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Helgoland Marine Research

Open Access

The seaweedGracilaria confervoides, an important object for autecologic and cultivation research in the northern Adriatic Sea

  • G. Simonetti1,
  • G. Giaccone1 and
  • S. Pignatti1
Helgoländer wissenschaftliche Meeresuntersuchungen20:BF01609890


1. The seaweedGracilaria confervoides Grev. is the only source of agar extraction in Italy. Large populations are present in the coastal lagoons of the Northern Adriatic Sea. In these habitats (e. g. Bay of Goro near Ferrara) periodical recordings were made during 1968 and 1969 of temperature, salinity, micronutrients, light intensity and O2 concentration.

2. The lagoon bays offer the best condition for the development ofGracilaria confervoides populations, especially near places of fresh water inflow containing large amounts of nutrients. Fresh water inflow also limits critical temperature rise during summer.

3. The natural habitat is shallow (average depth: 1 m); since the bottom is muddy, the water is very turbid and the light intensity significantly reduced.

4.Gracilaria confervoides lies unanchored on the mud in the vegetative sterile form in long densely branched threads, while the spores settle on shells.

5. In view of the industrial importance of this alga, we have established an experimental cultivation field in a lagoon fishing resort in order to assess the influence of various ecological factors. This study was made from 1968 through 1969 together with productivity tests (photosynthesis rates and biomass measurements).


FishingCritical TemperatureCoastal LagoonPhotosynthesis RateCultivation Research