Southeast Alaska Red King Crab Stock Assessment King and Tanner - PowerPoint PPT Presentation

Southeast Alaska Red King Crab Stock Assessment King and Tanner Task Force Mtg. December 2 nd , 2016 Image: northpacificseafoods.com

RKC Assessment / Management • Assessment – 7 areas surveyed with ~364 pot lifts – Biomass estimated using Catch-Survey Analysis (CSA) model • Management plan – Season November 1 – January 24 – Appropriate harvest rate – Regional GHL set using survey biomass – Pot limits based on GHL • Ex. 200,000 GHL = 20 pot limit per vessel – Minimum GHL threshold of 200,000 lbs legal crab – Mark/Recapture expansion factor incorporated into biomass estimate – Males only, 7-inch minimum CW

Southeast Alaska Major Commercial Red King Crab Fishing Grounds

Southeast Alaska 2015 Survey Updates: • Budget reductions caused survey sources to be re-allocated into historically more important survey areas • Port Frederick, Holkham Bay, and Rodman Bay removed due to historically low catch rates and abundance • No significant impact on biomass estimate

RKC Biomass / Harvest 2.0 Legal biomass Commercial closures Mature biomass 1.5 Biomass (million lbs) 1.0 0.5 baseline time period (93-07) 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 Figure 1. Total biomass estimates of mature and legal red king crab for surveyed areas in Southeast Alaska. Estimates based on Catch-Survey Analysis (CSA) methodologies. This does not include Holkham Bay, Port Frederick or non-surveyed areas. Biomass values in this graph are slightly less than previous years due to the removal of Port Frederick from the survey areas. Reference line represents long-term (1993 – 2007) average legal biomass estimate. Triangles represent years in which there was a commercial harvest closure. 5

ADJUSTED Equil. mature Survey area Biomass Biomass ADJUSTED ADJUSTED 2016 of legal of mature legal mature exploitation Total Personal Commercial crab crab biomass biomass rate GHL use catch GHL (lb) 34,200 37,201 108,741 118,281 5.0% 5,914 n/a 5,914 Pybus Bay 24,059 29,839 7,018 n/a 7,018 113,164 140,352 5.0% Gambier Bay 28,849 39,126 265,659 360,290 1.0% 3,603 n/a 3,603 Seymour Canal 7,853 15,372 11,656 22,816 10.0% 2,282 n/a 2,282 Peril Strait Juneau Area a 253,308 354,469 253,308 354,469 53,170 31,902 21,268 15.0% 5,108 7,010 8,032 11,023 10.0% 1,102 n/a 1,102 Lynn Sisters 17,184 35,373 84,931 174,832 5.0% 8,742 n/a 8,742 Excursion Inlet 219,504 307,071 48,473 1,000 48,473 500,832 700,203 7.0% Other Areas 3,935 5,504 8,978 12,551 869 869 Blue King Crab 594,000 830,965 1,355,301 1,894,818 98,270 Total a The Juneau area was closed to personal use harvest in 2016 , but is left in here for demonstrative purposes. “n/a” r epresents data that is not available or readily estimable from the other bays.

Pybus Bay 10 Prerecruit Recruit CPUE (number / pot) 8 Postrecruit Pybus Bay 6 4 2 • Stock health decreased from moderate to 0 below average 20 Juvenile males CPUE (number / pot) Juvenile females 15 Mature females • There is a significant short-term increasing 10 trend for juvenile females, no significant trends were detected for all other recruit 5 classes 0 0.4 100 Ratio poor clutch / pot • % Female clutch fullness was lowest on 80 Total % fullness 0.3 record 60 % Poor clutch 0.2 Total % clutch 40 0.1 • Both legal and mature male biomass still 20 0.0 0 remain low compared to historic levels 800 Legal biomass (x 1000 lbs) CSA Harvest M/R Adjustment 600 400 200 0 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 Year

Gambier Bay 8 CPUE (number / pot) Prerecruit Recruit 6 Postrecruit Gambier Bay 4 2 • Stock health remains below average 0 CPUE (number / pot) 20 Juvenile male • Short term increases in pre-recruit and Juvenile female 15 Mature female post recruit males, along with juvenile and 10 mature females. 5 • % Female clutch fullness was lowest on 0 0.4 100 record Ratio poor clutch / pot 80 Total % fullness 0.3 • 60 Both legal and mature male biomass % Poor clutch 0.2 Total % clutch 40 estimates increased from 2015 yet were 0.1 20 still low compared to historic levels 0.0 0 Legal biomass (x1000 lbs) CSA 300 Harvest M/R Adjustment 250 200 150 100 50 0 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 Year

