title: Complex responses of intertidal molluscan embryos to a warming and acidifying ocean in the presence of UV radiation.
abstract: Climate change and ocean acidification will expose marine organisms to synchronous multiple stressors, with early life stages being potentially most vulnerable to changing environmental conditions. We simultaneously exposed encapsulated molluscan embryos to three abiotic stressors-acidified conditions, elevated temperate, and solar UV radiation in large outdoor water tables in a multifactorial design. Solar UV radiation was modified with plastic filters, while levels of the other factors reflected IPCC predictions for near-future change. We quantified mortality and the rate of embryonic development for a mid-shore littorinid, Bembicium nanum, and low-shore opisthobranch, Dolabrifera brazieri. Outcomes were consistent for these model species with embryos faring significantly better at 26°C than 22°C. Mortality sharply increased at the lowest temperature (22°C) and lowest pH (7.6) examined, producing a significant interaction. Under these conditions mortality approached 100% for each species, representing a 2- to 4-fold increase in mortality relative to warm (26°C) non-acidified conditions. Predictably, development was more rapid at the highest temperature but this again interacted with acidified conditions. Development was slowed under acidified conditions at the lowest temperature. The presence of UV radiation had minimal impact on the outcomes, only slowing development for the littorinid and not interacting with the other factors. Our findings suggest that a warming ocean, at least to a threshold, may compensate for the effects of decreasing pH for some species. It also appears that stressors will interact in complex and unpredictable ways in a changing climate.
authors: Institute for Conservation Biology and Environmental Management, School of Biological Sciences, University of Wollongong, Wollongong, New South Wales, Australia. adavis@uow.edu.au
authors: Andrew R
authors: AR
authors: Davis
authors: Daniel
authors: D
authors: Coleman
authors: Allison
authors: A
authors: Broad
authors: Maria
authors: M
authors: Byrne
authors: Symon A
authors: SA
authors: Dworjanyn
authors: Rachel
authors: R
authors: Przeslawski
mesh_terms: D000143:Acids / Q000737:chemistry*; D000818:Animals; D057231:Climate Change; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000528:radiation effects*; D004777:Environment; D057232:Global Warming; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008974:Mollusca / Q000196:embryology / Q000528:radiation effects*; D009792:Oceans and Seas; D014466:Ultraviolet Rays
chemical_list: D000143:Acids