Research Initiatives, Past and Present

The following is a description of the research projects active in our group at the present. We list results via publications and presentations in scientific journals and symposia. This is instead of writing hundreds of words here. For further information, by all means contact us.


dawg fish

Spiny Dogfish Research

The spiny dogfish (Squalus acanthias) is a small, long-lived elasmobranch of the order Squalidae (dogfish sharks) and family Squaliformes (bramble, sleeper and dogfish sharks). The dogfish grows slowly and matures late in life; dogfish from the west coast of the US and Canada have been estimated to live 85 years or more. This species is ovoviviparous, with litter sizes of 2-12 pups (average 6-7 on the Canadian west coast), and has a gestation period of approximately 22 months. This species is particularly vulnerable to overfishing because of its late maturity, low reproductive capacity and longevity; its life history, characteristic of larger sharks, indicates a slow growth rate and relatively low resilience to catastrophic events. Despite this, it has been suggested that the spiny dogfish may be the most abundant of the shark species; in some regions, this small shark achieves densities high enough to become a pest to fishermen.

Research is being conducted to better understand the life history, population structure, and fishing vulnerability of spiny dogfish on the west coast of the US and Canada. Demographic and genetic information are being collected from along the latitudinal gradient for analysis of stock structure, and bycatch rates and predation are being studied. Additionally, a survey is underway for determination of the precision of aging in this species.

Research projects on dogfish are carried out cooperatively with the University of Alaska Fairbanks, Juneau, with the Pacific Biological Station (DFO), Nanaimo, and with the Washington Department of Fish and Wildlife (WDFW). The interaction between our group and WDFW has been particularly fruitful.

Recent Publications & Presentations

  1. Rice, J., V.F. Gallucci, C. Tribuzio, G. Kruse. Statistical methods for determining the consistency of age readings among laboratories from spines of dogfish. Marine Science in Alaska: 2005 Symposium. January 2005, Anchorage, Alaska
  2. Tribuzio, C., G. Kruse, J. Rice, V.F. Gallucci. Life history, ecology and population dynamics of spiny dogfish, Squalus acanthias, in Alaska. Marine Science in Alaska: 2005 Symposium. January 2005, Anchorage, Alaska
  3. Menon, M. V.F. Gallucci, B. Leaman, L. Conquest. 2005. Sampling longlines to estimate by catch for spiny dogfish and sleeper sharks. Proc. Internat. Symp. on Data-Limited Situations. Alaska Sea Grant College Program. In press.
  4. Tribuzio, C., V.F. Gallucci, G. Bargmann. 2005. Dogfish reproductive biology and use for management. Proc. Internat. Symp. on Data-Limited Situations. Alaska Sea Grant College Program. In press.
  5. Menon, M., V.F. Gallucci, L. Conquest, B. L. General linear model analysis of by-catch in the halibut test fishery of sleeper and dogfish sharks in the N. Pacific. In preparation for 2005.
  6. Tribuzio, C., V.F. Gallucci, G. Bargmann. Making fishing policy on the basis of reproductive periods and intensity for the dogfish fishery in Washington State. In preparation for 2005.
  7. Dogfish sharks: the fish in fish and chips and ecosystem function. AAAS Annual Meeting. Half-day symposium. February 2004, Seattle, Washington.
    1. McFarlane, S. and G. Bargmann.  Trans-boundary Differences in Dogfish Management Strategies in Washington State and British Columbia.
    2. Gallucci, V. and P. Rago. Consequences of Gastronomic Demand: Events of the Last Decade in Atlantic and Pacific Dogfish Inhabited Ecosystems.
    3. Tribuzio, C. Dogfish Reproductive Strategy and Implications for Management.
    4. Taylor, I. Is There Sustainable Management for Low Productivity, Long Lived, High on the Food Chain, Dogfish Sharks?
    5. Hauser, L. and V. Gallucci. Population Genetics, Demographics and the Stock Concept in Sharks.
    6. Miller, M. and V. Gallucci. Sharks in Western Art History and the Power of the Sublime.
  8. Taylor, I and V.F. Gallucci. 2003. A metapopulation model for spiny dogfish in the NE Pacific. 19th Annual Meeting of the American Elasmobranch Society. Manaus. Amazon, Brazil, June 26-July 1.
sixgill shark

