ALBERT

Description: 〈p〉Publication date: 20 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Science of The Total Environment, Volume 697〈/p〉 〈p〉Author(s): Alessandra Gallo, Raffaele Boni, Maria Cristina Buia, Vincenzo Monfrecola, Maria Consiglia Esposito, Elisabetta Tosti〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Rising atmospheric CO〈sub〉2〈/sub〉 is causing a progressive decrease of seawater pH, termed ocean acidification. Predicting its impact on marine invertebrate reproduction is essential to anticipate the consequences of future climate change on species fitness and survival. Ocean acidification may affect reproductive success either in terms of gamete or progeny quality threating species survival. Despite an increasing number of studies focusing on the effects of ocean acidification on the early life history of marine organisms, very few have investigated the effects on invertebrate gamete quality. In this study, we set up two experimental approaches simulating the ocean conditions predicted for the end of this century, 〈em〉in situ〈/em〉 transplant experiments at a naturally acidified volcanic vent area along the Ischia island coast and microcosm experiments, to evaluate the short-term effects of the predicted near-future levels of ocean acidification on sperm quality of the ascidian 〈em〉Ciona robusta〈/em〉 after parental exposure. In the first days of exposure to acidified conditions, we detected alteration of sperm motility, morphology and physiology, followed by a rapid recovery of physiological conditions that provide a new evidence of resilience of ascidian spermatozoa in response to ocean acidification. Overall, the short-term tolerance to adverse conditions opens a new scenario on the marine species capacity to continue to reproduce and persist in changing oceans.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Sperm sensitivity assessment in 〈em〉Ciona robusta〈/em〉 after short-term acidified seawater exposure by setting up two experimental approaches: 〈em〉in situ〈/em〉 transplant and microcosm. In the former, animals in cages were exposed to natural CO〈sub〉2〈/sub〉 vent emissions at Castello Aragonese (Island of Ischia, Gulf of Naples); in microcosm experiments seawater was acidified by means of a bubbling system suppling CO2 gas. After parental exposure, spermatozoa were collected from sperm duct. Different sperm quality parameters, as concentration, motility, fertilizing ability, reactive oxygen species, mitochondrial activity, intracellular pH, viability, lipid peroxidation, morphology, were evaluated by means of counting chamber, 〈em〉in vitro〈/em〉 fertilization, spectrofluorimetry and electron microscopy.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S004896971934077X-ga1.jpg" width="256" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