Riccardo Fiorin

Threatened fishes of the world: Pomatoschistus canestrinii Ninni, 1883 (Gobiidae).

Common names: Canestrini’s goby; black-spotted goby. Conservation status: strictly protected – Annex II of the ‘Convention on the Conservation of European wildlife and natural habitats’, Bern 1979 (Decision 82/72/EEC); endangered or threatened – ‘Protocol concerning specially protected areas and biological diversity in the Mediterranean’, Barcelona 1995; species of Community interest – ‘Habitat and Species Council Directive’ (92/43/EEC). Identification: D1: VI. D2: I + 8–10. A: I + 7–9. P: 15–17. Greyish to yellowish, with numerous scattered, tiny, intense black spots on the body and head, and smaller spots in vertical dark bars across sides of body, especially in adult males. Large pale area on the neck and at the basis of pectoral fins. Black spot with a white edge between the fifth and sixth ray on the first dorsal fin. Female is in general paler, with black spots denser and with less definite contours, than male. Maximum size (TL) approximatively 65 mm in male and 50 mm in female. Drawings by Riccardo Fiorin. Distribution: P. canestrinii is endemic species to the Adriatic Sea (Miller 1986). It occurs in the lagoons and estuaries of the northern Adriatic Sea, from Monfalcone to the Po River Delta (Gandolfi et al. 1982), and in the Jadro estuary, Dalmazia (Kolombatovich 1891). Its occurrence also in the Ionian Sea (Gulf of Taranto) and in the Trasimeno Lake is probably due to recent introductions (Gandolfi et al. 1982; Freyhof 1998). Abundance: The species is always present with small populations (Gandolfi et al. 1991), as confirmed also by the low number of specimens examined in the literature. P. Franzoi and P. Torricelli (personal communication) report small population sizes of P. canestrinii in the Venice Lagoon, the largest lagoon of the Mediterranean, with a mean adult population density of 0.06 individuals m. Habitat and ecology: P. canestrinii lives in the shallow waters of the lagoons and river-mouths, in unvegetated salt marshes and creeks, selecting salinities ranging from 2 to 20 PSU and never exceeding 30 PSU (Gandolfi et al. 1982; P. Franzoi and P. Torricelli, personal communication). It has a lifespan of about 16 months, and is an epibenthic species, feeding mainly on small meiobenthic invertebrates (Gandolfi et al. 1982; Maccagnani et al. 1985). Reproduction: Breeding (from March–April to June–July) occurs over territories maintained by males, which build reproductive nests using shells of bivalves, stones, pebbles, and other submerged objects. Males give parental care until hatching (Gandolfi et al. 1982). Threats: P. canestrinii, as confirmed also by P. Franzoi and P. Torricelli (personal communication), is wholly dependent on the presence of oligohaline marshes within the lagoonal or estuarine environments. Therefore, the degradation of these habitats (due to chemical pollution, land uses, etc.), which has been considerable in the Mediterranean basin, mainly during the 20th century (Ibañez et al. 2000), together with the restricted geographical range of occurrence of the species, constitute a threat for it. Conservation action: The first step for the conservation of P. canestrinii comes from the identification of sites of Community importance (as recommended by the Council Directive 92/43/EEC) in the salt marshes areas of the Venice lagoon and in the Marano and Grado lagoons, where the species occurs. This would result in the preservation of the habitats suitable for the species, even though no conservatory plans for the species are yet applied (the LIFE projects aiming at this are yet under consideration). Conservation recommendation: Efforts should be done to make the Habitat and Species Directive (92/43/EEC) operative, by creating protection plans for the habitats to be conserved, and by regulating the human activities involving their use.

The soundscape of a mussel farm: Biophony and man-made noise levels

During the summer of 2015, four Passive Acoustic Monitoring (PAM) surveys were carried out over a mussel farm in the Venetian (Italy) littoral zone at night-time hours. A qualitative and quantitative analysis of the soundscape was carried out. The high frequencies component of the soundscape (i.e above 2 kHz) was dominated by snapping shrimps sounds, while the low frequency component (i.e. below 2 kHz) was characterized by fish vocalization, mainly emitted by Sciaena umbra (Sciaenidae), with less frequent occurrences emitted by Gobidae spp. S. umbra highest vocal activity was recorded from June to August inside the mussel farm. The low frequency component of the soundscape was dominated by boat noise; in particular, low frequency noise (i.e. below 4 kHz) emitted by commercial ships and passenger cruises. The Acoustic Complexity Index (ACI) was found to increase concurrently with the number of S. umbra vocalizations: ACI highest values corresponded with S. umbra chorus recorded during July. The results of ...

Is the Venice Lagoon Noisy? First Passive Listening Monitoring of the Venice Lagoon: Possible Effects on the Typical Fish Community

Three passive listening surveys have been carried out in two of the three Venice lagoon tide inlets and inside the Venice island. The spectral content and the intensity level of the underwater noise as well as the presence or absence of Sciaena umbra and the distribution of its different sound patterns have been investigated in all the recording sites. The passive listening proved to be successful in detecting S. umbra drumming sounds in both Venice lagoon tide inlets. Our results indicate that the spectral content and the level of underwater noise pollution in the Venice lagoon could affect fish acoustic communication.

Using passive acoustics to assess habitat selection by the brown meagre Sciaena umbra in a northern Adriatic Sea mussel farm: HABITAT SELECTION BY SCIAENA UMBRA

Passive acoustic monitoring (PAM) of the brown meagre Sciaena umbra was conducted in a northern Adriatic Sea mussel farm. The level of acoustic activity was found to be constantly high from June to August before declining sharply in September and there was significantly higher acoustic activity in the structured habitats within the mussel farm than in the bare sandy bottom outside the farm. Results are discussed in the context of the use of this species as an indicator species of artificial rocky habitats along the Mediterranean coastal environments.