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Assessing individuals’ abundance, residency (presence at a site within a certain period) and site fidelity (tendency to return to the same site in subsequent seasons or years) is crucial for evaluating and improving the effectiveness of spatial conservation/management measures regarding ecologically and socio-economically valuable species. Using underwater visual census (UVC) and photo-identification (photo-ID) techniques, we estimated the abundance, residency and site fidelity of the dusky grouper, Epinephelus marginatus, at two protected sites within the Tavolara-Punta Coda Cavallo Marine Protected Area (Sardinia, Italy) in the summers of 2017–2018. The scope and spatio-temporal resolution of the study was extended by involving volunteer recreational divers in the photo collection. Grouper mean densities varied significantly across sampling dates, with a significant variability between the 2 years and the two investigated sites. At least 94 grouper visited the study sites in the summers of 2017–2018 based on the analysis of 968 high-quality photos using a semi-automated software to photo-identify individuals. Overall, the most frequently sighted grouper was recorded on 32 different days and 21 individuals (22%) identified in 2017 were re-sighted in 2018. The participation of volunteer recreational divers helped detect the inter-site (3.5–4 km apart) movements of a female and a male, supporting previous findings regarding the occurrence of reproduction-related movements. This study provides novel insights into the residency and site-fidelity patterns of the dusky grouper, and its small-scale movements probably related to reproduction. Specifically, we provide indications that effective protection from fishing should encompass the entire area used by grouper for reproductive movements.

The aim of this study was to define the simplest and least expensive protocol for total protein extraction for three different macroalgae of the genus Caulerpa (the invasive C. taxifolia and C. cylindracea and the autochthonous C. prolifera). Five multi-step protein extraction procedures, set up for other macroalgal species, were tested. For each of them, different pre-treatment and extraction conditions were simultaneously examined, according to a factorial design, considering the starting material, the solvent-to-biomass ratio, and the incubation temperature. Protein yield in the obtained extracts was estimated with the Bradford method. Further, polyacrylamide gel electrophoresis (SDS-PAGE) was used to resolve proteins, assessing their quality and integrity. Significant differences in protein yield were observed among the extraction protocols and the conditions tested, also in relation to the considered species. Profiles having an acceptable quality were obtained for C. prolifera and C. cylindracea, and from the obtained results, the best method to obtain high yield and quality protein extracts for the two above-mentioned species appears to require the use of a primary TCA/acetone extraction buffer followed by a lysis buffer with NaCl, KCl, urea, Triton, SDS and a protease inhibitor. The best results, in particular, were obtained starting from fresh pulped material with a buffer-to-biomass ratio of 10:1 and an incubation temperature of 4°C. For C. taxifolia, instead, none of the tested protocols produced satisfactory results and further studies will be required.

Seagrass wrack are commonly found on the beach face of the sandy shore all around the world and often persists in situ during the whole year, favouring the emergence of conflicts for the use of the sandy coasts for bathing or for other recreational purposes. As a consequence, these deposits are often removed from the beach during the summer months, temporary stocked, and relocated on the shore face in the next autumn or winter season. The selection of the sites on the shoreline where the leaves should be released before the storms season is often an issue, considering the optimization needs between the transportation costs and the oceanographic features of the dumping site. In this study, a numerical approach was proposed to identify the most suitable areas for the autumnal repositioning of the seagrass wracks for two beaches of Sardinia, an island located in the Western Mediterranean Sea where Posidonia oceanica (L. Delile, 1813) is the most widespread seagrass species. The method is based on the use of hydrodynamic, wave, and particle tracking models and provides important indications useful for the management of this type of practice that can be extended to all different type of beaches along the Mediterranean coasts.