Sixgill Shark Research

The sixgill shark, Hexanchus griseus, has a worldwide distribution in temperate coastal waters. The species is most often found in very deep water and its population dynamics and life history are not well understood. In Puget Sound, sixgill sharks have been observed in very shallow water, and an increase in catches by sport fishermen from urban piers led to a closure of the fishery by Washington Department of Fish and Wildlife (WDFW) until the dynamics of the species could be better understood. The research conducted by the University of Washington Shark Lab, in a cooperation with WDFW and other local groups, is an effort learn more about the sixgill sharks and their role in the Puget Sound ecosystem.

Research on sixgill sharks in Puget Sound includes a year-round tagging program with observation of size and maturity patterns, and an investigation of ageing methods. Testing for contaminants is being conducted by WDFW, and samples are being collected for genetic analyses. Patterns of feeding and the interaction with spiny dogfish are being studied.

The interactions between our group, WDFW, and the NOAA Northwest Fisheries Science Center have been particularly valuable.

Recent Publications & Presentations

  1. Gallucci, V., G. McFarlane, G. Bargmann. Biological hotspots and Northern latitude sharks. The North Pacific Marine Science Organization (PICES) Annual Meeting. October, 2004, Honolulu, Hawaii
  2. Gallucci, V., G. Bargmann, D. Badger. The demography and ecology of a sixgill shark population in the N. Pacific and Puget Sound. American Fisheries Society Annual Meeting. Elasmobranch Research in the eastern North Pacific and Bering Sea. September 2005, Anchorage, Alaska.
salmon shark

Salmon Shark Research

Salmon sharks (Lamna ditropis) are large sharks that inhabit the cold and temperate waters of the North Pacific Ocean. This species is found in both costal and oceanic environments and is strong swimmer capable of long distance migrations. The salmon shark can grow to lengths longer than three meters and weigh more than 350 lbs. Salmon sharks reproduce by aplacental viviparity with litter sizes ranging from 2-5 young. Young of the year and age 1 salmon sharks have been caught off the coast of California giving rise to the theory that a breeding ground might exist in the Eastern North Pacific. Large aggregations of salmon sharks have been spotted in parts of South East Alaska from time to time. Apart from humans, salmon sharks are one of the principal predators of pacific salmon (Oncorhynchus) for which they are named. An interesting biological characteristic is that salmon sharks are able to maintain body temperatures higher than the ambient water. Salmon sharks are often caught as bycatch in offshore gill nets by commercial fisheries. Recently salmon sharks have become a target of sport fishermen as well.

Currently the UW Shark Lab is conducting research regarding the foraging behavior, and migratory movements of salmon sharks in the North East Pacific. This research utilizes satellite tracking technology to establish movement patterns. Data on patterns of feeding and the interaction with other species also being studied.

Recent Publications and Presentations

  1. Hulbert, L.B., A.M. Aires-da-Silva, V.F. Gallucci, J.S. Rice. 2005. Seasonal foraging movements and migratory patterns of female salmon sharks Lamna ditropis tagged in Prince William Sound, Alaska. J. Fish Biol. In press.
  2. Tribuzio, C., V.F. Gallucci, P. Swanson. Hormonal analysis of Salmon shark blood as an indicator of reproductive status. In ms. for 2005.
  3. Gallucci, V., G. McFarlane, G. Bargmann. Biological hotspots and Northern latitude sharks The North Pacific Marine Science Organization (PICES) Annual Meeting. October, 2004, Honolulu, Hawaii
  4. Gallucci, V.F. Mathematical Modeling of Competitive interactions: Sea lions and salmon sharks. Marine Science in the NE Pacific. January 2003. Anchorage, Alaska.
  5. Gallucci, V.F. Sharks, Pinnipeds and Ecosystem Dynamics. AAAS Annual Meeting. Half Day Symposium on Not Enough Sea Lions, Too Many Sharks: Global Warming Signal? February 2002, Boston, Massachusetts
blue shark

