Caulerpa racemosa (Forsskål) J. Agardh è una specie lessepsiana altamente invasiva e le conoscenz... more Caulerpa racemosa (Forsskål) J. Agardh è una specie lessepsiana altamente invasiva e le conoscenze sull'effetto della sua diffusione sui popolamenti zoobentonici in Mediterraneo sono molto scarse. Lo scopo di questo studio è quello di valutare l'effetto immediato della rimozione di C. racemosa sui popolamenti zoobentonici dell'infralitorale superficiale roccioso. E' stato condotto un esperimento manipolativo in un sito prospiciente un'area urbanizzata del nord Sardegna (Porto Torres). Durante l'estate 2004 sono state scelte delle aree random di 20x20 cm, nelle quali C. racemosa è stata rimossa, e delle aree di controllo. Successivamente (ad un giorno e ad un mese di distanza dopo la prima rimozione), sono stati raccolti campioni attraverso l'uso di cilindri di plastica (diametro 40 mm) e di un raschietto metallico. Il materiale è stato fissato in formalina e gli animali raccolti sono stati identificati e contati. Dall'analisi multivariata risulta che ...
In the summer months of 2008 hard benthic coastal substrates were monitored within the marine pro... more In the summer months of 2008 hard benthic coastal substrates were monitored within the marine protected area of Tavolara-Punta Coda Cavallo in order to early detect Crysophaeum taylori Lewis & Bryan (Pelagophyceae) blooms, which occurred in 2007, and to eventually investigate environmental triggers for mucilage formation.
Une etude pilote dans le Parc National de l'Ile d'Asinara (Mediterranee nord-occidentale)... more Une etude pilote dans le Parc National de l'Ile d'Asinara (Mediterranee nord-occidentale) situee dans la Baie Giordano a permis d'examiner la variation spatiale de l'abondance des petits invertebres vivant sur les fonds rocheux couverts d'algues de l'infralittoral superieur. Six zones experimentales ont ete selectionnees dans un assemblage mixte d'algues dressees dans la baie. Les echantillons de faune benthique ont ete preleves en coupant les algues a la surface du rocher avec des cylindres en plastique ouverts a l'extremite et d'un diametre de 40, 60 et 80 mm (petite, moyenne et grande taille respectivement). Les resultats montrent que l'abondance des taxons les plus communs de la macrofaune ou de la meiofaune, n'est pas influencee par la taille de l'echantillon: ceci revele que la distribution des organismes est heterogene spatialement et que la distance moyenne dans l'agregation des assemblages est plus grande que les tailles considerees des. unites d'echantillonnage. De plus, la resolution taxonomique utilisee est discutee comme cause possible des resultats obtenus. L'analyse des avantages et des couts a permis de determiner la position optimale des ressources utilisees en vue de l'echantillonnage futur des petits invertebres benthiques de ce site.
Journal of the Marine Biological Association of the United Kingdom, 2005
Ophelia bicornis sensu lato is a polychaete living in intertidal sandy habitats of Mediterranean ... more Ophelia bicornis sensu lato is a polychaete living in intertidal sandy habitats of Mediterranean and European Atlantic coasts, whose systematics have been strongly debated in the past few decades. In the present work the count of nephridiopores was coupled with genetic analysis carried out with DNA markers (inter simple sequence repeats) for a total of 30 individuals collected at six Italian beaches. Exact test, analysis of molecular variance, non-metric multidimensional scaling and assignment tests clearly separated individuals with five nephridiopore pairs from those with six pairs. This finding validated results of a recent allozyme study in which O. bicornis sensu lato was split into O. bicornis sensu stricto (six nephridiopore pairs) and O. barquii (five nephridiopore pairs). This paper represents a further contribution to the estimation of biodiversity within marine invertebrates.
