Black rockfish otolith and early life history data

Understanding how future ocean conditions will affect populations of
marine species is integral to predicting how climate change will impact
both ecosystem function and fisheries management. Fish population dynamics
are driven by variable survival of the early life stages, which are highly
sensitive to environmental conditions. As global warming generates extreme
ocean conditions (i.e., marine heatwaves) we can gain insight into how
larval fish growth and mortality will change in warmer conditions. The
California Current Large Marine Ecosystem experienced anomalous ocean
warming from 2014-2016, creating novel conditions. We examined the otolith
microstructure of juveniles of the economically and ecologically important
species black rockfish (Sebastes melanops) collected from 2013-2019 to
quantify the implications of changing ocean conditions on early growth and
survival. Our results demonstrated that fish growth and development were
positively related to temperature, but survival to settlement was not
directly related to ocean conditions. Instead, settlement had a
dome-shaped relationship with growth, suggesting an optimal growth window.
Our results demonstrated that the dramatic change in water temperature
caused by such extreme warm water anomalies increased black rockfish
growth in the larval stage; however, without sufficient prey or with high
predator abundance these extreme conditions contributed to reduced
survival.