Dosidicus gigas: northern range expansion events Emma M.C. Hatfield & F.G. Hochberg
59ºN Dosidicus gigas 20ºC?? 20ºC??ºS Distribution in the Eastern Pacific Ocean
Northernmost Confirmed Range Extensions YEAR(s) STATE LOCALITY N Lat 1862 CALIFORNIA Santa Cruz Island 34º00 1889 CALIFORNIA Santa Rosa Island 1894 CALIFORNIA San Pedro 33º40 1899 CALIFORNIA Santa Catalina Island 33º20 1908-10 CALIFORNIA Monterey Bay 36º50 1934-37 CALIFORNIA Monterey Bay 1956 CALIFORNIA La Jolla 32º50 1974-76 CALIFORNIA Goleta 34º20 1982-83 CALIFORNIA Santa Barbara 1990-91 CALIFORNIA Eureka 40º45 1997-99 OREGON Newport 44º40 2002-06 ALASKA Yakutat 59º30
Yakutat 60º Northern Range Extensions CANADA WASHINGTON Newport OREGON CALIFORNIA Monterey Los Angeles MEXICO 40º 02-06 90-91 74-76 34-36 97-99 82-83 56 08-10 2000s 1900s 99 94 1800s 89 62 20º
COLLECTIONS SURVEYED California Cabrillo Marine Aquarium, San Pedro California Academy of Sciences, San Francisco Hopkins Marine Station, Pacific Grove Moss Landing Marine Laboratory (SBMNH) Museum of Natural History, Los Angeles Museum of Natural History, Pacific Grove Museum of Natural History, San Diego Museum of Natural History, Santa Barbara Scripps Institute of Oceanography, La Jolla Oregon Oregon State University, Corvallis (SBMNH) Oregon Coast Aquarium, Newport (SBMNH) Other National Museum of Natural History, Washington, DC
1908: San Francisco California Academy of Sciences
1935: Monterey Ed Ricketts Museum of Natural History Pacific Grove
1974: Santa Barbara Museum of Natural History Santa Barbara
Examination of museum specimens p 10000 immature mature 1908 Mass (g) 5000 1974 1935 0 100 200 300 400 500 600 700 ML (mm)
2002 Strandings 28 August 25 July 19 June 19 June
June 2002 MEXICO: La Paz
July 2002 CALIFORNIA: La Jolla Cove
August 2002 CALIFORNIA: Goleta & Santa Barbara beaches
September October 2004 ALASKA: off Yakutat (Gulf of Alaska) CANADA: off Swiftsure Bank (Vancouver Island) WASHINGTON: off Westport OREGON: off Newport
January 2005 CALIFORNIA: Pt. Sal, Newport Beach, Monterey & Half Moon Bay
Measurements of fresh specimens obtained during northern range expansions events 12000 10000 Body mass (g) 8000 6000 4000 July 2002 Jan 2005 2000 0 0 100 200 300 400 500 600 700 800 Dorsal Mantle Length (mm) 1976 SoCalif 2002 SoCalif 2003 Oregon 2004 Canada 1999 SoCalif 2005 SoCalif 2004 Oregon 2005 Alaska
Recreational & Commercial Landings
Dosidicus: California Landings 1990 to 2005 Nos landed Numbers 35000 30000 25000 20000 15000 10000 5000 Recreational Recreational 87,880 164,534 Catches 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 The North San Francisco Monterey Los Angeles San Diego 150 334 t t Commercial 125 Tons landings (t) 100 75 50 25 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Commercial Squid Landings: 1990-2005 Dosidicus gigas 400 350 Dosidicus landings (t) Commercial landings (t) 300 250 200 150 100 50 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 150000 Loligo landings (t) Doryteuthis opalescens Commercial landings (t) 125000 100000 75000 50000 25000 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Commercial Landings by Gear Type: 1990-2005 350 300 250 200 150 100 50 Dosidicus commercial landings by gear: 1990 to 2005 Dosidicus gigas Landings (t) 0 Gillnet Hook-andline gears Other Seine Trap Trawl Unclass. 1000000 Loligo commercial landings by gear: 1990 to 2005 Doryteuthis opalescens Landings (t) 750000 500000 250000 0 Gillnet Hook-and-line gears Other Seine Trap Traw l Unclass.
Comparison of Commercial Landings: 1991-2003 150 334 334 t California 125 landings (t) Tons 100 75 50 25 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Mexican Pacific landings (t) Tons 140,000 120,000 100,000 80,000 60,000 40,000 20,000 0 The North San Francisco Monterey Los Angeles San Diego Mexico 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 BAJA CALIFORNIA BAJA CALIFORNIA SUR SONORA SINALOA
TOPICS FOR DISCUSSION What triggers migration of Dosidicus into northern waters? normal part of range? population explosion at center of range northern migration of core population correlations with oceanographic events (ENSO) tropical depressions global warming following prey north Do populations reside and reproduce in far northern waters?
What contributes to mortality and strandings? Natural causes post-spawning spawning mortality (spent & dying) chasing grunion onto beaches driven ashore by predators parasites, pathogens &/or diseases changes in water temperature (cold shock) changes in salinity (freshwater influx from heavy rains) changes in sediment load (increased turbidity in near shore waters) starvation natural chemical toxins (domoic( acid)
Other causes of mortality manmade pollution, biotoxins,, or antibiotics sonic pressure waves (secret naval maneuvers) swarms of mini earthquakes distance impacts from SE Asian earthquakes & tsunamis mass mass suicides during aerial attacks on coastal cities in California
Acknowledgements: To date 38 people have assisted our project Collection of animals & sighting/stranding records Access to specimens, specimen data, &/or photographs Assistance with specimen measurements Access to oceanographic information Access to commercial and recreational fishing records MEXICO: Baja California USA: California, Oregon, Washington, Alaska CANADA: British Columbia Media contacts & archives