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Roberto Carlucci
Ruolo
Ricercatore
Organizzazione
Università degli Studi di Bari Aldo Moro
Dipartimento
DIPARTIMENTO DI BIOLOGIA
Area Scientifica
AREA 05 - Scienze biologiche
Settore Scientifico Disciplinare
BIO/07 - Ecologia
Settore ERC 1° livello
Non Disponibile
Settore ERC 2° livello
Non Disponibile
Settore ERC 3° livello
Non Disponibile
Population abundance, distribution and habitat preference of the Mediterranean sympatric seahorses Hippocampus guttulatus and Hippocampus hippocampus were investigated in a semi-enclosed sea system (Apulian coast, Ionian Sea). A total of 242 individuals of seahorses were sighted in the 11 transects surveyed in summer 2011. Hippocampus guttulatus (n = 225) were 14 times more abundant than H. hippocampus (17). The mean abundance of H. guttulatus for all the pooled sites was 0.018 m-2 (SE ± 0.003) ranging from a maximum of 0.035 (SE ± 0.007) to a minimum of 0.008 (SE ± 0.002). The size structure of long-snouted seahorse shows a population ranging from 7 to 14 cm (SL) with a peak at 10 cm (TL). Juveniles (96.0 ± 8.0 mm) represent a significant fraction of the population, accounting more than 21% of the sighted individuals. In Mar Piccolo, H. guttulatus is able to shelter both in monotonous habitats, including the algal beds, and diversified ones, such as the rich filter-feeder communities that colonize hard substrates. By contrast, H. hippocampus is mainly associated with habitats of low complexity. Today, the Mar Piccolo di Taranto is among the most heavily polluted water bodies in South Italy, with trace metals, hydrocarbons, pesticides and organic wastes affecting both biotic and abiotic matrices. However, despite the high level of degradation, the presence of a large mussel farm has avoided the impact of towed fishing gears, and eutrophication of water bodies has ensured a high trophic level that supports large crustacean populations, potential prey for seahorses.
Age and growth of L. crocodilus (Osteichthyes, Myctophidae) were estimated using otoliths by direct and backcalculation methods. Data were collected in the Ionian Sea during nine seasonal trawl surveys carried out between 2000 and 2004. The maximum age identified was 8 years. The age-length keys obtained by the two different methods provided comparable results
The Santa Maria di Leuca (SML) cold-water coral (CWC) province is a proposed priority conservation area according to several conservation initiatives in the Mediterranean Sea. Part of it is a Fisheries Restricted Area (FRA). Anthropogenic impacts due to fishing on this FRA were investigated using a towed camera system during 2005. The geographic distribution of fishing effort in the SML CWC province was examined through an observers' program of longline and trawl fishing activities during 2009 and 2010 and Vessel Monitoring by satellite System (VMS) data from 2008 to 2013. Using the video system, it was possible to observe evidence of impacts in the FRA due to longlines, proved by remains of lines on the bottoms and/or entangled in corals, and those due to trawl nets, proved by trawl door scars on the bottom. The application of Generalized Liner Models indicates that the impacts due to longline were significantly related to a geographic site characterized by carbonate mounds while those from trawl net were significantly related to the soft bottoms, consisting of bioturbated fine-grained sediments. The presence of waste of various types was also observed in the FRA; plastic was the most widespread waste and was significantly related to a macrohabitat characterized by the presence of corals. The geographic distribution of fishing effort for each type of fishing were rather superimposed in the two years of the observers' program and six years of VMS data with a significantly greater fishing effort outside the FRA than inside this area. The trawlers generally fished on the muddy bottoms of the upper and middle slope within the SML CWC province and near and inside the northward limit of the FRA. The longliners fished mainly on the shelf in north and off the FRA. The coral by-catch was only recorded during 2009 in 26% of the trawl hauls. No coral by-catch was recorded from longlining in either year. The catches from longlining mainly consisted of Chelidonichthys lucerna, Merluccius merluccius and Conger conger while those from trawling mostly consisted of Aristeus antennatus, Aristaeomorpha foliacea and M. merluccius. The information collected during the observers' program and VMS data indicated greater impact due to trawling than longlining. The conservation and effective management of this vulnerable marine ecosystem remain difficult.
