Dodatni nalaz rasprostranjenosti Seriola fasciata (Carangidae) u Sredozemnom moru

An additional record of the non-indigenous species (NIS) Seriola fasciata from the southern coast of Sicily (Central Mediterranean Sea) is here described in this note. The catch record is the first in the area and confirms the key role of the area for NIS spreading. In addition, an updated map of its spatial distribution is provided as well as a discussion on the possible misidentification and competition with the native greater amberjack Seriola dumerili.U ovoj je bilješci opisan dodatni nalaz o vrsti Seriola fasciata s južne obale Sicilije (Sredozemno more). Ovaj nalaz je prvi na tom području i potvrđuje ključnu ulogu područja za širenje stranih vrsta (NIS). Osim toga, prikazana je ažurirana karta prostorne raspodjele vrste Seriola fasciata, kao i rasprava o mogućoj pogrešnoj identifikaciji i kompeticiji s vrstom Seriola dumerili

A Tale on the Demersal and Bottom Dwelling Chondrichthyes in the South of Sicily through 20 Years of Scientific Survey

In the present work, an overview of the demersal (sharks‐chimaera) and bottom dwelling (batoids) of experimental survey international bottom trawl survey in the mediterranean (MEDITS) data, from 1994 to 2013, is provided. The analysed data refer to a wide area located off the southern coast of Sicily, namely south of Sicily (according to the general fisheries commission for the mediterranean (GFCM) classification, Geographical Sub‐Area 16). A checklist of the recorded Chondrichthyes was integrated by density index, D.I. (N/Km2) and average individual weight (as the ratio between biomass index, D.I. (N/Km2) and D.I.). Results suggest that most of the Chondrichthyes in South of Sicily are in a steady state, although in the last few years, they seemed to recover. The spatial distribution of sharks‐chimaera in the geographical sub‐area (GSA) 16 is mainly concentrated in the southern and north‐western zones. Nevertheless, possible management actions to promote the recovering of these very important ecological and threatened species are discussed

Prvi nalaz mača srebrenjaka Trachipterus trachypterus Gmelin 1789 (Lampriformes) u Sicillijanskom tjesnacu

On July 7th 2018 a specimen of Mediterranean dealfish (Trachipterus trachypterus Gmelin 1789) was caught in the shallow waters of Selinunte (in the South-Western coast of Sicily) by trammel net. It was a female in maturing phase and the gonadosomatic index resulted as 1.1%. The specimen measured 1638 mm in total length and weighed about 2480 g. The estimated age through growth increments in vertebra was of 41 years. The finding of the Mediterranean dealfish in the Strait of Sicily might be linked to its spawning period during which it approaches the shallow waters. The present specimen represents the first record in the Strait of Sicily.Dana 7. srpnja 2018. uzorak mediteranskog dealfish (Trachipterus Trachypterus Gmelin 1789) je uhvaćen u plitkim vodama primorskog mjesta Marinella di Selinunte (na jugozapadnoj obali Sicilije) s troslojnom mrežom. Bila je to ženka u fazi sazrijevanja, a gonadosomatski indeks rezultirao je 1,1%. Uzorak je izmjeren 1638 mm ukupne duljine i težio je oko 2480 g. Procijenjena dob kroz povećanje rasta kralježaka bila je 41 godinu. Otkrivanje mediteranskog delfish u Sicilijskoj tjesnac mogao bi biti povezan s njegovim razdobljem mrijesta tijekom kojeg se približava plitkim vodama. Sadašnji uzorak predstavlja prvi zapis u Siciliji

Aerobic Microbial Inactivation Kinetics of Shrimp Using a Fixed Minimal Ozone Discharge: A Fact or Fib During Iced Storage?

