Saturation state of the surface waters of the Greater Caribbean Region (including the Gulf of Mexico) with respect to aragonite

Abstract

The carbonate chemistry of seawater is changing due to the uptake of increasing atmospheric C02 and is of major scientific concem. The decrease in the aragonite saturation state (Qaragonite) is of special interest, because the ability of some marine organisms (e.g. corals) to form calcium carbonate via biomineralization is suspected to be depending on aragonite saturation in the surrounding seawater. The objective of this thesis was to investigate the aragonite saturation state of two marginal seas, the Gulf of Mexico and the Caribbean Sea. Presented are the results of five cruises that were carried out in the Greater Caribbean Region (including the Gulf of Mexico) in 2008. At least two carbonaterelated analytical parameters were determined on each cruise, which made possible the calculation of the other parameters of the carbonate system, including the aragonite saturation state. All surface waters were supersaturated with respect to Ωaragonite with an average aragonite saturation state of 4.16 (± 0.3) in the Gulf of Mexico and 4.18 (± 0.09) in the Caribbean Sea