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The common shrimps of the genus Palaemon are often reported as living in Mediterranean submarine caves. The present study quantifies the distribution pattern of a Palaemon spp. populations throughout 1 year of observations in a shallow submarine cave in South-eastern Italy, Ionian Sea. The cave was subdivided into six sectors from the entrance towards the inner portion of the ‘blind cave’ and 16 dives (four per season, during both day and night) were performed with SCUBA equipment. The population was estimated in situ using visual census. Four different species of Palaemon were identified. This study has shown that Palaemon spp. assemblages live throughout the year in submarine caves. Moreover, the results suggest submarine caves play an important role in the biology of Palaemon spp. populations, by providing refuge, juvenile recruitment and food resources. [ABSTRACT FROM AUTHOR]

Coastal exposure may affect the structure of littoral fish assemblages. To evaluate its effects, fish assemblages associated with shallow (0-3 m depth) rocky reefs were investigated by visual census at the Asinara Island National Park (northwestern Sardinia, Italy, Mediterranean Sea) during autumn 2003. Distribution patterns of ichthyofauna in sheltered and exposed rocky reefs were assessed over the spatial scales of locations (i.e. kilometres) and sites (i.e. hundreds of metres). Overall, 38 fish taxa belonging to 17 families were recorded, with Labridae, Sparidae and Serranidae being the families with the most species. Univariate analyses showed that the average density of Labridae and Serranidae was significantly greater at sheltered locations, while particulate organic matter feeders (i.e. Mugilidae) were more abundant at the exposed ones. Significant differences in species richness, total fish abundance and densities of Labridae and planktivorous fish were observed at the spatial scale of sites. Multivariate analyses revealed that whole fish assemblages differed more at the scale of locations than among sites. Planktivorous species contributed most to the dissimilarity between fish assemblages associated with exposed and sheltered stretches of coast. Direct and indirect effects of coastal exposure were hypothesized to explain the potential role of wave action in structuring fish assemblages associated with shallow rocky reefs. In particular, direct effects could affect the distribution patterns of fish, depending on their swimming ability, while indirect effects could include changes in the benthic cover (especially macroalgae) caused by wave action, which then had a repercussion on the fish. [ABSTRACT FROM AUTHOR]

The present study aimed to improve the knowledge of the bivalve Pinna nobilis L. population distribution in Mar Grande of Taranto (Ionian Sea). Although historical references report the local abundant presence of this endangered species, there is a lack of updated information about its exact distribution. For this purpose, a visual census of P. nobilis was performed by SCUBA diving in the Mar Grande basin from September 2004 to March 2005. Pinnids were found at depths from 3 to 16 m, with a density ranging from 0.1 to 0.7 ind ha−1. The survey method employed in this study was non-destructive, relatively simple to perform and easily applicable for monitoring studies. Field data were stored in a database and linked with the study area by means of the GIS technology. The results of the present study indicate a tentative of recovery of P. nobilis population in Mar Grande in spite of all the difficulties of a degraded and heavily polluted environment and the damages of illegal fishing methods. [ABSTRACT FROM AUTHOR]

From 1970 to the present 10 artificial reef sites have been developed in coastal waters of the Ligurian Sea, Italy. They range from Ventimiglia, in the west, to La Spezia, in the east, with the largest and best known reef complex being located in the Gulf of Genoa at Loano and consisting of 2,745 m3, about 5,200 t of material and covering a surface of 350 ha. Design and construction practices have advanced from an initial, unsuccessful effort that used automobile bodies (now banned) to current use of custom-designed concrete modules deployed systematically. Funding for reef construction has come since 1983. The earliest aim of reefs was as a physical barrier to protect habitats against illegal otter trawl fishing. Newer objectives include habitat restoration, enhancement of biodiversity and fishing catch, and research to test materials and designs for physical and ecological performance. Reefs also functions as environmental observation stations, with the invasive species Caulerpa taxifolia (Vahl) C. Agardh, being recorded on the reef at Alassio. For some Artificial Reefs (Ars), benthic organisms and fishes, settlement, biomass and development of community are recorded. In Loano AR, immersed in 1986, more than 150 algae species are recorded, more than 200 benthic animal species and 78 species (87 taxa) of fishes. Fifty-six species (61 taxa) of fishes are recorded by visual census, the others are caught only by trammel net and long line. Trammel catches at Loano are on average about 2. 32 kg/100 m net. Comparisons among ARs reveal that age of the reef, location and presence of seagrass meadows are crucial for success. An indication of functional equivalence between ARs and natural rocky reefs is seen if both fish and sessile macrobenthos are compared. After 34 years of investigation a database comprising at least one hundred scientific articles based on research programs of up to 15 years, and other unpublished reports, provides information to guide future planning of reefs. On the basis of acquired experience, some management advice is suggested and the best design for the basic module in the Ligurian sea is described. The role of ARs, providing protection of coastal environment against the illegal otter trawling, nursery, microhabitat and food supply, while increasing biodiversity, biomass of benthos and fishes, and facilities for ecotourism, is outlined. [ABSTRACT FROM AUTHOR]

The main objective of this study is to improve the knowledge of the coastal fish assemblage of ‘Cinque Terre’ Italian national Marine Protected Area (Ligurian Sea), focusing on the characterization of the fish fauna in the core zone A (no entry–no take). The study relates to the main sea-bottom types and bathymetric ranges, and evaluates the effect of the protection on fish abundance and size composition in this 5-yr-old MPA. Field activities were carried out in 2003 by means of visual census techniques. In the A zone, fish-assemblage composition are strictly related to depth and sea-bottom type. Recorded data did not permit detection of a clear reserve effect on fish fauna, probably due to the recent institution of the MPA. Several significant differences were detected only considering the size-class composition of target species. [ABSTRACT FROM AUTHOR]

A study of the coastal fish assemblages in the marine park of Ustica Island (Southern Tyrrhenian Sea, Mediterranean) was conducted from June 1994 to September 1995 and from June 1996 to September 1997. The principal aims of the research were to: (1) define the faunistic features of local fish communities; (2) assess the effectiveness of the protection regime of the marine park on the fish assemblages (‘reserve effect’); (3) provide information on the distribution of some Epinephelus and Diplodusspecies in the shallowest depth zone of the island. During seasonal surveys, underwater visual censuses were carried out at several sites located in three zones of the island, each with a different level of protection. Observations were made along 250 m2 transects at 3–5, 10–15 and 25–30 m depth ranges. Additional surveys were made by SCUBA diving and snorkelling. A statistically significant effect of depth on the fish community parameters was observed, whereas differences linked to protection level, zones, sites and seasons were not significant. The abundance and frequency of occurrence of some species, particularly dusky grouper Epinephelus marginatus, were positively correlated with the degree of protection of the different zones of the marine park. Certain sites of the island are important as nursery areas for three species of the genus Diplodus (i.e., D. puntazzo, D. sargus and D. vulgaris). [ABSTRACT FROM AUTHOR]