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Brown foundation seaweeds are key elements increasing substrate heterogeneity and shaping the biodiversity in rocky coastal ecosystems. They are, however, vulnerable species that are declining due to multiple anthropogenic and climate change stressors, leading to a shift to less structural complex habitats. We investigate the role of structural attributes of two intertidal macroalgae, Ericaria amentacea and Laurencia obtusa, in shaping the abundance and diversity of their associated epifaunal assemblages. For this aim, we measured seaweeds' biomass, thallus volume and length (used here as proxy of substrate complexity), and explored which seaweeds' substrate attribute explained better variation of epifaunal assemblages. Results showed that E. amentacea was more complex than L. obtusa and hosted a higher number of epifaunal individuals. However, unlike that expected, the epifaunal assemblage of L. obtusa was more structured with higher Shannon–Wiener diversity and Pielous' evenness. Our findings indicate that, besides seaweed's substrate attributes, other mechanisms such as wave action and chemical defense might play a role in structuring epifaunal assemblages. We suggest that a shift from E. amentacea to L. obtusa population could have effect on structure and abundance of associated epifaunal assemblages. Certainly, further investigations are needed to clear up the consequences of these changes. [ABSTRACT FROM AUTHOR]

In the Mediterranean, the gastropodDendropoma cristatum(sin.D. petraeum(Monterosato, 1884)) is the primary builder of the vermetid reef, an intertidal bioconstruction of exceptional ecological importance. Despite awareness of the need for conservation of this key species, the biology ofD. cristatumremains poorly understood. The recruitment ofD. cristatumdeserves particular attention because the absence of a planktonic larval stage limits its dispersal ability. We examined the temporal pattern of recruitment during the breeding season ofD. cristatumfrom June to September in 2013. Specifically, we compared the two portions of the vermetid reef (i.e. the inner edge and the outer edge) at localities with different exposures to wave motion. The number of recruits peaked in July, when it was significantly higher in the outer than in the inner edge. No differences emerged between localities with different wave exposures; however, the width of the reef was significantly related to the exposure index. Although there are still several gaps in our knowledge of the recruitment dynamics ofD. cristatum, this study contributes to characterising recruitment rate variation at small spatial and temporal scales. [ABSTRACT FROM PUBLISHER]

The occurrence of the invasive seaweedCaulerpa taxifoliain the Straits of Messina (Italy) provides an excellent opportunity to examine the spatial and temporal patterns of abundance of the endemic Mediterranean sacoglossanOxynoe olivacea.Densities of this species were recorded in March, June and October 2000 on three different habitats: the underside of boulders (UNB), the upper side of boulders (UPB), and the surface of concrete blocks (CB). Results showed that in March,O. olivaceawas consistently more abundant on UNB whereas in June it was present exclusively on CB. The density ofO. olivaceawas similar in the three habitats in October. The hiding behaviour ofO. olivaceaand its seeming disappearance in March did not coincide with a decline of abundance of phylloids ofC. taxifolia.The results represent an important basis for further studies devoted to the investigation of abundance of these marine invertebrates, which has been traditionally thought of as unpredictable. [ABSTRACT FROM PUBLISHER]

1. To better understand the role and importance of body size in hermaphroditic mating system theory, the mating behaviour of the shelled sacoglossanOxynoe olivaceawas studied. This simultaneous hermaphrodite exhibits bilateral and unilateral sperm transfer and thus it is particularly suitable for studies on hermaphrodite sexual conflict.2. In this study three hypotheses on body size were tested: thatO. olivaceapartner size has an effect on (i) mating mode choice, (ii) duration of mating modes, and (iii) choice of sexual role. Furthermore, we tested Charnov's hypothesis that inO. olivacea, like many simultaneous hermaphrodites, a sexual conflict exists and the male role is preferred.3. A laboratory experiment was done to test the aforementioned hypothesis and to observe the general mating behaviour ofO. olivacea. Pairs of similar (S) and different (D) sizes were considered for a total of five different treatments (S1, S2, S3, D1, D2).4. During the five copulatory treatmentsO. olivaceamated up to 93 times. Specifically, pairs of the same size mated with bilateral sperm transfer while unilateral copulation was common in pairs of slightly differing size. Contrary to predictions, animals of small body size started mating in the female role.O. olivaceashowed an active alternation of sexual roles and thus did not specialize in one particular sexual role.5. This study produced evidence of a relationship between mating mode and body size inO. olivaceaand highlighted the need for new studies on this simultaneously hermaphroditic species.Functional Ecology(2004)18, 899 –906 [ABSTRACT FROM AUTHOR]

