Can anthropogenic forcing shape ascidian invasive potential in a warming ocean?

REPOLHO TIAGO; CLUTTON ELIZABETH; ALURRALDE GASTÓN

Puerto Madryn

Conferencia; X International Conference on Marine Bioinvasions.; 2018

High alleged levels of pollutants in anthropogenically-modified marine environments may exert high pressure on maximum physiological responses of sessile organisms acting as powerful agents of selection. Thus, local adaptation or acclimation capacity play an important evolutionary role by enabling or conditioning species tolerance to stressful environmental conditions. Temperature modulates marine ectotherms physiology, influencing survival,abundance and distribution of sessile organisms. While native species could be susceptible to ocean warming, thermal tolerance might favour the spread of non-native species. We studied the effect of a simulated heat wave on the developmental performance of Ciona intestinalis early life stages (ELS), derived from populations of anthropogenically modified and undisturbed environments. The fertilization rate, embryo and larvae development, settlement and metamorphosis success, and juvenile heart beat rate were assessed as experimental endpoints. Excepting fertilization and heart beat rates, temperature affected all analysed endpoints. Ciona intestinalis ELS derived from undisturbed sites were the mostnegatively affected by increased temperature conditions. Opposingly, populations from anthropogenically modified sites showed an overall positive response to thermal stress. Interaction between temperature and population origin (i.e. anthropogenically modified or undisturbed), was statistically significant for embryo and larvae development, and metamorphosis. For anthropogenically modified sites, a higher proportion of larvae development and settlement and metamorphosis success were observed under increased temperature conditions. No differences were observed for heart beat rates between sampled populations and experimental temperature conditions. We propose that selection resultingfrom anthropogenic forcing could shape stress resilience of species in their native range and subsequently confer them advantageous traits for invasion