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)

Background – Red King Crab Fishery

Background – Blue King Crab Fishery

• 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?

Anchorage

Ovigerous Female Collection

Hatchery Setup

Alutiiq Pride Shellfish HatcherySeward Marine Center

2007

Densities 25 - 194 per L

Diets - Algae

Live/Paste Algae

Diets - Artemia

Frozen/Fresh GSL Artemia

Diets - Additive

2007 Production Experiments

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


25 & 50 per L

Diets - Algae

Live/Paste Algae

Live/No Algae

Diets - Artemia


Enriched/Not

Enriched SFB

Artemia,

Diets - Additive

With/without EDTA

2007 2008 2009


25 & 50 per L

44 & 50 per L

Diets - Algae

Live/Paste Algae

Live/No Algae

Live/No Algae

Diets - Artemia


Enriched/Not

Enriched SFB

Artemia,

Enriched SFB

Artemia

Diets - Additive

With/without EDTA

With/without EDTA


Stage

Sur

viva

l

2010 Production ExperimentsLipid Index

Lipi

d In

dex

Stage

2010 Production ExperimentsFouling by bacteria

Development time

Per

cent

Fou

ling

Day

s

Juvenile Production

• Can king crab larvae be cultured at large scale in Alaska?


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


Blue King Crab

Hatchery Culture: Juvenile Nursery

Issues: Cannibalism & optimize growth

Vary diet, density & substrate

Daly et al. 2009 Aquaculture

C1-C3DietDensitySubstrateDiet*Density

DietDensitySubstrate

DietDensitySubstrateDiet*Density

Daly et al. 2009 Aquaculture

C3-C6DensitySubstrate

Substrate

Substrate


Issues: Cannibalism, color deficiency

Vary diet & density

Survival

Daly et al. in prep

Sur

viva

l

Color: Hue

Daly et al. in prep

Hue

Inde

x

Color: Brightness

Daly et al. in prep

Brig

htne

ss In

dex


Issues: Cannibalism

Size grading -- diet & density

Survival

Daly et al. in prep

Sur

viva

l

Size Grading


Increasing survival:

•Complex substrates: reduces antagonistic interactions




•Size grading: reduces cannibalism on smaller crabs





•Diet supplements: increases nutrition






•Stocking density: decreases cannibalism







Increasing growth:








Increasing growth:


•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

*


QuickTime™ and aMotion JPEG OpenDML decompressor

are needed to see this picture.

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


Westphal 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

One-year old juvenile red king crab

Nine-month old juvenile blue king crab

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...

Alaskan king crab enhancement: advances in aquaculture and king crab ecology Ginny L. Eckert...

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