The short-term response of Mediterranean upper infralittoral macroalgal species to experimental human trampling was investigated. Disturbances of six different intensities were applied within the integral reserve of the Ustica Island marine protected area (Italy, Mediterranean Sea). The dominant macroalgal species Cystoseira brachicarpa v. balearica and Dictyota mediterranea were strongly affected by human trampling. Higher levels of disturbance significantly affected both algal percentage cover and canopy at an increasing rate. Three months after trampling, for both variables it was highlighted that the algal recovery from disturbance was incomplete, being significantly different among trampling intensities. The current study revealed that in the short-term it was not possible to identify critical levels of trampling that are sustainable for this shallow community. [ABSTRACT FROM PUBLISHER]

Marine Protected Areas (MPAs) are playing a central role in the achievement of ocean sustainability and, since 2000, their global coverage has increased over ten times. The success of MPAs, and therefore the delivery of their potential outcomes for human well-being and global sustainability, requires multi-disciplinary, holistic, and comprehensive approaches for its achievement. In this study, the global scientific literature on MPAs was quantitatively reviewed through bibliometrics approaches, investigating patterns and trends in its development over time. In particular, bibliometric network and citation burst analyses of keywords were performed using VOSviewer and CiteSpace software. The bibliographic search on the Scopus and Web of Science databases resulted in a total number of 5908 and 6036 scientific documents published on MPAs. The network analysis of the keywords co-occurrence produced four main clusters whose connections and overlapping showed a multidisciplinary structure of MPA science, in which the ecological, social, and economic domains of research are strongly interlinked. Temporal analyses showed a recent focus on topics related to the social-ecological systems theory (e.g., ecosystem services, marine spatial planning, governance, and small-scale fisheries) suggesting that newer research lines recognize the importance of integrating the "human dimension" in conservation and sustainability studies. Overall, the results of both the performed bibliometric analyses pointed out the evolution of MPA science from the conventional concept of "marine reserves" to a broader scope integrating ecological, economic, and social aspects. In conclusion, MPA research is timely responding to the identification of MPAs as ocean sustainability tools, opening MPA science to multi-disciplinary research lines by linking the ecological and socio-economic dimensions of sustainability. MPA research is expected to play a crucial role in generating the interdisciplinary scientific knowledge needed to fully contribute to global ocean sustainability and human well-being. Unlabelled Image • Scientific research on MPAs is highly interdisciplinary. • MPA research evolved over time encompassing ecological and socio-economic aspects. • Over the years, human-related keywords increased in MPA scientific literature. • The human dimension plays a central role in marine conservation. • MPA research is responding to international commitments for ocean sustainability. [ABSTRACT FROM AUTHOR]

Characterized by interlinked social, economic, and ecological dynamics, Marine Protected Areas (MPAs) are a management tool for achieving sustainability goals in social-ecological systems. The recent increase in their establishment worldwide, fostered by international policies, highlights the need for comprehensive and integrated assessment frameworks able to address the evaluation of their social-ecological effectiveness and management performance, which is of fundamental importance for their adaptive management and decision making processes. Although several indicators and methodologies exist to assess MPAs ecological or social performances, no comprehensive assessment framework currently captures their broad range of objectives, encompassing the ecological, socio-cultural, and economic spheres. In this study, we present a novel quantitative framework (named MPAs Overall Success Evaluation – MOSE) able to assess the overall effectiveness and management performance of MPAs under the perspective of social-ecological systems. The multicriteria framework includes indicators linked to nature conservation, socio-cultural, socio-economic, and management objectives, integrating the multidisciplinary knowledge on MPAs in a single but comprehensive approach. The proposed framework was applied to the case study of Cerbère-Banyuls Natural Marine Reserve (France), the first MPA included in the IUCN Green List. Results showed that a high level of management effort is applied to the investigated MPA, generating several social-ecological benefits. This study showed the applicability of the MOSE framework and its potential usefulness as a tool to inform managers and decision-makers in charge for developing adaptive management strategies. Image 1 • The MPAs Overall Success Evaluation (MOSE) framework is presented. • The framework is applied to the Cerbère-Banyuls Natural Marine Reserve (France). • Results show the MPA management effort and generated social-ecological benefits. • The framework represents a useful tool for adaptive management. • Future applications will target a wide variety of MPAs at different scales. [ABSTRACT FROM AUTHOR]

