Important structural species

Species that create habitat for many other organisms, like Cystoseira, are key for the stability of the ecosystems. Moreover, as primary producers, they are at the base of the trophic pyramid. Loss of Cystoseira leads to a decrease in biodiversity and productivity resulting insignificant changes in the processes that maintain rocky benthic ecosystems.

Low success of natural restoration

Once a Cystoseira population disappears from an area, it is hard for the population to be naturally restored. Actually, most of the remaining threatened populations are isolated, preventing the natural restoration from neighboring areas.

Vulnerability to human threats

Most Cystoseira species are very sensitive to human perturba-tions such as habitat loss, eutrophication, pollution, climate change, and the invasion by alien species. Overgrazing by sea urchins due to modifications in trophic interactions by fishing may also result in decline of Cystoseira populations.

Habitat loss is the most serious threat to Cystoseira today. Coastal development and construction, among other human actions are proved to directly destroy Cystoseira habitats, or indirectly change the proper environmental conditions for their persistence.

Eutrophication and other kinds of pollution: Urban waste and the runoff of fertilizers and other chemicals into coastal waters have a harmful effect not only on adult survival, but also on fertilization and juvenile survivorship.