Blue Shark Research

Blue sharks are an important part of the bycatch in international tuna and swordfish fisheries in the North Atlantic. The multifleet logbooks available with fishery data are not considered to be complete given the large number of incidental captures, variation in release status (alive vs. dead) and unreported captures over time. Thus these data alone offer several limitations for stock assessment and population modeling. Furthermore, stock assessment analysis of a highly migratory species such as the blue shark is difficult at best. The complex sexual and life-stage segregation patterns of the population in the North Atlantic make the modeling process even more difficult. Alternative methods are needed to deal with the problem.

This project uses the tag-recapture database of the National Marine Fisheries Service (NMFS) Cooperative Shark Tagging Program (CSTP) to investigate the blue shark population dynamics in the North Atlantic Ocean. The use of tag–recapture data is among ICCAT’s recommendations for future stock assessment work. Our approach relies on a statistical framework for estimating blue shark movement and fishing mortality rates from the tagging data. Bayesian estimation methods are used to estimate and quantify the uncertainty associated with the parameters.

Recent Publications & Presentations

  1. Aires-da-Silva, A.M., R.L. Ferreira and J.J. Pereira. In press. Blue shark catch rate patterns from the swordfish longline fishery in the Azores, eastern North Atlantic. In: Sharks of the Open Ocean. E.K. Pikitch and M. Camhi, eds. Blackwell Scientific.
  2. Aires-da-Silva, A.M., H. Marques-da-Silva, K. Erzini and V.F. Gallucci. In review. A meta-analysis on the growth of the blue shark (Prionace glauca) in the North Atlantic with implications for conservation.
  3. Aires-da-Silva, A.M. V.F. Gallucci, A.B. Bolten, H.R. Martins, E. Isidro, M. Santos, R. Ferreira, E. Bettencourt, V.S. Pires, A. Giga, A. Cruz, N. Carvalho, and K.A. Bjorndal. In preparation. Reproductive parameters and spatial distribution patterns of the blue shark, Prionace glauca, in the Azores, eastern North Atlantic.
  4. Aires-da-Silva, A.M., I. Taylor, A.E. Punt, V.F. Gallucci, N.E. Kohler, P.A. Turner, R. Briggs and J.J. Hoey. 2004. A framework for estimating movement and fishing mortality rates of the blue shark, Prionace glauca, in the North Atlantic Ocean from tag-recapture data. International Commission for the Conservation of Atlantic Tunas, SCRS/2004/112.
  5. Aires-da-Silva, A.M., N.E. Kohler, P.A. Turner, R. Briggs, J.J. Hoey, M. Logsdon. and V.F. Gallucci. 2003. Estimation of population parameters for the blue shark (Prionace glauca) in the North Atlantic from mark-recapture analysis. 19th Annual Meeting of the American Elasmobranch Society. Manaus. Amazon, Brazil, June 26-July 1.
blue shark

Mathematical Modeling/Stock Assessment

Recent Publications & Presentations

  1. Gallucci, V.F., Taylor, I., Erzini, K. Conservation and Management of Exploited Shark Populations Based on Reproductive Value. Submitted to Can. J. Fish. Aquat. Sci.
  2. Taylor I. and V.F. Gallucci. Using Reproductive Value to Evaluate Surplus Production Models for Sharks. Proc. Internat. Symp. on Data-Limited Situations. Alaska Sea Grant College Program. In press.
  3. Menon, M., V.F. Gallucci, L. Conquest, B. L. General linear model analysis of by-catch in the halibut test fishery of sleeper and dogfish sharks in the N. Pacific. In preparation for 2005.
  4. Gallucci, V.F. Mathematical Modeling of Competitive interactions: Sea lions and salmon sharks. Marine Science in the NE Pacific. Anchorage, Alaska. January 2003.
blue shark

