Susitna River Chinook Salmon Escapement Goals 1 Recommended - PDF document

Susitna River Chinook Salmon Escapement Goals 1 Recommended Northern Cook Inlet King Salmon Escapement Goals Talkeetna River Eastside Susitna River Yentna River Area of Detail 2 Map showing current single aerial survey index streams with goals (labeled streams), and the new stock goal areas (shaded area). Note that Alexander Creek and the Chulitna River still have a single aerial survey index goal, and all labeled streams (plus others as funding and conditions allow) will continue to be surveyed.

Susitna Chinook Run Reconstruction Design Mark- recapture Weir counts Harvest data Aerial surveys Age data abundance State – Space Model Stock Recruit Run Reconstruction analysis (Escapements) (Escapement Goals) Diagram depicting the inputs and outputs of the run reconstruction/ stock recruit model used to develop new escapement goals and estimate escapements to assess annual performance of each stock relative to the goals. Example of Outputs 4 Example of escapements (top graph), and returns per spawner (bottom graph) from stock-recruit analysis, for illustration purposes (data not from Susitna River Chinook).

Stock Goals and Recent Escapements Deshka River 70,000 60,000 50,000 40,000 30,000 20,000 10,000 0 5 Weir counts for years 2004 – 2019 (blue bars) and updated escapement goal range (9,000 – 18,000 fish, red lines) for Deshka River Chinook salmon. Stock Goals and Recent Escapements Eastside Susitna River 40,000 4/5 35,000 5/5 30,000 4/5 3/3 2/3 25,000 2/5 20,000 3/4 1/5 1/3 2/5 1/4 1/4 15,000 1/5 1/5 10,000 5,000 0 6 Modeled escapement values for 2004 – 2017 (blue bars), and escapement goal range (13,000 – 25,000 fish, red lines) for the Eastside Susitna River Chinook salmon stock. Fraction above escapement indicates single aerial surveys that met the low end of the current goal (numerator) versus the number of surveys completed that year (denominator).

Stock Goals and Recent Escapements Talkeetna River 30,000 2/2 2/2 25,000 20,000 2/2 2/2 2/2 1/2 15,000 1/2 2/2 2/2 0/2 0/1 1/2 10,000 0/2 0/2 5,000 0 7 Modeled escapement values for 2004 – 2017 (blue bars), and escapement goal range (9,000 – 17,500 fish, red lines) for the Talkeetna River Chinook salmon stock. Fraction above escapement indicates single aerial surveys that met the low end of the current goal (numerator) versus the number of surveys completed that year (denominator). Stock Goals and Recent Escapements Yentna River 70,000 3/3 60,000 50,000 3/3 3/3 3/3 40,000 3/3 3/3 3/3 3/3 30,000 20,000 1/2 2/3 2/3 0/3 0/2 0/3 10,000 0 8 Modeled escapement values for 2004 – 2017 (blue bars), and escapement goal range (13,000 – 22,000 fish, red lines) for the Yentna River Chinook salmon stock. Fraction above escapement indicates single aerial surveys that met the low end of the current goal (numerator) versus the number of surveys completed that year (denominator).

Susitna Chinook Productivity 9 Chinook salmon productivity for each of four Susitna Chinook salmon stocks, 1979 - 2014. Points above zero line (Y-axis) represent above average productivity, and those below represent below average productivity. Susitna Chinook Run Reconstruction and EG Analysis Summary • This approach is advantageous for setting escapement goals because it uses all available data sets to describe the stock recruit relationship for Susitna Chinook, and stocks are the level we manage to. • A detailed report of this analysis is scheduled for publication in early winter 2020. • Questions? 10