scholarly journals Life history traits of the fish community in Lake Annecy: evidence from the stable isotope composition of otoliths

Author(s):  
D. Gerdeaux ◽  
E. Dufour
2010 ◽  
Vol 67 (7) ◽  
pp. 1425-1431 ◽  
Author(s):  
Ángel Guerra ◽  
Alejandro B. Rodríguez-Navarro ◽  
Ángel F. González ◽  
Chris S. Romanek ◽  
Pedro Álvarez-Lloret ◽  
...  

Abstract Guerra, Á., Rodríguez-Navarro, A. B., González, Á. F., Romanek, C. S., Álvarez-Lloret, P., and Pierce, G. J. 2010. Life-history traits of the giant squid Architeuthis dux revealed from stable isotope signatures recorded in beaks. – ICES Journal of Marine Science, 67: 1425–1431. Carbon and nitrogen isotope profiles constructed from the upper beaks of four giant squid Architeuthis dux from the Bay of Biscay and Namibian waters provided a time-integrated record of their diet. Values of δ15N ranged from 5.5 to 13.4‰ and of δ13C from −14.4 to −17.8‰. Nitrogen isotope profiles differed significantly in shape among the four animals analysed, but δ15N increased along each profile, with lowest values around the rostral tip. The difference between the lowest and the highest δ15N values was ∼5.8‰, slightly less than a two-level difference between the trophic position of small and large A. dux. The increase in δ13C values was not as pronounced as for the δ15N profiles, but the changes suggest an ontogenetic shift in diet early in life from smaller prey of relatively low trophic status to larger prey of higher status. Fluctuations in δ13C values observed near the rostral tip may be associated with a greater intrinsic variability in the carbon isotope composition of relatively small prey, and/or transient migratory behaviour early in life. The relative stability of the δ13C profiles over the remainder of their lifespan is consistent with the hypothesis that adult giant squid inhabit relatively small, well-defined, and productive areas, where food resources have a constant carbon isotope composition.


2019 ◽  
Vol 98 ◽  
pp. 07013
Author(s):  
Thomas Kretzschmar ◽  
Matteo Lelli ◽  
Ruth Alfaro ◽  
Juan Ignacio Sanchez ◽  
Yann Rene Ramos

It is important to develop a regional hydrogeological model to identify possible recharge and discharge areas for a sustainable use of a geothermal reservoir. The Los Humeros geothermal area is situated within five surficial watersheds and coveres an area of more than 15.000 km2. A total of 208 well and spring samples were collected between June 2017 and November 2018. The stable isotope data for this region define a regression line of δDH2O = 8.032·δ18O + 12 and indicate that groundwater is recharged by regional precipitation. At least 39 groundwater wells, with a maximum temperature of 35 °C, show temperatures above the reported mean average surface temperature of 15 °C. Characteristic elements for geothermal reservoir fluids (B, Li, As) are also present in these groundwaters, indicating a possible connection between the reservoir fluid and the local groundwater through local fracture systems. Concentration of B in these hot wells is between 150 and 35000 ppb.


PLoS ONE ◽  
2013 ◽  
Vol 8 (12) ◽  
pp. e82205 ◽  
Author(s):  
Tatiana Lemos Bisi ◽  
Paulo Renato Dorneles ◽  
José Lailson-Brito ◽  
Gilles Lepoint ◽  
Alexandre de Freitas Azevedo ◽  
...  

2005 ◽  
Vol 19 (14) ◽  
pp. 1937-1942 ◽  
Author(s):  
Bojlul Bahar ◽  
Frank J. Monahan ◽  
Aidan P. Moloney ◽  
Padraig O'Kiely ◽  
Charlie M. Scrimgeour ◽  
...  

2015 ◽  
Vol 523 ◽  
pp. 781-789 ◽  
Author(s):  
Grzegorz Skrzypek ◽  
Adam Mydłowski ◽  
Shawan Dogramaci ◽  
Paul Hedley ◽  
John J. Gibson ◽  
...  

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