This document presents a preliminary assessment of CMIP6 models focusing on projected climate change impact on primary production in the Southern Indian Ocean.
• At the Southern Indian Ocean basin-scale, primary productivity is projected to increase in response to climate change (between 5% and 10% by 2081-2100 with respect to 1995-2014 under the current "modest mitigation" scenario SSP2-4.5);
• Increase south of 40°S is spatially heterogeneous, being twice as strong near the Antarctic continent ([60,70]S) with respect to mid-latitudes ([40,60]S);
• Primary production trends are similar for mitigation scenarios SSP-4.5 ("modest mitigation") and SSP1-2.6 ("high mitigation"), but they diverge on the long term (end of century).
• Essential to more effective and future-proof conservation is (i) a better understanding of trophic relations (in particular intermediate levels), (ii) the maintaining of long term (multidecadal) ecological observing systems and (iii) the development of regional ecological climate change modelling tools.