Modificazioni nelle comunità fitobentoniche di fouling in relazione all’impatto antropico ed alla geometria del substrato

Questo studio è stato condotto nella primavera del 2006 in due località del Golfo di Palermo (Arenella e Bandita) a differente grado di impatto antropico. All’interno di ogni località, sono stati scelti siti a differente inclinazione (orizzontale vs verticale). Sono stati campionati i popolamenti mesolitorali dei massi frangiflutti che, insieme a quelli della frangia infralitorale, risentono maggiormente dell’eventuale presenza di inquinamento organico. Le comunità algali nelle due località hanno mostrato differenze in funzione delle diverse caratteristiche ambientali e dei diversi livelli di impatto antropico, in termini di copertura %, strutturazione e diversità specifica. Sono stati inol…

Efficacia delle AMP nella conservazione della biodiversità: i popolamenti a Cystoseira nell’AMP “Capo Gallo-Isola delle Femmine” (PA)

Present-day Mediterranean marine biodiversity is undergoing rapid alteration. Species belonging to genus Cystoseira (biological “formers” of habitat structure) are strongly affected by variations of the environmental conditions (pollution, turbidity, etc.); modification, regression and disappearance of these “canopy-forming algae” have been yet observed in different areas of the Mediterranean Sea. Parks and MPAs, aimed at protecting marine environments, are certainly a central component of conservation strategies and a very successful way to preserve marine biodiversity. The aim of this paper was to assess the current state of Cystoseira assemblages inside the MPA “Capo Gallo-Isola delle Fe…

Interspecific variation in total phenolic content in temperate brown algae

Marine algae synthesize secondary metabolites such as polyphenols that function as defense and protection mechanisms. Among brown algae, Fucales and Dictyotales (Phaeophyceae) contain the highest levels of phenolic compounds, mainly phlorotannins, that play multiple roles. Four temperate brown algae (Cystoseira amentacea, Cystoseira compressa, Dictyopteris polypodioides and Padina pavonica) were studied for total phenolic contents. Total phenolic content was determined colorimetrically with the Folin-Ciocalteu reagent. Significant differences in total phenolic content were observed between leathery and sheetlike algae and also within each morphological group. Among the four species, the she…

La flora e la vegetazione sommersa del porto di Cala Santa Maria nell'isola di Ustica (Pa): contributo allo Studio di Impatto Ambientale (S.I.A.)

ROLE OF SICILY AND CIRCUM-SICILIAN ISLANDS AS RECIPIENT AND DONOR AREA FOR ALIEN MARINE MACROPHYTES IN THE CENTRAL MEDITERRANEAN SEA

The spread of alien species is an ongoing phenomenon which is widely recognized as a major threat to biodiversity at all levels. The particularly high rate of alien introductions to the Mediterranean Sea has been mainly fuelled by the opening of the Suez Canal, by shipping, aquaculture and by a rising trend in seawater temperature. As far as marine macrophytes are concerned, a total of 134 species have been listed as possible aliens in the Mediterranean Sea. Among the possible pathways of introduction, shipping is considered the dominant vector of unintentional species introduction in coastal marine systems worldwide. Traversing the Strait of Sicily, the chief passageway from south to north…

INVESTIGATION ON OLD-GROWTH FORESTS OF SICILY: PRELIMINARY RESULTS

Old-growth forests are natural forests that have developed over a long period of time, without experiencing severe, stand-replacing disturbance a fire, windstorm, or logging. According to UNEP/CBD/SBSTTA definition, an old-growth forest is a primary or a secondary forest which has achieved an age at which structure and species normally associated with old primary forests of that type have sufficiently accumulated to act as a forest ecosystem distinct from any younger age class. In a thematic contribution to the National Biodiversity Strategy, the authors report the following definition of Italian old-growth forests: Forest in which human disturbance is absent or negligible, and in which nat…

<p class="HeadingRunIn"><strong>An additional record of <em>Kyphosus vaigiensis</em> (Quoy & Gaimard, 1825) (Osteichthyes, Kyphosidae) from Sicily clarifies the confused situation of the Mediterranean kyphosids</strong></p>

The lowfin chub, Kyphosus vaigiensis, is reported for the first time off Favignana Island, Sicily, central Mediterranean Sea. The specimen was identified on the basis of morphometric and meristic characters as well as mitochondrial DNA sequences (COI and 16S-rDNA). Two, perhaps three, Kyphosus species-K. bigibbus, K. sectatrix and K. vaigiensis-have been occasionally recorded in the Mediterranean. These species occur both in the Atlantic and Indo-Pacific regions but it is likely they entered the Mediterranean through the Strait of Gibraltar. However, it is unclear whether they have established reproductive native populations in the Mediterranean.

Invasions of the non-indigenous red alga Lophocladia lallemandii (Montagne) F. Schmitz off the Island of Ischia (Tyrrhenian Sea, Italy)

This paper describes the distribution and spread of the non-indigenous red alga Lophocladia lallemandii (Montagne) F. Schmitz along the coast of the Island of Ischia (Tyrrhenian Sea, Italy). Lophocladia lallemandii was monitored through surveys from July 2019 to January 2020 at the Capo Sant’Angelo (Ischia), where L. lallemandii was observed, but not reported, in the years preceding the invasion of the upper rocky infralittoral shore reported here. It is noteworthy that a large portion of the study area is included within one of the two “B no-take” zones of the Marine Protected Area of the “Regno di Nettuno” (“Neptune’s Realm”). During the surveys, the alga was first observed in the middle …

Antibacterial activity and HPLC analysis of extracts from Mediterranean brown algae

The antibacterial activity of methanolic extracts of eight Mediterranean brown algae belonging to the genera Cystoseira sensu lato, Dictyopteris and Padina was investigated. Extracts from Sargassaceae showed antibacterial activity. Specifically, Carpodesmia crinita and Carpodesmia brachycarpa extracts inhibited the growth of the Gram-positive strain Kocuria rhizophila whereas Cystoseira compressa and Carpodesmia amentacea extracts showed antibacterial activity against the Gram-positive strains, Kocuria rhizophila and Staphylococcus aureus. None of them inhibited the growth of the Gram-negative bacterium Escherichia coli. The extracts of Cystoseira sp. pl. and Treptacantha ballesterosii did …

Composizione e struttura della comunità di fouling in un impianto di maricoltura (Golfo di Castellammare, Sicily N-O)

Algal assemblage response to fish-farm biodeposition in southern Tyrrhenian (Gulf of Castellammare, Sicily): preliminary data

Diatoms from thermal-sulphur waters of “Fiume Caldo” (North-western Sicily).

