Special Oceanography Seminar
May 15, 3:00pm - 4:00pmMānoa Campus, Pacific Ocean Science and Technology (POST) 723
Dr. Allen H. Andrews
Research Fisheries Biologist
NOAA Fisheries – PIFSC
“Maximum age and missing time in shark vertebrae: the limits and validity of age estimates using bomb radiocarbon datingâ€
Abstract: Bomb radiocarbon dating has become a common tool in determining valid measures of age for marine organisms and has led to some recent discoveries about the longevity of large shark species. This method relies on a conserved record of the radiocarbon (14C) signal, created by the atmospheric testing of thermonuclear devices in the 1950s and 1960s, as a time-specific signal that can be used to determine valid measures of age. The first use of bomb 14C dating to marine fishes was a direct comparison of the 14C record stored in otoliths (fish ear stones) to known-age hermatypic corals for temporal alignment. Since this inaugural application, numerous marine organisms have been age validated using this technique, but the approach is not as straightforward as it may appear to be. Successful use of this method requires a firm understanding of the requirements and necessary assumptions. In the latest research on large shark species, complications with using bomb 14C dating can lead to perplexing results and in some cases assumptions that were made may not have been valid.
For most shark species, estimates of age were made by counting growth-band pairs in vertebrae and usually in the corpus calcareum of vertebral cross-sections. These estimates of age have been either supported or refuted using measured 14C values (reported as ∆14C) that are equated to a year-of-formation, and subsequently compared to an appropriate ∆14C reference record. Two of the most important considerations are the sources of carbon available to the vertebrae and the use of a valid ∆14C reference to provide validated age estimates. Recent findings for some species indicate the vertebrae cease growth and as a consequence ages have been underestimated by decades (i.e. sand tiger shark, Carcharias taurus). However, proper alignment of the ∆14C measurements from vertebral samples to the ∆14C reference record does not always provide well-defined ages and many are still considered estimates that require some assumptions (i.e. white shark, Carcharodon carcharias). The aim of this presentation is to provide an overview of how bomb radiocarbon dating works and what the special considerations are for shark vertebrae, with some insight on how the method can fall short of expectations.
Ticket Information
Free
Event Sponsor
Oceanography, Mānoa Campus
More Information
(808) 956-7633
Tuesday, March 19 |
|
9:30am |
Graduating Student Global Seal of Biliteracy Testing
Mānoa Campus, Moore Hall 153B EWA Computer Lab
|
12:00pm |
East-West Toastmasters Leadership/Public Speaking Club Meeting
Mānoa Campus, Hemenway Hall 215
|
Thursday, March 21 |
|
12:00pm |
NDPTC Webinar - Disaster Planning for Vulnerable Populations
Mānoa Campus, Online
|
Monday, March 25 |
|
12:30pm |
Linguistics Final Oral
Mānoa Campus, Moore Hall, Room 155A and Zoom, Link Below
|
Wednesday, March 27 |
|
9:00am |
Community Dialogues: “Microaggressions” with Jessica Lau
Mānoa Campus, ACCESS Lounge, Dean Hall, room 5/6
|
11:00am |
Community Dialogues: “Microaggressions” with Jessica Lau
Mānoa Campus, Online
|
12:00pm |
Law School Admissions Zoom Information Session
Mānoa Campus, Virtual
|
3:00pm |
Fifty Years as Historians of Southeast Asia: Personal Perspectives
Mānoa Campus, UHM Music Building, Room: 36
|
4:30pm |
Student Sustainability Council Meeting
Mānoa Campus, Gilmore Hall 212
|
4:30pm |
Entrepreneurship Live x ThriveHI
Mānoa Campus, Walter Dods,Jr. RISE Center, Level 2
|
6:00pm |
Turning to the Archives to Decenter the Settler State
Mānoa Campus, Kuykendall 410
|
Thursday, March 28 |
|
9:00am |
PI-CASC Graduate Student Symposium
Mānoa Campus, Inmin Conference Room, East West Center
|
9:30am |
Mathematics Final Oral
Mānoa Campus, George 213
|
12:00pm |
Lunchbreak Mindfulness Series: The Spring Refresh
Mānoa Campus, Online
|
2:00pm |
ASUHWO General Senate Meeting
West Oʻahu Campus, Student Life Center, C-214 OR Online via Zoom
|
3:00pm |
Gaza is Palestine: On Bakers and Storytellers
Mānoa Campus, 3114 Paliuili st
|
4:30pm |
Gaza is Palestine: On Bakers and Storytellers
Mānoa Campus, 3114 Paliuili st
|
5:00pm |
Part Time JD Flex and Law School Admissions - Zoom Information Session - March
Mānoa Campus, Virtual
|
7:00pm |
Navigators Bible Study
Mānoa Campus, Honolulu Christian Church 2207 Oahu Ave, Honolulu, HI 96822
|
Friday, March 29 |
|
3:00pm |
Business Administration Final Oral
Mānoa Campus, Zoom
|
Saturday, March 30 |
|
7:30pm |
JAVANESE GAMELAN CONCERT
Mānoa Campus, Music Department Barbara Smith Amphiteater
|
Sunday, March 31 |
|
12:00pm |
Kalo Grant 3rd Round Application
Mānoa Campus, Walter Dods,Jr. RISE Center, Level 2
|