Conservation of exploited fish populations is a priority for environmental managers. Spatio-temporal knowledge on reproductive sites is mandatory for species and habitat conservation but is often difficult to assess, particularly over vast geographic areas. Regular and long-term standardized surveys are necessary to identify reproductive sites, assess population trends and their distribution. Here we emphasize the utility of Passive Acoustic Monitoring (PAM) for the survey and management of a depleted vulnerable Mediterranean fish species, the brown meagre, Sciaena umbra. Acoustic surveys of reproductive calls were conducted combining 1) spatial data from standardized surveys within three MPAs and from 49 unprotected sites throughout the Northwestern Mediterranean basin, as well as 2) temporal data from a two-year-long survey at a presumed spawning location. The MPA surveys, which rapidly scanned ~30-50 km of the rocky coastlines per MPA, unveiled maps of distribution and reproductive activity of the brown meagre, including potential spawning sites. They were also effective in emphasizing effects linked to management actions: Full-protection zones had a higher number of vocalizations (70% of the listening sites) compared to less protected zones (30% of the sites) or sites outside MPAs (45% of the sites). This was also reflected in the number of singers that was generally low (< 3 individuals) in less protected zones and outside MPAs, implying lower fish densities. Highest calling aggregations were observed in potential spawning areas that represented only 0.04% of all listening sites, and were almost all in older, fully protected MPAs, which thus play a key role for fish stock recovery. The two-year survey revealed a 5-month reproductive season (from May to October) with a strong positive correlation between calling activity and temperature. Overall this study confirms the role of PAM as an efficient, replicable and standardized non-invasive method for population management that can identify functional sites and key protection zones, provide valuable information on reproduction, spatial and temporal occurrence, but also on population trends and climate-driven changes.HighlightsMonitoring of threatened species and their key habitats is critical for environmental managers.Management requires methods to assess population trends at large spatial and temporal scales.Passive acoustics (PA) is efficient in mapping and monitoring vulnerable fish species.Distribution, reproductive sites and population dynamics can be assessed over vast geographical areas.We show the utility of PA to identify key conservation zones and assess effects of management actions.

This paper focuses on the interactive short and long-term effect of three different stressors on a macroalgal assemblage. Three stressors are considered: herbivory, nutrients and mucilage. The experiment was conducted in Tavolara Punta Coda Cavallo Marine Protected Area (Mediterranean Sea) during a bloom of the benthic mucilage-producing microalga Chrysophaeum taylorii (Pelagophyceae); this microalga is recently spreading in the Mediterranean Sea. On a rocky substratum, 36 plots 20 × 20 cm in size were prepared. Factorial combinations of three experimental treatments were applied in triplicate, including three grazing levels crossed with two nutrient enrichment and two mucilage removal treatments. Significant differences were observed among treatments 8 weeks later, at the end of summer. In particular, dark filamentous algae were more abundant in all enriched plots, especially where mucilage and macroalgae had been removed; a higher percent cover of crustose coralline algae was instead observed where nutrients had been increased and no grazing pressure acted. Furthermore, the abundance of Dictyota spp. and Laurencia spp. was significantly higher in enriched mucilage-free plots where the grazing pressure was null or low. However, the effects of the treatments on the overall assemblage of the macroalgal community were not long persistent (36 weeks later). These results illustrate the capacity of a shallow-water macroalgal community to quickly recover from the simultaneous impacts of herbivory, nutrient enrichment, and mucilage.

Chrysophaeum taylorii Lewis & Bryan (Pelagophyceae) is a mucilage-producing benthic microalga that has recently begun to spread in the Mediterranean Sea, where a range expansion is occurring. This paper presents the results of three field experiments that aimed to increase the knowledge on mucilage provision mechanisms for this benthic microalga and to evaluate the importance of mucilage in its range expansion. By means of two correlative field experiments (several years of data were considered to encompass the variability of mucilage cover) we found that, on the sea bottom, mucilage cover does not depend on epilithic cell density and that both its cover and settling are affected by water flow. We also tested the hypothesis that cells embedded in floating mucilage fall on the underlying substratum, where their abundance depends on water flow. To this aim, in the field we manipulated the presence of floating mucilaginous aggregates in cages with different levels of exposure to winds. The abundance of C. taylorii cells on the substratum under cages with mucilage was compared with that of two control treatments: cages without mucilage and mucilage in still water, in the field and lab, respectively. The results suggested that mucilage can represent an excellent strategy for the species to disperse, as C. taylorii cells fall from the floating mucilage and, if the water flow is unimportant, settle on hard substrata just underneath the cage. This study enriches the portfolio of knowledge of the dispersal strategies of microalgae and contributes to the understanding of the spread of invasive species.