The wide range of anthropogenic disturbances influencing marine coastal assemblages is of increas... more The wide range of anthropogenic disturbances influencing marine coastal assemblages is of increasing concern. Rocky intertidal communities are particularly sensitive to disturbance from indirect agents, such as sewage and industrial effluents (Littler and Murray, 1975), and to more direct agents, such as harvesting and trampling (Duran and Castilla, 1989; Underwood and Kennelly, 1990;
We studied the spatial variability and within-year temporal changes in hydrological features, gra... more We studied the spatial variability and within-year temporal changes in hydrological features, grain size composition and chemical characteristics of sediments, as well as macrofaunal assemblages, along a heavily modified inlet in the Gulf of Oristano (western Sardinia, Italy). The inlet connects the Cabras lagoon to the gulf through a series of convoluted creeks and man-made structures, including a dam and fish barriers built in the last three decades. Sediments were muddy and mainly composed of the ''non-sortable'' fraction (i.e., <8 lm particle size) in all four areas investigated: Lagoon, Creeks, Channel and Seaward. Along the inlet, however, the ratio between the <8 lm and the 8-64 lm fractions was highest in Creeks and Channel, between the fish barriers and the dam, suggesting impaired hydrodynamics. Consistently, steep gradients in water salinity, temperature and dissolved oxygen concentrations were found in proximity to the fish barriers. The whole inlet was characterized by a major organic enrichment of sediments, with up to an annual mean of 33.6% of organic matter and 11.7% of total organic carbon in Seaward due to the presence of seagrass leaf litter. Acid-volatile sulphide and chromiumreduced sulphur concentrations were highest throughout the year in Seaward and Lagoon, respectively, with a peak in summer. Consistently, the whole inlet supported low structured macrofaunal assemblages dominated by few opportunist species, with a relatively lower diversity in Lagoon throughout the year and the highest abundances in Seaward in summer. We infer that the presence of artificial structures along the inlet, such as fish barriers and the dam, impair the lagoon-gulf hydrodynamics, sediment exchange and animal recruitment and colonization. We suggest that the removal of these structures would favour water renewal in the Cabras lagoon, but would also increase the outflow of organic C-bonding fine particles into the gulf with serious consequences for Posidonia oceanica and Cymodocea nodosa seagrass meadows. We conclude that all possible consequences of such initiatives should be carefully considered before any action is taken.
In organic-enriched sedimentary systems, like many Mediterranean coastal lagoons, a detailed anal... more In organic-enriched sedimentary systems, like many Mediterranean coastal lagoons, a detailed analysis of sediment grain size composition and partitioning within the muds is crucial to investigate sedimentological trends related to both hydrodynamic energy and basin morphology. In these systems, sediment dynamics are particularly important because the partitioning and transport of fine sediments can strongly influence the redistribution and accumulation of large amounts of organic matter, and consequently the distribution of benthic assemblages and the trophic status and functioning of a lagoon. Nevertheless, studies on benthic-sediment relationships have been based mainly on a rather coarse analysis of sediment grain size features. In muddy systems, however, this approach may impede a proper evaluation of the relationships and effects of the distribution of fine sediment and organic matter on the biotic benthic components. Here we show that the distribution of sedimentary organic matter (OM) and total organic carbon (TOC) in the Cabras lagoon (Sardinia, Italy) can be explained (i.e., predicted) as a function of a nonlinear increase in the amount of the cohesive fraction of sediments (68 lm grain size particles) and that this fraction strongly influences the structure, composition and distribution of macrobenthic assemblages. Even in such a homogeneously muddy system, characterized by ''naturally" occurring impoverished communities, impaired benthic assemblages were found at 68 lm, OM, TOC contents of about 77%, 11% and 3.5%, respectively. A review of studies conducted in Mediterranean coastal lagoons highlighted a lack of direct integrated analysis of sediment features and the biotic components. We suggest that, especially in organic-enriched coastal lagoons, monitoring programs should primarily investigate and consider the cohesive fraction of sediments in order to allow a better assessment of benthic-sediment relationships and ecological quality of the system.
The effect of human trampling on the abundance of small invertebrates inhabiting rocky shallow bo... more The effect of human trampling on the abundance of small invertebrates inhabiting rocky shallow bottoms was studied at Asinara Island MPA. To this aim we have conducted two experiments. The first was a quantitative study and tested the hypothesis that small invertebrates are more abundant at no-entry locations than at the location visited by tourists through time (before, during and after tourist season). The second was a manipulative experiment and tested the hypothesis that the abundance of small invertebrates is indirectly related to experimental trampling intensities. The effect due to tourist visitation was not highlighted on overall assemblages, suggesting that present seasonal tourist load at the MPA does not cause a significantly negative effect on the zoobenthic community studied. Although tourists exhibited trampling activity at the visited location, none of taxa examined showed a significant lower abundance during and strictly after the end of seasonal tourism peak in the visited location, rather than at control locations. However, results obtained with the second experiment suggested that the effects of different experimental trampling intensities on small invertebrates were variable among taxa. The experimental trampling caused immediate declines in the density of tanaids, nematodes, acari, bivalves, gammarids, echinoderms, isopods, and harpacticoids. For some of these taxa a recovery in abundance was observed within one month.
