A validated description of age and growth of western Atlantic bluefin tuna (Thunnus thynnus)

2008 ◽  
Vol 65 (8) ◽  
pp. 1523-1527 ◽  
Author(s):  
John D. Neilson ◽  
Steven E. Campana
Keyword(s):  
Bluefin Tuna ◽  
Age And Growth ◽  
Thunnus Thynnus ◽  
Western Atlantic ◽  
Atlantic Bluefin Tuna ◽  
Structured Population ◽  
Length Relationship ◽  
Stock Assessments ◽  
Bomb Radiocarbon ◽  
Age Structured

Current stock assessments of western Atlantic bluefin tuna ( Thunnus thynnus ) use age-structured population analyses, but the age assignment in the population model is made using an age–length relationship derived from mark and recapture studies largely completed during the 1970s. In our study, the deposition of bomb radiocarbon was used as a dated mark to validate age inferences of bluefin tuna and to compare the validated ages with those predicted from the age–length relationship. The results support the view that the age–length relationship currently in use for the assessment overestimates growth rate and the ultimate size of the fish. These findings have implications for the estimation of stock productivity and may negatively impact the rebuilding schedules established by fisheries managers.

Diet of young Atlantic bluefin tuna (Thunnus thynnus) in eastern and western Atlantic foraging grounds

2010 ◽  
Vol 158 (1) ◽  
pp. 73-85 ◽  
Author(s):  
John M. Logan ◽  
Enrique Rodríguez-Marín ◽  
Nicolas Goñi ◽  
Santiago Barreiro ◽  
Haritz Arrizabalaga ◽  
...  
Keyword(s):  
Bluefin Tuna ◽  
Thunnus Thynnus ◽  
Western Atlantic ◽  
Atlantic Bluefin Tuna

scholarly journals Erratum to: Diet of young Atlantic bluefin tuna (Thunnus thynnus) in eastern and western Atlantic foraging grounds

2011 ◽  
Vol 158 (9) ◽  
pp. 2147-2148 ◽  
Author(s):  
John M. Logan ◽  
Enrique Rodríguez-Marín ◽  
Nicolas Goñi ◽  
Santiago Barreiro ◽  
Haritz Arrizabalaga ◽  
...  
Keyword(s):  
Bluefin Tuna ◽  
Thunnus Thynnus ◽  
Western Atlantic ◽  
Atlantic Bluefin Tuna

Complex migration routes of Atlantic bluefin tuna (Thunnus thynnus) question current population structure paradigm

2010 ◽  
Vol 67 (6) ◽  
pp. 966-976 ◽  
Author(s):  
Benjamin Galuardi ◽  
François Royer ◽  
Walt Golet ◽  
John Logan ◽  
John Neilson ◽  
...  
Keyword(s):  
Site Fidelity ◽  
Bluefin Tuna ◽  
Thunnus Thynnus ◽  
Migration Routes ◽  
Western Atlantic ◽  
Spawning Period ◽  
Atlantic Bluefin Tuna ◽  
Spawning Site ◽  
Archival Tags ◽  
Spawning Areas

Movements of Atlantic bluefin tuna ( Thunnus thynnus , ABFT) from specific western Atlantic forage grounds are not well described, and the extent of their spawning areas is mainly surmised. In 2005 and 2006, we deployed 41 pop-up satellite archival tags (PSATs) on adult Atlantic bluefin tuna off the coast of Nova Scotia, Canada, and on Georges Bank. During the assumed spawning period, 56% of the tagged ABFT occupied a known spawning area, while 44% were located in distant oceanic regions. Assuming obligate annual spawning, these results are inconsistent with the notion of spawning site fidelity to the Gulf of Mexico. The ocean-wide migrations of adult ABFT tagged on a common forage ground suggest evidence of a metapopulation requiring more spatially explicit management than the current simple two-stock structure.

Natal origin of Atlantic bluefin tuna (Thunnus thynnus) from Canadian waters based on otolith δ13C and δ18O

2010 ◽  
Vol 67 (3) ◽  
pp. 563-569 ◽  
Author(s):  
Ryan W. Schloesser ◽  
John D. Neilson ◽  
David H. Secor ◽  
Jay R. Rooker
Keyword(s):  
Eastern Mediterranean ◽  
Bluefin Tuna ◽  
Maximum Likelihood Estimates ◽  
Thunnus Thynnus ◽  
Western Atlantic ◽  
Atlantic Bluefin Tuna ◽  
Declining Populations ◽  
Catch Rates ◽  
And Migration ◽  
Stock Mixing

