A5. Since about 1950 many marine species across various groups have undergone shifts in geographical range and
seasonal activities in response to ocean warming, sea ice change and biogeochemical changes, such as oxygen loss, to
their habitats (high confidence). This has resulted in shifts in species composition, abundance and biomass production of
ecosystems, from the equator to the poles. Altered interactions between species have caused cascading impacts on
ecosystem structure and functioning (medium confidence). In some marine ecosystems species are impacted by both the
effects of fishing and climate changes (medium confidence). {3.2.3, 3.2.4, Box 3.4, 5.2.3, 5.3, 5.4.1, Figure SPM.2} Continue reading →