AbstractAmong researchers worldwide, the combination of preservation methods aimed to achieve improved effects on microbial inactivation of seafood products is an area of research receiving increasing interest. Globally also, the demand for high quality minimally processed food products are on the increase. Ozone treatment, three decade – long declared 'Generally Recognized As Safe' and approved as food contact sanitizing agent has evolved up to recent times where it assumes the likes of domestic food-processing facilities manufactured with environment-friendly status ensuring consumer safety. On the other hand, the subject of inactivation kinetics of seafood microorganisms following ozone treatment is still under debate. Furthermore, kinetic models remain the economical and quick approach to predict the preservation parameters. Nevertheless, there is paucity of information regards aerobic microbial inactivation of crustacean product arising from fixed minimal ozone discharge. Is the phenomenon of aerobic microbial inactivation kinetics of shrimp product subject to a fixed minimal ozone discharge during iced storage a fact or fib? To answer this, the aerobic microbial inactivation kinetics of shrimp during iced storage of up to 11 days was inspected. The process conditions comprised of a fixed ozone concentration of 100mg/h minimally discharged at wash time of 1min as well as iced storage of up to 11 days. Minimal ozone treatment was applied either prior to or during iced storage situations. Aerobic microbial inactivation presented significant effects during iced storage (P<0.05). Line of fit that could best describe the aerobic microbial inactivation kinetics showed adequacy only at the fourth order of storage time 'x' variable, which could only but account for between 75 - 96% of explained variance. Overall, aerobic microbial inactivation kinetics of shrimp using a fixed minimal ozone discharge appears quantitatively possible even though it decreases as iced storage progresses

Escape Survival and Scale Damage Assessment of Red Mullet (Mullus barbatus Linnaeus, 1758) during Bottom Trawling in the Central Mediterranean Sea

Stock assessments routinely evaluate the status of commercially harvested species, but seldom account for the possible mortality of released or escaping fish. This study presents a method for estimating the escape survival of the red mullet (Mullus barbatus) from demersal trawling in the Central Mediterranean Sea. Fish escaping from the trawl codend were collected in a detachable cage, which was lined to reduce water flow and protect the sampled fish from further fatigue and injury. Control fish (from an open codend) showed high survival, 94% (87–97%, 95% Confidence Interval), and minimal injuries, while fish escaping through codend meshes had significantly increased injuries and reduced survival, 63% (55–70%). During 7 days of captive monitoring, treatment group mortality was highest in the first 24 h and ceased for both groups within 48 h. Conflicting length-related mortality was observed, where larger treatment fish had a higher probability of dying, while the opposite was observed in the controls. Analysis showed that treatment fish were significantly more injured than control fish, with treatment fish predominantly injured in the head zone. In conclusion, this improved methodology should be repeated to provide accurate escape mortality estimates for the improved stock assessment of the red mullet in the Central Mediterranean

Length-Weight Relationships of 52 Species from the South of Sicily (Central Mediterranean Sea)

The Length-Weight relationships (LWRs) of 52 species (14 never reported before) of fishes, crustaceans and cephalopods living on the shelf and upper slope off Southern Sicily are provided. Data were collected in the framework of the International bottom trawl survey in the Mediterranean (MEDITS) in the South of Sicily (Central Mediterranean), covering a time frame ranging from 2012 to 2019. Linear regressions were significant for all species (p &lt; 0.05) with R-2 values ranging from 0.86 to 0.99. The intercept (a) of LWRs ranged from 0.0003 to 0.4677, while the slope (b) ranged from 2.1281 to 3.306. The Welch t-test, used to evaluate differences between the obtained LWRs with those reported in the literature, revealed that most of the LWRs (about 55%) reported in this study are in disagreement with those obtained previously by other authors from the Strait of Sicily. It is expected that the results obtained from this study will contribute to filling the knowledge gap of fish populations in this area and also assist fisheries scientists in future stock assessment studies

British sharks in Sicily: records of long distance migration of tope shark (Galeorhinus galeus) from North-eastern Atlantic to Mediterranean Sea.

The study reports information about the recapture of two tagged adult females of tope shark, Galeorhinus galeus (Linnaeus 1758), in the central Mediterranean Sea (south coasts of Sicily) in 2014 and 2017. The two females were tagged in North-East Atlantic, respectively in Scotland in 2009 and Ireland in 2015. The Scottish specimen was a 175 cm female increasing of about 10 kg in body weight and 37 cm in total length during its 1967 days at liberty (5.39 years). The Irish one, was a pregnant female of an estimated age of 15-17 year which spent 248 days at liberty increasing 14 cm during this period. The growth rate of the two specimens was therefore between 6.8 and 7.8 cm year-1, faster than the annual increments of adults suggested in previous studies. Previous tope recapture records in the Mediterranean Sea were limited to the Alboran Sea, coast of Valencia and the Algerian coasts. The two tope females recaptured in the Strait of Sicily provided the first evidence of long distance entrance of NE Atlantic tope in the Mediterranean Sea. The well known occurrence of mature females and juveniles in this area of the Mediterranean suggest the hypothesis of a migration of adults female from their feeding grounds in north eastern Atlantic to lower latitudes up to the Mediterranean Sea for parturition

