Stable carbon isotope variations in otoliths of Atlantic cod (Gadus morhua)

1998 ◽  
Vol 55 (8) ◽  
pp. 1798-1806 ◽  
Author(s):  
H P Schwarcz ◽  
Y Gao ◽  
S Campana ◽  
D Browne ◽  
M Knyf ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Dissolved Inorganic Carbon ◽  
Stable Carbon Isotope ◽  
Atlantic Canada ◽  
Stable Carbon ◽  
Dietary Shift ◽  
C Value ◽  
Early Rise

Stable carbon isotope ratios (13C) were measured in annual layers of otoliths of Atlantic cod (Gadus morhua) from the northeastern Scotian Shelf, Atlantic Canada. Layers deposited during the first 4-6 years of otolith growth increased in 13C from minimum values between -5‰ and -2.5‰ to a maximum near 0‰. This pattern of increase was independent of the years in which the fish was collected. Layers formed after reaching the maximum 13C value displayed decreasing or nearly constant isotopic ratios. Early rise in 13C may be a combined result of (i) decrease in the fraction of metabolic oxidized carbon in the fishes' blood as they mature, relative to the proportion of seawater-derived carbon, and (ii) dietary shift to higher trophic-level foods with higher 13C values. Age of maximum in 13C may be indicative of age of maturity of cod. The maximum 13C value attained by otoliths decreased steadily between 1983 and 1993, while cod stocks in Atlantic Canada were declining. Drop in age of attainment of maximum 13C between 1984 and 1985 coincides with changes in population dynamics of the 4Vs stock. This decrease, as well as the post maximum decrease in 13C values of the mature cod otoliths may represent movement of the fish to deeper waters of the shelf, where 13C of dissolved inorganic carbon is lower.

scholarly journals Measurements of the stable carbon isotope composition of dissolved inorganic carbon in the northeastern Atlantic and Nordic Seas during summer 2012

2015 ◽  
Vol 7 (1) ◽  
pp. 127-135 ◽  
Author(s):  
M. P. Humphreys ◽  
E. P. Achterberg ◽  
A. M. Griffiths ◽  
A. McDonald ◽  
A. J. Boyce
Keyword(s):  
Carbon Isotope ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Isotope Composition ◽  
Stable Carbon Isotope ◽  
Carbon Isotope Composition ◽  
Stable Carbon ◽  
Nordic Seas ◽  
Stable Carbon Isotope Composition ◽  
Northeastern Atlantic

Abstract. The stable carbon isotope composition of dissolved inorganic carbon (δ13CDIC) in seawater was measured in a batch process for 552 samples collected during two cruises in the northeastern Atlantic and Nordic Seas from June to August 2012. One cruise was part of the UK Ocean Acidification research programme, and the other was a repeat hydrographic transect of the Extended Ellett Line. In combination with measurements made of other variables on these and other cruises, these data can be used to constrain the anthropogenic component of dissolved inorganic carbon (DIC) in the interior ocean, and to help to determine the influence of biological carbon uptake on surface ocean carbonate chemistry. The measurements have been processed, quality-controlled and submitted to an in-preparation global compilation of seawater δ13CDIC data, and are available from the British Oceanographic Data Centre. The observed δ13CDIC values fall in a range from −0.58 to +2.37 ‰, relative to the Vienna Pee Dee Belemnite standard. The mean of the absolute differences between samples collected in duplicate in the same container type during both cruises and measured consecutively is 0.10 ‰, which corresponds to a 1σ uncertainty of 0.09 ‰, and which is within the range reported by other published studies of this kind. A crossover analysis was performed with nearby historical δ13CDIC data, indicating that any systematic offsets between our measurements and previously published results are negligible. Data doi:10.5285/09760a3a-c2b5-250b-e053-6c86abc037c0 (northeastern Atlantic), doi:10.5285/09511dd0-51db-0e21-e053-6c86abc09b95 (Nordic Seas).

scholarly journals Measurements of the stable carbon isotope composition of dissolved inorganic carbon in the Northeastern Atlantic and Nordic Seas during summer 2012

2015 ◽  
Vol 8 (1) ◽  
pp. 57-82 ◽  
Author(s):  
M. P. Humphreys ◽  
E. P. Achterberg ◽  
A. M. Griffiths ◽  
A. McDonald ◽  
A. J. Boyce
Keyword(s):  
Carbon Isotope ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Isotope Composition ◽  
Stable Carbon Isotope ◽  
Carbon Isotope Composition ◽  
Stable Carbon ◽  
Nordic Seas ◽  
Stable Carbon Isotope Composition ◽  
Northeastern Atlantic

Abstract. The stable carbon isotope composition of dissolved inorganic carbon (δ13CDIC) in seawater was measured in samples collected during two cruises in the Northeastern Atlantic and Nordic Seas from June to August 2012. One cruise was part of the UK Ocean Acidification research programme, and the other was a repeat hydrographic transect of the Extended Ellett Line. In combination with measurements made of various other variables on these and other cruises, these data can be used to constrain the anthropogenic component of DIC in the interior ocean, and also assist in determining the influence of biological carbon uptake on surface ocean carbonate chemistry. The measurements have been processed, quality-controlled and submitted to an in-preparation global compilation of seawater δ13CDIC data, and are available from the British Oceanographic Data Centre. The observed δ13CDIC values fall in a range from −0.58 to +2.37‰, relative to the Vienna Peedee Belemnite standard. From duplicate samples collected during both cruises, the precision for the 552 results is 0.07‰, which is similar to other published studies of this kind. Data doi:10.5285/09760a3a-c2b5-250b-e053-6c86abc037c0 (Northeastern Atlantic), doi:10.5285/09511dd0-51db-0e21-e053-6c86abc09b95 (Nordic Seas).

Sign in / Sign up

Export Citation Format

Share Document