1. Distribution and connectivity between spawning and settling locations of Greenland halibut (Reinhardtius hippoglossoides) in the Bering Sea Dongwha Sohn 1, Lorenzo Ciannelli 1, Janet T Duffy-Anderson 2, Ann Matarese 2, and Kevin Bailey 2 1 College of Oceanic and Atmospheric Sciences, Oregon State University 2 National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Alaska Fisheries Science Center

2. Circumpolar species (both the Atlantic and Pacific) Slope spawner during winter Cold water species (-2 to 4 o C) Max wt 45 kg, max size 120cm, max age 30 yrs Photo by Morgan Busby Greenland halibut (Reinhardtius hippoglossoides) Order: Pleuronectiformes Family: Pleuronectidae Genus: Reinhardtius Species:R. hippoglossoides

3. Study area

4. Spawning Stock Biomass Recruitment Year Motivation

5. To examine spatial distribution and connectivity between spawning and potential settling locations during early life stages of Greenland halibut - Egg distribution - Larval distribution - Pelagic juveniles (or late larvae) distribution - Settled juveniles distribution Objective

6. Historical data from the Alaska Fisheries Science Center (AFSC). For the horizontal distribution of larvae, Ichthyoplankton survey database (ICHBASE;1982-2005) - 60cm Bongo net (60BON; larvae) - Modified Beam Trawl (MBT; late larvae) - Methot (METH; late larvae) For the vertical distribution of larvae Ichthyoplankton survey database (ICHBASE;1992-1994) - Multiple Opening/Closing Net Environmental Sampling System (MOC; larvae) For the horizontal distribution of settled juveniles, Groundfish survey database (RACEBACE;1982-2006) - Bottom Trawl (BT; settled juveniles) METH/ to May) Data

7. Results Distributions and connectivity from eggs to newly settled juveniles in the Bering Sea - Egg distribution - Larval distribution - Pelagic late larval distribution - Settled juveniles distribution

8. Egg distribution in Feb 2008 73 eggs using bongo and the late stage of development

9. Results Distributions and connectivity from eggs to newly settled juveniles in the Bering Sea - Egg distribution - Larval distribution - Pelagic late larval distribution - Settled juveniles distribution

10. Larval distribution during spring (March to May) from 1982 to 2005 60BON: Larvae (8.8-22.4mm SL) were mostly found on the continental slope (below 500m isobath) and cross slope to shelf through Bering Canyon during spring.

11. Larval distribution in Feb 2008 3 yolk-sac larvae (10.1-14.3 mm SL) were collected in bongo tows.

12. Larval distributions in May 2007 and 2008 41 larvae (15.8-26.0 mm SL) in May 2007 and 11 larvae (14.8-24.0 mm SL) in May 2008

13. Vertical distribution of larvae in April from 1992 to 1994 60BON MOC

14. Results Distributions and connectivity from eggs to newly settled juveniles in the Bering Sea - Egg distribution - Larval distribution - Pelagic juveniles distribution - Settled juveniles distribution

15. Distribution of pelagic juveniles during summer (July to Aug) from 1982 to 2005 METH/MBT: Late larvae & pelagic juveniles (18-54mm SL) were found on the middle shelf (50-100m isobath) near the Pribilof Is. during summer.

16. Results Distributions and connectivity from eggs to newly settled juveniles in the Bering Sea - Egg distribution - Larval distribution - Pelagic late larval distribution - Settled juveniles distribution

17. Distribution of newly settled juveniles during summer (June to Oct) from 1982 to 2006 BT: Newly settled juveniles (60-90mm SL) occurred on the middle shelf near St. Matthew Is. during summer.

18. Distributions of age-0 vs. age-1 Two length-size classes based on stock assessment modeling: one class (age-0) is less than 100mm and another (age-1) is between 140 mm - 220 mm. Age-1Age-0

19. BT MBT METH 60BON Larvae Pelagic juveniles Newly Settled juveniles Distribution and drift pathways Schematic of mean circulation the upper 40 m. Aleutian North Slope Current (ANSC), Bering Slope Current (BSC) (Stabeno et al., 1999).Stabeno et al., 1999

20. We reconstructed larval drift pathways using a particle drift model and a Regional Ocean Model System (ROMS) by Pacific Marine Environmental Laboratory. Simulated holey-sock drifters were tracked from April 15 - August 30 (about 140 days). They were released at multiple vertical (0-100m) and horizontal locations (in Bering, Pribilof, and Zhemchug Canyons) Alaska Pribilof Canyon Bering Canyon Zhemchung Canyon Modeling transport pathways

21. Schematic representation of distribution and connectivity from larvae to settled juveniles GH have an extensively pelagic period and have a geographical variety of habitats such as spawning, nursery, settling habitats throughout different life history stages.

22. GH have an extensively pelagic period and have a geographical variety of habitats such as spawning, nursery, settling habitats throughout different life history stages. Greenland halibut hatch in deep water (below 500m), and it is likely that larvae slowly rise after hatching. The presence of larger larvae in the upper water column (<45 m depth). Larvae likely drift along the continental shelf edge, eventually crossing from the slope to the shelf to settle. Conclusions

23. Mechanisms of slope-shelf connectivity are strongly related with BSC (upper 40m). Variation of dispersal pathways induced by BSC variability could play an important role in early life history of GH and their recruitment. Settling area of juveniles in Greenland halibut is the middle shelf (50-100m) near St. Matthew Is. during summer in the eastern Bering Sea. Greenland halibut require specific location for settling and prefer different environmental conditions for their ontogenetic stages as they develop after settlement. Conclusions

24. Vertical distribution model by egg density Stomach content analysis Otolith analysis Adult distribution Ongoing work

25. Thank you! This project is funded by the North Pacific Research Board COAS at OSU Dongwha Sohn Lorenzo Ciannelli Alaska Fisheries Science Center Janet Duffy-Anderson Ann Matarese Kevin Bailey Collaborators: Phyllis Stabeno Tom Wilderbuer Jim Iannelli

26. Adults distribution during spawning seasons The horizontal distributions of Greenland halibut adult by bottom trawl catch data from Dec to Feb. A bubble indicates catch station and plus sign represents a non catch station.

27. Density profiles with respect to length and depth and estimated length–depth surfaces

28. The relationships between the larval abundances and maximum gear depths of 60cm bongo net