Highlights
- Elevated pCO2 influences growth and chemical composition of some intertidal algae.
- Herbivore preference is reinforced by resilience of preferred alga to pCO2 exposure.
- Preference is also influenced by changes in lesser-preferred algal species.
- Specialist and generalist feeding may be indirectly affected by ocean acidification.
Abstract
Ocean acidification (OA) can induce changes in marine organisms and species interactions. We examined OA effects on intertidal macroalgal growth, palatability, and consumption by a specialist crab (Pugettia producta) and a generalist snail (Tegula funebralis) herbivore. Moderate increases in pCO2 increased algal growth in most species, but effects of pCO2 on C:N and phenolic content varied by species. Elevated pCO2 had no effect on algal acceptability to herbivores, but did affect their preference ranks. Under elevated pCO2, electivity for a preferred kelp (Egregia menziesii) and preference rankings among algal species strengthened for both P. producta and T. funebralis, attributable to resilience of E. menziesii in elevated pCO2 and to changes in palatability among less-preferred species. Preferred algae may therefore grow more under moderate pCO2 increases in the future, but their appeal to herbivores may be strengthened by associated shifts in nutritional quality and defensive compounds in other species.
Fieber A. M. & Bourdeau P. E., 2021. Elevated pCO2 reinforces preference among intertidal algae in both a specialist and generalist herbivore. Marine Pollution Bulletin 168: 112377. doi: 10.1016/j.marpolbul.2021.112377. Article.
