Field l/o r3 11/17/07 11:54 AM Page 131 FIELD ET AL.: JUMBO SQUID TROPHIC INTERACTIONS CalCOFI Rep., Vol. 48, 2007 RANGE EXPANSION AND TROPHIC INTERACTIONS OF THE JUMBO SQUID, DOSIDICUS GIGAS, IN THE CALIFORNIA CURRENT JOHN C. FIELD AND KEN BALTZ A. JASON PHILLIPS NOAA Fisheries Southwest Fishery Science Center Cooperative Institute for Marine Resources Studies 110 Shaffer Road Oregon State University Santa Cruz, California 95060 Hatfield Marine Science Center
[email protected] 2030 Marine Science Drive Newport, Oregon 97365 WILLIAM A. WALKER NOAA Fisheries National Marine Mammal Laboratory Alaska Fisheries Science Center 7600 Sand Point Way N.E., Building 4 Seattle, Washington 98115 ABSTRACT than males, with DMLs as large as 100 to 120 cm, cor- Although jumbo squid (Dosidicus gigas) have been oc- responding to weights of 30 to 50 kg (Nigmatullin casional visitors to the California Current over the last et al. 2001). Nigmatullin et al. (2001) described some century, their abundance and distribution increased be- apparent population structure of jumbo squid, with tween 2002 and 2006. We report several time series of individuals growing to a smaller size and maturing ear- jumbo squid relative abundance from commercial and lier in the core of their range in the ETP, and growing recreational fisheries as well as resource surveys and food (and maturing) larger at the poleward fringes of their habits studies. To evaluate the trophic relationships of range, consistent with the observation by O’dor (1992) jumbo squid, we report the results of 428 stomach sam- that squid tend to grow larger and reproduce later in ples collected between 2005 and 2006 at various loca- cooler waters.