Growth response of the barnacle Balanus improvisus and the bryozoan Electra pilosa from Kiel Fjord to biogenic pH fluctuations and global ocean acidification scenarios ...

• Main Authors: Johnson, Mildred Jessica, Hennigs, Laura Margarethe, Pansch, Christian, Wall, Marlene
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: PANGAEA 2020
• Subjects: fluctuations; growth; Ocean acidification; pH
• Online Access: https://dx.doi.org/10.1594/pangaea.917864; https://doi.pangaea.de/10.1594/PANGAEA.917864

We investigated the effect of pH fluctuations, generated by the brown alga Fucus serratus' biological activity, on the calcifying epibionts Balanus improvisus and Electra pilosa in two temperatures (10 °C and 15 °C) and under ocean acidification (OA). For this, epibionts were grown on inactive (Plexiglas) and biologically active (F. serratus) surfaces and exposed to (i) constant pH scenarios under ambient (pH 8.1) or OA conditions (pH 7.7), or (ii) oscillating pH scenarios mimicking benthic boundary layer conditions at ambient (pH 7.7-8.6) or OA conditions (pH 7.4-8.2). The initial size of barnacles (diameter of basal plate) was determined for ~50 randomly chosen individuals on Plexiglas and algal surfaces by analysing pictures taken under the microscope one day prior to the start of the experiment, using ImageJ. The resulting start sizes were 0.72 ± 0.09 mm on Plexiglass and 0.70 ± 0.09 mm on algal surfaces, respectively. Final sizes of B. improvisus were determined from pictures taken at the end of the ...