Chrysophaeum taylorii Lewis and Bryan (Pelagophyceae) is an allochthonous benthic microalga recently recorded in the Mediterranean Sea where it is spreading quickly. Although this species secretes mucilage which is seriously affecting marine communities, it has been scarcely studied and no information on its ecologyisavailableyet.Wepresenttheresultsofa fiveyearstudyaimedtoincreaseknowledgeonsubstratum and depth preferences of this bloom-forming microalga with special emphasis on its colonisation efficiency. Three separate field experiments established that cell abundances of Chrysophaeum taylorii were significantly lower on macroalgae, mollusc shells and sand than on hard granitic substrata, where the microalga settled efficiently and proliferated immediately independently of the colonisation level of the substratum (bare vs colonised) and the substratum stability (mobility) (cobbles vs rocks). Furthermore, C. taylorii abundance (density) decreased with depth >2 m, showing it prefers shallow waters in which it is able to resist to high light intensities. These results offer some important insights into the ecology of this bloom-forming microalga that will contribute to the planning of future research and strategies for management of bloom events.

Marine protected areas (MPAs) are a key tool for conservation purposes, but few studies have assessed the responses of small macrozoobenthic assemblages to different protection levels in the Mediterranean Sea. In this study, we used a hierarchical sampling design spanning 3 orders of magnitude (1, 10 and 100 m) to investigate whether a MPA exerts an effect on amphipod assemblages associated with Posidonia oceanica meadows. We report spatial and temporal variability patterns of amphipod assemblages in 4 different protection levels and discuss potential confounding effects, such as habitat features. The structure of amphipod assemblages based on density data was patchy at all spatial scales investigated, but differed markedly among protection levels. Among outstanding points, multiscale analyses showed that lower densities and/or biomasses of several taxa occurred within fully protected and external areas, in comparison with partially protected areas (PPAs). Furthermore, P. oceanica meadow features (shoot density, leaf and epiphyte biomasses, coefficient A and litter biomass) accounted for only a low proportion of the total variability. We consequently infer that the observed patchiness is likely to occur for multiple and interconnected reasons, ranging from the ecological and behavioural traits of amphipod species to protection-dependent processes (e.g. fish predation). Long-term multiscale spatial and temporal monitoring, as well as experimental manipulations, are needed to fully understand the effects of protection on macrozoobenthic assemblages.

The benthic mucilage producing microalga Chrysophaeum taylorii Lewis and Bryan ( Pelagophyceae ) has recently received attention for its rapid spread in the Mediterranean Sea, where its blooms have remarkable detrimental effects. So far no information on C. taylorii response to multiple stressors, especially in terms of mucilage hyperproduction, is available in the literature yet, and a manipulative field experiment in this topic was designed in Tavolara Punta Coda Cavallo Marine Protected Area. The aim of the study was to test the effects of nutrient enrichment (addition of nutrients), mechanical disturbance (partial and total benthic organisms removal) and hydrodynamics (increased water turbulence) on C. taylorii cell density and mucilage abundance. To the purpose, the three above mentioned stressors were simulated and the three treatments were assigned to 20 × 20 cm plots following a full-factorial design (n = 3). Interactive effects of the three stressors affected significantly both benthic C. taylorii cell density and mucilage cover although differently. Mechanical disturbance and high hydrodynamics produced consistent effects on cell density and mucilage production (i.e. the former factor enhancing and the latter decreasing). Nutrient enrichment on the contrary led to contrasting effects, promoting cell abundance and inhibiting mucilage production. Therefore, important mucilage blooms are expected in oligotrophic sheltered coastal locations where barren areas are present.