The present study describes the taxonomic composition, richness and seasonal dynamics of the diatom community from thermal-sulphur waters of "Fiume Caldo" (Northwestern Sicily). The diatom flora of these waters consists of 64 taxa, showing similarities with thermal diatom communities from different geographical areas. Among the recorded taxa, Diadesmis confervacea Kütz. is a new record for Sicily. Seasonal changes in assemblage composition and richness have been recorded; the highest diversity values were observed during winter and spring, while during summer the diatom community consisted of a limited number of organisms whereas blue-green algae were quantitatively dominant. Inside the stu…

INTERSPECIFIC VARIATION IN TOTAL PHENOLIC CONTENT IN TEMPERATE BROWN ALGAE

The aim of this study was to focus on interspecific variation of total phenolic contents (TPC) in temperate brown algae also considering their relationship with environmental conditions. In particular, we compared the TPC of four species characterized by different thallus morphology, growth cycle and bathymetric level: Cystoseira amentacea (C. Agardh) Bory, Cystoseira compressa (Esper) Gerloff & Nizamuddin, Dictyopteris polypodioides (A.P. De Candolle) J.V. Lamouroux and Padina pavonica (Linnaeus) Thivy, collected in summer 2011 from the north-western coast of Sicily.

An updated overview of invasive Caulerpa taxa in Sicily and circum- Sicilian Islands, strategic zones within the NW Mediterranean Sea

The spread dynamics of invasive Caulerpa taxa (i.e. Caulerpa cylindracea, C. taxifolia var. taxi- folia and C. taxifolia var. distichophylla) in Sicily and circum-Sicilian Islands, based on relevant publications, grey literature, unpublished data and in situ observations during the last 23 years, is presented here and discussed. Their known distribution is mapped. New records are also reported. Transport-stowaway is considered the most plausible vector of introduction of invasive Caulerpa in the area. The three invasive taxa showed different spread dynamics. Caulerpa cylindracea and C. taxifolia var. distichophylla, behaved as highly successful and fast-spreading taxa, i.e. as true invasive…

Assessment of the environmental quality of the Sicilian coast through a phytoecological and biogeographic analysis

Large-scale habitat measurements have been aided greatly by advances in remote sensing and GIS software. However, the degree of resolution of this technique is still inadequate for many purposes, such as detail monitoring of many habitats that occur on the coast (e.g. temporary Mediterranean pools or ephemeral therophytic grasslands). Lists and distribution mapping of taxa are probably the most commonly used surrogate for overall biodiversity at both local and broader scales. For the Sicilian coasts a complete study, dating back more than 25 years ago and based on a multidisciplinary approach of flora, vegetation and fauna, exists (Raimondo & al. 1990. Quad. Bot. Amb. Appl. 1: 131-182).…

Temporal dynamic of biofilms enhances the settlement of the central-1 Mediterranean reef2 builder Dendropoma cristatum (Biondi, 1859)

Research on marine invertebrate settlement provides baseline knowledge for restoration technique implementation, especially for biogenic engineers with limited dispersion ability. Previously, we determined that the maturity of a biofilm strongly enhances the settlement of the vermetid reef-builder Dendropoma cristatum . In order to elucidate which biofilm features support a higher settlement of this species, we analyse the structure and composition of a marine biofilm over time, through microscopic observations, eukaryotic and prokaryotic fingerprinting analyses and 16S rDNA Illumina sequencing. The vermetid settlement temporal increase matched with the higher biofilm extent on the substrat…

Effects of Caulerpa cylindracea Sonder (Chlorophyta Caulerpaceae) on marine biodiversity

The chief purpose of Marine Protected Areas (MPAs) is biodiversity conservation. The effects that invasive alien species (IAS) have on MPAs are not yet fully known, even though assessing them is fundamental. Effective management plans, indeed, also require knowledge on the dis- tribution, spread dynamics and impact of IAS. We report first observations on the effects of Caulerpa cylindracea Sonder (Chlorophyta Caulerpaceae) on the communities living along the coasts of the Island of Favignana (Egadi Islands MPA, Sicily, Italy). We found that C. cylindracea may have negative effects on the habitat where it settles in two different ways: a) affecting the structure of the native algal community…

Caratteristiche fisico-chimiche e vegetazionali negli ambienti iperalini di bassofondo delle saline di Trapani e Paceco: dati preliminari

Nuove segnalazioni di Caulerpa racemosa var. cylindracea in aree protette della Sicilia nord-occidentale

Searching for the competitive ability of the alien seagrass Halophila stipulacea with the autochthonous species Cymodocea nodosa

The tropical seagrass Halophila stipulacea (Forsskål) Ascherson, 1867 entered in the Mediterranean Sea through the Suez Canal more than 100 years ago. In coastal-marine ecosystems the spatial niche of H. stipulacea is often overlapped with that of native Mediterranean Sea seagrasses and therefore it might out-compete them. Aiming to better understand its invasiveness potential, we monitored a Southern Mediterranean shallow coastal-marine water habitat from August 2010 to August 2011, where H. stipulacea co-occurred with the native seagrass Cymodocea nodosa (Ucria) Ascherson, 1870. Besides, the year-round dynamics of H. stipulacea was also monitored in four periods. To test the hypothesis th…

An updated overview of the marine alien and cryptogenic species from the Egadi Islands Marine Protected Area (Italy)