In this paper, two benthic habitats have been investigated in a fully protected site and two cont... more In this paper, two benthic habitats have been investigated in a fully protected site and two control sites at the Tavolara-Punta Coda Cavallo marine protected area (MPA) (NE Sardinia). Overall, a protection effect on the benthic assemblages was highlighted in the shallow subtidal (5 m deep) rather than at intertidal algal turf habitat. Structure of assemblages at the shallow subtidal habitat is different in the fully protected site vs. controls, while this was not true for the intertidal habitat. At the subtidal, this finding is probably linked to indirect effects due to an increase of consumers in the protected site (e.g., sea urchins), while the lack of direct impacts in the intertidal at control sites is indicative of very similar assemblages. Cover of encrusting algae was significantly higher at the subtidal protected site suggesting a possible higher grazing pressure. Possible causes underlying the inconsistency of results obtained between habitats include the possibility that trophic cascade effects have a different influence at different heights on the shore. The need to estimate the interconnection among benthic habitats through trophic links is also highlighted to provide an estimate of the vulnerability to protection of various habitats.
Marine protected areas (MPAs) represent a potentially useful management tool to preserve biodiver... more Marine protected areas (MPAs) represent a potentially useful management tool to preserve biodiversity. Protection effectiveness was investigated at Tavolara-Capo Coda Cavallo MPA by comparing assemblages of rocky shores at a location ÔAÕ level of protection (island), with those at two locations at ÔBÕ level of protection (one on an island and one on the mainland coast) and two at ÔCÕ level of protection (one on an island and one on the mainland coast). Results did not indicate significant differences in structure of intertidal assemblages among locations under different levels of protection (ÔAÕ, ÔBÕ and ÔCÕ). Protection was not found to be a significant source of variation to low-shore assemblages investigated. In contrast, assemblages seemed to be more dependent on the geographical location within the MPA. Results have important implications for conservation of marine coastal assemblages and would indicate that inclusion of representative assemblages within systems of marine protected areas should target rocky shores both on the mainland and on islands.
... MARCO CURINI-GALLETTI Dipartimento di Zoologia e Antropologia Biologica, Corso Margherita di ... more ... MARCO CURINI-GALLETTI Dipartimento di Zoologia e Antropologia Biologica, Corso Margherita di Savoia 15, I ... ALBERTO CASTELLI Dipartimento di Scienze dell&#x27;Uomo e dell&#x27;Ambiente, Via Volta 6, I ... Vilanova i la Geltni, Barcelona Portopalo, Ragusa Vigo Porto Torres Ancona ...
... Simple associations included a positive relationship of both Ficopomatus enigmaticus and Coro... more ... Simple associations included a positive relationship of both Ficopomatus enigmaticus and Corophium sextonae, patchily distributed along the shores, with sediment sorting (σ), an index of sediment selection due to hydrodynamic energy. ...
La ricerca qui descritta si è svolta nell'area marina protetta (AMP) dell'Isola dell'Asinara e ha... more La ricerca qui descritta si è svolta nell'area marina protetta (AMP) dell'Isola dell'Asinara e ha cercato di valutare l'effetto del calpestio sulla comunità zoobentonica associata ad alghe dell'infralitorale superiore di fondo roccioso. E' stato condotto un esperimento multifattoriale di simulazione del calpestio: in due cale "no entry, no take" sono state scelte 6 aree e, 3 intensità di calpestio sperimentale (0, 60 e 120 calpestii per quadrato di 20x20 cm), sono state attribuite a random nelle aree. I prelievi sono stati compiuti con cilindri di plastica (diametro 40 mm) e un raschietto metallico; sono stati raccolti 2 campioni per quadrato. Il materiale è stato fissato in formalina. In laboratorio sono state separate le due componenti mediante adeguati setacci; gli animali raccolti sono stati identificati e contati. Dall'analisi delle similarità risulta che, per entrambe le componenti, vi è differenza significativa tra i controlli e le aree dove è stato effettuato il calpestio (ANOSIM macrofauna p=0,4% R=0,45, meiofauna p=0,5% R=0,50). Inoltre dai confronti a coppie tra i livelli di calpestio risulta una differenza significativa tra i controlli e le due intensità di calpestio (60 e 120), mentre non vi è differenza significativa tra questi ultimi due trattamenti. Sebbene non si possa fare nessuna previsione sulla resilienza della comunità, questi risultati suggeriscono che sia la macrofauna sia la meiofauna siano estremamente vulnerabili a questo tipo di disturbo.
Caulerpa racemosa (Forsskål) J. Agardh è una specie lessepsiana altamente invasiva e le conoscenz... more Caulerpa racemosa (Forsskål) J. Agardh è una specie lessepsiana altamente invasiva e le conoscenze sull'effetto della sua diffusione sui popolamenti zoobentonici in Mediterraneo sono molto scarsi. Lo scopo di questo studio è quello di valutare l'effetto immediato della rimozione di ...
