In the northern Adriatic Sea, rocky outcrops called “trezze” or “tegnúe” are known as biodiversity hotspots. A total of 45 rocky outcrops were studied by using non-destructive photographic sampling ...during SCUBA diving. Ten invertebrate phyla with 196 taxa were recorded, 86% of which were determined at species level. Among them, 65% of the taxa were sessile, primarily represented by the phyla Porifera and Chordata. The aims of the study were: to characterize the species richness and composition of epifaunal invertebrates living on rocky outcrops; to test the efficiency of using the outcrop area as a predictor of epifauna richness, using the Arrhenius Species-Area Relationship (SAR) model; and to compare the expected richness resulting from the SAR model with the richness observed from the analysis of random photo-squares. Our results show that the SAR model describes the relationship between epibenthic species richness and outcrop size well and may have important practical applications for biodiversity estimations and nature conservation implications. It provides a useful tool, also in terms of economy and speed, to estimate the species richness of the benthic epifauna of the numerous outcrops that remain unsurveyed, based on their size.
Dissolved oxygen (DO) is a key element for the survival of marine organisms and is a supporting element in the current Water Framework Directive (WFD). DO deficiency is a common event that occurs in ...coastal environments such as estuaries and lagoons, but a long-term DO database that helps detect daily and seasonal oscillations is difficult to obtain with commonly used sampling and analytical procedures. In this work, a network of multi-parametric probes was deployed in the Marano and Grado Lagoon (northern Adriatic Sea, Italy) in order to obtain a dataset from the continuous monitoring of DO and complementary parameters. DO showed a high degree of variability both in terms of spatial and seasonal distribution and was dependent on solar radiation and water temperature. During the summer and in areas characterised by scarce water renewal, DO was below the threshold set as the minimum requirement for aquatic life, thus some water bodies (WBs) were classified as moderate sensu WFD. The inputs of freshwater discharge from inland and marine waters during tides are, however, able to well oxygenate most of the lagoon. These results will be useful in supporting the management and protection of this vulnerable environment.
In the last years, increasing interest has been dedicated to the quality assessment of brackish-water systems. Traditionally, fish community is an important biological element used to assess the ...quality status of transitional water bodies. In this study, we analysed the effect of anthropogenic pressures on the population of a small teleost, the sand smelt
Atherina boyeri
, in a Mediterranean lagoon by means of body condition. Fish were sampled once a year during the period 2010–2012, in 32 sampling sites, and for each specimen individual body condition factor was estimated. A negative significant correlation was found between condition factor and pressures related to alteration of the hydrographic regime, while a significant positive correlation was found with trophic status indicators and fishery activities. Therefore, morphological and hydrological alteration of coastal lagoons, modifying the quality and the availability of resources, seems to influence the health of resident populations.
Le barriere artificiali (BA) sono strutture solitamente utilizzate per incrementare le rese di pesca. Nel 2006 e stata realizzata una BA, costruita con tre diverse tipologie di moduli e situata in ...prossimita di un dotto fognario sottomarino. Gli obiettivi del progetto erano: (a) sperimentare la BA per il ripopolamento di alcune specie di interesse commerciale e (b) promuovere la biodiversita. La macrofauna epibentonica insediata su questa BA e stata monitorata a cadenza annuale durante 5 anni (2007-2011) per mezzo di rilievi fotografici. Complessivamente sono stati identificati 88 taxa appartenenti ad 8 phyla, in cui i Porifera, Mollusca ed Ascidiacea sono stati prevalenti. I pannelli in rete di polietilene sono stati efficaci durante il primo anno per ffinsediamento dei molluschi bivalvi, mentre nel lungo periodo il cemento si e dimostrato il piu efficace per promuovere la biodiversita in termini di ricchezza specifica. Il monitoraggio di 5 anni comunque non e stato del tutto soddisfacente per trarre conclusioni sulla successione ecologica della comunita insediata sulla BA.