Data on the soft bottom benthic communities of the Vlora Gulf along the Albanian coast were collected in the context of the international Centro Internazionale di Scienze del Mare (CISM) project funded by the Apulian region. The present study investigated and mapped the different communities inside the Gulf of Vlora, Albania, which are continuously affected by various natural and anthropogenic sources. Two research cruises were carried out in the Vlora Gulf during May 2007 and January 2008. During the first exploratory survey, the depth and morphology of the soft bottom was identified with a multibeam echo sounder and the Side-Scan–Sonar system; a preliminary map of the biocoenosis was created and a sampling plan was defined. In the second survey, 58 sampling stations were established in the study area using Van Veen grabs and scuba dives. A total of 151 taxa were identified (1 Foraminifera, 6 Cnidaria, 3 Nemertea, 2 Sipuncula, 36 Mollusca, 53 Annelida, 25 Crustacea Decapoda, 7 Bryozoa, 15 Echinodermata, 1 Hemichordata, and 2 Tunicata); 54 species were reported for the first time in Albania. The analyses showed there were three main habitats in the investigated area: the biocoenosis of terrigenous mud; a wide, muddy matte of Posidonia oceanica; and the narrow residual areas of P. oceanica meadows. The present study represents the first experience in mapping the benthic biocoenosis of the Vlora Gulf of Albania and shows a progressive decay of the benthic communities in the area, especially if compared with the previous few studies.
Using longline a comparison of H. dactylopterus abundance and length distribution between coral and non coral habitats inside the Santa Maria di Leuca coral province is provided
Two experimental longline surveys were carried out in the Santa Maria di Leuca (SML) cold-water coral province (Mediterranean Sea) during May-June and September-October 2010 to investigate the effect of corals on fish assemblages. Two types of “megahabitat” characterized by the virtual absence of fishing were explored. One was characterized by complex topography including mesohabitats with carbonate mounds and corals. The other type of megahabitat, although characterized by complex topographic features, lacks carbonate mounds and corals. The fishing vessel was equipped with a 3000 m monofilament longline with 500 hooks and snoods of 2.5 m in length. A total of 9 hauls, using about 4500 hooks, were carried out both in the coral megahabitat and in the non-coral megahabitat during each survey. The fish Leucoraja fullonica and Pteroplatytrygon violacea represent new records for the SML coral province. The coral by-catch was only obtained in the coral megahabitat in about 55% of the stations investigated in both surveys. The total catches and the abundance indices of several species were comparable between the two habitat typologies. The species contributing most to the dissimilarity between the two megahabitat fish assemblages were Pagellus bogaraveo, Galeus melastomus, Etmopterus spinax and Helicolenus dactylopterus for density and P. bogaraveo, Conger conger, Polyprion americanus and G. melastomus for biomass. P. bogaraveo was exclusively collected in the coral megahabitat, whereas C. conger, H. dactylopterus and P. americanus were found with greater abundance in the coral than in the non-coral megahabitat. Differences in the sizes between the two megahabitats were detected in E. spinax, G. melastomus, C. conger and H. dactylopterus. Although these differences most probably related to the presence-absence of corals, both megahabitats investigated play the role of attraction-refuge for deep-sea fish fauna, confirming the important role of the whole SML coral province as a refuge area from fishing.