L'istituzione delle Aree Marine Protette (AMP) consente adeguate misure di conservazione dell'amb... more L'istituzione delle Aree Marine Protette (AMP) consente adeguate misure di conservazione dell'ambiente marino. Tuttavia l'efficacia di tale protezione dovrebbe essere verificata attraverso programmi di monitoraggio, utilizzando specie che siano facili da identificare e analizzare in maniera non distruttiva. In tale contesto è stata individuata Patella ferruginea, che risulta essere l'invertebrato marino più minacciato del Mediterraneo occidentale. L'obiettivo dello studio è quello di stimare i livelli di diversità genetica e flusso genico di alcune popolazioni di P. ferruginea dell'AMP dell'Isola dell'Asinara. È stato prelevato il materiale biologico di 10 esemplari da 3 diversi siti, tramite escissione di piccole quantità di tessuto muscolare, seguendo un protocollo da noi sperimentato sulla specie P. ulyssiponensis. Tale protocollo assicura la sopravvivenza degli esemplari campionati. L'analisi genetica è stata condotta effettuando la genotipizzazione di un subcampione di individui per ciascun sito utilizzando la tecnica ISSR (Inter-Simple Sequence Repeat). I risultati ottenuti indicano una notevole uniformità genetica tra gli individui appartenenti a ciascun sito, contrapposta ad una moderata eterogeneità genetica tra gli individui appartenenti ai tre siti. Questi fatti suggeriscono inoltre che P. ferruginea possa aver subito erosione genetica negli anni passati in relazione alla sua raccolta, e che i livelli di flusso genico non siano elevati anche su piccola scala geografica.
Caulerpa racemosa (Forsskål) J. Agardh è una specie lessepsiana altamente invasiva e le conoscenz... more Caulerpa racemosa (Forsskål) J. Agardh è una specie lessepsiana altamente invasiva e le conoscenze sull'effetto della sua diffusione sui popolamenti zoobentonici in Mediterraneo sono molto scarse. Lo scopo di questo studio è quello di valutare l'effetto immediato della rimozione di C. racemosa sui popolamenti zoobentonici dell'infralitorale superficiale roccioso. E' stato condotto un esperimento manipolativo in un sito prospiciente un'area urbanizzata del nord Sardegna (Porto Torres). Durante l'estate 2004 sono state scelte delle aree random di 20x20 cm, nelle quali C. racemosa è stata rimossa, e delle aree di controllo. Successivamente (ad un giorno e ad un mese di distanza dopo la prima rimozione), sono stati raccolti campioni attraverso l'uso di cilindri di plastica (diametro 40 mm) e di un raschietto metallico. Il materiale è stato fissato in formalina e gli animali raccolti sono stati identificati e contati. Dall'analisi multivariata risulta che ...
In the summer months of 2008 hard benthic coastal substrates were monitored within the marine pro... more In the summer months of 2008 hard benthic coastal substrates were monitored within the marine protected area of Tavolara-Punta Coda Cavallo in order to early detect Crysophaeum taylori Lewis & Bryan (Pelagophyceae) blooms, which occurred in 2007, and to eventually investigate environmental triggers for mucilage formation.
Une etude pilote dans le Parc National de l'Ile d'Asinara (Mediterranee nord-occidentale)... more Une etude pilote dans le Parc National de l'Ile d'Asinara (Mediterranee nord-occidentale) situee dans la Baie Giordano a permis d'examiner la variation spatiale de l'abondance des petits invertebres vivant sur les fonds rocheux couverts d'algues de l'infralittoral superieur. Six zones experimentales ont ete selectionnees dans un assemblage mixte d'algues dressees dans la baie. Les echantillons de faune benthique ont ete preleves en coupant les algues a la surface du rocher avec des cylindres en plastique ouverts a l'extremite et d'un diametre de 40, 60 et 80 mm (petite, moyenne et grande taille respectivement). Les resultats montrent que l'abondance des taxons les plus communs de la macrofaune ou de la meiofaune, n'est pas influencee par la taille de l'echantillon: ceci revele que la distribution des organismes est heterogene spatialement et que la distance moyenne dans l'agregation des assemblages est plus grande que les tailles considerees des. unites d'echantillonnage. De plus, la resolution taxonomique utilisee est discutee comme cause possible des resultats obtenus. L'analyse des avantages et des couts a permis de determiner la position optimale des ressources utilisees en vue de l'echantillonnage futur des petits invertebres benthiques de ce site.
