Natural acidification changes the timing and rate of succession, alters community structure, and increases homogeneity in marine biofouling communities. (11th September 2017)

• Record Type: Journal Article
• Authors: Brown, Norah E. M.; Milazzo, Marco; Rastrick, Samuel P. S.; Hall‐Spencer, Jason M.; Therriault, Thomas W.; Harley, Christopher D. G.
• Is Part Of: Global change biology. Volume 24:Number 1(2018)
• Page Start: e112
• Page End: e127
• Publication Date: 2017-09-11
• Subjects: climate change -- community -- marine biodiversity -- natural analogue -- Ocean acidification; Climatic changes -- Environmental aspects -- Periodicals; Troposphere -- Environmental aspects -- Periodicals; Biodiversity conservation -- Periodicals; Eutrophication -- Periodicals; 551.5
• DOI: 10.1111/gcb.13856
• Languages: English
• ISSNs: 1354-1013

Abstract

Abstract: Ocean acidification may have far‐reaching consequences for marine community and ecosystem dynamics, but its full impacts remain poorly understood due to the difficulty of manipulating p CO2 at the ecosystem level to mimic realistic fluctuations that occur on a number of different timescales. It is especially unclear how quickly communities at various stages of development respond to intermediate‐scale p CO2 change and, if high p CO2 is relieved mid‐succession, whether past acidification effects persist, are reversed by alleviation of p CO2 stress, or are worsened by departures from prior high p CO2 conditions to which organisms had acclimatized. Here, we used reciprocal transplant experiments along a shallow water volcanic p CO2 gradient to assess the importance of the timing and duration of high p CO2 exposure (i.e., discrete events at different stages of successional development vs. continuous exposure) on patterns of colonization and succession in a benthic fouling community. We show that succession at the acidified site was initially delayed (less community change by 8 weeks) but then caught up over the next 4 weeks. These changes in succession led to homogenization of communities maintained in or transplanted to acidified conditions, and altered community structure in ways that reflected both short‐ and longer‐term acidification history. These community shifts are likely a result of interspecific variability in response to increased p CO2 and changes in species interactions. High p CO2 altered biofilm development, allowing serpulids to do best at the acidified site by the end of the experiment, although early (pretransplant) negative effects of p CO2 on recruitment of these worms were still detectable. The ascidians Diplosoma sp. and Botryllus sp. settled later and were more tolerant to acidification. Overall, transient and persistent acidification‐driven changes in the biofouling community, via both past and more recent exposure, could have important implications for ecosystem function and food web dynamics. Abstract : Rising carbon dioxide concentrations are rapidly altering the carbonate chemistry of the oceans. Here, we used reciprocal transplant experiments along a natural shallow water volcanic p CO2 gradient to assess the importance of the timing of high p CO2 exposure on patterns of succession in a benthic fouling community. Our work highlights how historical contingency and species interactions can shape community structure and succession in light of p CO2 heterogeneity at a variety of temporal scales.