The Santa Maria di Leuca (SML) coral banks represent a rare example of living Lophelia-Madreporabearing coral mounds in the Mediterranean Sea. They are located between 350 and 1100m in depth, in the northern Ionian Sea (eastern-central Mediterranean). Using a multi-beam echo sounder, side-scan sonar, high-resolution seismics and underwater video, the zones were identified for the sampling demersal fauna without damaging the coral colonies. During September–October 2005 experimental samplings were carried out with longlines and trawl nets inside the coral habitat and outside, where fishery exploitation occurs. No significant differences were shown between the abundance of fish recorded using longlines in the coral and non-coral habitat even though some selachians and teleosts were more abundant in the former than in the latter. Large specimens of rockfish (Helicolenus dactylopterus) and blackspot seabream (Pagellus bogaraveo) were commonly caught using longlines in the coral habitat. Data from trawling revealed refuge effects in the coral habitat and fishing effects outside. Significant differences were detected between the recorded abundances in the two study areas. Greater densities and biomasses were obtained inside the coral area, and fish size spectra and size distributions indicate a greater abundance of large fish inside the coral habitat. The SML coral habitat is a spawning area for H. dactylopterus. The remarkable density of the young-of-the-year of the deep-water shark Etmopterus spinax as well as of Merluccius merluccius, Micromesistius poutassou, Phycis blennoides and H. dactylopterus, indicates that the coral habitat also acts as nursery area for these demersal species, which are exploited outside. Considering the evidence of the negative impact of bottom trawling and, to a lesser extent, of longlining, the coral banks can provide a refuge for the conservation of unique species and habitats as well as in providing benefit to adjacent fisheries through the spill-over effect both of eggs, larvae, juveniles and adults.
Adequacy in describing the growth of the elasmobranch Etmopterus spinax (Squaliformes, Etmopteridae) of the classical von Bertalanffy growth model in contrast with a two-phase growth model is discussed. Values computed for Akaike Information Criteria (AIC) and AIC weight testify that the best trade off between descriptive precision and complexity lies in the two-phase growth model.
Biometry, growth, survival and mortality rates as well as reproduction of O. edulis have been evaluated in the Taranto Sea, a semi-enclosed basin of the North-Western Ionian Sea (Mediterranean Sea). A crossed experimental design with 3 factors (container, depth and stocking density) was defined to investigate their effect on the sizes, growth performance, survival and mortality rates. Moreover, the reproduction was studied to better understand the life cycle of the species in the basin. The investigated experimental conditions caused significantdifferences inbothsizechangesandgrowthparameters. In particular, the density was the main factor influencing both biometry and growth. The oysters cultivated at low density showed L∞ (155.46±46.38mmDVL), k (0.42±0.25 year−1) andΦ′ (2.00) values significantly higher than those reared at high density L∞ (134.28±36.13 mm DVL), k (0.35±0.22 year−1) and Φ′ (1.80). The winter point (WP) occurred during winter and the strength of the seasonal oscillation (C) ranged between 0.10 and 0.37. No significant differences between the experimental rearing conditions were observed in either survival (S) or mortality (Z) rates. Oysters reared at low and high density showed mean S values equal to 0.88±0.03 and 0.89± 0.03, respectively as well as mean Z values equal to 0.13±0.03 and 0.12±0.04. Maturation of gonads occurred continuously during the year showing a slackening during summer when the highest temperatures were recorded in the water column. In addition, the highest percentages of fluent gonads were observed during winter. Histological analysis confirmed the macroscopic observation of gonads. In particular, gamete differentiation was observed during late autumn and early winter. An inverse correlation between the condition index and themean temperature in the water columnwas observed throughout the study period. The present results indicate an optimal crop age of about 2 years, corresponding to the commercial size of 8–9 cmdorsal–ventral length and weight of 55–60 g.
Canyons play a fundamental role in enhancing the abundance and diversity of marine organisms through the transport of organic matter and food resources, the presence of complex physical habitats and the absence of trawl fishing. During four baited lander deployments carried out in the Bari Canyon (Southern Adriatic Sea, Central Mediterranean), at depths of 443–788 m, about 43 h of video records were taken, for a total of 619,200 video frames. A total of 12 benthopelagic fish species (five chondrichthyes and seven osteichthyes) were identified. The blackspot seabream (Pagellus bogaraveo) was the most often observed fish species. The depth of 787 m represents a new depth record for this fish in the Adriatic Sea. Groups of up to 40 individuals of P. bogaraveo were attracted to the bait and were shown in single frames. The individuals were observed both exploring the area and feeding actively on the bait. The European conger (Conger conger) was recorded at each deployment. Clear scavenger behaviour was also observed in this teleost fish and in the shark Etmopterus spinax. The shark species Centrophorus granulosus and Hexanchus griseus, which are considered ‘vulnerable’ on the published IUCN Mediterranean Regional Red List, were also recorded but, although attracted by the bait, they were never seen feeding on it. Other fish species, harvested on fishing grounds, such as Merluccius merluccius, Helicolenus dactylopterus and Polyprion americanus, were also recorded. This study represents the first in situ documentation, at very low impact, of the fish fauna in the Bari Canyon, providing new insights into its small scale distribution and behaviour, the first in situ direct observation of the variable feeding behaviour of P. bogaraveo and its gregarious habits, as well as indicating that this canyon could act as a refuge area for species that are vulnerable to fishing on the open slope.