Policy

Recent Publications & Presentations

  1. Morrison, S. and V.F. Gallucci. A history of exploitation and recovery of the dogfish shark in the Pacific NW. In preparation for 2005.
  2. Herndon, A., V.F. Gallucci, D. Demaster, W. Burke. The case for, and  structure of, a proposed International Elasmobranch Commission (IES). In preparation for 2005.
  3. Gasper, J.R. The sportfishery in the Icy Strait/Glacier Bay/Cross Sound region of Southeastern Alaska: an analysis of charter guide-client power interactions and sportfishing catch, harvest, and effort. In preparation for 2005.
  4. Director, R.A. 2000. The spiny dogfish fishery of Puget Sound and the Pacific Northwest Coast: management options and recommendations. Thesis: University of Washington School of Marine Affairs.


Symposia

First International Dogfish Symposium

June 2005, Seattle, Washington

Organizers: V.F. Gallucci, G. Bargmann, G. McFarlane.

American Fisheries Society Annual Meeting

September 2005, Anchorage, Alaska

Invited Symposium on Northern Latitude Sharks. Three accepted presentations.

Marine Science in Alaska: 2005 Symposium

January 2005, Anchorage, Alaska

  1. Rice, J., V.F. Gallucci, C. Tribuzio, G. Kruse. Statistical methods for determining the consistency of age readings among laboratories from spines of dogfish.
  2. Tribuzio, C., G. Kruse, J. Rice, V.F. Gallucci. Life history, ecology and population dynamics of spiny dogfish, Squalus acanthias, in Alaska.

The North Pacific Marine Science Organization (PICES) Annual Meeting

October, 2004, Honolulu, Hawaii

  1. Gallucci, V., G. McFarlane, G. Bargmann. Biological hotspots and Northern latitude sharks.

AAAS Annual Meeting
Dogfish Sharks: The Fish in Fish and Chips and Ecosystem Function—A Half-Day Symposium

February 2004, Seattle, Washington

  1. McFarlane, S. and G. Bargmann.  Trans-boundary Differences in Dogfish Management Strategies in Washington State and British Columbia.
  2. Gallucci, V. and P. Rago. Consequences of Gastronomic Demand: Events of the Last Decade in Atlantic and Pacific Dogfish Inhabited Ecosystems.
  3. Tribuzio, C. Dogfish Reproductive Strategy and Implications for Management.
  4. Taylor, I. Is There Sustainable Management for Low Productivity, Long Lived, High on the Food Chain, Dogfish Sharks?
  5. Hauser, L. and V. Gallucci. Population Genetics, Demographics and the Stock Concept in Sharks.
  6. Miller, M. and V. Gallucci. Sharks in Western Art History and the Power of the Sublime.

Wakefield Symposium on Data Limited Situations: October 2003—Anchorage, Alaska

Papers have been submitted and accepted—see above.

19th Annual Meeting of the American Elasmobranch Society. Manaus. Amazon, Brazil, June 26-July 1.

  1. Taylor, I and V.F. Gallucci. A metapopulation model for spiny dogfish in the NE Pacific
  2. Tribuzio, C. and V.F. Gallucci. A tale of two ovaries: reproduction in the salmon shark
  3. Aires-da-Silva, A.M., N.E. Kohler, P.A. Turner, R. Briggs, J.J. Hoey, M. Logsdon. and V.F. Gallucci. 2003. Estimation of population parameters for the blue shark (Prionace glauca) in the North Atlantic from mark-recapture analysis.

Marine Science in the NE Pacific January 2003—Anchorage, Alaska

  1. Gallucci, V.F. Mathematical Modeling of Competitive interactions: Sea lions and salmon sharks.

AAAS Annual Meeting
Half Day Symposium: Not Enough Sea Lions, Too Many Sharks: Global Warming Signal?

February 2002, Boston, Massachusetts

  1. Gallucci, V.F., B. Wright, L. Hulbert.  Perspectives on the Appearance of Salmon and Sleeper Sharks in Abundance in Alaska.
  2. Gallucci, V.F. Mathematical Modeling of the Dynamics of an Ecosystem and The Decline of a Keystone Predator.
  3. Loughlin, T. History of the Decline of the Stellar Sea Lion in Alaska.

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