This paper has some information: http://www.pnas.org/content/115/25/6506 http://www.pnas.org/content/115/25/6506 (see "The Distribution of Biomass Across Enviro

This paper has some information: http://www.pnas.org/content/115/25/6506 http://www.pnas.org/content/115/25/6506 (see "The Distribution of Biomass Across Environments and Trophic Modes"). They divide biomass up into three environments, with 6 Gt C in "marine", 70 Gt C in "deep subsurface" and 470 Gt C in "terrestrial". You can also see in their analysis that the huge biomass bias towards the land is due to plants and fungi, which overwhelmingly favour the land; among animals there is actually more biomass in the oceans.