The relationships between the abundance of demersal resources, environmental variables, and fishing pressure in the northwestern Ionian Sea in the last two decades were evaluated. Data on the density collected during seventeen trawl surveys carried out from 1985 to 2005 were used. The following species were considered: Aristaeomorpha foliacea, Nephrops norvegicus, and Parapenaeus longirostris for crustaceans; Merluccius merluccius, Phycis blennoides, and Mullus barbatus for teleost fish. The recruitment index was also considered for N. norvegicus, P. longirostris, M. merluccius and Mullus barbatus. Six candidate models were evaluated for each density and recruitment data set either combining fishing effort with global (NAO) and regional (SST and precipitation) climatic indices, or models separately involving fishing effort, NAO, or regional climatic indices as the only predictive variable. Model selection was carried out using an information-theoretical approach that applies Akaike’s Information Criterion (AIC). High changes over time were observed for the density data and recruitment indices in each species. Apart from hake abundance and recruitment data, for which a clear positive relationship with the NAO index alone was detected, the changes observed in the other species seem to be the consequence of the interaction between bottom-up effects linked to changes in physical environment and top-down ones due to the fishing pressure.
A population of the bivalve Donax semistriatus was found on the sandy shallow seabed of the Adriatic coasts of Apulia (Mediterranean Sea) with a density of more than 200000 No./km2. The description of the length-frequency distribution within the population proved the dominance of juveniles, showing a probable high fishing pressure.
This paper reports the first finding of the sea pen Protoptilum carpenteri Kölliker, 1872 in theMediterranean Sea. A total of three colonies were collected in 2010 with an epibenthic sledge, and one colony in 2013 with a bottom-trawl net, in the Santa Maria di Leuca (SML) coral province in the Ionian Sea. The main anatomical features and taxonomic characteristics are reported and discussed in order to update the knowledge of this species. A description of morphologies and dimensions of the sclerites, taken from different parts of the colony, is reported. A comparison with Atlantic records is given and discussed.
Occurrence of juveniles of Scyliorhinus canicula and Mustelus mustelus was investigated as part of trawl surveys carried out from 1994 to 2009 in the North-western Ionian Sea. Two main finding areas were observed for juveniles of S. canicula and one of M. mustelus
The presence of the basking shark Cetorhinus maximus (Lamniformes: Cetorhinidae) in the central-eastern Mediterranean Sea has been documented by means of 15 sightings and two accidental catches which occurred from February 2011 to January 2014 in the northwestern Ionian and southern Adriatic Sea. Specimens were observed exhibiting typical feeding behaviour, swimming slowly on the surface, during each sighting. In the case of the accidental catches, the basking shark specimens were released still alive by local fishermen. The observed specimens measured between 4 and 9 m in total length (TL). The sightings could be due to an increase in effort in the monitoring of the species occurring in the Mediterranean Sea as a consequence of a rise interest in the conservation of threatened species.
This paper reports recent bio-ecological data on the Posidonia oceanica meadows located in two Marine Protected Areas of the Apulia region, Tremiti Islands and Porto Cesareo, placed in the Southern Adriatic Sea and North-Eastern Ionian Sea, respectively. The main features of the meadows (morpho-ecology, phenology, lepidochronology) were estimated. Moreover, in situ (-15 depth) continuous recording of light intensity (Lux) and water temperature (°C) was carried out during the period Oct. 2008-Sept. 2009.
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