Characteristics of positive parental effects under exposure to climate change in marine invertebrates

Due to the rapid rate of climate change, aquatic species might acclimate via phenotypic plasticity as a first defense. Parental effects, where the phenotype of an individual depends on the environment of its parents, could play an important role in driving population responses to climate change. Furthermore, characteristics of the species and stress exposure could be important for determining the outcome of this plasticity. Using a meta-analysis approach, we investigated the role of parental effects in allowing marine invertebrate species to cope with climate change. We summarized 107 fully-factorial sets of comparisons from 23 peer-reviewed papers that assessed how exposing parents to ambient or stressful conditions influenced responses of offspring exposed to ambient or stressful conditions. We calculated effect sizes (Hedges’ g) for these four contexts of ancestral-progeny experimental environments and collected life history information from the literature for the 20 species included in our study. We conducted subgroup analyses and meta-regressions to assess important characteristics leading to significant parental effects. We found that the level of environmental predictability between parents and offspring determined whether offspring performed better when their parents had also been exposed to stressful conditions representative of climate change. These observed parental effects were significant for species exposed to elevated CO₂ levels that were subtidal, sessile as adults, and had non-feeding larvae (i.e., recruit relatively locally). Understanding links between life stages, including characteristics associated with the strongest links, will aid in evaluating whether adults are likely to prime their offspring for future climates.