Peril Strait 8 CPUE (number / pot) Prerecruit Recruit 6 Postrecruit Peril Strait 4 2 • Stock health remains poor 0 20 • Juvenile males Short term increases in juvenile and CPUE (number / pot) Juvenile females 15 Mature females mature females. No indication of 10 improvement for any other classes 5 • % Female clutch fullness was lowest on 0 record 0.4 100 Ratio poor clutch / pot 80 Total % fullness 0.3 • Legal biomass levels are lowest since the 60 % Poor clutch 0.2 Total % clutch survey began, mature biomass increased 40 0.1 due to increases in pre-recruit CPUE 20 0.0 0 Legal biomass (x 1000 lbs) 250 CSA 200 Harvest M/R Adjustment 150 100 50 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 9 9 9 9 0 0 0 0 0 1 1 1 1 1 9 9 9 9 0 0 0 0 0 0 0 0 0 0 1 1 1 1 2 2 2 2 2 2 2 2 2 2 Year

Seymour Canal 8 Prerecruit CPUE (number / pot) Recruit Postrecruit 6 Seymour Canal 4 2 • Stock health increased from poor to 0 below average 20 Juvenile male CPUE (number / pot) Juvenile female Mature female 15 • No short term trends 10 • % Female clutch fullness healthy 5 0 • Biomass levels increased slightly 0.4 100 Ratio poor clutch / pot 80 Total % fullness 0.3 % Poor clutch 60 Total % clutch 0.2 40 0.1 20 0.0 0 2000 Legal biomass (x 1000 lbs) CSA Harvest 1500 M/R Adjustment 1000 500 0 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 9 9 9 9 9 0 0 0 0 0 1 1 1 1 1 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 Year

Juneau 8 Prerecruit CPUE (number / pot) Recruit 6 Postrecruit Juneau Area 4 2 • Stock health remains at below average 0 and continues to improve 20 CPUE (number / pot) Juvenile male Juvenile female Mature female 15 • Short term increases in male pre-recruit 10 and recruit classes 5 • % Female clutch fullness healthy 0 0.4 100 Ratio poor clutch / pot • Biomass levels increased and are the 80 Total % fullness 0.3 largest they have been since 2006 yet still 60 % Poor clutch 0.2 Total % clutch below the long-term baseline 40 0.1 20 0.0 0 500 Legal biomass (x 1000 lbs) CSA Harvest 400 300 200 100 0 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 Year

Lynn Sisters 8 Prerecruit CPUE (cumber / pot) Recruit 6 Postrecruit Lynn Sisters 4 2 • Stock health declined from below average 0 to poor 20 Juvenile male CPUE (number / pot) Juvenile female Mature female 15 • No short term trends 10 • % Female clutch fullness healthy 5 0 • Biomass levels continue to decline and 0.4 100 Ratio poor clutch / pot stock health is of concern 80 0.3 Total % fullness 60 % Poor clutch 0.2 Total % clutch 40 0.1 20 0.0 0 80 Legal iomass (x 1000 lbs) CSA Harvest M/R Adjustment 60 40 20 0 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 Year

Excursion Inlet 10 CPUE (number / pot) Prerecruit Recruit 8 Postrecruit Excursion Inlet 6 4 2 • Stock health remains poor 0 25 CPUE (number / pot) • Juvenile male No short term trends Juvenile female 20 Mature female 15 • % Female clutch fullness was lowest on 10 record 5 0 • Legal biomass increased slightly, but 0.5 100 Ratio poor clutch / pot mature biomass declined substantially 0.4 80 Total % fullness % Poor clutch 0.3 60 Total % clutch 0.2 40 0.1 20 0.0 0 Legal biomass (x 1000 lbs) CSA 500 Harvest M/R Adjustment 400 300 200 100 0 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 Year

RKC equilibrium exploitation rate 0.6 Example: Year 1 – 50,000 0.4 Population Change (proportion) Year 2 – 55,000 0.2 Change = (55,000-50,000)/ 0.0 50,000 = 0.10 proportion increase -0.2 -0.4 Harvest rate = -0.6 4000/50,000 = 0.08 HR 0.0 0.1 0.2 0.3 0.4 Harvest rate Where regression line crosses 0 is the harvest rate that would ideally give an average of 0 or “no change” over time.