Using an ensemble of global-scale marine ecosystem and fisheries models   with the CMIP5 ESM ensemble, SROCC concludes that projected ocean warming and decreased phytoplankton production and biomass will reduce global marine animal biomass during the 21st century . The simulated declines  are -3.5 + 4.8% and -14.0 + 14.6% under RCP2.6 and RCP8.5, respectively, by 2080- 2099 relative to 1995-2014 6. Updated Fish-MIP simulations with CMIP6  confirm the projected decline in total marine animal biomass in the 21st century . The simulated
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report