An updated overview of the marine alien and cryptogenic species recorded in the Egadi Islands Marine Protected Area (Tyrrhenian Sea, Italy), based on relevant publications, grey literature and unpublished data, is presented and discussed. Altogether, 17 species (14 aliens and 3 cryptogenic) belonging to five taxa are present in the area: Rhodophyta (Antithamnionella elegans, Asparagopsis armata, Asparagopsis taxiformis, Bonnemaisonia hamifera, Botryocladia madagascariensis, Ceramium strobiliforme, Laurencia caduciramulosa, Lophocladia lallemandii, Neosiphonia harveyi, Womersleyella setacea), Chlorophyta (Caulerpa cylindracea and Caulerpa taxifolia), Mollusca (Aplysia dactylomela), Arthropod…

Total phenolic content in brown algae from the Sicilian coast

Phlorotannins are polyphenolic secondary metabolites found in almost all brown algae that function as defense against grazers, pathogens and epiphytes but are also involved in photoprotection mechanisms. These com- pounds, produced in the Golgi apparatus, are accumulated in cytoplasm, within vesicules called physodes, or bound to the cell wall. The concentration of phlorotannins differs within and between species, shows geograph- ical variations but may be also affected by abiotic or biotic factors. We present here an overview of the studies carried out on total phenolic content in brown algae collected along the north-western coast of Sicily. The aims of these studies were in particular a)…

Thermal variance affects algal assemblage in rocky pools

The intertidal rocky pools are habitats that, when disconnected from the sea, become highly stressful for sessile organisms such as algae. Algae experience wide changes of water temperature on short temporal scale (e. g. hour or lower) and their coverage and diversity are expected to depend on thermal variance of small water masses trapped at low tide. Here, we want to investigate the relationship between daily thermal variance and the composition, coverage and diversity of rocky pool’s algal community in Western Sicily (Southern MED). We chose 15 intertidal rocky pools and we deployed, in August 2012, thermo-loggers for two days to record temperature changes every 5-min (12 recordings per …

Seasonal patterns of biodiversity in Mediterranean coastal lagoons

Aim: Understanding and quantifying the seasonal patterns in biodiversity of phyto- benthos, macro-zoobenthos and fishes in Mediterranean coastal lagoons, and the species dependence upon environmental factors. Location: The study was carried out in the “Stagnone di Marsala e Saline di Trapani e Paceco,” the largest coastal lagoon system in the central Mediterranean Sea (Sicily, Italy), a Special Protection Area located along one of the central ecological corridors joining Africa and Europe. Methods: The coastal lagoon system was selected as a model ecosystem to investi- gate the seasonal variations in biodiversity indices and dominance–diversity relation- ships in phytobenthos, macro-zoobent…

Effects of Caulerpa cylindracea on marine biodiversity

The Mediterranean sea is an important hotspot for alien species. Following habitat loss, Invasive Alien Species (IAS) are considered to be amongst the most serious threats to biodiversity and natural ecosystem functioning. Among the IAS recorded in the Mediterranean sea, Caulerpa cylindracea Sonder, introduced from Australia and New Caledonia, has raised serious concern due to its negative impact on native communities. We provide some observations on the effects of the presence of C. cylindracea on the communities living along the coasts of the Island of Favignana (Egadi Islands, Marine Protected Areas).

Citizen science projects for monitoring alien macrophytes

To understand the invasive potential and the spread dynamics of an alien species, any newly colonized area needs to be quickly detected. Therefore, regular monitoring programs and public awareness campaigns are essential. Since intensive monitoring activities involving scientists are expensive, the occurrence and spread of marine species could remain undetected or could be detected only years after the initial colonization. Citizen Science initiatives, a potential solution to this problem providing supplemental information that would otherwise be lost, are able to involve different groups of volunteers: students, tourists, divers, underwater photographers, amateurs and fishermen. Volunteers…

The Shallow Seagrass System in W-Sicily (Italy): a large reservoir of organic matter available to upper consumers.

Modeling Macroalgal Forest Distribution at Mediterranean Scale: Present Status, Drivers of Changes and Insights for Conservation and Management

Macroalgal forests are one of the most productive and valuable marine ecosystems, but yet strongly exposed to fragmentation and loss. Detailed large-scale information on their distribution is largely lacking, hindering conservation initiatives. In this study, a systematic effort to combine spatial data on Cystoseira C. Agardh canopies (Fucales, Phaeophyta) was carried out to develop a Habitat Suitability Model (HSM) at Mediterranean scale, providing critical tools to improve site prioritization for their management, restoration and protection. A georeferenced database on the occurrence of 20 Cystoseira species was produced collecting all the available information from published and grey lit…

Unpublished Mediterranean records of marine alien and cryptogenic species

Este artículo contiene 18 páginas, 4 figuras.

Biodiversità e strategie adattative dei vegetali acquatici in un sistema iperalino di bassofondo mediterraneo

Preliminary data on the occurrence of alien macroalgae in the vermetid reef along the coasts of Favignana Island (Southern Tyrrhenian Sea)

Intertidal vermetid reefs are highly diverse systems that provide numerous habitats for animal and vegetal species, leading to an increase of intertidal biodiversity. These habitats, particularly vulnerable to environmental changes and human activities, are now experiencing high mortality in several areas of the Mediterranean Sea. Since alien macroalgae are nowadays considered one of the most serious threats to biodiversity and natural ecosystem functioning, we provide a first baseline assessment of the occurrence of alien species in the vermetid reef along the coasts of the Island of Favignana (Egadi Islands Marine Protected Area). Surveyes carried out in 2015 revealed the only presence of…

Effects of fish-farm biodeposition on periphyton assemblages on artificial substrates in the southern Tyrrhenian Sea (Gulf of Castellammare, Sicily)

An algal assemblage growing on artificial substrata of fish-farm cages was investigated. Specifically, algal response to the effects of fish-farm facilities was studied, in order to identify a possible future descriptor of biodeposition impact. Some sites were positioned upstream of the farms (at least 750 m; ‘controls’) and other sites were positioned downstream of the farms (‘impacts’). All sites were situated in the Tyrrhenian Sea. Control and impact sites differed significantly with regard to the dissolved nutrient profile. The fouling community (samples were scraped from buoys) displayed a reduction gradient in diversity which increased with the effect of fish farms. A total of 51 taxa…

First record of Aplysia dactylomela (Opisthobranchia: Aplysiidae) from the Egadi Islands (western Sicily)

The alien mollusc Aplysia dactylomela is recorded for the first time from the Egadi Islands marine protected area (western Sicily). This species has been widely reported in the Mediterranean and has established populations in Sicily. The presence of a few specimens let us suppose that its occurrence in this area is a recent event and that soon new populations will be sighted in the whole Egadi Islands and on the western and southern coasts of Sicily.

