RADIOMETRIC AGE DETERMINATION of the GIANT GRENADIER (A/Batrossia Pectoralis) USING 210Pb: 226Ra DISEQUILIBRIA
Total Page:16
File Type:pdf, Size:1020Kb
I . RADIOMETRIC AGE DETERMINATION OF THE GIANT GRENADIER (A/batrossia pectoralis) USING 210Pb: 226Ra DISEQUILIBRIA A thesis submitted to the faculty of San Francisco State University in partial fulfillment of the requirements for the degree Master of Science in Marine Science by Erica Janis Burton San Francisco, California December, 1999 Copyright by Erica Janis Burton 1999 RADIOMETRIC AGE DETERMINATION OF THE GIANT GRENADIER (Aibatrossia pectoralis) USING 210Pb: 226 Ra DISEQUILIBRIA Erica Janis Burton San Francisco State University 1999 Age estimates determined from growth increments in sagittal otolith sections indicated that Albatrossia pectoralis is slow growing (K :<:: 0.023) and lives up to 56 years. Growth increments found in otolith sections, however, were difficult to interpret. The von Bertalanffy growth function for A. pectoralis otolith section age estimates did not fit size-at-age data well. To validate age and longevity estimates, ages were determined using the radioactive disequilibria of 210Pb: 226 Ra in otolith cores from adult A. pectoralis. Radiometric and growth increment ages agreed for 6 of the 12 pooled otolith age-groups. Radiometric age determination confirmed longevity to at least 32 years for females and 27 years for males. Additional age and longevity estimates are still necessary to develop an informed fishery management plan for A. pectoralis. I certify that the Abstract is a correct representation of the content of this thesis. ~~~-~ (Date) - ACKNOWLEDGEMENTS Although a thesis is authored by one person, it is not accomplished alone. I have many people to thank who contributed their time, sweat, and talent. I sincerely thank my thesis committee members. Dr. Gregor Cailliet provided advice, guidance, support, and trust throughout my graduate career at MLML. Dr. Kenneth Coale enthusiastically explained radiochemistry and decay mathematics with unceasing encouragement and confidence. Dr. Ralph Larson eagerly accepted another graduate student studying radiochemistry and expeditiously edited the manuscript with insightful advice. Specimens, otoliths, and length measurements were collected by scientists from the Alaska Fisheries Science Center, including Bob Lauth, Jerry Hoff, Bill Flerx, Robin Harrison, Michael Martin, Terry Sample, and Skip Zenger. Special thanks to Bob and Jerry for always offering to sample Albatrossia pectoralis, choreographing the "slime crew", and graciously accepting any and all collection requests. In addition, valuable ship-time was provided by the National Marine Fisheries Service. Chuck Crapo from the Fishery Industrial Technology Center at the University of Alaska Fairbanks in Kodiak, Alaska learned how to extract otoliths frorn A. pectoralis, and collected otoliths and length measurements (including the rare and invaluable total length measurements) during his own study, "Utilization of v Giant Grenadier." Bob Lea from California Department of Fish and Game, Monterey, and Mike Hosie from Oregon Department of Fish and Wildlife, Charleston donated otoliths from larger specimens captured by commercial fishermen. Pete Holden at the University of California, Santa Cruz measured radium in otolith samples using the thermal ionization mass spectrometer. Brown Lines Trucking Company donated shipping supplies and the expense for delivery of 1 ton of fish collected by the Alaska Fisheries Science Center. Lara Ferry Graham, Allen Andrews, and Leigh Nerney helped extract otoliths and recorded length from 1 ton of fish. Special thanks to Lisa deMarignac and Allen Andrews for reading 50 extremely difficult-to-age otoliths several times. My literature collection would not be complete without the help of librarians Joan Parker and Sheila Baldridge, and their assistants Sandy O'Neil, Crystal Chisolm, Sally Wittlinger, Terry Darcy, Stephanie Nichols, and Kim Puglise. Gail Johnston, Sandy Yarbrough, and Kathleen Baker made the distance between Moss Landing and San Francisco State University seem not so far. Andrei Suntsov from the Russian Academy of Sciences in Moscow expediently and afford ably translated three Russian papers into English. Kate Stanbury illustrated the map of sampling locations. Special thanks to my partners in crime, Allen Andrews and Jocelyn Nowicki Douglas, for their guidance in the radiochemistry lab, and vi perseverance during mathematical chaos. Finally, I am ever grateful to my parents for their love and continued support throughout my education. This research was funded in part by the Dr. Earl H. Myers and Ethel M. Myers Oceanographic and Marine Biology Trust; and by a grant from the National Sea Grant College Program, National Oceanic Atmospheric Administration, U.S. Department of Commerce, under grant number NA36RG0537, project number R/F-148 through the California Sea Grant College System. The views expressed herein are those of the author and do not necessarily reflect the views of NOAA or any of its sub-agencies. The U.S. Government is authorized to reproduce and distribute for governmental purposes. vii TABLE OF CONTENTS List of Tables .......................................................................................................viii List of Figures ....................................................................................................... ix Introduction ........................................................................................................... 1 Methods ................................................................................................................ 8 Partial length analysis ...................................................................................... 9 Otolith size and fish length analysis ............................................................... 10 Age estimation ............................................................................................... 11 Radiometric analysis ...................................................................................... 13 Core extraction and age-group determination .......................................... 13 210Pb determination ................................................................................... 16 226Ra determination ................................................................................... 21 Radiometric age determination ................................................................. 21 Growth ........................................................................................................... 23 Results ................................................................................................................ 25 Partial length analysis .................................................................................... 26 Otolith size and fish length analysis ............................................................... 28 Age estimation ............................................................................................... 30 Radiometric analysis ...................................................................................... 33 Core extraction and age-group determination .......................................... 33 210 Pb and 226Ra determination ................................................................... 35 Radiometric age determination ................................................................. 36 Growth ........................................................................................................... 37 Discussion ........................................................................................................... 39 Partial length analysis .................................................................................... 41 Otolith size and fish length analysis .............................................................. .41 ~eestimation ............................................................................................... ~ Radiometric analysis ...................................................................................... 45 Growth ........................................................................................................... 47 Fishery ........................................................................................................... 52 Literature Cited .................................................................................................... 57 viii LIST OF TABLES Table Page 1. Capture dates, gegraphic location, and depth of Albatrossia pectoralis specimens collected during research cruises ........................ 66 2. Capture dates, general region, and depth of Albatrossia pectoralis specimens collected by commericial fishermen ..................................... 67 3. Precision of Reader 1 age estimates ..................................................... 68 4. Ra-226 determination for whole Albatrossia pectoralis otoliths ................................................................................................... 69 5. Otolith core age-groups used for radiometric analyses ......................... 70 6. Radiometric results for pooled Albatrossia pectoralis age-groups ........................................................................................... 71 7. Von Bertalanffy growth parameters for Albatrossia pectoralis pre- anal fin length and estimated age data .................................................. 72 8. Gompertz and linear growth parameters for Albatrossia pectoralis pre-anal fin length and estimated age data ........................................... 73