'Changes to sea temperature have altered the phenology, or timing of key life-history events such as plankton blooms, and migratory patterns, and spawning in fish and invertebrates, over recent decades . There is medium to high agreement that these changes pose significant uncertainties and risks to fisheries, aquaculture and other coastal activities.' The highly productive high-latitude spring bloom systems in the northeast Atlantic are responding to warming , with the greatest changes being observed since the late 1970s in the phenology, distribution and abundance of plankton assemblages, and the reorganisation of fish assemblages, with a range of consequences for fisheries . 'Observed changes in the phenology of plankton groups in the North Sea over the past 50 years are driven by climate forcing, in particular regional warming .' 'On average, spring events in the ocean have advanced by 4.4 + 0.7 days per decade .' 'Shifts in the timing and magnitude of seasonal biomass production could disrupt matched phenologies in the food webs, leading to decreased survival of dependent species . If the timing of primary and secondary production is no longer matched to the timing of spawning or egg release, survival could be impacted, with cascading implications to higher trophic levels. This impact would be exacerbated if shifts in timing occur rapidly .' 'There is medium to high confidence that climate-induced disruptions in the synchrony between timing of spawning and hatching of some fish and shellfish and the seasonal increases in prey availability can result in increased larval or juvenile mortality or changes in the condition factor of fish and shellfish species in the Arctic marine ecosystems.'
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report