Potential consequences for species distribution, abundances and diversity and their imprint in food chains and ecosystems call for more studies of the short and long term impacts of ocean acidification. Bryozoans have been overlooked in this respect even though they play an important role in benthic temperate ecosystems. Flustra foliacea colonies from the North and Baltic Seas were used to assess morphology, growth rates, wall structure and preservation aiming to build up a baseline to use this species as a ‘sentinel’ of acidification levels. Though no significant differences in mean zooid size among the studied basins were found, North Sea colonies show periodic oscillations across generations in mean frontal area index and zooid density. Preliminary geochemistry analyzes show: (1) similar carbon contents (TC, TIC, TOC) in both basins; (2) skeletal walls composed of IMC; (3) over 50% weight loss in dissolution experiments during the first hour. A winter growth stop marked by growth-check lines is postulated. Experimental data are needed to calibrate results and assess collections done over the last 200 years.
Fortunato H., Schäfer P. & Blaschek H., 2012. Growth rates, age determination and calcification levels in Flustra foliacea (L.) (Bryozoa: Cheilostomata): preliminary assessment – Morphology, growth and calcification levels in Flustra foliacea (L.). In: Ernst A., Schäfer P. & Scholz J. (Eds.), Bryozoan Studies 2010, Lecture Notes in Earth System Sciences 143, pp: 59-73. Berlin Heidelberg: Springer Verlag. Book chapter.