Meeting Abstract
Early life stages of marine organisms are predicted to be vulnerable to ocean acidification. For many macroalgae, reproduction and population persistence rely on spores to settle, adhere and continue the algal life cycle, yet the effect of ocean acidification on this critical life stage has been largely overlooked. We explicitly tested the biomechanical impact of reduced pH on early spore adhesion. At the University of Washington’s Friday Harbor Laboratories Ocean Acidification Environmental Laboratory, we developed a shear flume to examine the effect of reduced pH on spore attachment time and strength on two intertidal rhodophyte macroalgae, one calcified (Corallina vancouveriensis) and one non-calcified (Pterosiphonia bipinnata). We found that reduced pH delayed spore attachment of both species and also weakened attachment strength in C. vancouveriensis, but had no effect on the attachment strength of P. bipinnata. Our results demonstrate that ocean acidification negatively impacts spore adhesion in two macroalgae, and this may negatively affect macroalgal communities via loss of spore function and viability, regardless of the physiological tolerance of mature thalli.
