Pollution impacts and recovery potential in three species of the genus Cystoseira (Fucales, Heterokontophyta)

Macroalgae of the genus Cystoseira are experiencing substantial decline in the Mediterranean Sea, which has been generally attributed to increased pollution. A field experiment was conducted to examine the effects of pollution in three Cystoseira species and to study the recovery potential of Cystoseira populations after water quality improvement. Cystoseira specimens were transplanted from a non-polluted area to two areas displaying different levels of pollution, where the disappearance of Cystoseira stands had been documented. Reduced survival and growth of specimens at the highly polluted area suggested that the disappearance of Cystoseira stands was due to heavy metal pollution. Meanwhile, the healthy state exhibited by specimens transplanted to the slightly polluted area, especially by Cystoseira barbata, indicated that the current water quality in this area was good enough for the recovery of Cystoseira populations. The method used to transplant Cystoseira specimens is suggested as a tool for restoring extinct populations.

► Effects of pollution and recovery capacity of Cystoseira species are assessed.
► Heavy metal pollution has negative effects on survival and growth of Cystoseira spp.
► Cystoseira spp. survive in an ameliorated area from where they had disappeared.
► Transplantation of adults is suggested as a tool for restoring extinct populations.