Here we investigated whether the decreasing annual productivity (i.e. larval abundances) of Baltic Sea herring over the last decade is linked to warmer springs exceeding the physiological optimum of early life stages. Linking physiological thermal tolerance and recruitment indexes from the field, we found that warming is at least partially responsible for the steady decline in recruitment.
The stability of marine fish populations is, next to natural or fishing mortality, based on the annual recruitment of the young-of-the-year. The variability in the number of these recruited fish is determined by effects of several abiotic and biotic …
Climate change will reduce the salinity in the Baltic Sea to levels that marine fish species may not be able to tolerate. We acutely exposed Atlantic herring larvae from different Baltic Sea populations to low salinities, and modelled the survival threshold now, and for salinity projections at the end of the 21st century. Climate-driven freshening will make some Baltic habitats unsuitable for larvae.