Food habits of some commercially important groundfish off the

184 Pages·2001·3.14 MB·English

NOAA Technical Memorandum NMFS-AFSC-102
Food Habits of Some Commercially
Important Groundfish off the Coasts
of California, Oregon, Washington, and
British Columbia
by
T. W. Buckley, G. E. Tyler, D. M. Smith, and P. A. Livingston
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Marine Fisheries Service
Alaska Fisheries Science Center
August 1999
NOAA Technical Memorandum NMFS
The National Marine Fisheries Service's Alaska Fisheries Science Center
uses the NOAA Technical Memorandum series to issue informal scientific and
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are not appropriate or feasible. Documents within this series reflect sound
professional work and may be referenced in the formal scientific and technical
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The NMFS-AFSC Technical Memorandum series of the Alaska Fisheries
Science Center continues the NMFS-F/NWC series established in 1970 by the
Northwest Fisheries Center. The new NMFS-NWFSC series will be used by
the Northwest Fisheries Science Center.
This document should be cited as follows:
Buckley, T. W., G. E. Tyler, D. M. Smith, and P. A. Livingston. 1999.
Food habits of some commercially important groundfish off the coasts
of California, Oregon, Washington, and British Columbia. U.S. Dep.
Commer., NOAA Tech. Memo. NMFS-AFSC-102, 173 p.

Reference in this document to trade names does not imply endorsement by
the National Marine Fisheries Service, NOAA.
NOAA Technical Memorandum NMFS-AFSC-102
Food Habits of Some Commercially
Important Groundfish off the Coasts
of California, Oregon, Washington,
and British Columbia
by
2
T. W. Buckley, G. E. Tyler D. M. Smith’, and P. A. Livingston’
Alaska Fisheries Science Center
1
Resource Ecology and Fisheries Management Division
7600 Sand Point Way N.E., BIN C-15700
Seattle, WA 98115-0070
2
University of Washington
School of Fisheries
Box 357980
Seattle, WA 98195
U.S. DEPARTMENT OF COMMERCE
William M. Daley, Secretary
National Oceanic and Atmospheric Administration
D. James Baker, Under Secretary and Administrator
National Marine Fisheries Service
Penelope D. Dalton, Assistant Administrator for Fisheries
August 1999
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iii
ABSTRACT
This report describes the food habits of some commercially important groundfish
collected off the coasts of California, Oregon, Washington, and British Columbia.
Generally, the groundfish reported on were sampled during three cruises - the triennial
groundfish survey of 1989 and the continental slope surveys of 1991 and 1992. Some
young-of-the-year Pacific hake (also known as Pacific whiting, Merluccius productus)
were examined from 1987 and 1988 surveys. Where possible, the diet of each groundfish
species was examined for possible ontogenetic, latitudinal, depth, and seasonal changes.
Typically, ontogenetic shifts in the diet of the predators examined on this study were
based on the ability of the larger fish to eat larger prey. Effects of latitude, depth, and
season were also detected for some of these species.
The diet of age-0 Pacific hake shifted from copepods to euphausiids with
increasing size (33-128 mm total length) in 1987, but not in 1988. Pacific hake became
increasingly piscivorous with size, and cannibalism was an important diet component in
1991 in the Monterey INPFC (International North Pacific Fisheries Commission)
statistical area. Sablefish (Anoplopoma fimbria) and shortspine thornyhead
(Sebastolobus alascanus) consumed a wide variety of locally abundant prey items
including large amounts of offal from fish-processing operations conducted at sea. The
diet of juvenile sablefish captured over the continental shelf was similar to the diet of
Pacific hake, but the diet of larger sablefish sampled from the upper continental slope
was more similar to the shortspine thornyhead diet. Arrowtooth flounder (Atheresthes
stomias) was the most piscivorous predator examined in this study, consuming mostly
Pacific hake, Pacific herring (Clupea pallasi) and unidentified gadids. Longspine
thornyhead (S. altivelis) consumed a variety of benthic crustaceans, and the presence of
fishery offal in the diet indicated that longspine thornyhead also scavenged the slope
bottom. Giant grenadier (Albatrossia pectoralis) consumed mostly deepwater
crustaceans and fishes in this study, by weight. Pacific grenadier (Coryphaenoides
acrolepis) stomachs contained mostly squid and a variety of crustaceans, by weight. A
majority of the diet of Dover sole (Microstomuspaczjkus) and deepsea sole
(Embassichthys bathybius) was polychaete worms and brittlestars.

V
CONTENTS
Page
ABSTRACT ...................................................... iii
INTRODUCTION ................................................. 1
METHODS ....................................................... 1
RESULTS and DISCUSSION. ....................................... 6
Young-of-the-year Pacific Hake ................................ 6
Pacific Hake ................................................ 11
Sablefish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
ShortspineThornyhead ....................................... 43
LongspineThornyhead ....................................... 57
GiantGrenadier ............................................. 65
Pacific Grenadier ............................................ 71
Dover Sole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Deepsea Sole ............................................... 93
Arrowtooth Flounder ........................................ 99
Species Interactions ......................................... 107
ACKNOWLEDGEMENTS ......................................... 123
CITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
APPENDIX ...................................................... 131