Increased knowledge of stock mixing and migration of Atlantic bluefin tuna ( Thunnus thynnus ) is required to properly manage and conserve declining populations. Here, we predicted the nursery origin of giant bluefin tuna (n = 224) present in samples from Canadian waters using stable δ13C and δ18O isotopes in otoliths. The isotopic composition of milled otolith cores (corresponding to the first year of life) of giant bluefin tuna from three decades (1970s, 1980s, 2000s) and three regions within or adjacent to the Gulf of St. Lawrence was compared with otolith δ13C and δ18O of yearling bluefin tuna collected from eastern (Mediterranean Sea – eastern Atlantic, n = 136) and western (western Atlantic, n = 103) nurseries. Maximum likelihood estimates indicated that greater than 99% of bluefin tuna in our Canadian samples originated from the western nursery. No significant differences in estimates of origin for bluefin tuna were detected among decades or among regions, suggesting little to no mixing of eastern and western populations in the Canadian samples examined. These findings justify the use of catch rates from the Gulf of St. Lawrence area as an index of abundance for the oldest members of the western population.

Individual assignment of Atlantic bluefin tuna in the northwestern Atlantic Ocean using single nucleotide polymorphisms reveals an increasing proportion of migrants from the eastern Atlantic Ocean.

2021 ◽  
Author(s):  
Gregory Neils Puncher ◽  
Alex Hanke ◽  
Dheeraj Busawon ◽  
Emma Sylvester ◽  
Walter Golet ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Gulf Of Maine ◽  
Age Groups ◽  
Subsequent Development ◽  
Bluefin Tuna ◽  
Nucleotide Polymorphisms ◽  
Western Atlantic ◽  
Individual Assignment ◽  
Atlantic Bluefin Tuna ◽  
Stock Assessments

Identifying the origin of fish contained in a mixed fishery is critical for accurate stock assessments and the subsequent development of appropriate management strategies. Using a panel of 92 SNPs developed to differentiate Atlantic bluefin tuna (Thunnus thynnus) from the two main spawning areas (Gulf of Mexico and Mediterranean Sea), we used individual assignment to determine composition of feeding aggregations in the northwestern Atlantic Ocean (Gulf of Maine, Bay of Fundy, Scotian Shelf, Gulf of St. Lawrence, coastal Newfoundland). Among the 3,163 individuals collected between 2004 and 2018, we found that among lower age groups (<15 years) the spawning stock providing the most recruits to the Canadian fishery transitioned from Western Atlantic to Mediterranean origin over time. While the majority of older adults (>15 years) have consistently been of Western Atlantic origin, the disparity in the proportional contribution of western and eastern spawning groups narrowed significantly over the 14-year study period. Our results can be used to inform population-specific exploitation rates, improve stock assessments, identify age-dependent habitat use and areas suitable for additional conservation efforts.

Age and growth of Atlantic bluefin tuna,Thunnus thynnus(Osteichthyes: Thunnidae), in the Mediterranean Sea

2009 ◽  
Vol 25 (1) ◽  
pp. 38-45 ◽  
Author(s):  
N. Santamaria ◽  
G. Bello ◽  
A. Corriero ◽  
M. Deflorio ◽  
R. Vassallo-Agius ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Bluefin Tuna ◽  
Age And Growth ◽  
Thunnus Thynnus ◽  
Atlantic Bluefin Tuna ◽  
The Mediterranean

Internal Zonations in Sections of Vertebrae from Atlantic Bluefin Tuna, Thunnus thynnus, and Their Potential Use in Age Determination

1985 ◽  
Vol 42 (5) ◽  
pp. 938-946 ◽  
Author(s):  
Eric D. Prince ◽  
Dennis W. Lee ◽  
Joaquin C. Javech
Keyword(s):  
Age Groups ◽  
Age Determination ◽  
Fork Length ◽  
Bluefin Tuna ◽  
Age And Growth ◽  
Thunnus Thynnus ◽  
Thin Sections ◽  
Section Method ◽  
Atlantic Bluefin Tuna ◽  
Cone Surface

Internal zonations (bands) were observed in thin sections of vertebrae from 98% of the 200 Atlantic bluefin tuna, Thunnus thynnus, we examined between 49.5 and 284.5 cm fork length (FL). These zones occurred in the solid bone area of the sections corresponding to the outer margin of the vertebral cone surface. The remaining area of the section nearest the focus is characterized by spongy bone which obstructs internal zonations associated with early growth history. We present a modified method of determining vertebra age of Atlantic bluefin tuna by adopting a counting procedure which involves enumerating distal internal bands in the sections, as well as proximal external bands on the cone surface to assign ages. Accuracy of this methodology was assessed by evaluating fish where age was known from length frequency and tagging data. The accuracy and precision of estimating age of giant bluefin tuna [Formula: see text] was improved using our vertebral section method of age determination compared with the more traditional whole vertebra method of ageing. However, results of the vertebral section method in ageing medium tuna (146.0–208.9 cm FL) were inconclusive and this method overestimated age of school tuna (49.5–145.9 cm FL) and should not be used for juvenile age groups. The occurrence of internal zonations in vertebrae of teleosts other than bluefin tuna should be examined as a possible source of age and growth information.

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