The Green-Eyed Survivor Dogfish Shark Life History & Populations in the Gulf of Alaska

2. The Green-Eyed SurvivorDogfish Shark Life History & Populations in the Gulf of Alaska Cindy A Tribuzio School of Fish and Ocean Sciences University of Alaska Fairbanks Juneau Center

3. In Cooperation With…… Alaska Department of Fish and Game NMFS AFSC Auke Bay Lab

4. Outline • Sharks in Alaska • Dogfish Biology and Fishery Info • Project Objectives • Data Collection • Objective Results and Conclusions • Current and Future Research

5. Gulf of Alaska Sharks • 8 shark species, 6 families • 12+ skate species, 2 families • 1 chimera, ratfish Hydrolagus colliei

6. Gulf of Alaska Sharks • Blue Shark, Prionace glauca

7. Gulf of Alaska Sharks • Family Lamnidae Mackerel sharks Great White Shark Carcharodon carcharias Salmon Shark Lamna ditropis

8. Gulf of Alaska Sharks • Basking Shark, Cetorhinus maximus

9. Gulf of Alaska Sharks • Sleeper Shark, Somniosus pacificus

10. Gulf of Alaska Sharks • Brown Cat Shark, Aprisurus brunneus • Cookie Cutter

11. Gulf of Alaska Sharks Raja family • Big Skate Raja binoculata • Longnose Skate Raja rhina

12. Gulf of Alaska Sharks Bathyraja family

13. Spiny Dogfish, Squalus acanthias

14. Worldwide distribution in temperate coastal areas www.flmnh.ufl.edu Geographic Distribution

15. Worldwide distribution in temperate coastal areas Small size (up to 1.3m long) and long lived (100 years) Dogfish Biology • Stigma of being a “Nuisance Species” • Ecologically important as both predator and prey

16. Considered a nuisance species National Fisherman, Nov 2004: “Dogfish are wolves of the sea” Blames dogfish for the decline in more desirable species such as sea bass, porgies and “baby codfish” Common Perceptions http://new-brunswick.net/new-brunswick/sharks/species/spinydogfish.html

17. Cultural Importance

18. Qqaaxhadajaat, the Dogfish Woman A woman went traveling with her husband. She used to make fun of the dogfish. They went to visit a small rock in the sea. When they were out there, the dogfish, whose home the rock was, came and took the woman down into the sea. There she discovered that the dogfish were really people. They had taken off their dogfish blankets. After she had stayed in the house for some time, fins began to grow upon her arms, her legs and her back. Her husband was searching for her everywhere, but he was not able to find her. After a number of years he found her. Her face had remained unchanged; but fins had grown on her arms, on her legs, on her back, and on her head. She never returned. Ever since that time her family have used the dogfish crest, and their house is called Dogfish House.

19. Mitch Age: 5 Clint Age: 3 Size and Age of Spiny Dogfish Height: 44 in, 112 cm Height: 39 in, 99 cm

20. Size and Age of Spiny Dogfish Mitch, Age 5 Height: 44 in, 112 cm Spiny Dogfish, Age 5 Length: 13 in, 35 cm Clint, Age 3 Height: 39 in, 99 cm Spiny Dogfish, Age 3 Length: 11 in, 28 cm

21. Size and Age of Spiny Dogfish Mitch, Age 5 Height: 44 in, 112 cm Spiny Dogfish, Age >100 years!!! Length: 44 in, 112 cm Clint, Age 3 Height: 39 in, 99 cm Spiny Dogfish, Age 48 years!!! Length: 39 in, 99 cm

22. Photo by Rustin Director Reproductive Biology • Females mature at ~35 yrs • ~22 month gestation, 7-12 pups average • Fecundity and offspring survival increase as female ages/grows larger

23. Commercial Shark Fishing

24. North Atlantic Experience • The situation: • Fishery developed rapidly (1988), was stable for a short period then declined • 40 years of fishery independent survey data • Commercial fishery targeted large individuals, landings were dominated by mature females

