Impacts of climate change on fish, relevant to the coastal and marine environment around the UK.

• Main Authors: Wright, Peter, Pinnegar, John K., Fox, Clive
• Format: Book
• Language: English
• Published: MCCIP 2020
• Subjects: atlantic cod; Ocean acidification
• Online Access: https://pure.uhi.ac.uk/en/publications/3f5bd7ac-7a5e-430f-974c-faf1dbf3fdf1; https://doi.org/10.14465/2020.arc16.fsh; https://pureadmin.uhi.ac.uk/ws/files/8166064/16_fish_2020.pdf

The appearance of warm-water (Lusitanian) fish species in UK waters along with local declines of some cold-affinity species provides the most compelling evidence of a climate-change effect. • Distinguishing between climate-induced effects on fish distribution and other drivers is a key challenge. Some past studies have not accounted for geographic attachment and population structure in studies of distributional shifts in species including Atlantic cod and mackerel. • The synchrony between winter–spring hatching fish larvae (e.g. cod, sole, sandeel) and their plankton prey appears to be changing, with consequences for recruitment. These changes reflect both changes in the timing of fish reproduction as well as that of their plankton prey. • Temperature changes are affecting fish growth and age at maturation. Rising temperatures also decrease oxygen solubility and increase metabolic costs and there is now considerable debate as to whether this is limiting the maximum size that fish species can attain. • Fin-fish larvae may be sensitive to expected changes in ocean acidification, but species have shown a variety of responses in experiments. For example, the use of end-of-century CO2 concentration under the IPCC RCP 8.5 scenario resulted in a doubling of daily mortality rates in Atlantic cod larvae, but only had a minor effect on European seabass and herring larvae. Advances in both statistical and mechanistic models have increased our ability to provide future projections for climate change impacts on fish. Scientists have started to provide ‘forecasts’ for some species at the seasonal to decadal time horizon, but there have been insufficient runs to yet be confident in these projections.