Citizen science: uno strumento di successo per monitorare le specie aliene marine. Il caso studio nelle acque della Sicilia (Mediterraneo centrale)

L’introduzione di specie non indigene invasive (IAS, organismi introdotti in aree esterne al loro areale naturale con comportamento invasivo) è considerata una delle maggiori minacce alla biodiversità e al funzionamento degli ecosistemi naturali (Katsanevakis et al. 2014, Vergeś et al. 2016). Una specie non-nativa (NIS) può diventare invasiva e causare perdita di biodiversità e cambiamenti nei servizi ecosistemici (Giakoumi 2014, Vergés et al. 2016). Nel Mediterraneo oggi sono presenti circa 1.000 NIS, delle quali 134 sono macroite (Verlaque et al. 2015, Alós et al. 2016). Per ridurre il rischio di future introduzioni e meglio comprendere il potenziale invasivo e le dinamiche di diffusione …

Citizen and scientists work together to monitor marine alien macrophytes

The introduction of non-indigenous species (NIS) is an ongoing phenomenon which has been pointed out as a major threat to biodiversity at different levels (Wallentinus, Nyberg 2007, Katsanevakis et al. 2014, Vergés et al. 2016). NIS may in time become invasive (Invasive Alien Species “IAS”) and may cause biodiversity loss and ecosystem service changes (Brunel et al. 2013, Giakoumi 2014, Vergés et al. 2016). The Mediterranean Sea is an important hotspot for marine NIS (ca. 1,000 such species recorded to date, Zenetos et al. 2012, Galil et al. 2015, Verlaque et al. 2015). To reduce the risk of future IAS introduction and to better understand their invasive po- tential and spread dynamics, mon…

The role of Characeae in the communities of the vegetation class Potametea

The stonewort vegetation is commonly classified into the phytosociological class Charetea fragilis F. Fukarek ex Krausch 1964; however, the Characeae are not exclusively found in vegetation stands ascribed to this class but also in other habitat types. In our preliminary investigations, we draw the attention to the relationship between the classes Charetea fragilis and Potametea pectinati Klika in Klika & Novák 1941 in some Sicilian biotopes. In some cases, the Charetea vegetation is ecologically and spatially distinct, although close, from that referable to the Potametea. In some other cases, one or more species of Characeae are structurally intrinsic to the vegetation of Potametea: on…

Citizen and scientsts work together to monitor marine alien species in Sicilian waters (central Mediterranean)

We report on the experience of two citizen science projects: the Project “Caulerpa cylindracea – Egadi Islands” and the Project “Invasive Algae”, included within the “Seawatchers” platform. The first one, sponsored by the STEBICEF Department of the University of Palermo and by the Egadi Islands Marine Protected Area (MPA), aims at creating a database on the spread dynamics of C. cylindracea within the Egadi Islands MPA. The second one, coordinated by the Institute of Marine Sciences of Barcelona (CSIC, Spain), collects data on 10 marine invasive alien species. The results of these projects highlighted the important role that citizen science campaigns can have as early-warning systems. We al…

Tracking marine alien macroalgae in the mediterranean sea: The contribution of citizen science and remote sensing

The accelerating rate of the introduction of non-indigenous species (NIS) and the magnitude of shipping traffic make the Mediterranean Sea a hotspot of biological invasions. For the effective management of NIS, early detection and intensive monitoring over time and space are essential. Here, we present an overview of possible applications of citizen science and remote sensing in monitoring alien seaweeds in the Mediterranean Sea. Citizen science activities, involving the public (e.g., tourists, fishermen, divers) in the collection of data, have great potential for monitoring NIS. The innovative methodologies, based on remote sensing techniques coupled with in situ/laboratory advanced sampli…

Habitat use and selection, daily rhythm, food intake and predation risk of the invasive grapsoid crab Percnon gibbesi in the Mediterranean Sea

Temporal and spatial variation of the algal community in a southern Mediterranean shallow system

The algal community of a shallow system located in Western Sicily (Mediterranean Sea) has been investigated over 1 year in eight ponds (fredde). The spatio-temporal variation in total algal coverage, species richness and coverage in relation to environmental variables has been analysed. The algal community was very species-poor. A total of 50 taxa, mainly detached algae, were identified. A dominance of filamentous and foliose taxa was observed. Significant spatio-temporal differences in total algal coverage, species richness and coverage between the ponds of group A and those of group B were found. The separation into groups A and B was made a priori on the basis of different levels of prox…

Invasive alien species in Mediterranean Marine Protected Areas: the Egadi Islands (Italy) case study

Invasive alien species (IAS) are one of the most severe threats to Mediterranean Sea biodiversity. Currently, the effectiveness of Marine Protected Areas (MPAs) in providing protection for marine biodiversity from IAS is still not fully understood. Here, we analysed eight Mediterranean MPAs located in a strategic geographic position within the Mediterranean basin. All the analysed MPAs were affected by the presence of IAS - evidence of the vulnerability of MPAs to biological invasion. Valuable habitats such as vermetid reef and coralligenous formations have become victim to numerous alien species. Alien species populations are likely to continue increasing in the Mediterranean Sea, so imple…

Diploid Ruppia cirrhosa populations from a southern Mediterranean shallow system

Abstract This paper focuses on the morphology and karyology of representative Ruppia populations from a southern Mediterranean shallow system. The cosmopolitan genus Ruppia L. generally inhabits shallow waters such as coastal lagoons and brackish habitats. Ruppia species are characterised by a simplified morphology and high intraspecific phenotypic plasticity. The chromosome number of Sicilian Ruppia populations is reported here for the first time. The analysed populations showed morphological and reproductive characters of Ruppia cirrhosa (Petagna) Grande but a diploid cytotype (2n = 20). A low fruit production was also observed, suggesting that vegetative reproduction is the main reproduc…

Shifts in macroalgal communities in relation to some abiotic factors: a functional group approach

The aim of the present study was to test whether the functional group approach is effective in describing changes in community structure, resulting from exposure to different substratum inclination and levels of organic pollution. The results of this study suggest that the functional group approach could detect changes in community structure as response to some abiotic factors. However, since species response is not always a functional group response, this method is difficult to generalize and a better definition of the functional group model is required.

