The report from this activity is available for download HERE, and can also be viewed online below.

The oceanographic community has continued to improve comparability of nutrient data from the world's oceans in many ways, including through 3 international inter-laboratory comparison studies since 2003 and the development of nutrient reference materials (RMs). However, adequate comparability and traceability of nutrient data have not yet been achieved.

Certified reference materials, CRMs, for nutrients in seawater that cover wide range of nutrients concentration became available in 2014. IOCCP and Japan Agency for Marine-Earth Science and Technology (JAMSTEC) co-organized an inter-laboratory comparison study of nutrients in seawater using: four lots of recently certified reference materials (CRMs) prepared by KANSO, Japan; three CRMs by National Metrology Institute of Japan; one recently developed reference material (RM) from the Korean Institute of Standards (KIOST), and the silicate stock solution provided by the Royal Netherlands Institute for Sea Research (NIOZ).

A set of samples was distributed to all 71 participating laboratories from 28 countries. Results from 54 participating laboratories were collected as of 30 June 2015 deadline. A few more participants informed the organizers about short delays in data analysis. Detailed results are described in the report.