Substrate limitation of a habitat-forming genus Fucus under different water clarity scenarios in the northern Baltic Sea

Substrate limitation significantly restricts the potential distribution of bladderwrack (Fucus spp.), a key habitat-forming macroalga, under varying water clarity scenarios in the northern Baltic Sea. Research reveals that while increased euphotic depth—light penetration—could expand Fucus distribution by up to 803% if all substrates were suitable, actual expansion is limited to 9–270% due to a lack of hard rocky bottoms. Conversely, a 50% decrease in water transparency narrows its range by 24–100%, depending on the region. The study used species distribution modeling and two correction methods—field data from underwater videos and a habitat model—to quantify substrate limitation without comprehensive bottom maps. These findings underscore the need to integrate substrate availability into environmental management strategies for UNESCO World Heritage Sites like High Coast/Kvarken Archipelago, balancing local measures for cost-effective conservation outcomes.

Lappalainen, J., Virtanen, E. A., Kallio, K., Junttila, S., & Viitasalo, M. (2019). Substrate limitation of a habitat-forming genus Fucus under different water clarity scenarios in the northern Baltic Sea. Estuarine, Coastal and Shelf Science, 218, 31–38. https://doi.org/10.1016/j.ecss.2018.11.010