Mediterranean identities - environment, society, culture

The Mediterranean Sea, one of the most complex marine ecosystems, is inhabited by a rich and diverse biota which is disproportionate to its dimensions. It is cur‐ rently affected by different pressures, mainly driven by human activities such as cli‐ mate change and bioinvasions. This Sea, also due to its geographic position (wedged between the temperate climate of central Europe and the arid climate of northern Africa), seems to be one of the regions most susceptible to global climate change. The increased rates of introduction and spread of marine alien species may represent a supplementary stress factor to Mediterranean marine native biota already challenged by climatic abnormalities. The…

Ecological function of phenolic compounds from mediterranean fucoid algae and seagrasses: An overview on the genus Cystoseira sensu lato and Posidonia oceanica (L.) Delile

Biodiversity is undergoing rapid and worrying changes, partially driven by anthropogenic activities. Human impacts and climate change (e.g., increasing temperature and ocean acidification), which act at different spatial scales, represent the most serious threats to biodiversity and ecosystem structure and function. In the Mediterranean Sea, complex systems such as fucoid algae and seagrasses, characterized by a high associated biodiversity, are regularly exposed to natural and anthropogenic pressures. These systems, particularly sensitive to a variety of stressors, evolved several physiological and biochemical traits as a response to the different pressures which they are subjected to. For…

La comunità fitobentonica nelle vasche di fredda della Riserva Naturale Orientata “Saline di Trapani e Paceco” (Sicilia nord-occidentale): osservazioni preliminari.

Phycological Herbaria as a Useful Tool to Monitor Long-Term Changes of Macroalgae Diversity: Some Case Studies from the Mediterranean Sea

The Mediterranean Sea is currently experiencing a decline in the abundance of several key species, as a consequence of anthropogenic pressures (e.g., increase in human population, habitat modification and loss, pollution, coastal urbanization, overexploitation, introduction of non-indigenous species and climate change). Herbaria and natural history collections are certainly fundamental for taxonomic studies, but they are also an invaluable, if currently underestimated, resource for understanding ecological and evolutionary responses of species to environmental changes. Macroalgae herbarium collections, which are really consistent (ranging from 200,000 to approximately 500,000 specimens) in …

Interactions among introduced and indigenous submerged macrophytes in a Mediterranean shallow system

In Termini Imerese H. stipulacea has been recorded inside artificial basins, characterized by a sandy bottom (0.80‐2.5 m depth). H. stipulacea in good health conditions shows a competition strategy with C. nodosa. But during winter denudations, C. racemosa var. cylindracea seems to negatively interfere with the rhizomes of H. stipulacea.

The effect of Ruppia cirrhosa features on macroalgae and suspended matter in a Mediterranean shallow system

Relationships among chemical–physical features, total gross suspended organic matter, coverage of the seagrass Ruppia cirrhosa and its associated algal community in eight ponds of a saltworks system of western Sicily (Mediterranean Sea) were investigated in spring and summer 2004. All biological features varied both at different levels of seagrass coverage and between seasons. A low algal diversity (46 taxa, 14.75 ± 1.41 on average) was highlighted; algal coverage and species richness showed to be negatively correlated. Ruppia cirrhosa coverage was negatively correlated with algal coverage, but positively correlated with species richness. Moreover, a significant correlation among R. cirrhos…

A contribution to the characterization of Ruppia drepanensis (Ruppiaceae), a key species of threatened Mediterranean wetlands

To elucidate the taxonomic status of Ruppia drepanensis Tineo ex Guss. (Alismatales, Ruppiaceae), we performed morphological analysis and DNA barcoding of historical materials (including the lectotype) and fresh samples (including those from a recently discovered population near the locus classicus in Sicily, Italy). We conclude that R. drepanensis is a separate species, closely related to R. spiralis L. ex Dumort., that occurs in temporary inland waters from the western to central sectors of the Mediterranean region. We also highlight the importance of vouchers and the need to link molecular investigations to field, ecological, and morphological investigations.

Competition among introduced and indigenous submerged macrophytes in a southern mediterranean shallow system

In Termini Imerese H. stipulacea has been recorded inside artificial basins, located near the harbour, built arranging breakwater barriers along the coast in order to protect the coastal road. From July until the beginning of November the seagrass formed beds with cover values ranging from 70% to 80%, and it was in contact either with the seagrass Cymodocea nodosa (Ucria) Ascherson (cover values of 20-25%) or the green alga Caulerpa prolifera (Forsskål) Lamouroux (cover values of 10-15%). H. stipulacea in good health conditions showed a clear competition strategy with C. nodosa as proved by registered cover values. But during natural denudations occurring in winter, C. racemosa var. cylindr…

Life cycle and reproductive phenology of Ruppia cirrhosa (Petagna) Grande in a southern Mediterranean shallow system

Along Mediterranean coasts, highly variable shallow systems with salinities higher than in marine environment, as saltworks basins or some marginal secondary shallow environments, are widespread; shallow waters function as a dynamic buffer system between open sea and land, and aquatic macrophytes represent key species regulating fluxes of energy and matter. In these systems Ruppia species are often the dominant macrophytes, and markedly colonise shallow habitats with extended beds. Ruppia cirrhosa (Petagna) Grande, mainly found in permanent lagoons, plays a crucial role in Mediterranean hyper-haline shallow waters, being a very important primary contributor to many food webs. In the context…

Efficacia delle AMP nella conservazione della biodiversità: i popolamenti a Cystoseira nell’AMP “Capo Gallo-Isola delle Femmine” (Pa)

