Publication Date:
2024-03-15
Description:
Ocean acidification represents a pervasive environmental change that is predicted to affect a wide range of species, yet our understanding of the emergent ecosystem impacts is very limited. Many studies report detrimental effects of acidification on single species in lab studies, especially those with calcareous shells or skeletons. Observational studies using naturally acidified ecosystems have shown profound shifts away from such calcareous species, and there has been an assumption that direct impacts of acidification on sensitive species drive most ecosystem responses. We tested an alternative hypothesis that species interactions attenuate or amplify the direct effects of acidification on individual species. Here, we show that altered competitive dynamics between calcareous species and fleshy seaweeds drive significant ecosystem shifts in acidified conditions. Although calcareous species recruited and grew at similar rates in ambient and low pH conditions during early successional stages, they were rapidly overgrown by fleshy seaweeds later in succession in low pH conditions. The altered competitive dynamics between calcareous species and fleshy seaweeds is probably the combined result of decreased growth rates of calcareous species, increased growth rates of fleshy seaweeds, and/or altered grazing rates. Phase shifts towards ecosystems dominated by fleshy seaweed are common in many marine ecosystems, and our results suggest that changes in the competitive balance between these groups represent a key leverage point through which the physiological responses of individual species to acidification could indirectly lead to profound ecosystem changes in an acidified ocean.
Keywords:
Alkalinity, total; Alkalinity, total, standard deviation; Aragonite saturation state; Aragonite saturation state, standard deviation; Benthos; Bicarbonate ion; Calcite saturation state; Calcite saturation state, standard deviation; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, partial pressure, standard deviation; Category; CO2 vent; Coast and continental shelf; Community composition and diversity; Coverage; Coverage, standard error; Entire community; Field observation; Figure; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Group; Growth/Morphology; Growth rate; Mediterranean Sea; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; pH, standard deviation; Proportion; Proportion, standard error; Rocky-shore community; Salinity; Salinity, standard deviation; Site; Species richness; Species richness, standard error; Temperate; Temperature, water; Temperature, water, standard deviation; Time in weeks; Treatment; Type
Type:
Dataset
Format:
text/tab-separated-values, 1634 data points
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