CA.<\/p><\/div>\n

\"\"

Figure 7. USGS gaged daily average flow (log scale) in lower Scott River, Klamath River tributary, 4\/1\/2014-10\/31\/2014, with 78 year average daily median flow for that date.<\/p><\/div>\n

 <\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

The Scott River Coho salmon population is one of the last remaining self-sustaining wild Coho salmon runs in California and in the Southern Oregon Northern California Coho (SONCC) Evolutionarily Significant Unit (ESU).\u00a0 The SONCC ESU is listed as \u201cthreatened\u201d under … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[19],"tags":[],"class_list":["post-3013","post","type-post","status-publish","format-standard","hentry","category-coho"],"jetpack_featured_media_url":"","jetpack-related-posts":[],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/calsport.org\/fisheriesblog\/index.php?rest_route=\/wp\/v2\/posts\/3013","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/calsport.org\/fisheriesblog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/calsport.org\/fisheriesblog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/calsport.org\/fisheriesblog\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/calsport.org\/fisheriesblog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3013"}],"version-history":[{"count":3,"href":"https:\/\/calsport.org\/fisheriesblog\/index.php?rest_route=\/wp\/v2\/posts\/3013\/revisions"}],"predecessor-version":[{"id":3023,"href":"https:\/\/calsport.org\/fisheriesblog\/index.php?rest_route=\/wp\/v2\/posts\/3013\/revisions\/3023"}],"wp:attachment":[{"href":"https:\/\/calsport.org\/fisheriesblog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3013"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/calsport.org\/fisheriesblog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3013"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/calsport.org\/fisheriesblog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3013"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}