Scopo dello studio è quello di i) valutare lo stato di salute e di conservazione delle comunità a Cystoseira presenti nell’A.M.P. “Capo Gallo-Isola delle Femmine” ii) confrontarlo con i dati storici, iii) confrontarlo con quello di siti di controllo al di fuori dell’A.M.P. e quindi iv) verificare il successo/efficacia dell’A.M.P nel proteggere e mantenere queste comunità e quindi la biodiversità di questi ecosistemi dalla sempre più intensa pressione antropica. Lo studio viene condotto, in particolare, sui popolamenti a Cystoseira dell’infralitorale di siti chiave all’interno della Riserva (Zone A, B e C) e di due siti di controllo: Punta Priola (PA) e Monte Cofano (TP). Lo stato di conserv…

Shallow waters as ecological corridors: preliminary data on wind-exposure, physico-chemical features and vegetation structure of the Western Sicilian saltworks system (Saline di Trapani e Paceco, MED)

The study was carried out in the Natural Reserve of Trapani and Paceco saltworks shallow system (western Sicily: 37° 52’ North; 12° 28’East).The main goal is to deepen our understanding of whether the alteration of the complexity of these particular ecosystems is manifested through a consequent reduction of the number of migrant species and their density. To achieve this, we focalized our attention on organic matter fluxes (in terms of origin and availability for apex consumers), and on the density and distribution of aquatic birds.

Sneaking into a Hotspot of Biodiversity: Coverage and Integrity of a Rhodolith Bed in the Strait of Sicily (Central Mediterranean Sea)

Habitat mapping, physical characteristics and benthic community of a rhodolith bed in the Pelagie Islands (Strait of Sicily, Mediterranean Sea) were studied through Multi–Beam Echo–Sounder (MBES), Remotely Operated Vehicle (ROV) and grab samples. The geomorphological analysis revealed an articulated and wide rhodolith bed; video inspections highlighted a bed with high coverage, few sandy patches and with a prevalence of the boxwork morphotype. A total of 207 taxa with 876 specimens were identified, and Polychaeta was the dominant taxon. Linguimaera caesaris, a Lessepsian benthic amphipod, was recorded in all sampling sites, and its presence represents an input to deepen the benthic assembla…

The fouling community as an indicator of fish farming impact in Mediterranean

Fouling species richness, abundance and composition and biomass were chosen as the descriptors of effect of fish farm organic enrichment. The study was carried out in September 2004 in the Gulf of Castellammare (South Tyrrhenian, Mediterranean). The fouling species were sampled from plastic buoys spaced throughout the study area both up- [UP] and down-stream [DOWN]. The results showed that fouling community responded to the chronic input of allochthonous organic matter experiencing local changes more or less significantly with regard to abundance, species composition and general community diversity. Upper fouling would work as a first filter naturally opposed by environment resistance assim…

A new contribution to the alien macroalgal flora of the Ustica Island Marine Protected Area (Tyrrhenian Sea, Italy)

A second record of the non-indigenous species Botryocladia madagascariensis G. Feldmann (Rhodophyta) along the coasts of the “Ustica Island” Marine Protected Area (Tyrrhenian Sea, Italy) is reported. With this additional record for the Sicilian coasts, we provide a description of collected specimens of B. madagascariensis and habitat details. Numerous fertile female gametophytes with cystocarps immersed in vesicles were also observed, for the second time in the Mediterranean Sea, and described.

Seasonal variation in total phenolic content of Dictyopteris polypodioides (Dictyotaceae) and Cystoseira amentacea (Sargassaceae) from the Sicilian coast

This study focuses on the differences in total phenolic content and its seasonal variations in two temperate brown algae, Cystoseira amentacea (C. Agardh) Bory and Dictyopteris polypodioides (A.P. De Candolle) J.V. Lamouroux, inhabiting respectively the infralittoral fringe and the upper infralittoral zone. Phenolic compounds are secondary metabolites, found in almost all brown algal orders, that function as defense against grazers, epiphytes and UV radiation. Total phenolic content was determined colorimetrically with the Folin-Ciocalteu reagent. Results showed significant differences in total phenol content between D. polypodioides and C. amentacea with higher values observed in the first…

Competition between algae and seagrasses: a Ruppia cirrhosa (Petagna) Grande bed in western Mediterranean Sea

Measurement and Conservation of Species and Habitat Biodiversity at Different Scales on Small Mediterranean Islands

In this paper we discuss current methodologies for measuring biodiversity, analyse pros and cons at different scales, and finally propose distribution mapping as the most suitable method for measuring floristic biodiversity on small Mediterranean islands. These territories often host endangered flora and habitats, and have peculiarities that distinguish them from the mainland and the larger islands.

The shallow seagrass system in Southern Mediterranean (Sicily, Italy): a large sink of organic matter available to upper consumers.

The effects of human activities related to salt production on the global complexity of a shallow hyperhaline system (Sicily, Italy) were investigated. This through monitoring dynamics of some physical, chemical and trophic factors recognised as main constraints for the origin of organic matter and its availability to apex consumers. The system was dominated by seagrass Ruppia cirrhosa and large stands of macroalga Chaetomorpha linum; isopods and gasteropods were the most abundant taxa among benthic organisms, while Aphanius fasciatus and Atherina boyeri represented up to 90% of all catch among the small resident fishes. Ruppia could function as a multidimensional framework able to increase …

The Project “Caulerpa cylindracea in the Egadi Islands”: citizens and scientists working together to monitor marine alien species

The creation of early-warning systems is crucial for preventing and reducing the risk of invasive species introduction. In this respect, the contribution of citizen-scientists (tourists, students, teachers, divers and fishermen) in providing information and data (validated by taxonomic experts) on the occurrence of marine invasive species that would otherwise be impossible to collect, is crucial in understanding the phenomenon of biological invasions. The Citizen Science Project “Caulerpa cylindracea - Egadi Islands”, launched in 2014 and ended in 2016, aimed at creating a database on the spread dynamics and the levels of threat of the invasive green alga Caulerpa cylindracea within the Ega…

