Triploid Chinook Salmon Brood Year 2003: 4 Minute Duration 100%

Sterile Fish Production for Lake Stocking Programs Using hydrostatic pressure to induce triploidy in five salmonid species

Diane Loopstra Alaska Department of Fish and Game Species (% contribution to 2007 production)

„ Arctic char (5%) „ Arctic grayling (5%) „ Chinook salmon (14%) „ Coho salmon (10%) „ Rainbow trout (66%) Lake Classification Landlocked Non-landlocked

„ All species „ All species „ 2N and 3N „ Primarily 3N „ 122 lakes „ 50 lakes „ 80% of fish „ 20% of fish Why Stock Triploids?

„ Reduce risk to native fish populations „ Expand stocking programs „ Increased growth? „ Reduce or delay early male maturation

Diploid male Chinook salmon Triploid Induction

„ Rainbow trout „ Heat shocking

„ All other species „ Pressure shocking Triploid Certification

„ All-female triploids

„ Rainbow trout

„ 140 of 150 tested

„ Mixed-sex triploids

„ All other species

„ 299 of 300 tested Pressure shock experiments Reported Data

„ Treatments were replicated „ Survival rate „ Mean of both replicates „ Relative to mean control survival rate „ ≈ 300 eggs in each treatment replicate „ Triploid Rate „ Mean of both treatment replicates „ n= 10 to 55 fish Triploid Arctic char Brood year 2002 (5 minute shock with 9,500 psi of pressure) 100% 80%

60% 40%

20% 0% 200 CTMs 250 CTMs 300 CTMs 350 CTMs Shock initiation time

Two replicates: n=45 % Emerged % Triploid Production 3N char (5-minute shock with 9,500 psi @ 250 CTMs)

„ Brood year 2005 „ 17% of production „ 70.4% survival to emergence „ 100% triploid „ Brood year 2006 „ 12% of production „ 75.6% survival to emergence „ 100% triploid „ Brood year 2007 „ 100% of production (≈ 200,000 eggs) Triploid Chinook Salmon Brood year 2003: 4 minute duration 100%

80%

60%

40%

20%

0% 9,000 psi 9,500 psi 10,000 psi 9,000 psi 9,500 psi 10,000 psi

240 CTMs 400 CTMs 2 replicates: n=14 to 45 % Emerged % Triploid Triploid Chinook Salmon

Broodyear 2004 Chinook salmon (10,000 psi of pressure applied) 100%

80%

60%

40%

20%

0% 3 minutes 4 minutes 3 minutes 4 minutes 3 minutes 4 minutes

300 CTMs 400 CTMs 500 CTMs % Em e rge d % Triploid

2 replicates: n=45 Production 3N Chinook salmon (4-minute shock with 10,000 psi at 400 CTMs)

„ Brood year 2007 „ 100% of catchable production „ Eyed egg survival rates: 87.6 to 96.3% „ Problems

„ Egg volume > Chamber volume

„ Intermittent loss of pressure Triploid Coho Salmon

Brood year 2003 (4 minute pressure shock)

100%

80% 60% 40% 20%

0%

9,000 psi 9,500 psi 10,000 psi 9,000 psi 9,500 psi 10,000 psi

240 CTMs %360 Emerged CTMs% Triploid Most treatments 2 replicates: n=45 Production 3N coho salmon (4-minute shock with 10,000 psi at 360 CTMs)

„ Brood year 2006 „ 52.7% of fingerling „ 91.9% survival to emergence „ 100% triploid Triploid Arctic Grayling

Brood year 2004 (5 minute treatment)

100% 80% 60% 40% 20% 0% 9,000 9,500 10,000 9,000 9,500 10,000 9,000 9,500 10,000 psi psi psi psi psi psi psi psi psi

100 CTMs 175 CTMs 250 CTMs % Emerged % Triploid 2 replicates: n=10 to 45 Triploid Arctic Grayling Brood year 2005 (5 minute treatment at 175 CTMs) 100%

80%

60%

40%

20%

0% 7,500 psi 8,500 psi 9,500 psi Pressure % Emerged % Triploid 2 replicates: n=55 Triploid Arctic Grayling Brood year 2006 (8,500 psi at 175 CTMs) 100%

80%

60%

40%

20%

0% 3 minutes 5 minutes 7 minutes

Shock duration 2 replicates: n=55 % Emerged % Triploid Production 3N Arctic grayling (5-minute shock with 8,500 psi at 175 CTMs) „ Brood year 2006

„ 8% of fingerling

„ 82.5% estimated survival to emergence

„ 100% triploid „ Brood year 2007

„ 6% of fingerling

„ 50% estimated survival to emergence

„ 100% triploid Triploid Rainbow Trout „ Heat shock procedure „ 20 min – 26°C – 20 min „ 96 to 100% triploid

„ All female „ xx males is the limiting factor

„ Sterile fish

„ Delayed maturation Pressure-Shocked Rainbow Trout

Brood year 2004 Rainbow trout

100%(5 minute shock at 300 CTMs)

80%

60%

40%

20%

0% 9,000 psi 9,500 psi 10,000 psi

9,000 psi treatment not replicated: n=45 Pressure % Em e rge d % Triploid Pressure-Shocked Rainbow Trout Brood year 2005 Rainbow trout (5 minute pressure shock)

100% 80% 60% 40% 20% 0%

9,000 psi 9,500 psi 10,000 psi,000 9 psi 9,500 psi 10,000 psi

375 CTMs 475 CTMs

% Emerged % Triploid 2 replicates: n=55 Production AFT Rainbow trout Brood year 2007 „ ≈ 1.7 million rainbow trout eggs „ ≈ 49% of rainbow trout production „ 98% triploid Future plans

„ Evaluate performance „ In hatchery „ In lakes „ Increase triploid production