Age and growth of the Pacific grenadier (Family Macrouridae, Coryphaenoides acrolepis) with age estimate validation using an improved radiometric ageing technique.

Allen H. Andrews
email: Andrews@mlml.calstate.edu

Thesis: Part I

Application of a new ion-exchange separation technique and isotope- dilution thermal ionization mass spectrometry to ²²⁶Ra determination in otoliths for radiometric age determination of long-lived fishes.

Published in Canadian Journal of Fisheries and Aquatic Sciences, Andrews et al. 1999b

To improve the accuracy and precision of radiometric age determination using ²¹⁰Pb:²²⁶Ra disequilibria in otoliths of fishes,a technique was developed using isotope-dilution thermal ionization mass spectrometry (TIMS) to determine ²²⁶Ra. Because TIMS measures radium directly by counting ionized atoms, the accuracy and precision of the technique is superior to conventional alpha-spectrometric methods. Due to their chemical similarities, radium must be separated from interfering quantities of calcium and barium in the otolith matrix. This was accomplished using a new ion-exchange separation procedure. This procedure was tested by applying it to otolith samples from three fish species in three separate radiometric ageing studies. The resultant separations and TIMS determinations indicate the procedure efficiently separates radium from calcium and barium. Measured ²²⁶Raactivities for each species were comparable to previous radiometric ageing studies, with the exception of one sample. When results are compared to traditional ²²⁶Ra determination techniques, radon emanation and alpha-spectrometry, the new separation technique with isotope-dilution TIMS has significant advantages. Samples over three times smaller than attempted in other studies were processed with increased accuracy and decreased processing time.

Thesis: Part II

Age and growth of the Pacific grenadier (Family Macrouridae, Coryphaenoides acrolepis) with age estimate validation using an improved radiometric ageingtechnique

Published in Canadian Journal of Fisheries and Aquatic Sciences, Andrews et al. 1999a

Current and historic longevity estimates for the Pacific grenadier range from 6 to greater than 60 years. Age estimates in this study using the quantification of growth increments in thin otolith (ear-bone) sections indicate the Pacific grenadier is a long-lived fish that may approach 75 years. To validate this trend, age was determined using the radioactive disequilibria of ²¹⁰Pb and ²²⁶Ra in otolith cores from adult Pacific grenadier. Radiometric ages closely agree with age estimates from the quantification of growth increments. This confirms the annual periodicity of these increments. Radiometric results indicate the Pacific grenadier can live at least 56 years and growth increments indicate longevity may be greater than 73 years. Because the Pacific grenadier is long-lived and matures late in life, it may be vulnerable to heavy fishing pressure. Therefore, conservation measures need to be taken immediately to sustain this rapidly developing fishery.

Other Research Projects

• Age and Growth
• Spotted Sand Bass
• Radiometric age determination:
• Atlantic Tarpon
• Atlantic Sturgeon
• Bocaccio Rockfish


• Taxonomy
• Leptochilichthyid

Publications

Andrews, A.H., G.M. Cailliet, and K.H. Coale. 1999a. Age and growth of the Pacific grenadier

(Coryphaenoides acrolepis) with age estimate validation using an improved radiometric

ageing technique. Canadian Journal of Fisheries and Aquatic Sciences. 56:1339-1350.

Andrews, A.H., K.H. Coale, J.L. Nowicki, C. Lundstrom, Z. Palacz, E.J. Burton, and G.M. Cailliet.

1999b. Application of an ion-exchange separation technique and thermal ionization mass

spectrometry to ²²⁶Ra determination in otoliths for radiometric age determination of long-lived

fishes. Canadian Journal of Fisheries and Aquatic Sciences 56:1329-1338.

Burton, E.J., A.H. Andrews, K.H. Coale, and G.M. Cailliet. 1999. Application of radiometric age

determination to three long-lived fishes using ²¹⁰Pb:²²⁶Ra disequilibria in calcified structures:

A review. In: J.A. Musick (Editor). Life in the slow lane: ecology and conservation of long-lived

marine animals. American Fisheries Society Symposium 23, Bethesda, Maryland. p. 77-87.

Cailliet, G.M., Andrews, A.H., Wakefield, W.W., Moreno, G., Rhodes, K.L. 1999. Fish faunal and habitat

analyses using trawls, camera sleds and submersibles in benthic deep-sea habitats off central California.