Exploring the feasibility of technological transfers of two by-catch reduction devices in the crustacean bottom trawling of the central Mediterranean

Introduction: Most Mediterranean fish stocks are overexploited owing to high fishing efforts and poor exploitation patterns. Demersal trawl fisheries are considered the most impactful fishery type because of the high quantities of unwanted catch that is then routinely discarded at sea. Methods: In the present study, two types of by-catch reduction devices (BRDs), that is a sorting grid (Grid-T45 40 mm) and a T90 50 mm codend, were compared to a typical commercial bottom trawl net (control) in terms of size structures and catch per unit effort to assess the effect of gear modification on the selectivity of crustacean fisheries in the central Mediterranean Sea. In particular, three randomly selected trawlers were involved in a paired hauls experiment fishing at the same time in the same fishing ground. Each trawler carried out four hauls per day during a 3-day campaign for a total of 36 hauls. The target species of the fishery is Parapenaeus longirostris (herein DPS), and the main commercial by-catch is Merluccius merluccius (herein HKE). Results: The results showed that the landing per unit effort (LPUE) of DPS was higher for Grid-T45 40 mm net, although it did not differ significantly from that of the control net. Conversely, the discard per unit effort (DPUE) of the control net was significantly higher than of both BRD configurations. For HKE, a slightly higher LPUE was recorded using the T90 50 mm codend compared to that of the control, but this result was not statistically significant. The lowest DPUE was found for the T90 50 mm codend, with significant differences compared to that of the control and Grid-T45 40 mm net. The catch comparison of the size structures analysed through generalised linear mixed models highlighted that the Grid-T45 40 mm net was more effective in catching adult DPS, whereas the T90 50 mm codend was more selective for adult HKE Discussion: In conclusion, although further studies should be carried out in future to test the performance of the BRDs in different areas and seasons, the investigated gear seems to be promising for reducing the catch of undersized individuals and contributing to mitigating the current overfishing of DPS and HK

Chilomycterus reticulatus (Actinopterygii : Tetraodontiformes : Diodontidae) in the southern Sicilian waters, central Mediterranean Sea

A recently discovered fish specimen representing the family Diodontidae has been documented in the waters off Mazara del Vallo in southwest Sicily, Italy. A detailed description of the morphological and meristic characteristics of the specimen is reported. Molecular identification was performed through sequence analysis of the Cytochrome Oxidase subunit I (COI). The specimen was identified as Chilomycterus reticulatus (Linnaeus, 1758) both morphologically and genetically. The finding marks the third confirmed record of Chilomycterus reticulatus in the Mediterranean Sea and Italian waters. The significance of the presence of this uncommon fish in the basin is briefly discussed, shedding light on its occurrence and potential implications.peer-reviewe

All is fish that comes to the net: metabarcoding for rapid fisheries catch assessment

Monitoring marine resource exploitation is a key activity in fisheries science and biodiversity conservation. Since research surveys are time‐consuming and costly, fishery‐dependent data (i.e. derived directly from fishing vessels) are increasingly credited with a key role in expanding the reach of ocean monitoring. Fishing vessels may be seen as widely ranging data‐collecting platforms, which could act as a fleet of sentinels for monitoring marine life, in particular exploited stocks. Here, we investigate the possibility of assessing catch composition of single hauls carried out by trawlers by applying DNA metabarcoding to the dense water draining from fishing nets just after the end of hauling operations (hereafter ‘slush’). We assess the performance of this approach in portraying β‐diversity and examining the quantitative relationship between species abundances in the catch and DNA amount in the slush (read counts generated by amplicon sequencing). We demonstrate that the assemblages identified using DNA in the slush satisfactorily mirror those returned by visual inspection of net content (about 71% of species and 86% of families of fish) and detect a strong relationship between read counts and species abundances in the catch. We therefore argue that this approach could be upscaled to serve as a powerful source of information on the structure of demersal assemblages and the impact of fisheries