Contact: Maite Maldonado (University of British Columbia, Canada).
Trace elements are essential for many metabolic pathways. Furthermore, biological activity can have profound effects on the distribution and speciation of trace elements and isotopes (TEI). In order to fully understand biogeochemical cycles of TEI in the sea, it is essential to elucidate biological processes that influence the geochemistry and fate of trace elements in marine systems. This is the goal of implementing a BioGEOTRACES component of GEOTRACES.
Given the constraints in laboratory space and wire time on most global section GEOTRACES cruises, sampling efforts for biological parameters have been limited to three laboratories: Penny Chisholm (MIT), Julie LaRoche (Dalhousie University) & Gerhard Herndl (University of Vienna), and have focused on "omic" data. However, other oceanographic studies (e.g. GEOTRACES process studies) focus on specific biological processes that enhance our understanding of trace metal biogeochemical cycles. Even though these cruises do not measure all the core parameters of GEOTRACES, they normally measure at least one trace element, in addition to multiple hydrographic and biological parameters/rate processes (e.g. chlorophyll a, HPLC pigments, nutrients, PAR, flow cytometry, functional genes, primary and secondary productivity, trace metal uptake and stoichiometry). Access to these data will benefit the interpretation of TEI results.
To ensure BioGEOTRACES data is dully intercalibrated, intercalibration protocols for BioGEOTRACES data have been developed and included in the GEOTRACES cookbook. Data must be submitted to the Standards and Intercalibration Committee and follow the flow chart available here. As shown in the flow chart, the GEOTRACES International Data Assembly Centre (GDAC) is happy to accept biological parameters as approved by the GEOTRACES SSC. All data submitted must include a detailed methodology and comply with the strict metadata data requirements of GEOTRACES (minimum supporting metadata - event, station, lat, long, depth, bottle number). The data should be submitted to GDAC with sufficient ancillary data to allow interpretation of results. These include at least temperature and salinity, and, preferably, nutrients and oxygen. Collection of CTD and other data that aid in interpreting TEI data should follow GO-SHIP guidelines on how to produce good quality CTD data, at: http://www.go-ship.org/HydroMan.html
BioGEOTRACES will follow GEOTRACES Data Policy, including:
a) Submission of post-cruise metadata and cruise report. Guidelines for preparing the cruise report and a metadata template form are also available at: http://www.bodc.ac.uk/geotraces/cruises/documentation/
b) Submission of data to the GDAC in a timely manner, and no less than two years after the cruise.
c) Permit public access to the data beginning two years after the cruise, with exceptions allowed for parameters that have a long lead time for sample processing.
d) Ensure that the waypoints of the cruise track are included in the cruise report.
Documents of interest:
- Detailed measurements
- GEOTRACES cruises with BioGEOTRACES activities (updated October 2015)
- GEOTRACES Cookbook, including BioGEOTRACES intercalibration protocols