Mollusc assemblages of three concrete artificial reefs (ARs) in the Gulf of Castellammare were compared with those of two nearby natural reefs (NRs). The reefs were located in areas characterized by different degrees of water transparency, with average annual Secchi disk visibility ranging from clear (>20 m) to turbid waters (<6 m). In spring 1995, 28 samples of 400 cm2 were scraped off the reefs at depths of 16–22 m (20 from ARs; 8 from NRs), which yielded a total of 116 species and 1084 specimens of molluscs. The assemblage derived from a NR in clear water showed the highest diversity, species richness, and evenness, while the highest number of specimens and dominance values were observed at an AR in turbid water. The lowest values of diversity and species richness were found at ARs in turbid water and the lowest number of specimens at a NR in turbid water. Comparison of the five reefs showed significant differences in average number of species and in diversity values, while differences in the number of specimens were not significant. Factorial correspondence analysis showed a pattern that was strongly polarized along the first axis by the NR in clear water and by the AR in turbid water. The most distinctive feature was the dominance of Bittium latreillii at AR sites. Three years after deployment, mollusc assemblages of ARs in the Gulf remain entities that are distinct from those of nearby natural reefs. However, the potential of the assemblages in terms of density of individuals is comparable to that of natural reefs. Copyright 2002 International Council for the Exploration of the Sea. Published by Elsevier Science Ltd. All rights reserved. [ABSTRACT FROM PUBLISHER]

Canopy-forming seaweeds of the genus Cystoseira (Fucales, Phaeophyceae) form diverse and productive habitats along temperate rocky coasts of the Mediterranean Sea. During the last decade, Cystoseira forests have retracted their range considerably due to many interacting environmental, biological and anthropogenic pressures. We investigated how reducing in patch-size of C. montagnei affects their associated molluscan communities at the shallow northwest rocky shores of Palermo (Sicily, Italy). Molluscs were sampled from the fronds of individual thalli, clumps of 3 and 5 thalli of C. montagnei over an annual vegetative cycle (May–September) in two sites within the Marine Protected Area "Capo Gallo-Isola delle Femmine". We measured five substrate attributes of the alga (thallus volume, canopy volume, interstitial volume, algal surface, and biomass) and explored their relationships with the diversity of the associated molluscan assemblage. A total of 3756 individuals of molluscs were collected, belonging to 30 families and 57 species, being Rissoidae the most speciose family and Barleeidae the dominant in terms of abundance. The molluscan assemblage on C. montagnei displayed significant spatial and seasonal variations, with the maximum number of individuals and species in summer, whereas evenness and diversity displayed maximum values in spring. The abundance, species richness and diversity of the molluscan assemblage decreased with decreasing in patch-size of C. montagnei , regardless of the vegetative phase of the alga or the sites considered in the study, while evenness showed an opposite trend. The substrate attributes of C. montagnei changed over the vegetative cycle of the alga and showed a similar pattern across sites with values that tended to decrease in autumn during the quiescence phase of the alga. Variation in patch-size of C. montagnei affected also the substrate attributes of the individual alga, with individual thalli becoming smaller with increasing patch-size. The algal surface of a single thallus of C. montagnei ranged on average from 956 cm2 in spring to 289 cm2 in autumn. Furthermore, algal surface together with thallus volume and dry weight were the substrate attributes that explained better the variation of the number of molluscan individuals and species. Overall, our results suggest that the reduction of both patch-size and algal substrate of C. montagnei forests altered the structure and composition of its associated molluscan assemblage. We argue that a reduction or loss of Cystoseira forests could probably trigger bottom-up effects in rocky shores habitats, with consequences for the whole ecosystem structure, functioning and services provided to humans. Image 1 • Decrease in patch-size of Cystoseira reduces the diversity of associated molluscs. • Seasonal phenological changes of the algal contributed to the observed variation. • Molluscan abundance and diversity changed with variation in algal surface. • Algal surface of Cystoseira ranged from 956 cm2 in spring to 289 cm2 in autumn. • Structural features of Cystoseira decreased with increasing patch-size. [ABSTRACT FROM AUTHOR]

