@article{fdi:010064088,
title = {{A}n evaluation of {M}g/{C}a, {S}r/{C}a, and {B}a/{C}a ratios as environmental proxies in aragonite bivalve shells},
author = {{P}oulain, {C}. and {G}illikin, {D}. {P}. and {T}h{\'e}bault, {J}. and {M}unaron, {J}. {M}. and {B}ohn, {M}. and {R}obert, {R}. and {P}aulet, {Y}. {M}. and {L}orrain, {A}nne},
editor = {},
language = {{ENG}},
abstract = {{T}he influence of salinity and water chemistry on {M}g/{C}a, {S}r/{C}a, and {B}a/{C}a ratios in the aragonitic shells of the {M}anila clam was investigated. {C}lams were reared at constant temperature (20 degrees {C}) under different controlled conditions of salinity, commonly encountered in their natural habitat. {C}lams were held in three tanks with a constant salinity of 35 for the first 35 days, and then two tanks were changed to lower salinities (20 and 28) for the next 29 days. {I}ndividual shell {M}g/{C}a, {S}r/{C}a, and {B}a/{C}a ratios were studied through time. {D}espite stable conditions (temperature, salinity, and {M}g/{C}a-water) for clams reared at salinity 35 during the experiment, {M}g/{C}a shell ratios increased through the time. {M}oreover the salinity decrease at t(35) slowed the increase of {M}g/{C}a shell ratios at salinity 28 and resulted in an {M}g/{C}a-shell decrease at salinity 20, despite similar {M}g/{C}a-water ratios in the different salinity treatments. {M}icroprobe analyses illustrate that {M}g varies along contemporaneous growth lines. {T}he variable shell {M}g/{C}a ratios suggest that incorporation of magnesium into shell carbonate is strongly regulated by the organism and not by environmental conditions. {I}nterestingly, microprobe analyses illustrated that {M}g was not associated with shell sulfur as other studies have suggested. {S}r/{C}a shell ratios of clams reared at salinity 35 and under constant conditions were also not as constant as expected if {S}r/{C}a ratios were an environmental proxy. {T}here was an inverse correlation between shell {S}r/{C}a and salinity despite a slight positive correlation between salinity and {S}r/{C}a ratios of the water, indicating that {S}r/{C}a ratios do not reflect environmental conditions. {A} strong inverse correlation between salinity and {B}a/{C}a shell ratios (and a positive correlation between {B}a/{C}a shell and {B}a/{C}a water) was observed. {T}herefore, {B}a/{C}a shell ratios seem to be a promising proxy of high-resolution (1 day) salinity variations in estuarine waters (via the relationship between {B}a/{C}a water and salinity). {T}his study clearly illustrates that both {M}g/{C}a and {S}r/{C}a ratios in aragonite shells are not under environmental control and that {B}a/{C}a ratios are, with the later tracking high-resolution water {B}a/{C}a ratios and hence estuarine salinity variations.},
keywords = {{R}uditapes philippinarum ; {A}ragonite ; {S}clerochronology ; {B}ivalved mollusk ; {T}race element ; {P}roxy},
booktitle = {},
journal = {{C}hemical {G}eology},
volume = {396},
numero = {},
pages = {42--50},
ISSN = {0009-2541},
year = {2015},
DOI = {10.1016/j.chemgeo.2014.12.019},
URL = {https://www.documentation.ird.fr/hor/fdi:010064088},
}