Damage and partial mortality of the gorgonian Paramuricea clavata in the Strait of Messina (Tyrrhenian Sea)

A massive development of mucilage and a case of partial mortality in the Mediterranean gorgonian Paramuricea clavata is reported..

Production of the meiobentic harpacticoid copepod Canuella perplexa

Secondary production of the meiobenthic harpacticoid Canuella perplexa was estimated in a brackish water lagoon of the Po river delta from 1978 to 1979. The population was sampled approximately fortnightly with 3 replicate cores at a central, subtidal station. Three generation peaks and a nonreproductive overwintering population were observed

Ecological and zoogeographical study of some Mediterranean associations of brackish water harpacticoids.

Original lists of harpacticoid species both of five Italian lagoons and of five Mediterranean and Pontic brackish environments were submitted to cluster analysis..

Effects of a mucilage event on the Mediterranean gorgonian Paramuricea clavata. II - Population recovery after two years.

A population of the Mediterranean gorgonian Paramuricea clavata was heavily damaged by a mucilage coverage of colonies at the end of summer 1993, and suffered relatively high mortality. Gorgonian population structure before (summer 1992) and two years after (summer 1995) the mucilage event was compared in order to assess the recovery of the population. Despite gorgonian mean density being practically identical on both dates, suggesting that the local population had fully recoveres its effectives, the demographic structure of the P. clavata population showed changes from one sampling date to the other. The most striking effect of disturbance due to mucilage was the rejuvenation of the population: in 1995, juveniles constituted 26.1% of the population, while in 1992 they were only 4.2%

Growth of the Mediterranean gorgonian Lophogorgia ceratophyta (L. 1758).

Growth of the gorgonian Lophogorgia ceratophyta was investigated in an infralittoral station located in La Spezia Gulf, Ligurian Sea. Mean annual height growth rate was estimated to be 2.57 cm a. The fractal dimension of the colonies was found to gradually evolve in complexity

Drilling platforms as artificial reefs: Distribution of macrobenthic assemblages of the "Paguro" wreck (northern Adriatic Sea)

Offshore drilling raises the issue of disposal of platforms at the end of their productive cycle and re-use as artificial reefs has been proposed. The wreck of the "Paguro" drilling platform, which sank in the northern Adriatic Sea in 1965, offers the opportunity to study the performance of offshore structures as artificial reefs in a region where this solution has not been explored before. We provide a description of the macrobenthic assemblages present at the wreck at different sites and at different depths, based on destructive and photographic sampling. Results show that the wreck has been colonized by a rich and diversified fauna. Primary space has been dominated by mussels and oysters, which provide suitable habitats for a variety of benthic invertebrates. Assemblages vary among sites, species richness is greatest at those sites facing prevailing currents. Distribution patterns vary vertically, evenness (Hill's N10) decreasing significantly with depth. It is argued that the results contribute to the background knowledge required in rigs-to-reefs programmes. \ua9 2002 International Council for the Exploration of the Sea. Published by Elsevier Science Ltd. All rights reserved

Composition, biomass and secondary production of the macrobenthic invertebrate assemblages in a coastal lagoon exploited for extensive aquaculture: Valle Smarlacca (Northern Adriatic Sea)

Macrobenthic invertebrate assemblages were investigated monthly, from June 1998 to October 1999, at four sites in Valle Smarlacca pond, a north-western Adriatic coastal lagoon, in order to estimate secondary production exploitable for extensive fish aquaculture and to investigate the factors affecting this production. Benthic assemblages comprised 28 taxa, of which Hydrobia sp., Chironomus salinarius and Abra segmentum were the main contributors to both overall biomass and secondary production. Annual secondary production varied from 102.7 gAFDM m-2 y-1, in the unvegetated perimeter channel, to 152.6 gAFDM m-2 y-1 in the shallowest area where a Ruppia cirrhosa meadow was present. Multivariate correlations between environmental variables and the macrobenthic assemblage biomass highlighted the role of the water level, temperature, sediment organic carbon content and dissolved oxygen in the differentiation of the communities in the pond. Composition, biomass and secondary annual production of macrobenthic communities were dramatically affected by summer dystrophic crises. The isolation of this habitat limits the recovery of the invertebrate benthic assemblages. Only populations of two species, Hydrobia sp. and C. salinarius, seemed to be able to recover quickly after the dystrophic crises, which, in turn, could compromise the overall secondary production, with negative effects on the aquaculture activities. Water renewal and nutrient inputs should be regulated in this pond to reduce the risk of zoobenthic mass mortality and to ensure a sustainable extensive aquaculture based on natural primary and secondary production