1. Squid Overload: Berryteuthis magister in the Bering Sea Paige Drobny, UAF Brenda Norcross, UAF Nate Bickford, UAF

2. Berryteuthis magister Magister armhook squid  Hooks on their arms  Maximum recorded length = 43 cm DML  Weight to 2.6 kg  Up to 2 year life cycle  Die after spawning  Sexual dimorphism  Central to the ecosystem food web  Temperature sensitive: good bioindicator! Photo credit Alaska Fisheries Science Center

3. Distribution Modified from Okutani et al. 1983  Pelagic up to 1000 m  Associated with the continental shelf  Diel migrations  Ontogenetic shifts  Subspecies  B. magister nipponensis  B. magister shevtsovi Kubodera 1982

4. Housed in statocyst with endolymph fluid Controls orientation in space Daily rings Take up trace elements in relative proportion as the surrounding water mass The role of statoliths in squid

5. Bering Sea Stabeno and Reed 1994

6. Objectives 1.To establish age and growth patterns for Bering Sea B. magister and determine if there are changes in age and growth across the Bering Sea. 2.Use statolith chemistry to determine past movement patterns of individual B. magister. 3.Use statolith chemistry to combine B. magister into stock units, to develop a stock movement pattern.

7. Western Bering Sea study on B. magister Dispersed during summer September and October formed large dense schools over the continental shelf Stock stucture: Summer-hatched Fall-hatched Winter-hatched Growth, maturation, and mortality rates varied among seasonal cohorts Each cohort used the same areas for different portions of the life cycle Arkhipkin et.al, 1996

8. Growth Obtain length and weight Age Polished both sides with water on fine grit paper Magnify 100x to count daily rings LA-ICP-MS Core = hatch location Edge = capture location Transect =movement through lifetime Methods Core line Edge line Transect line

9. Opportunistic sampling locations 2004 samples (numbered locations) collected from the Bering Sea Slope survey (AFSC/NMFS)- June to August 2006 samples (red triangle) caught as bycatch in pollock trawls -September Northern Central Southern

10. Size Distribution 20042006

11. Results

12. Max Age =188 days

13. Age = 127-166 days Age = 73- 113 days Age = 114- 151 days Age = 95- 122 days Age = 84-115 days Age = 120-177 days

14. 2006 180

15. 2006

17. Location 22/ southern Location 180/ central Location 115/ northern

18. 2004 samples

19. 2006 samples

20. BM1 BM182 BM10 BM219

21. Conclusions Squid in the Eastern Bering Sea may only live up to one year Two cohorts are present in 2004 At least 2 natal areas are represented by the 2 different cohorts Squid are moving to the continental shelf from a natal area Northern Central Southern

22. Acknowledgements North Pacific Research Board Dr. George Jackson, U. Tasmania Dr. Ron O’Dor, Census of Marine Life Mary Hunsicker, U. Washington NMFS