Dear Marmamers, Workshop announcement for age determination in marine mammals at this years ECS conference. Thanks, Fiona Read --------------------------------------------------------------------- Age determination in marine mammals: with special reference to techniques employed, interpretation of GLGs and anomalies, using both tooth sections and digital photos. Saturday 1st April 2005, 8:30 - 17.00 The workshop will be held immediately prior to the 20th European Cetacean Society in Gdynia, Poland at the Institute of Oceanography, University of Gdansk (Pilsudskiego 46) - only 15 min. walk away from the conference venue. Equipment available will include stereo microscopes (magnification x 10-50) and a laptop and a beamer/projector. Organisers: Fiona Read1, Patricia Lastra2 and Christina Lockyer3 (1) Department of Virology, Erasmus Medical Centre, Rotterdam, The Netherlands (f.read@erasmusmc.nl ) (2) Department of Zoology, University of Aberdeen, Aberdeen, U.K. (p.lastra@abdn.ac.uk ) (3) Age Dynamics, Kongens Lyngby, Denmark (agedynamics@mail.dk ) Max. attendance: 20 Registration: The workshop is aimed at people already working on materials for determining age parameters and the number of participants is limited to 20 people. Registration will cost 10 euros per person, excluding lunch and pre-registration is essential. To register please contact Fiona Read (f.read@erasmusmc.nl). For those who are interested in bringing their own material (either teeth preparations or digital images), we would be deeply grateful whether you could let us know as soon as possible. Background and objectives: Background The estimation of age is important for the interpretation of many aspects of the biology, ecology and physiology of marine mammals and to provide information on population structure to underpin conservation and management measures. Interpretation of incremental and depositional structures (tooth dentine and cement, tympanic bulla, jaw bones, baleen plates, ear-plug, etc.,) is routinely used to estimate age in long-lived species such as marine mammals. Pinnipeds and Odontocetes are readily aged by counting incremental growth lines or Growth Layer Groups (GLGs; sensu Perrin & Myrick, 1980) present in dentine and/or cementum (Klevezal & Kleinenberg, 1967; Perrin & Myrick, 1980; Hohn et al., 1989; Lockyer, 1995; Hohn, 2002). Different preparation techniques and viewing platforms have been developed for estimating age in cetaceans and each has advantages and disadvantages. Nevertheless, the reliability of the technique depends on methodology, interpretation of GLGs, reader variability and availability of known-age animals to validate readings. Objectives The aim of this workshop is to bring together biologists working on life histories and population biology of marine mammals to discuss recent advances in age determination methods. We will review advantages and disadvantages of different techniques and identify gaps in knowledge. Finally, we will compile all the information gathered into a short report on the current status of age determination methods for marine mammals. Main aspects to be covered during the workshop 1- General background: Importance of age determination in the study of population biology in marine mammals. 2- Review of materials and methods (baleen, teeth, ear bones, eye lens, aspartic acid racemisation, etc.) and techniques used. Discuss new techniques / approaches for age determination and problems people have experienced during their work. 3- Discuss the term Growth Layer Group (GLG): Group discussion with a practical session. Split everyone into small groups to analyze prepared teeth from various species using different methods and then draw together an interpretation of GLGs. Discuss approaches to calibration of age in marine mammals: Known-age or known history animals Time-marking hard tissues by using tetracycline antibiotic treatments Other biological parameters supporting age: pregnancy records, female ovulation, etc. Tooth reading exercises using slides of own preparations. Discuss results from the practical session: Use of dentine and / or cementum Comparisons of our readings: inter-reader comparison. 4- Anomalies: Investigate and interpret unusually contrasting layering patterns present in the tooth ultra-structure (dentine &/or cement) of marine mammals. a- Slides presentation of different kind of anomalies b- Discuss causative factors likely linked to anomalies c- Discuss how to deal with such problems d- Use of anomalies in distinguishing populations, and life-history events Practical session: Small groups focusing on anomaly interpretation in different species. Summarized by a short group discussion. 5- Microscope investigations of prepared tooth sections with age trials followed by a question and answer session focusing on the slides examined. 6- Summary and conclusions of workshop and future work 7-Close Materials: All participants are encouraged to bring samples to the workshop, especially from known-age animals, teeth with anomalies, time-marked specimens, and samples from all types of marine mammals e.g. cetaceans, pinnipeds, polar bears, otters, etc. NOTE that this will be easy within the EC countries. If coming from outside the EC, a CITES permit for export and import may be necessary, and may need to be initiated a.s.a.p.. To circumvent this issue, we suggest bringing digital photographs instead wherever possible! References: Hohn, A.A., 2002. Age Determination. Encyclopedia of marine mammals. Edited by W. F. Perrin, B. Würsig and J. G. M. Thewissen. San Diego, Academic Press: 6-13. Hohn, A.A., Scott, M.D., Wells, R.S., Sweeney, J.C. and Irvine, A.B. 1989. Growth layers in teeth from known-age, free-ranging bottlenose dolphins. Mar. Mamm. Sci. 5(4): 315-342. Klevezal, G.A. and Kleinenberg, S.E. 1967. Age determination of mammals from annual layers in the teeth and bones. Translated from Russian by the Israel Program for Scientific Translations, Jerusalem, Israel, 1969: 128pp. Lockyer, C. 1995. A review of factors involved in zonation in odontocete teeth, and an investigation of the likely impact of environmental factors and major life events on harbour porpoise tooth structure. Rep.int. Whal.Commn (Special Issue 16) : 511 -529. Perrin, W.F. and Myrick Jr, A.C. (Eds) 1980. Age determination of toothed whales and sirenians.Rep.int.Whal.Commn (Special Issue 3) : 229pp.
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Fiona Read Life History of Harbour Seals Department of Virology Erasmus MC P.O. Box 1738 3000 DR Rotterdam The Netherlands Tel: +31 (0)10 408 8069 Fax: +31 (0)10 408 9485 E-mail: f.read@erasmusmc.nl Visiting address: Dr Molewaterplein 50 3015 GE Rotterdam
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