“…Significant progress has been made in this regard by fifteen years' worth of work in the Southern Ocean (Varela et al, 2004;Cardinal et al, 2005;De La Rocha et al, 2011;Fripiat et al, 2011), in the North, Equatorial and South Pacific (De La Rocha et al, 2000;Reynolds et al, 2006;Beucher et al, 2008Beucher et al, , 2011de Souza et al, 2012a), and recently in the Arctic Ocean (Varela et al, 2016), in conjunction with various models (De La Rocha and Bickle, 2005;Reynolds, 2009;Coffineau et al, 2014), not the least of which are global circulation models (Wischmeyer et al, 2003;de Souza et al, 2014de Souza et al, , 2015Holzer and Brzezinski, 2015). It is now widely understood that fractionation of silicon isotopes during uptake and biomineralization of silica in surface waters increasingly elevates the δ 30 Si DSi in surface waters (De La Rocha et al, 1997;Sutton et al, 2013).…”