Mesoscale patterns in barnacle reproduction are mediated by upwelling-driven thermal variability

Abstract

Environmental variables are known to regulate the reproductive output of marine intertidal organisms, but typically these variables are studied as averages and interpreted at a macroscale level. Along 200 km of coast in NW Iberia, great variability in the reproductive activity of the stalked barnacle Pollicipes pollicipes was found among 7 different locations. We found the highest number of broods reported to date in this species and suggest a more realistic method of predicting reproductive success that takes into account sea surface temperature (SST). At these same locations, we studied 13 yr of SST, thermal upwelling index (UI), ground skin temperature and chlorophyll a (chl a) satellite data, using spectral analyses to partition their temporal variability over ecologically relevant time scales. SST played the most relevant role as an environmental driver, explaining 48% of the variability in the proportion of breeding individuals (BI), but the SST-BI goodness-of-fit decreased sharply northwards. Variance-partitioning analyses indicated that cycles between 20 and 100 d in SST and UI were more important southwards, which is consistent with a latitudinal gradient in upwelling intensity and frequency along this coast. Thus, we found better biophysical coupling towards the south, where shorter fluctuation time scales in SST match the gonadal development period (around 1 mo). This pattern may explain the spatial variability in the strength of association between key environmental variables and the reproductive cycle of coastal species along their distribution range.

Influence of maternal effects and temperature on fecundity of Sebastes fasciatus on the Flemish Cap

“…It is important to highlight that S. mentella has a distribution towards more northern and colder waters than S. fasciatus. Reproduction of other aquatic species can also be affected by variability of environmental factors such as sea surface temperature, which plays an important role in regulating brooding activity in crustaceans (Chang et al 2021) and barnacles (Román et al 2022) through the primary productivity.…”

Influence of a changing wave climate on the quality and morphometry of the stalked barnacle Pollicipes pollicipes (Gmelin, 1789), along the coasts of NW Iberia

“…Its life cycle is biphasic, with a planktonic larval stage developing in the coastal ocean through 6 nauplius stages and a cyprid stage before recruiting to the adult habitat back in the rocky intertidal (Molares et al 1994 ). Connectivity between isolated adult populations, as well as their total biomass and reproductive output, is highly dependent larval dispersal and the seasonal variability of the coastal upwelling process (Macho et al 2005 ; Quinteiro et al 2007 ; Campo et al 2010 ; Rivera et al 2013 ; Höfer et al 2017 ; Román et al 2022 ). Barnacles are a highly valued commercial species and are intensively harvested in Morocco, Spain, and Portugal (Boukaici et al 2012 ; Parada et al 2012 ; Sousa et al 2013 ).…”