The unexpected species richness of Arctic rhodolith beds

Pyko I, Wisshak M, Knebelsberger T, Halfar J, Hetzinger S, Teichert S (2023)

Publication Language: English

Publication Type: Conference contribution, Abstract of lecture

Publication year: 2023

Event location: Reykjavik


Rhodolith beds are an important benthic habitat created by so-called ecosystem engineers. Rhodoliths are free-living, photoautotrophic structures of calcium carbonate (CaCO3) formed by different species of crustose coralline algae (CCA). This particular group of red algae precipitate CaCO3 within their cell walls to form a stable skeleton and next to rhodoliths, they also form crusts of varying thickness on fixed substrates. The shelfs around the high Arctic Svalbard archipelago (Norway) are intensely covered by such rhodolith beds and cm-thick crusts of CCA in shallow waters. The beds occur in water depths of about 10 to 50 m and the algae can live for more than 100 years.

Quantitative biodiversity analyses of samples collected by dredge and manned submersible indicate that rhodolith beds form coral reef like structures at higher latitudes and thus represent an important ecological resource. However, research methods outlined above only allow for a snapshot on biodiversity with a focus on the benthic fauna associated with rhodoliths. Furthermore, there are no studies in relation to biodiversity and the CCA crusts.

We performed a multi-marker eDNA metabarcoding survey (COX1, rbCL, 16S, ITS) to assess the entire spectrum of potentially occurring species within the Arctic rhodolith beds as well as within the CCA crusts. First results indicate about 650 potentially occurring different taxa (species and genus level).

This survey is a step forward in order to estimate the impact of CCA on Svalbard’s shelf biodiversity and provides a background for their inclusion in future policy recommendations and strategic plans for biodiversity conservation.

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Pyko, I., Wisshak, M., Knebelsberger, T., Halfar, J., Hetzinger, S., & Teichert, S. (2023). The unexpected species richness of Arctic rhodolith beds. Paper presentation at 56. European Marine Biology Symposium, Reykjavik.


Pyko, Ines, et al. "The unexpected species richness of Arctic rhodolith beds." Presented at 56. European Marine Biology Symposium, Reykjavik 2023.

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