Assessment of the effects of multiple stressors on the pelagic larvae of VME species

A series of laboratory experiments tested the impacts of climate change (ocean warming, acidification) and human activities (sediment exposure arising from trawling, deep-sea mining, microplastics) on the survival, development and swimming ability of the embryonic, larval and juvenile stages of different cold-water coral (CWC) species and juvenile stages of vent fauna (mussels, gastropods and a commensal worm). Because of the limited information on the early life stages of deep-sea species, for some case studies, e.g. the Azores, embryo and larval development of the respective species were firstly described, before testing their response to increased seawater temperature. For species for which there is already information of their embryo and larval biology, as is the case of Lophelia pertusa (renamed as Desmophyllum pertusum), the approach followed was to test the effects of individual human stressors (sediment exposure, microplastics, and mining particles) and climate change (ocean acidification), and then combine it in multiple stressor experiments. In some cases, where larval stages were not available for experimentation, studies were conducted with juvenile stages of CWCs and vent mussels. The inclusion of juvenile stages increased the scope of the research reported here, by looking at different stages of the life cycle of Vulnerable Marine Ecosystem (VME) indicator species.