Rocky banks (i.e. sea mountain-like structures rising from the sea bottom) are hard substrate habitats of high socio-economic value (e.g. for fishermen and divers) and ecological relevance as they often host unusually high density of fish. Here we tested whether the response of fish assemblages to protection (i.e. related to the presence of a Marine Protected Area (MPA)) in rocky banks is comparable with the response of rocky reefs dropping from the coast (hereafter called ‘coastal rocky substrates’), and whether there are differences between fish assemblages associated with protected and unprotected rocky banks. Fish assemblages were assessed in shallow and deep coastal rocky substrates, and in rocky banks, in unprotected and protected conditions at a Mediterranean MPA in north-east Sardinia in August 2007 and 2008. Whole fish assemblage structures (in terms of biomass) differed between protected and unprotected conditions in both study years. Fish assemblages at rocky banks, in addition, differed from those associated with coastal rocky substrates. Total fish biomass (summing contribution of all species) was higher under protected than unprotected condition in 2007, while species richness and total fish density did not demonstrate any significant change related to protection. The responses to protection displayed by the target species Epinephelus marginatus and Diplodus sargus were clear especially in terms of greater frequency of large-sized specimens in both study years. Biomass of E. marginatus in 2007 and density of D. sargus in 2007 and 2008 were significantly higher in protected than unprotected conditions, especially in protected rocky banks. This study emphasizes the ecological and socio-economic role of protection and the potential role of rocky banks within management/conservation programmes in the Mediterranean Sea.

Marine Protected Areas (MPAs) are acknowledged globally as effective tools for the protection and management of the marine environment; however, to get effective results it is necessary to set up a proper and continuous mapping of the marine territory, in order to gain detailed knowledge of its different aspects. Therefore, the implementation and maintenance of a modern GIS (Geographic Information System) has become an indispensable task for the MPA of Tavolara - Punta Coda Cavallo to collect, aggregate, classify, and track the conducted mapping activities. Between 2011 and 2012 the sea bottom of the MPA was surveyed using different methods: by means of a multi-beam echo sounder and of a side scan sonar, as well as conducting fast scientific scuba divings with re-breathers and underwater position system technologies. High resolution geodatasets, characterized by a significantly high quality in representing and describing the sea bottom and its habitats, were produced in both feature (scale up to 1:1.250) and raster formats (up to 30cm/pixel for sonar images and 1m/pixel for bathymetry) and they currently constitute the basis of the MPA's GIS, including its 3D applications and its web map services for desktop and mobile devices (iPhone & Android). To update the above described geodatasets during time, acquiring new data on the conservation targets considered in monitoring activities, among which the status of P. oceanica meadows is of the most important ones, a long term mapping plan was realized on the basis of an innovative methodology elaborated by the MPA considering both the wideness of the area and the limited funds available at present. The whole MPA was divided in territorial units by means of a regular grid of square cells having a 100m side with the logic of starting the mapping activities from the mainly important areas and then to spread the surveys up to fill the whole mosaic. All the new data acquired with this methodology could then be mixed, compared and indexed within the same cell and/or in the many already available geodatases, starting from those dated 2006 having a regular grid with square cells of 500m per side.

Fish assemblages were assessed by visual census in sublittoral rocky reefs at the Tavolara-Punta Coda Cavallo Marine Protected Area (TMPA; Mediterranean Sea) and compared among locations characterised by different protection levels: no-take/no-access zones, two types of partial protected areas (PPAs, where professional and recreational fishing are regulated in a different way) and locations outside the TMPA. Fish assemblage structures evaluated on abundance data did not differ among different protection levels, while no-take/no-access zones clearly differed from the rest when data were expressed as biomass. Biomass of many target species was higher in no-take/no-access zones mostly due to greater fish size rather than density. For some fish (e.g. the dusky grouper Epinephelus marginatus), however, both greater density and larger size contributed to the greater biomass in no-take/no-access zones. No differences were found between the two types of PPAs, and between PPAs and the locations outside the TMPA, in terms of assemblage structures, and in density, size and biomass of target species. These results suggest the need to 1) improve management in PPAs or re-think of their role, and 2) quantitatively assess pressure of both professional and recreational fishing operating within and adjacent to MPAs, in order to allow MPAs to set up proper regulations (e.g. limiting professional or recreational fishermen, number and type of gears), and 2) achieve the best balance between ecological targets and reduction of conflicts among different categories of marine resource users.