Seasonal variation in total phenolic content of Dictyopteris polypodioides (Dictyotaceae) and Cystoseira amentacea (Sargassaceae) from the Sicilian coast

Phlorotannins are polyphenolic secondary metabolites found in almost all brown algae that function as defense against grazers, pathogens and epiphytes but are also involved in photoprotection mechanisms. These compounds, produced in the Golgi apparatus, are accumulated in cytoplasm, within vesicules called physodes, or bound to the cell wall. The concentration of phlorotannins dif-fers within and between species, shows geographical variations but may be also affected by abiotic or biotic factors. Aims of this study were to evaluate: (i) the temporal variation of total phenolic content in two brown algae, Dictyopteris polypodioides and Cystoseira amentacea, living respec-tively in the upper …

Human activities trigger change in marine landscape

Biodiversity is undergoing rapid and worrying changes, partially driven by anthropogenic activities. Human impacts and climate change (e.g. increasing temperature and ocean acidification), which act at different spatial scale, represent the most serious threats to biodiversity and ecosystem structure and function. In this overview, the effects of anthropogenic pressures on unique and valuable Mediterranean systems, such as Cystoseira sp. pl. forest and Posidonia oceanica meadows, are examined. These complex systems, characterized by a high associated biodiversity, are regularly exposed to natural and anthropogenic pressures. Due to the central role they have for several important ecological…

Temporal dynamic of biofilms enhances the settlement of the central-Mediterranean reef-builder Dendropoma cristatum (Biondi, 1859).

Abstract Research on marine invertebrate settlement provides baseline knowledge for restoration technique implementation, especially for biogenic engineers with limited dispersion ability. Previously, we determined that the maturity of a biofilm strongly enhances the settlement of the vermetid reef-builder Dendropoma cristatum. To elucidate settlement-related biofilm features, here we analyse the structure and composition of marine biofilms over time, through microscopic observations, eukaryotic and prokaryotic fingerprinting analyses and 16S rDNA Illumina sequencing. The vermetid settlement temporal increase matched with the higher biofilm coverage on the substratum and the reduction of th…

Differences in the growth cycle ofRuppia cirrhosa(Petagna) Grande in a Mediterranean shallow system

Ruppia cirrhosa growth cycle was analysed in a southern Mediterranean shallow system throughout 1 year. We examined the temporal variation in R. cirrhosa cover percentage, shoot density, biomass, leaf length, no. flowers m-2 and no. fruits m-2 in two groups of pond characterized by differences in some environmental parameters. Ponds were comparable for salinity and temperature but they differed for other environmental parameters such as water depth, level of suspended organic matter and chlorophyll a (CHL a). Biological parameter values were higher in B ponds, characterized by lower values of water depth, suspended organic matter and CHL a. A seasonal trend for all considered biological par…

Citizen science: a successful tool for monitoring invasive alien species (IAS) in Marine Protected Areas. The case study of the Egadi Islands MPA (Tyrrhenian Sea, Italy)

The chief purpose of Marine Protected Areas (MPAs) is biodiversity conservation. The effects that invasive alien species (IAS) have on MPAs, and vice versa, are not yet fully known, even though assessing them is crucial for MPA planning. Management plans require sound knowledge of the pathways of introduction, the impact and current distribution of IAS. Monitoring plans are essential for preventing and reducing the risk of IAS introduction. In this respect, the involvement of citizen scientists in gathering data (validated by taxonomic experts) on the occurrence of IAS, that would otherwise be impossible to collect, may be crucial. We report on our experience of citizen science in the Egadi …

Spreading of the alien seagrass Halophila stipulacea (Hydrocharitaceae) along the sicilian coast (western Mediterranean Sea)

Halophila stipulacea (Forsskål) Ascherson is a tropical seagrass distributed along the western coasts of the Indian Ocean and in the Red Sea (den Hartog, 1977). This species was previously considered a paleomediterranean element, survived as a relict in the eastern Mediterranean Sea, but later on Por (1971) hypothesized that it was a Lessepsian immigrant entered the Mediterranean Sea after the opening of the Suez Canal (1869). H. stipulacea remained in the eastern Mediterranean for several decades (Lipkin, 1975), and only recently it spreads towards the western basin through Malta and the Ionian coast of Sicily (Lanfranco, 1970; Van der Velte and Den Hartog, 1989; Alongi et al., 1993). The …

An additional record of Kyphosus vaigiensis (QuoyGaimard, 1825) (Osteichthyes, Kyphosidae) from Sicily clarifies the confused situation of the Mediterranean kyphosids.

The lowfin chub, Kyphosus vaigiensis, is reported for the first time off Favignana Island, Sicily, central Mediterranean Sea. The specimen was identified on the basis of morphometric and meristic characters as well as mitochondrial DNA sequences (COI and 16S-rDNA). Two, perhaps three, Kyphosus species - K. bigibbus, K. sectatrix and K. vaigiensis - have been occasionally recorded in the Mediterranean. These species occur both in the Atlantic and Indo-Pacific regions but it is likely they entered the Mediterranean through the Strait of Gibraltar. However, it is unclear whether they have established reproductive native populations in the Mediterranean.

The genus Ruppia L. (Ruppiaceae) in the Mediterranean region: An overview

Abstract This paper reviews the current knowledge on the diversity, distribution and ecology of the genus Ruppia L. in the Mediterranean region. The genus Ruppia, a cosmopolitan aquatic plant complex, is generally restricted to shallow waters such as coastal lagoons and brackish habitats characterized by fine sediments and high salinity fluctuations. In these habitats Ruppia meadows play an important structural and functional role. Molecular analyses revealed the presence of 16 haplotypes in the Mediterranean region, one corresponding to Ruppia maritima L., and the others to various morphological forms of Ruppia cirrhosa (Petagna) Grande, all together referred to as the “R. cirrhosa s.l. co…

Distribution of Caulerpa taxifolia var. distichophylla (Sonder) Verlaque, Huisman & Procaccini in the Mediterranean Sea