Abstract Experiments have shown that increasing dissolved CO 2 concentrations (i.e. Ocean Acidification, OA) in marine ecosystems may act as nutrient for primary producers (e.g. fleshy algae) or a stressor for calcifying species (e.g., coralline algae, corals, molluscs). For the first time, rapid habitat dominance shifts and altered competitive replacement from a reef-forming to a non-reef-forming biogenic habitat were documented over one-year exposure to low pH/high CO 2 through a transplant experiment off Vulcano Island CO 2 seeps (NE Sicily, Italy). Ocean acidification decreased vermetid reefs complexity via a reduction in the reef-building species density, boosted canopy macroalgae and led to changes in composition, structure and functional diversity of the associated benthic assemblages. OA effects on invertebrate richness and abundance were nonlinear, being maximal at intermediate complexity levels of vermetid reefs and canopy forming algae. Abundance of higher order consumers (e.g. carnivores, suspension feeders) decreased under elevated CO 2 levels. Herbivores were non-linearly related to OA conditions, with increasing competitive release only of minor intertidal grazers (e.g. amphipods) under elevated CO 2 levels. Our results support the dual role of CO 2 (as a stressor and as a resource) in disrupting the state of rocky shore communities, and raise specific concerns about the future of intertidal reef ecosystem under increasing CO 2 emissions. We contribute to inform predictions of the complex and nonlinear community effects of OA on biogenic habitats, but at the same time encourage the use of multiple natural CO 2 gradients in providing quantitative data on changing community responses to long-term CO 2 exposure. Graphical abstract Unlabelled Image Highlights • Carbon dioxide (CO 2) may act as a stressor or a resource for marine ecosystems. • Vermetid reef communities were transplanted along CO 2 gradients for 1 year. • Rapid dominance shifts from a reef- to a non-reef-forming habitat were documented. • Community-level changes were nonlinear and the food web simplified under increasing CO 2. • CO 2 disrupts the state of intertidal communities. [ABSTRACT FROM AUTHOR]

Marine and coastal ecosystems are among the most productive environments in the world and their stocks of natural capital offer a bundle of vital ecosystem services. Anthropogenic pressure seriously threatens health and long-term sustainability of marine environments. For these reasons, integrated approaches capable of combining ecological and socio-economic aspects are needed to achieve nature conservation and sustainability targets. In this study, the value of natural capital of the Egadi Islands Marine Protected Area (EI-MPA) was assessed through a biophysical and trophodynamic environmental accounting model. The emergy value of both autotrophic and heterotrophic natural capital stocks was calculated for the main habitats of the EI-MPA. Eventually, the emergy value of natural capital was converted into monetary units to better communicate its importance to local managers and policy-makers. The total value of natural capital in the EI-MPA resulted in 1.12·10 21 sej, equivalent to about 1.17 billion of euros. In addition, using Marxan software, the results of the environmental accounting were integrated with spatial data on main human uses. This integration took into account the trade-offs between conservation measures and human exploitation by means of two different scenarios, with and without considering human uses in the EI-MPA. The comparison between the scenarios highlighted the importance of taking into account human activities in marine spatial planning (MSP), allowing the identification of key areas for natural capital conservation. In conclusion, this study showed the importance of integrating environmental accounting with conservation planning to support effective strategies for ecological protection and sustainable management of human activities. The results of this study represent a first benchmark useful to explore alternative nature conservation strategies in the EI-MPA, and, more in general, in Mediterranean MPAs. [ABSTRACT FROM AUTHOR]