Combined effects of climate change stressors and predators with contrasting feeding-digestion strategies on a mussel species

We investigated the combined effects of Ocean Warming (OW), Acidification (OA) and predator cues (Non-Consumptive Effects; NCEs) of two predators with contrasting feeding-digestion strategies on the mussel Peru-mytilus pOuratus. We considered starfish-NCEs (partially external digestion) and snail-NCEs (internal digestion). Mussels were exposed for 13 weeks to cross-factored OA (-500 and-1400 mu atm, pCO2) and OW (-15 and-20 degrees C) conditions, in the presence/absence of NCEs from one or both predators. Mussels exposed to both NCEs exhibited smaller length and buoyant weight growth than those under control or snail-NCEs conditions. Mussels exposed to starfish-NCEs exhibited smaller wet mass than control mussels. OW and starfish-NCEs in isolation or combined with snail-NCEs increased mussel oxygen consumption. Byssal biogenesis was affected by the three-factors interaction. Clearance rates were affected by the OW x OA interaction. We suggest that mainly starfish-NCEs, in isolation or interacting with OA or/and OW, can threat mussel traits and the associated community.