Scaling up experimental ocean acidification and warming research: from individuals to the ecosystem

Chair: Victoria Cole

Ana Queirós (1), José Fernandes (1), Sarah Faulwetter (2), Joana Nunes (1), Samuel Rastrick (3, 4), Nova Mieszkowska (5), Yuri Artioli (1), Andrew Yool (6), Piero Calosi (3, 7), Christos Arvanitidis (2) , Helen Findlay (1), Manuel Barange (1), William Cheung (8) and Stephen Widdicombe (1)<o:p></o:p>

1Plymouth Marine Laboratory, PL1 3DH Plymouth, UK
2Hellenic Centre for Marine Research, Heraklion, 710 03 Crete, Greece
3Marine Biology and Ecology Research Centre, Plymouth University, PL4 8AA Plymouth,UK
4 Institute of Marine Research in Norway, Nordnesgaten 50, 5005 Bergen, Norway
5Marine Biological Association of the United Kingdom, PL1 2PB Plymouth, UK
6National Oceanography Centre, SO14 3ZH Southampton, UK
7 Université du Québec à Rimouski, 300 Allée des Ursulines, Rimouski, QC G5L 3A1, Canada
8Fisheries Centre, University of British Columbia, V6T 1Z4 Vancouver, Canada

Background
Understanding long-term, ecosystem-level impacts of climate change is challenging because experimental research frequently focuses on short-term, individual-level impacts in isolation.<o:p></o:p>

Methods
We address this shortcoming first through an inter-disciplinary ensemble of novel experimental techniques to investigate the impacts of 14-month exposure to ocean acidification and warming (OAW) on the physiology, activity, predatory behaviour and susceptibility to predation of an important marine gastropod (Nucella lapillus). We simultaneously estimated the potential impacts of these global drivers on N. lapillus population dynamics and dispersal parameters. We then used these data to parameterise a dynamic bioclimatic envelope model, to investigate the consequences of OAW on the distribution of the species in the wider NE Atlantic region by 2100. The model accounts also for changes in the distribution of resources, suitable habitat and environment simulated by finely resolved biogeochemical models, under three IPCC global emissions scenarios.

Findings
Experiments showed that temperature had the greatest impact on individual-level responses, while acidification has a similarly important role in the mediation of predatory behaviour and susceptibility to predators. Changes in Nucella predatory behaviour appeared to serve as a strategy to mitigate individual-level impacts of acidification, but the development of this response may be limited in the presence of predators. The model projected significant large-scale changes in the distribution of Nucella by the year 2100 that were exacerbated by rising greenhouse gas emissions. These changes were spatially heterogeneous, as the impact of OAW on the combination of responses considered by the model varied depending on local environmental conditions and resource availability.<o:p></o:p>

Conclusions
Changes in macro-scale distributions cannot be predicted by investigating individual level impacts in isolation, or by considering climate stressors separately. Scaling up the results of experimental climate change research requires approaches that account for long-term, multi-scale responses to multiple stressors, in an ecosystem context.<o:p></o:p>