Alaskan king crab enhancement: advances in aquaculture and king crab ecology Ginny L. Eckert...
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Transcript of Alaskan king crab enhancement: advances in aquaculture and king crab ecology Ginny L. Eckert...
Alaskan king crab enhancement:advances in aquaculture and king crab ecology
Ginny L. EckertUniversity of Alaska Fairbanks,
Juneau Center School of Fisheries and Ocean Sciences
AKCRRABAlaska King Crab Research Rehabilitation and Biology
Steering Committee Science Team Graduate Students
David Christie David Christie Ben Daly
Ginny Eckert Ginny Eckert Celeste Leroux
Jeff Hetrick Jeff Hetrick Jodi Pirtle
Bob Foy Bob Foy Scott Vulstek
Heather McCarty Jim Swingle Miranda Westphal
Chris Mierzeiek Al Stoner Jenni Stoutamore
Roger Painter David Tallmon
Jeff Stephan Doug Pengilly
Gale Vick
Early Enhancement Activities in Alaska
• 1992 International King Crab Rehabilitation and Enhancement Symposium
• 1990s-2000s Extensive research by Dr. Brad Stevens in Kodiak and Japan
• 2000s Continued research by NMFS Kodiak
• 2006 Alaska Crab Stock Enhancement and Rehabilitation Workshop
Small scale experiment setup
S. Persselin and B. Stevens
Stock Enhancement Programs
American lobster (Sastry, 1976 Tlusty et al., 2005)
European Lobster (Bannister and Addison, 1998; Beal et al., 2002)
Blue crab (Zmora et al., 2005)
Swimming crab (Secor et al. 2002)
Stock Enhancement Programs
Hanasaki king crab - Japan (Nakanishi and Naryu, 1981; Stevens 2006)
Southern king crab - Chile & Argentina(Lovrich and Tapella, 2006; Paschke et al., 2006)
Red king crab - Russia(Kovatcheva et al. 2006)
• Recruitment limitation
• Climate-driven fluctuations
• Overfishing - threshold effects
• Regime shift - Predation
Why have king crabs not recovered in the absence of fishing?
Glaucothoe
Zoea 3 Zoea 4
King Crab Life Cycle
Female with extruded eggs
Mating
Crab Instar 1
Zoea 1
Zoea 2
• Can king crabs be cultured at large scale in Alaska?
• 2007-2010
• Culturing at various densities, diets, temperatures, water conditions
Is king crab rehabilitation feasible?
2007
Densities 25 - 194 per L
Diets - Algae
Live/Paste Algae
Diets - Artemia
Frozen/Fresh GSL Artemia
Diets - Additive
Concern Course of ActionTemperature fluctuation Improve water system
Water quality Install carbon filters
Excessive aeration Decrease aeration
Nutritional deprivation Enrich Artemia
Changes post-2007
2007 2008
Densities 25 - 194 per L
25 & 50 per L
Diets - Algae
Live/Paste Algae
Live/No Algae
Diets - Artemia
Frozen/Fresh GSL Artemia
Enriched/Not
Enriched SFB
Artemia,
Diets - Additive
With/without EDTA
2007 2008 2009
Densities 25 - 194 per L
25 & 50 per L
44 & 50 per L
Diets - Algae
Live/Paste Algae
Live/No Algae
Live/No Algae
Diets - Artemia
Frozen/Fresh GSL Artemia
Enriched/Not
Enriched SFB
Artemia,
Enriched SFB
Artemia
Diets - Additive
With/without EDTA
With/without EDTA
• Can king crab larvae be cultured at large scale in Alaska?
Is king crab rehabilitation feasible?
YES!YES!
• Can king crab larvae be cultured at large scale in Alaska?
• Production of juveniles increasingly successful 2007-2010
• Algae not necessary in diet
•Artemia enrichment critical
•Adequate water quality critical
•Increasing water temperature speeds development
Is king crab rehabilitation feasible?
Hatchery Culture: Juvenile Nursery
Issues: Cannibalism & optimize growth
Vary diet, density & substrate
Daly et al. 2009 Aquaculture
C1-C3DietDensitySubstrateDiet*Density
DietDensitySubstrate
DietDensitySubstrateDiet*Density
Hatchery Culture: Juvenile Nursery
Increasing survival:
•Complex substrates: reduces antagonistic interactions
Hatchery Culture: Juvenile Nursery
Increasing survival:
•Complex substrates: reduces antagonistic interactions
•Size grading: reduces cannibalism on smaller crabs
Hatchery Culture: Juvenile Nursery
Increasing survival:
•Complex substrates: reduces antagonistic interactions
•Size grading: reduces cannibalism on smaller crabs
•Diet supplements: increases nutrition
Hatchery Culture: Juvenile Nursery
Increasing survival:
•Complex substrates: reduces antagonistic interactions
•Size grading: reduces cannibalism on smaller crabs
•Diet supplements: increases nutrition
•Stocking density: decreases cannibalism
Hatchery Culture: Juvenile Nursery
Increasing survival:
•Complex substrates: reduces antagonistic interactions
•Size grading: reduces cannibalism on smaller crabs
•Diet supplements: increases nutrition
•Stocking density: decreases cannibalism
Increasing growth:
•Diet supplements: increases nutrition
Hatchery Culture: Juvenile Nursery
Increasing survival:
•Complex substrates: reduces antagonistic interactions
•Size grading: reduces cannibalism on smaller crabs
•Diet supplements: increases nutrition
•Stocking density: decreases cannibalism
Increasing growth:
•Diet supplements: increases nutrition
•Density dependent growth: moderate density has best
growth
Competency of Hatchery Juveniles
Lab Predation
Role of habitat
• Sand• Hydroids• Hydroids/Macroalgae• Hydroid Mimics
Pirtle et al. in prep
Crabs Consumed by Cod
p < 0.0001
Habitat
Sand Complex Mimic
Hydroid Mimic
Complex Biogenic
Hydroid
Mean
Cra
bs
Con
sum
ed
0
2
4
6
8
10
12
14
16
*
Pirtle et al. in prep
Crab Stage
Age-0 Age-1
Cra
b s
urv
ival
(%)
0
20
40
60
80
100No Structure Structure Control
0
Structure p < 0.0001
Stage p = 0.07
Crab Field Survival
Pirtle et al. in prep
Ongoing Studies• Physical tags: elastomer, microwire, dactyl clipping
• Genetic structure of wild stocks
• Genetic mark to identify hatchery animals in wild
• Genetic risk - conserve genetic diversity
• Release strategies - size, behavior
Thanks
• Alaska Sea Grant College Program• AKCRRAB Science Team & Steering Committee• NOAA Aquaculture & Saltonstall Kennedy Programs• NOAA National Marine Fisheries Service• Alutiiq Pride Shellfish Hatchery• Alaska Department of Fish and Game• Industry & Community Partners: CBSFA, UFA, UFMA,
GOACC, APICDA, NSEDC
• … and more...