The state of the knowledge about the marine alien molluscan species from Italy is provided based on a critical review of records compiled from an extensive literature survey and from unpublished data obtained from 2005 to 2010. Based on the IUCN definition of ‘alien’, 35 molluscan taxa (18 Gastropoda, 16 Bivalvia and 1 Cephalopoda) are reported here, for each of which the following data (collected up to December 2010) are provided: published and unpublished records from the coastal and offshore territorial seawaters of Italy, including lagoons, within the 14 biogeographical sea divisions covering the Italian shores, date of first record, most plausible vector(s) of introduction and establishment status. The southern Ionian Sea, the northern Adriatic Sea and the eastern-central Tyrrhenian Sea resulted to be the areas most affected by alien molluscan introductions. The rate of records of new alien species (evaluated on the basis of live findings) is quite uniform over five decades, with six to eight species recorded per decade. The analysis of the vectors showed shipping/maritime transport to be the most common vector of introduction (40%), followed by trade (24%). Nineteen alien molluscan species (54%) were considered as established in Italy.

Abundance and production of the pelagic heterotrophic bacteria community were studied at northern Chile during winter and summer periods of 2006–2007 in relation to seasonal changes in physical and chemical variables, including the influence of a weak El Niño event. Bacterial abundance was estimated by flow cytometry and secondary bacterial production by protein synthesis after bacterial uptake of 14C-isoleucine. Bacterial biomass showed high values in the range of 2.84 at 96.6 µ g C l−1d−1 with a bacterial growth efficiency (BGE) of 37.4% in the summer of 2007, and 2.7% in the winter of 2006. High amounts of C (~1.2 to 1.8 g C m−2 d−1) were used for bacterial respiration in the upper 20 m. Environmental impact on bacterial abundance and BGE was reflected in a positive correlation with phytoplankton biomass (r2 > 0.40 P < 0.05), and a lack of correlation with temperature (P > 0.05). Seasonal differences in abundance and BGE were mainly attributed to an ‘abnormally’ warm winter of 2006, which caused a greater stratification of the water column—a weaker and much deeper oxycline. The oxycline is normally shallower (<20 m) in the zone because of the ascent of the oxygen minimum zone (OMZ) upon upwelling. Winter 2006 conditions indicated presence of a weak El Niño event. Bacteria abundance increased during this warming event, but their metabolic activity was drastically reduced, resulting in a very low BGE. Our study suggests that changes from a prevailing sub-oxic to a highly oxygenated water column could have impacted the bacterial community, thus reducing its productive capacity. Therefore, variation in vertical distribution of the OMZ forced by upwelling variability and the El Niño impact might play an important role in the dynamics of the microbial component in this highly productive upwelling system.

A total of 16 species of intertidal brachyuran crabs were recorded from the three major estuaries (Punta Banda, False Bay-San Quintín and Laguna Manuela) of the west coast of the state of Baja California, Mexico. The species belong to 7 families: Cancridae (3), Grapsidae (2), Ocypodidae (2), Panopeidae (3), Pinnotheridae (4), Portunidae (1) and Varunidae (1). New distributional records include an extension of the northern limits of Cyrtoplax schmitti Rathbun, 1935, Panopeus purpureus Lockington, 1877, Goniopsis pulchra (Lockington, 1877), Uca princeps (Smith, 1870) and Pinnixa longipes (Lockington 1877).

A specimen of the Indo-Pacific blacktip grouper was collected at a depth of 20 m from off the coast of Lebanon. This constitutes the first record of the species in the Mediterranean and adds to the number of exotic serranids in the Mediterranean Sea.

The aim of this study is to assess small-scale variations in and spatial comparisons among the composition, distribution and abundance of the main zooplankton groups in the Saint Peter and Saint Paul Archipelago (SPSPA). Plankton samples were collected in May 2008 by net with a 300 µm mesh size. Sampling was carried out at two stations, Inner and Outer, during five consecutive days in the early morning and late afternoon. A total of 153 zooplankton taxa were identified. Copepoda was the most abundant and frequent group (with 49 species identified). Exocoetidae (Teleostei) eggs were also present in large numbers. No significant differences were found between stations or between day and night samples. The observed biomass was low; however, it was superior to that observed in the open ocean. The density of zooplankton was also low, but it increased slightly during the night. Indicator species for upwelling, such as Phaenna spinifera and Flaccisagitta hexaptera, were observed. We conclude that physical factors are important for structuring the SPSPA zooplankton community.