Oceano. Acta. 22:579-592.

Publication Submitted

Andrews, A.H., E.J. Burton, K.H. Coale, G.M. Cailliet, and R.E. Crabtree. Submitted to Fishery

Bulletin. Application of radiometric age determination to the Atlantic tarpon, Megalops atlanticus.

Technical Publications

Andrews, A.H., E.J. Burton, K.H. Coale, and G.M. Cailliet. 1997. Chapter 2. Radiometric age

determination of the Atlantic sturgeon (Acipenser oxyrinchus): A feasibility study using

pectoral fin rays. Pages 63-80. In: D.H. Secor, J.T. Stevenson, and E.D. Houde (authors).

Age Structure and Life History Attributes of Atlantic Sturgeon (Acipenser oxyrinchus) in

the Hudson River. University of Maryland, Center for Environmental and Estuarine Studies,

Chesapeake Biological Laboratory, Ref. No. [UMCEES]CBL 97-107.

Andrews, A.H. 1998. Reliability assessment of season-of-capture determination for archaeological otoliths:

Final Report. For: Caltrans Cypress Project (F31529 and J24-98). Submitted to: Terry Jones, California

Polytechnic State University. 24p.

Nybakken, J., G.M. Cailliet, L.L. Weetman, A. Andrews, E. Cordes, M. Jacobi, M.D. White,

K. Johnson, E. Burton, and N. Laman. 1996. Ocean disposal site end point monitoring. MLML

Technical Publication 96-3, 37p. Navy Contract No. N62474-90-C-1147.

In Preparation

Andrews, A.H, Cordes, E., Mahoney, M.M., Munk, K., Coale, K.H., Cailliet, G.M., and Heifetz, J.

In preparation. Age and growth and radiometric validation of a deep-sea, habitat-forming gorgonian

(Primnoa resedaeformis) from the Gulf of Alaska. Submitted to Hydrobiologia (special proceedings

issue).

Wilson, M.T., Brown, A.L., Andrews, A.H., and Cordes, E. In preparation. Growth of the Axial Rod of a Sea Pen,

Halipteris willemoesi Kölliker. Submitted to Hydrobiologia (special proceedings issue).

Andrews, A.H., Burton, E.J., Cailliet, G.M., Coale, K.H., Pearson, D. In preparation. Application of radiometric

age determination to the bocaccio rockfish, Sebastes paucispinis. To be submitted to Can. J. Fish. Aquat. Sci.

Andrews, A.H., Laman, E.A., Bennett, T., Jones, E. and Cailliet, G.M. In preparation. Age and growth

of the spotted sand bass, Paralabrax maculatofasciatus, in Bahia de Los Angeles, Baja Norte, Mexico

with age validation using marginal increment analysis. To be submitted to Fisheries Bulletin.

Presentations

Andrews, A.H., K.H. Coale, and G.M. Cailliet. Age and growth of the Pacific grenadier (Family

Macrouridae, Coryphaenoides acrolepis) with age estimate validation using an improved

radiometric ageing technique. Oral Presentation, International Symposium on Fish Otolith

Research and Application. Bergen, Norway, June 1998.

Burton, E.J., A.H. Andrews, K.H. Coale, and G.M. Cailliet. Application of the radiometric ageing

technique using ²¹⁰Pb:²²⁶Ra disequilibria in calcified structures of two long-lived fishes: Atlantic

tarpon (Megalops atlanticus & Atlantic sturgeon (Acipenser oxyrinchus). Poster, International

Symposium on Fish Otolith Research and Application. Bergen, Norway, June 1998.

Andrews, A.H. Radiometric age determination of the Pacific grenadier (Coryphaenoides acrolepis),

a rapidly developing fishery in Monterey Bay. Oral Presentation, Eighth Deep Sea Biology

Symposium. Monterey, California, USA, September 1997.

Andrews, A.H., G.M. Cailliet, and K.H. Coale. Radiometric age determination of the Pacific grenadier

(Coryphaenoides acrolepis), a rapidly developing fishery of the northeastern Pacific Ocean.

Oral Presentation, American Society of Ichthyologists and Herpetologists. Seattle, Washington,

USA, June 1997.

Award Received

Eighth Deep Sea Biology Symposium Best Student Paper Award, 1997. Radiometric age determination

of the Pacific grenadier (Coryphaenoides acrolepis), a rapidly developing fishery in Monterey Bay.