25. North Atlantic Experience • The problems…… • 1988-2000: average size of landed female dogfish dropped from 4 kg to 2 kg and 95 to 79 cm • Almost no recruitment after 10 years of fishing pressure • 1989-2003: fishery removed nearly 213 K mt of spiny dogfish, biomass of spawning females dropped by 75%, total biomass of the population dropped by about 30%

26. North Atlantic Experience • The results • Few large females available to reproduce, small females producing pups with lower survival

27. North Atlantic Experience • The results • Few large females available to reproduce, small females producing pups with lower survival • Reduction in the number of juveniles recruiting to maturity

28. North Atlantic Experience • The results • Few large females available to reproduce, small females producing pups with lower survival • Reduction in the number of juveniles recruiting to maturity • NMFS declared over fished in 1998

29. North Atlantic Experience • The results • Few large females available to reproduce, small females producing pups with lower survival • Reduction in the number of juveniles recruiting to maturity • NMFS declared overfished in 1998 • Atlantic States Marine Fisheries Commission adopted catch limits of a 4 million pound bycatch cap quota and 300/600 pound trip limits for the 2005-2006 fishing season

30. North Pacific Ocean Fishery Commercially fished for over 100 years University of Washington Digital Image Collection www.sharkinfo.com

31. North Pacific Ocean Fishery • British Columbia and Washington State manage transboundary fishery independently • Washington State fishery is larger (tonnage) than BC fishery • Stock assessments in WA show decreasing abundances, reflected in catch. Opposite in BC.

32. North Pacific Ocean Fishery • Fishery Characteristics: • Targets larger females for size and ovaries • Most products exported internationally • Valuable marine export (with increasing market potential) • WA fishery generally targets inside (Puget Sound) dogfish, BC fishery targets outside (Coastal) dogfish • Outside dogfish more migratory, where inside dogfish tend to stay within home region (Strait of Georgia or Puget Sound) • Puget Sound and Strait of Georgia dogfish cannot be sold domestically for human consumption

33. Current Status of Alaskan Fishery • Federal bycatch fishery in Kodiak • Yakutat Bay: bycatch retention up to 35% of total catch in hook and line fisheries, retention up to 100% of total catch in set net fisheries • Cook Inlet: targeted fishery via Commissioners Permit began in April 2005

34. Fishery Concerns • Shark fisheries are generally not sustainable • Life history (late mature, low fecundity) does not support fishery • Ecological impact of fishery • Dogfish may have valuable role in ecosystem

35. Urgency and Management Issues • Regular bycatch in commercial fisheries • Longline • Trawl • Seasonal bycatch in commercial fisheries • Salmon fisheries • Sport fish bycatch

38. Urgency and Management Issues • No estimates of bycatch mortality and its impacts on dogfish populations • Increasing fishing pressure in federal waters where allowed as “other species” • Increased pressure in AK state waters for commercial fishery

39. Need for Research • No stock assessments of spiny dogfish • Little information on region specific biology and ecology • What levels of harvest might be sustainable? • Is a targeted fishery even economically feasible?

40. Alaskan Dogfish Research • Project funded by NPRB and NMFS Fellowship • Study began in July 2004 and planned though 2007 • Cooperative with UAF, UW, NMFS, and ADF&G • Goals: • Estimate demographic parameters, stock assessment • Develop conceptual model of life history • Describe food and feeding habits (food web model) • Analyze age/size composition data • Explore historical bycatch for trends in abundance • Investigate inter-lab variation in aging techniques

41. Data Collection • Size, sex and maturity • Reproductive Info • Stomach Contents • Age • Blood

42. Measurments

43. Male Maturity

44. Female Maturity

45. Female Maturity

46. Timing of reproductive events Embryo size and development Sex of embryos Reproductive Info

47. Pregnancy

48. Pregnancy Timeline

49. Stomach Contents • Gross ID in field • Contents stored in Formalin and returned to lab for specific ID and sizes of food items

50. Age and Blood • 2nd Dorsal Spine for aging • Blood for reproductive hormones