Effects of salinity on growth and survival of Cymodocea nodosa (Ucria) Ascherson and Zostera noltii Hornemann

The aim of the present study was to examine the effects of salinity on growth and survival of Cymodocea nodosa (Ucria) Ascherson and Zostera noltii Hornemann. Leaf growth and survival responses to salinity were characterized by several short-term experiments under controlled conditions. For each experiment, ten marked shoots were placed in plastic aquariums of 5 l and were exposed to different salinity treatments (ranging from 2 to 72 PSU). Growth and survival of both species were significantly affected by salinity. Under these laboratory conditions it has been detected that Zostera noltii tolerates hyposalinity conditions better than Cymodocea nodosa, but both species were very sensitive to salinity increases (> 41 PSU), what suggests that these seagrasses could be adversely affected by brine discharges from seawater desalination plants.