Jane Weinstock1,2, Jesús Pineda1, Claudio DiBacco3, Salvatore Genovese4, Victoria Starczak1, Kira Krumhansl3
1Woods Hole Oceanographic Institution, USA - 2Massachusetts Institute of Technology, USA - 3Fisheries and Oceans Canada, Canada - 4Boston University, USA
The timing of reproduction can substantially impact the conditions that released larvae experience, affecting larval development and mortality, larval dispersal, and population connectivity. Often, local temperature is critical in mediating invertebrate reproduction timing and, importantly, it can separately impact distinct reproductive processes (e.g., oogenesis, copulation, embryonic development and larval release), making inference about the effects of warming on “reproduction” timing complex. Here, we measured the influence of intertidal temperature on reproduction timing of the boreal barnacle Semibalanus balanoides, specifically quantifying: 1) the seasonal timing of fertilization of embryos, 2) the duration of embryonic brooding, and 3) the timing of larval release. We measured these processes at up to eight sites along a steep temperature gradient along the northwest Atlantic, to assess spatial/latitudinal patterns of temperature and reproduction. At four sites, we also compared reproduction timing between historical/cold years (2002-04) and modern/warm years (2019-24), to assess shifts in reproduction timing with warming. We found some evidence of warming-induced delays to fall fertilization, in line with phenology shifts observed in other taxa. More striking, we found that intertidal temperature explained regional differences in brooding duration and larval release timing, resulting in lower latitude/warmer populations releasing larvae up to 95 days earlier than higher latitude/colder populations. These differences in larval release timing may lead to consistent, regional differences in dispersal that run counter to theoretical expectations based purely on average surface water temperatures, indicating that local temperatures experienced during brooding may have outsized impacts on regional connectivity.
Biography
Jane Weinstock studies how environmental factors impact the timing and success of life history events, and how these in turn affect marine invertebrate larval dispersal and population connectivity. She is currently a Postdoctoral Investigator at the Woods Hole Oceanographic Institution, studying these processes in intertidal barnacles using timeseries measurements of local populations, satellite observations of surface temperatures and currents, and population genomics of both adults and larvae.