On 3rd June 2018 three juvenile specimens of Polyprion americanus were captured in the Gulf of Trieste. The wreckfish is a long-lived deep water demersal species characterized by an extended pelagic ...juvenile phase. The juvenile forms are recurrently recorded in the northern Adriatic and due to data deficiency for this species, original morphometric data are shown. The occurrence of P. americanus in the Gulf of Trieste is not a typical case of thermophilic species moving northward due to Mediterranean tropicalization, rather its recurrent appearance could be investigated for specific hydrological conditions coupled to its peculiar life span.
Dana 3. lipnja 2018. u Tršćanskom zaljevu ulovljena su tri jedinke mlađi kirnje glavulje Poly-prion americanus. Kirnja glavulja je dugovječna vrsta duboke vode, koju karakterizira produljena pelagična faza mlađi. Jedinke mlađi opetovano se bilježe u sjevernom Jadranu, a zbog nedostatka podataka za ovu vrstu, prikazani su izvorni morfometrijski podaci.Pojava P. americanus u Tršćanskom zaljevu nije tipičan slučaj termofilnih vrsta koje se kreću prema sjeveru zbog mediteranske tropikalizacije, već bi se njihov ponovljeni nalaz mogao istražiti u specifičnim hidrološkim uvjetima zajedno s osebujnim životnim vijekom ove vrste.
The authors report the finding of some specimens (8 sightings) of Okenia picoensis (Gastropoda: Nudibranchia) at three different sites in Croatia (northern Adriatic Sea). Although this seaslug ...species has only recently been described, this record confirms its rapid spread throughout the Mediterranean Sea. This finding represents the first substantiated record in the Adriatic Sea.
Coastal lagoons often require direct human intervention, such as dredging and the disposal of dredged material, to maintain the safety and accessibility of navigation channels. Dredging may have ...short and long-term effects on macrozoobenthic communities. Because they respond relatively quickly to anthropic and natural stress, benthic invertebrates are considered a biological quality element sensu Water Framework Directive 2000/60/CE (WFD) used to assess the ecological status in transitional water such as coastal lagoons.
The monitoring of dredged areas and the subsequent comparison to the ecological quality status (EcoQS) sensu WFD in the Marano and Grado Lagoon has revealed that macrozoobenthic communities are slightly unbalanced and tolerant species prevailed. In this naturally stressed environment, the recovery time after the disturbance caused by dredging was three to six months, and richness and diversity were mostly related to the salinity range and distance from sea inlets.
•The Marano and Grado Lagoon is often subject to dredging of waterways.•The monitoring of a macrozoobenthos community checked the effects of dredging.•Biological quality elements considered in the WFD were applied.•The recovery time of macrozoobenthos is 3–6 months after dredging disposal.
The macrozoobenthos is commonly considered to be the main agent of bioturbation in shallow water, and responsible for the enhancement of the interchange of both dissolved and gaseous species between ...the pore waters and the upper water column. As reported by several authors, this basic phenomenon is usually investigated by describing the vertical distribution of macrobenthic organisms. For this purpose, a site located in the central part of the Gulf of Trieste selected and, during 1999/2000, 9 core samples were collected in triplicate, to a maximum depth of 20 cm. The vertical distribution of the macrozoobenthic communities was described by applying the bioturbation activity index (BA). The vertical distribution of macro fauna showed a clear decrease in both number of taxa and abundance when moving downcore. The BA suggested that surficial, detritus-feeding polychaetes have a pivotal role in the bioturbation of muddy sediments, whereas suspension-feeding molluscs are also important if the only top layer is considered.
The macrozoobenthos is commonly considered to be the main agent of bioturbation in shallow water, and responsible for the enhancement of the interchange of both dissolved and gaseous species between ...the pore waters and the upper water column. As reported by several authors, this basic phenomenon is usually investigated by describing the vertical distribution of macrobenthic organisms. For this purpose, a site located in the central part of the Gulf of Trieste selected and, during 1999/2000, 9 core samples were collected in triplicate, to a maximum depth of 20 cm. The vertical distribution of the macrozoobenthic communities was described by applying the bioturbation activity index (BA). The vertical distribution of macro fauna showed a clear decrease in both number of taxa and abundance when moving downcore. The BA suggested that surficial, detritus-feeding polychaetes have a pivotal role in the bioturbation of muddy sediments, whereas suspension-feeding molluscs are also important if the only top layer is considered.
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