Application of a novel method for age estimation of a baleen whale and a porpoise

Nynne H. Nielsen; Eva Garde; Mads Peter  Heide-Jørgensen; Christina H. Lockyer; Susanne Ditlevsen; Droplaug  Òlafsdóttir; Steen Honoré Hansen

doi:10.1111/j.1748-7692.2012.00588.x

Application of a novel method for age estimation of a baleen whale and a porpoise

Nynne H. Nielsen, Eva Garde, Mads Peter Heide-Jørgensen, Christina H. Lockyer, Susanne Ditlevsen, Droplaug Òlafsdóttir, Steen Honoré Hansen

Institut for Matematiske Fag

3 Citationer (Scopus)

Abstract

Eyeballs from 121 fin whales (Balaenoptera physalus) and 83 harbor porpoises (Phocoena phocoena) were used for age estimation using the aspartic acid racemization (AAR) technique. The racemization rate (kAsp) for fin whales was established from 15 fetuses (age 0) and 15 adult whales where age was estimated by reading growth layer groups (GLGs) in the earplugs. The (kAsp) for harbor porpoises was derived from 15 porpoises (two calves and 13 > 1 yr old) age-estimated by counting GLGs in the teeth and two calves classified to age based on length. The (kAsp) values were estimated by regression of GLGs against D/L ratios. For the fin whales an (kAsp) of 1.15 × 10−3/yr (SE ± 0.00005) and a D/L ratio at birth [(D/L)0] of 0.028 (SE ± 0.0012) were estimated, which is in agreement with rates for other mysticeti. For the harbor porpoises a (kAsp) of 3.10 × 10−3/yr (SE ± 0.0004) and a (D/L)0 value of 0.023 (SE ± 0.0018) were estimated, which is considerably higher than found for other cetaceans. Correlation between chosen age estimates from AAR and GLG counts indicated that AAR might be an alternative method for estimating age in marine mammals.

Originalsprog	Engelsk
Tidsskrift	Marine Mammal Science
Vol/bind	29
Udgave nummer	2
Sider (fra-til)	E1-E23
Antal sider	23
ISSN	0824-0469
DOI	https://doi.org/10.1111/j.1748-7692.2012.00588.x
Status	Udgivet - apr. 2013

Adgang til dokumentet

10.1111/j.1748-7692.2012.00588.x

Citationsformater

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title = "Application of a novel method for age estimation of a baleen whale and a porpoise",

abstract = "Eyeballs from 121 fin whales (Balaenoptera physalus) and 83 harbor porpoises (Phocoena phocoena) were used for age estimation using the aspartic acid racemization (AAR) technique. The racemization rate (kAsp) for fin whales was established from 15 fetuses (age 0) and 15 adult whales where age was estimated by reading growth layer groups (GLGs) in the earplugs. The (kAsp) for harbor porpoises was derived from 15 porpoises (two calves and 13 > 1 yr old) age-estimated by counting GLGs in the teeth and two calves classified to age based on length. The (kAsp) values were estimated by regression of GLGs against D/L ratios. For the fin whales an (kAsp) of 1.15 × 10−3/yr (SE ± 0.00005) and a D/L ratio at birth [(D/L)0] of 0.028 (SE ± 0.0012) were estimated, which is in agreement with rates for other mysticeti. For the harbor porpoises a (kAsp) of 3.10 × 10−3/yr (SE ± 0.0004) and a (D/L)0 value of 0.023 (SE ± 0.0018) were estimated, which is considerably higher than found for other cetaceans. Correlation between chosen age estimates from AAR and GLG counts indicated that AAR might be an alternative method for estimating age in marine mammals.",

author = "Nielsen, {Nynne H.} and Eva Garde and Heide-J{\o}rgensen, {Mads Peter} and Lockyer, {Christina H.} and Susanne Ditlevsen and Droplaug {\`O}lafsd{\'o}ttir and Hansen, {Steen Honor{\'e}}",

year = "2013",

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T1 - Application of a novel method for age estimation of a baleen whale and a porpoise

AU - Nielsen, Nynne H.

AU - Garde, Eva

AU - Heide-Jørgensen, Mads Peter

AU - Lockyer, Christina H.

AU - Ditlevsen, Susanne

AU - Òlafsdóttir, Droplaug

AU - Hansen, Steen Honoré

PY - 2013/4

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N2 - Eyeballs from 121 fin whales (Balaenoptera physalus) and 83 harbor porpoises (Phocoena phocoena) were used for age estimation using the aspartic acid racemization (AAR) technique. The racemization rate (kAsp) for fin whales was established from 15 fetuses (age 0) and 15 adult whales where age was estimated by reading growth layer groups (GLGs) in the earplugs. The (kAsp) for harbor porpoises was derived from 15 porpoises (two calves and 13 > 1 yr old) age-estimated by counting GLGs in the teeth and two calves classified to age based on length. The (kAsp) values were estimated by regression of GLGs against D/L ratios. For the fin whales an (kAsp) of 1.15 × 10−3/yr (SE ± 0.00005) and a D/L ratio at birth [(D/L)0] of 0.028 (SE ± 0.0012) were estimated, which is in agreement with rates for other mysticeti. For the harbor porpoises a (kAsp) of 3.10 × 10−3/yr (SE ± 0.0004) and a (D/L)0 value of 0.023 (SE ± 0.0018) were estimated, which is considerably higher than found for other cetaceans. Correlation between chosen age estimates from AAR and GLG counts indicated that AAR might be an alternative method for estimating age in marine mammals.

AB - Eyeballs from 121 fin whales (Balaenoptera physalus) and 83 harbor porpoises (Phocoena phocoena) were used for age estimation using the aspartic acid racemization (AAR) technique. The racemization rate (kAsp) for fin whales was established from 15 fetuses (age 0) and 15 adult whales where age was estimated by reading growth layer groups (GLGs) in the earplugs. The (kAsp) for harbor porpoises was derived from 15 porpoises (two calves and 13 > 1 yr old) age-estimated by counting GLGs in the teeth and two calves classified to age based on length. The (kAsp) values were estimated by regression of GLGs against D/L ratios. For the fin whales an (kAsp) of 1.15 × 10−3/yr (SE ± 0.00005) and a D/L ratio at birth [(D/L)0] of 0.028 (SE ± 0.0012) were estimated, which is in agreement with rates for other mysticeti. For the harbor porpoises a (kAsp) of 3.10 × 10−3/yr (SE ± 0.0004) and a (D/L)0 value of 0.023 (SE ± 0.0018) were estimated, which is considerably higher than found for other cetaceans. Correlation between chosen age estimates from AAR and GLG counts indicated that AAR might be an alternative method for estimating age in marine mammals.

U2 - 10.1111/j.1748-7692.2012.00588.x

DO - 10.1111/j.1748-7692.2012.00588.x

M3 - Journal article

SN - 0824-0469

VL - 29

SP - E1-E23

JO - Marine Mammal Science

JF - Marine Mammal Science

IS - 2

ER -