Fluoride in non-symbiotic coral associated with seawater carbonate

In order to elucidate factors controlling incorporation of fluoride from seawater into non-symbiotic coral skeletons, the mole ratio of fluorine to calcium (F/Ca) in Flabellum corals was determined. The samples were collected from water depths between 185-350 m in Tosa Bay, Japan. The coral F/Ca ratio increased from 6.01 to 8.04 mmol/mol with increasing water depth. The factor controlling F/Ca ratio is discussed based on the proposed coprecipitation process of F in coral aragonite as the ion-exchange reaction: CaCO3 (s) + 2F- (aq) = CaF2 (s) + CO32- (aq). Based on the above reaction, F/Ca in coral is represented as: F/Ca = 0.5 KF´[F-]2/[CO32-]. Using the carbonate equilibrium system in seawater, [CO32-] in sampling depth was calculated. A strong correlation was observed between F/Ca in Flabellum corals and the calculated [CO32-] in seawater, while salinity, temperature and pressure have little or negligible effects on F/Ca in coral aragonite. Our results indicate that F/Ca in non-symbiotic coral aragonite possibly serves as a proxy of [CO32-] in seawater where the corals grew.

Tanaka K., Ono T., Fujioka Y. & Ohde S., in press. Fluoride in non-symbiotic coral associated with seawater carbonate. Marine Chemistry. Article (subscription required).

0 Responses to “Fluoride in non-symbiotic coral associated with seawater carbonate”



  1. Leave a Comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s




Subscribe to the RSS feed

Powered by FeedBurner

Follow AnneMarin on Twitter

Blog Stats

  • 789,891 hits

Ocean acidification in the IPCC AR5 WG II

OUP book


Follow

Get every new post delivered to your Inbox.

Join 988 other followers