The Non-Indigenous Species (NIS) Caulerpa taxifolia var. distichophylla (Sonder) Verlaque, Huisman & Procaccini has been reported for the first time in the Mediterranean Sea along the coast of South Turkey. This NIS is actively expanding into the Eastern and Western Mediterranean Sea. In this paper, we present an overview of the current distribution of this alga in the Mediterranean Sea, based on relevant scientific publications, grey literature and personal observations. New records from the Sicilian coast (Italy) are also reported. Caulerpa taxifolia var. distichophylla was found over a wide range of environmental conditions (depth, light and substratum), suggesting a broad ecolog…

Responses of macroalgal community to environmental changes

Species of Cystoseira (Ochrophyta, Fucales) seem to be sensitive to a variety of environmental changes, as a consequence of which, they are now used in ecological status assessment. On the contrary, invasive species tend to be more resilient to disturbances than Cystoseira species, and thus environmental changes to allow them to out-compete these species. All these evidences lead to consider Cystoseira species, as well as invasive species, as biological indicators of environmental changes. Therefore, the effects of environmental changes can be measured through: (1) the assessment of the current state of the popu- lations of Cystoseira species and of invasive species, (2) the comparison of i…

One Chara does not make Charetea in the Mediterranean aquatic vegetation

The results of preliminary phytosociological investigations on freshwater communities of Sicily biotopes with a significant presence of Characeae are presented. In spite of the relatively frequent occurrence of Characeae, a typical Charetea intermediae vegetation is rather rare in the investigated biotopes. Indeed, the Characeae are mainly part of communities attributable to the classes Potamogetonetea, Phragmito-Magnocaricetea, Juncetea maritimi and Isoeto-Nanojuncetea. Some ecological and functional implications are discussed, along with some consequences on conservation measures and policies, caused by the lack of knowledge on the Characeae of Sicily.

First assessment of the vermetid reefs along the coasts of Favignana Island (Southern Tyrrhenian Sea)

Intertidal vermetid reefs, particularly vulnerable to environmental changes and human activities, are now experiencing high mortality in several areas of the Mediterranean Sea. Since the increase of knowledge on this habitat is important for conservation purposes, we provide a first baseline assessment of the vermetid reefs along the coasts of the Favignana Island (Marine Protected Area “Egadi Islands”). Preliminary results showed the presence of a true reef, similar to a fringing reef, displaying at least three local patterns, distinguishable for width (from 2.3 to 15.5 m), height of the outer and of the inner margin (from 5.6 to 18 cm and from 8.3 to 26 cm, respectively) and number, width…

Effects of temperature on total phenolic compounds in Cystoseira amentacea (C. Agardh) Bory (Fucales, Phaeophyceae) from southern Mediterranean Sea

The aim of this study was to test the effects of temperature on phenolic content of the brown seaweed Cystoseira amentacea. Phenolic compounds are secondary metabolites involved in different protection mechanisms as, for example, against grazers, epiphytes and UV radiation. Seasonal variations of phenolic content in C. amentacea were analysed and laboratory experiments, in which C. amentacea was exposed to an increase of temperature (25°C and 30°C), were performed. Total phenolic content (TPC) was determined colorimetrically with the Folin–Ciocalteu reagent. In C. amentacea, a seasonal pattern in TPC was observed, with a maximum value in winter-spring. C. amentacea responded significantly t…

OBSERVADORES DEL MAR - A MARINE CITIZEN SCIENCE PLATFORM WORKING FOR A HEALTHY OCEAN

VII International Symposium on Marine Sciences (ISMS 2020), 1-3 July 2020 (Barcelona).-- 3 pages

Risposte agli stress ambientali in CYSTOSEIRA (C. AGARDH): effetti della temperatura sul contenuto dei composti fenolici

Phenolic compounds are secondary metabolites involved in different protection mechanisms as, for example, against grazers, epiphytes and UV radiation. Seasonal variations of phenolic content in C. amentacea were analysed and laboratory experiments, in which C. amentacea was exposed to an increase of temperature (258C and 308C), were performed. Total phenolic content (TPC) was determined colorimetrically with the Folin–Ciocalteu reagent. In C. amentacea, a seasonal pattern in TPC was observed, with a maximum value in winter-spring. C. amentacea responded significantly to the temperature treatments with a consistent decrease in TPC after 48 h.

Algal assemblages response to fish-farm biodeposition in a Southern Mediterranean area (Gulf of Castellammare, Sicily): preliminary data

This study, carried out in the Gulf of Castellammare (northern coast of Sicily), concerns the effects of fish-farm nutrient enrichment on the algal assemblage growing on artificial substrata of cages. A total of 51 taxa were identified (3 Cyanophyceae, 3 Phaeophyceae, 5 Bacillariophyceae, 3 Chlorophyceae, 6 Ulvophyceae and 31 Rhodophyceae). A dominance of opportunistic species was highlighted, following a gradient from impact areas to controls.

Vegetation strategy in a southern Mediterranean shallow system

First assessment of the epifauna associated with macroalgae of the vermetid reef along the coasts of Favignana Island (South Tyrrhenian Sea)

With this study we provide a first baseline assessment of the epifauna associated with the macroalgae of the vermetid reefs present along the coasts of the Island of Favignana (Egadi Islands Marine Protected Area, Italy). A total of 14 taxa were identified. Epifaunal assemblages differed according to structure and composition of algal communities. The amphipod group presented the highest number of individuals. The tubicolous species Ampithoe ramondi Audouin, 1826 (Ampithoidae) was the most abundant species.

Comunità vegetali acquatiche

La Riserva Naturale Orientata “Saline di Trapani e Paceco” (Sicilia occidentale: 37° 52’ Nord; 12° 28’ Est), una delle più importanti aree umide costiere della Sicilia occidentale, costituisce un ambiente poco stabile (sistema iperalino di bassofondo) caratterizzato da una marcata fluttuazione della salinità, da temperatura elevata (dovuta alla bassa profondità ed alla intensa radiazione solare) e da basse concentrazioni di ossigeno. Le condizioni ambientali estreme determinano una selezione forzata che porta all’affermarsi di comunità poco diversificate dominate da organismi caratterizzati da peculiari strategie adattative. Recentemente è stato condotto uno studio nei bacini di fredda dell…