FN Archimer Export Format PT J TI Relationship between Chlorophyll a Concentration, Light Attenuation and Diving Depth of the Southern Elephant Seal Mirounga leonina BT AF JAUD, Thomas DRAGON, Anne-Cecile Vacquie GARCIA, Jade GUINET, Christophe AS 1:1;2:1;3:1;4:1; FF 1:;2:;3:;4:; C1 Ctr Biol Chize, Marine Predator Dept, Villiers En Bois, France. C2 CNRS, FRANCE IN DOAJ IF 3.73 TC 34 UR https://archimer.ifremer.fr/doc/00589/70150/68129.pdf LA English DT Article CR BOUSSOLE AB Recently, a number of Antarctic marine environmental studies have used oceanographic parameters collected from instrumented top predators for ecological and physical information. Phytoplankton concentration is generally quantified through active measurement of chlorophyll fluorescence. In this study, light absorption coefficient (K-0.75) was used as an indicator of phytoplankton concentration. This measurement, easy to obtain and requiring low electric power, allows for assessing of the fine scale horizontal structuring of phytoplankton. As part of this study, Southern elephant seals (SES) were simultaneously equipped with a fluorometer and a light logger. Along the SES tracks, variations in K-0.75 were strongly correlated with chlorophyll, a concentration measured by the fluorometer within the euphotic layer. With regards to SES foraging behaviour, bottom depth of the seal's dive was highly dependent on light intensity at 150 m, indicating that the vertical distribution of SES's prey such as myctophids is tightly related to light level. Therefore, change in phytoplankton concentration may not only have a direct effect on SES's prey abundance but may also determine their vertical accessibility with likely consequences on SES foraging efficiency. PY 2012 PD OCT SO Plos One SN 1932-6203 PU Public Library Science VL 7 IS 10 UT 000311146900062 DI 10.1371/journal.pone.0047444 ID 70150 ER EF