Spatial implications of a temperature-based growth model for Atlantic cod (Gadus morhua) off the eastern coast of Canada

1995 ◽  
Vol 52 (11) ◽  
pp. 2445-2456 ◽  
Author(s):  
S. E. Campana ◽  
R. K. Mohn ◽  
S. J. Smith ◽  
G. A. Chouinard
Keyword(s):  
Water Temperature ◽  
Growth Model ◽  
Bottom Water ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Eastern Coast ◽  
Bottom Water Temperature ◽  
Relative Growth ◽  
Contour Maps ◽  
Size At Age

Lengths at age of Atlantic cod (Gadus morhua) off the eastern coast of Canada vary up to three-fold among geographic regions, with Georges Bank and the southern Gulf of St. Lawrence being the regions of fastest and slowest growth, respectively. Colour-coded contour maps of length at ages 2–8 (n = 59 518) based on research vessel surveys between 1971 and 1992 clearly showed the spatial variations in size at age. Corresponding maps of July–September bottom water temperature appeared to reflect relative growth rate, whereas those for depth did not. A polynomial expansion of a temperature-based von Bertalanffy growth model appeared to fit the data well, with no residual patterns across most ages, lengths, temperatures, or years. Model predictions were also consistent with reported lengths at age for cod in other regions and countries. Declines in bottom water temperature over the past 5–10 years appear to be at least partly responsible for observed declines in size at age of the cod stock on the eastern Scotian Shelf.

Reply: Spatial implications of a temperature-based growth model for Atlantic cod (Gadus morhua) off the eastern coast of Canada

1996 ◽  
Vol 53 (12) ◽  
pp. 2912-2914 ◽  
Author(s):  
S E Campana ◽  
R K Mohn ◽  
S J Smith ◽  
G A Chouinard
Keyword(s):  
Growth Model ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Eastern Coast

scholarly journals Reconstructing bottom water temperatures from measurements of temperature and thermal diffusivity in marine sediments

2014 ◽  
Vol 11 (5) ◽  
pp. 2391-2422
Author(s):  
F. Miesner ◽  
A. Lechleiter ◽  
C. Müller
Keyword(s):  
Steady State ◽  
Heat Flow ◽  
Water Temperature ◽  
Marine Sediments ◽  
Bottom Water ◽  
Measured Data ◽  
Temperature History ◽  
Artificial Data ◽  
Bottom Water Temperature ◽  
Steady State Heat

Abstract. Temperature fields in marine sediments are studied for various purposes. Often, the target of research is the steady state heat flow as a (possible) source of energy but there are also studies attempting to reconstruct bottom water temperature variations to understand more about climate history. The bottom water temperature propagates into the sediment to different depths, depending on the amplitude and period of the deviation. The steady state heat flow can only be determined when the bottom water temperature is constant while the bottom water temperature history can only be reconstructed when the deviation has an amplitude large enough or the measurements are taken in great depths. In this work, the aim is to reconstruct recent bottom water temperature history such as the last two years. To this end, measurements to depths of up to 6 m shall be adequate and amplitudes smaller than 1 K should be reconstructable. First, a commonly used forward model is introduced and analyzed: knowing the bottom water temperature deviation in the last years and the thermal properties of the sediments, the forward model gives the sediment temperature field. Next, an inversion operator and two common inversion schemes are introduced. The analysis of the inversion operator and both algorithms is kept short, but sources for further reading are given. The algorithms are then tested for artificial data with different noise levels and for two example data sets, one from the German North Sea and one from the Davis Strait. Both algorithms show good and stable results for artificial data. The achieved results for measured data have low variances and match to the observed oceanographic settings. Lastly, the desired and obtained accuracy are discussed. For artificial data, the presented method yields satisfying results. However, for measured data the interpretation of the results is more difficult as the exact form of the bottom water deviation is not known. Nevertheless, the presented inversion method seems rather promising due to its accuracy and stability for artificial data. Continuing to work on the development of more sophisticated models for the bottom water temperature, we hope to cover more different oceanographic settings in the future.

scholarly journals Orbital and suborbital variability in North Atlantic bottom water temperature obtained from deep-sea ostracod Mg/Ca ratios

2000 ◽  
Vol 162 (1-2) ◽  
pp. 45-57 ◽  
Author(s):  
T.M. Cronin ◽  
G.S. Dwyer ◽  
P.A. Baker ◽  
J. Rodriguez-Lazaro ◽  
D.M. DeMartino
Keyword(s):  
Water Temperature ◽  
North Atlantic ◽  
Deep Sea ◽  
Bottom Water ◽  
Bottom Water Temperature

On the interpretation of near-bottom water temperature anomalies

1976 ◽  
Vol 32 (1) ◽  
pp. 18-24 ◽  
Author(s):  
R.P. Lowell ◽  
P.A. Rona
Keyword(s):  
Water Temperature ◽  
Bottom Water ◽  
Bottom Water Temperature ◽  
Temperature Anomalies

TEX 86 paleothermometer as an indication of bottom water temperature in the Yellow Sea

2015 ◽  
Vol 86 ◽  
pp. 19-31 ◽  
Author(s):  
Lei Xing ◽  
Julian P. Sachs ◽  
Wenxian Gao ◽  
Shuqing Tao ◽  
Xiaochen Zhao ◽  
...  
Keyword(s):  
Water Temperature ◽  
Yellow Sea ◽  
Bottom Water ◽  
The Yellow Sea ◽  
Bottom Water Temperature
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