Globigerinoides ruber sediment trap data in the Gulf of Mexico

We present results here from a high-resolution (1-2 weeks) and long-running sediment trap time series from the northern Gulf of Mexico which allows for a detailed assessment of the seasonal distribution, size, morphological variability and geochemistry of co-occurring pink and white chromotypes of Globigerinoides ruber. The flux of both chromotypes is highly correlated, and both represent mean annual conditions in the surface mixed-layer. Under modern climatic conditions in the Gulf of Mexico, we find no significant offset in the Mg/Ca and δ18O of co-occurring pink and white G. ruber. Furthermore, we find the δ18O and δ13C among the two morphotypes (sensu stricto and sensu lato) of both pink and white G. ruber to be indistinguishable. The test size distribution within the population varies seasonally, with the abundance of large individuals increasing (decreasing) in summer (winter). Using paired Mg/Ca and δ18O we evaluate the performance of a suite of published equations for calculating sea surface temperature (SST), sea surface salinity (SSS) and isotopic composition of seawater (δ18Osw). In addition, we present new linear relationships between salinity and δ18Osw for the surface mixed-layer and the entire water column, based on 17 sampling trips to the Gulf of Mexico from 2008-2017.