Data from: Living in a high CO2 world: a global meta-analysis shows multiple trait-mediated responses of fish to ocean acidification

Understanding how marine organisms will be affected by global change is of
primary importance to ensure ecosystem functioning and nature
contributions to people. This study meets the call for addressing how
life-history traits mediate effects of ocean acidification on fish. We
built a database of overall and trait-mediated responses of teleost fish
to future CO2 levels by searching the scientific literature. Using a
meta-analytical approach, we investigated the effects of projected CO2
levels by IPCC for 2050-2070 and 2100 on fish eco-physiology and behavior
from 320 contrasts on 42 species, stemming from polar to tropical regions.
Moreover, since organisms may experience a mosaic of carbonate chemistry
in coastal environments (e.g. in estuaries, upwelling zones and intertidal
habitats), which may have higher pCO2 values than open ocean waters, we
assessed responses from additional 103 contrasts on 21 fish species using
pCO2 levels well above IPCC projections. Under mid- and end-of-century CO2
emission scenarios, we found multiple CO2-dose dependent effects on
calcification, resting metabolic rate, yolk, behavioral performances,
along with increased predation risk and decreased foraging, particularly
for larvae. Importantly, many of the traits considered will not confer
fish tolerance to elevated CO2 and far-reaching ecological consequences on
fish population replenishment and community structure will likely occur.
Extreme CO2 levels well above IPCC projections showed effects on fish
mortality and calcification, while growth, metabolism and yolk were
unaffected. CO2 exposures in short-term experiments increased fish
mortality, which in turn decreased in longer-term exposures. Whatever the
elevated CO2 levels considered, some key biological processes (e.g.
reproduction, development, habitat choice) resulted critically
understudied. Fish are an important resource for livelihoods in coastal
communities and a key component for stability of marine ecosystems. Given
the multiple trait-mediated effects evidenced here, we stress the need to
fill the knowledge gap on important eco-physiological processes and to
expand the number and duration of ocean acidification studies to
multi-generational, multiple stressor (e.g. warming, hypoxia, fishing) and
species interactions experiments to better elucidate complex
ecosystem-level changes and how these changes might alter provisioning of
ecosystem services.