Standardization of Otolith-based Ageing Protocols for Atlantic Bluefin Tuna
Workshop Agenda
16-18 January, Workshop url: http://fishconnectivity.cbl.umces.edu/2013-ageing-workshop
Chesapeake Biological Laboratory, Solomons, Maryland, US
Venue: Meetings, interpretation trials, and continental breakfast all held in 1120 Bernie Fowler Building,
Chesapeake Biological Laboratory. Two stereo-zoom microscopes with attached image presentation
systems, one system attached to large white board. Participants should each bring a lap-top with
installed PhotoShop (Adobe ©). Image sets will be provided on thumb drives or a common access drive
on CBL’s local area network.
Principal Product: An amendment to the ICCAT Bluefin Tuna Direct Ageing Manual on annulus
interpretation guidelines and ageing conventions.
Wednesday 16 January
8:30 Continental breakfast
9:00 Introductions, modifications to agenda
Session 1. Interpretation of annuli
9:30
Presentations followed by discussion
1. First annulus identification and measures
– Matt Siskey and Patricia Lastra Luque
2. Criteria for annulus identification and edge interpretation
– Ben Gahagan (transmitted light) Dheeraj Busawon (reflected light)
3. Concurrence on criteria for annuli interpretation
Session 2. Evaluation of sectioning plane and transmitted v. reflected light
12:00
Introduction to precision trials using serial sections and different light sources
12:30 Lunch at Kim’s Cafe
2:00
Individual assignment of annuli for trial set of otolith sections (varying section plan and light type).
Participants will be given the same set of 30-40 images to assign annuli using Photo-shop. Microscopes
will be available to view imaged otolith sections as well.
6:00 Dinner at local joint (participants polled on preference)
Thursday 17 January
8:30 Continental breakfast
Session 2 (cont). Evaluation of sectioning plane and transmitted v. reflected light
9:00
1. Presentation and discussion of effects of section plan and light type on annulus counts from trial
set of otoliths (Secor)
2. Group review of selected images from trial set
3. Concurrence on the effect of light type and sectioning plane on annulus interpretations
12:30 Lunch at local seafood restaurant, Captain’s Table
Session 3. Introduction to ageing conventions
2:00 Presentations and discussion
1. Collection date and age assignment (Robert Allman)
2. Precision criterion and reader sets (Secor)
Session 4. Evaluation of Precision Criteria
3:00
Individual assignment of annuli for reader sets of otolith sections (varying light type). Participants will be
given the same set of 30-40 images to assign annuli using Photo-shop, each image will be interpreted
twice. Microscopes will be available to view imaged otolith sections as well.
6:30 Dinner at Ruddy Duck (local brewpub)
Friday 18 January
8:30 Continental breakfast
Session 4 (cont). Evaluation of reader set precision
9:00
1. Presentation of within and between reader precision for reader sets; comparison of size at age
plot v. Restrepo growth model (Secor)
2. Group review of selected images from reader sets
3. Concurrence on precision criteria, use of reader sets, and other age assignment conventions
Session 5. Wrap up and products
12:00
Writing Assignments for Amendment to the ICCAT Bluefin Tuna Direct Ageing Manual
Discussion on publication of 2013 SCRS Document
Website for bluefin tuna age determination
1:00 Adjourn