MEPS 240:235-247 (2002)  -  doi:10.3354/meps240235

Effects of the 1997-1998 El Niño on early-juvenile Pacific hake Merluccius productus: age, growth, abundance, and diet in coastal nursery habitats

Jill J. Grover1,*, Troy W. Buckley2, David Woodbury3,**

1College of Oceanic and Atmospheric Sciences, Oregon State University, Hatfield Marine Science Center, Newport, Oregon 97365, USA
2Alaska Fisheries Science Center, National Marine Fisheries Service, 7600 Sand Point Way N.E., F\AKC2, Seattle, Washington 98115, USA
3Southwest Fisheries Science Center, National Marine Fisheries Service, 3150 Paradise Dr., Tiburon, California 94920, USA
*E-mail: **Present address: National Marine Fisheries Service, Western Administrative Services Center, 777 Sonoma Ave., Santa Rosa, California 95404-6515, USA

ABSTRACT: The effects of anomalous oceanographic conditions on growth, abundance, spawn-date distributions, and diet of early-juvenile Pacific hake Merluccius productus were examined in nursery grounds off the coast of central California, USA. Spring collections from 2 consecutive years of El Niño conditions, 1997 and 1998, 1 year of La Niña conditions, 1999, and 1 non-anomalous year, 1995, were examined. During spring of 1997, the first year of the El Niño event, early-juvenile hake appeared to compensate for anomalous ocean conditions by ingesting a wider variety of zooplankton taxa and sizes. Continuation of El Niño conditions through spring 1998 appeared to have a strong impact on the 1998 year class. Very low levels of macrozooplankton biomass in February 1998 resulted in poor growth and reduced survival of hake from early spawns.


KEY WORDS: Hake · El Niño effects · Age and growth · Food habits


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