The aim of this study was (1) to provide the first experimental evidence on the effect of pollution on Cystoseira spp. survival and fitness in Mediterranean coastal waters, and (2) to test if Cystoseira populations were able to recover in areas where management actions addressed to ameliorate seawater quality had been established.
Site Selection Criteria:
Three different environmental situations were selected, a control area (low to no pollution), a slightly polluted area, and a heavily polluted area. The first two sites had Cystoseira species still present, while in the heavily polluted area Cystoseira was absent but had been documented in the past. The disappearance of Cystoseira had been documented in both polluted areas.
Cause Of Decline:
Algae of the genus Cystoseira (Fucales, Heterokontophyta) are amongst the most important habitat-forming species in Mediterranean shallow waters, and are currently experiencing a severe decline in many Mediterranean regions. Observational studies have generally suggested pollution as the main factor influencing the disappearance of Cystoseira spp. The disappearance of populations is of particular concern when the species involved are long-lived and/or habitat engineers. This is the case of the algae of the orders Fucales and Laminariales whose losses cause strong shifts in abundance and diversity of associated flora and fauna. Furthermore, these habitat-forming algae take a long time to recover when water quality improves.
Pollution impacts and recovery potential in three species of the genus Cystoseira (Fucales, Heterokontophyta
Estuarine Coastal and Shelf Science, Vol. 92.https://doi.org/10.1016/j.ecss.2011.01.008