Journal of the Marine Biological Association of the United Kingdom, 2005
Ophelia bicornis sensu lato is a polychaete living in intertidal sandy habitats of Mediterranean ... more Ophelia bicornis sensu lato is a polychaete living in intertidal sandy habitats of Mediterranean and European Atlantic coasts, whose systematics have been strongly debated in the past few decades. In the present work the count of nephridiopores was coupled with genetic analysis carried out with DNA markers (inter simple sequence repeats) for a total of 30 individuals collected at six Italian beaches. Exact test, analysis of molecular variance, non-metric multidimensional scaling and assignment tests clearly separated individuals with five nephridiopore pairs from those with six pairs. This finding validated results of a recent allozyme study in which O. bicornis sensu lato was split into O. bicornis sensu stricto (six nephridiopore pairs) and O. barquii (five nephridiopore pairs). This paper represents a further contribution to the estimation of biodiversity within marine invertebrates.
The wide range of anthropogenic disturbances influencing marine coastal assemblages is of increas... more The wide range of anthropogenic disturbances influencing marine coastal assemblages is of increasing concern. Rocky intertidal communities are particularly sensitive to disturbance from indirect agents, such as sewage and industrial effluents (Littler and Murray, 1975), and to more direct agents, such as harvesting and trampling (Duran and Castilla, 1989; Underwood and Kennelly, 1990;
We studied the spatial variability and within-year temporal changes in hydrological features, gra... more We studied the spatial variability and within-year temporal changes in hydrological features, grain size composition and chemical characteristics of sediments, as well as macrofaunal assemblages, along a heavily modified inlet in the Gulf of Oristano (western Sardinia, Italy). The inlet connects the Cabras lagoon to the gulf through a series of convoluted creeks and man-made structures, including a dam and fish barriers built in the last three decades. Sediments were muddy and mainly composed of the ''non-sortable'' fraction (i.e., <8 lm particle size) in all four areas investigated: Lagoon, Creeks, Channel and Seaward. Along the inlet, however, the ratio between the <8 lm and the 8-64 lm fractions was highest in Creeks and Channel, between the fish barriers and the dam, suggesting impaired hydrodynamics. Consistently, steep gradients in water salinity, temperature and dissolved oxygen concentrations were found in proximity to the fish barriers. The whole inlet was characterized by a major organic enrichment of sediments, with up to an annual mean of 33.6% of organic matter and 11.7% of total organic carbon in Seaward due to the presence of seagrass leaf litter. Acid-volatile sulphide and chromiumreduced sulphur concentrations were highest throughout the year in Seaward and Lagoon, respectively, with a peak in summer. Consistently, the whole inlet supported low structured macrofaunal assemblages dominated by few opportunist species, with a relatively lower diversity in Lagoon throughout the year and the highest abundances in Seaward in summer. We infer that the presence of artificial structures along the inlet, such as fish barriers and the dam, impair the lagoon-gulf hydrodynamics, sediment exchange and animal recruitment and colonization. We suggest that the removal of these structures would favour water renewal in the Cabras lagoon, but would also increase the outflow of organic C-bonding fine particles into the gulf with serious consequences for Posidonia oceanica and Cymodocea nodosa seagrass meadows. We conclude that all possible consequences of such initiatives should be carefully considered before any action is taken.
In organic-enriched sedimentary systems, like many Mediterranean coastal lagoons, a detailed anal... more In organic-enriched sedimentary systems, like many Mediterranean coastal lagoons, a detailed analysis of sediment grain size composition and partitioning within the muds is crucial to investigate sedimentological trends related to both hydrodynamic energy and basin morphology. In these systems, sediment dynamics are particularly important because the partitioning and transport of fine sediments can strongly influence the redistribution and accumulation of large amounts of organic matter, and consequently the distribution of benthic assemblages and the trophic status and functioning of a lagoon. Nevertheless, studies on benthic-sediment relationships have been based mainly on a rather coarse analysis of sediment grain size features. In muddy systems, however, this approach may impede a proper evaluation of the relationships and effects of the distribution of fine sediment and organic matter on the biotic benthic components. Here we show that the distribution of sedimentary organic matter (OM) and total organic carbon (TOC) in the Cabras lagoon (Sardinia, Italy) can be explained (i.e., predicted) as a function of a nonlinear increase in the amount of the cohesive fraction of sediments (68 lm grain size particles) and that this fraction strongly influences the structure, composition and distribution of macrobenthic assemblages. Even in such a homogeneously muddy system, characterized by ''naturally" occurring impoverished communities, impaired benthic assemblages were found at 68 lm, OM, TOC contents of about 77%, 11% and 3.5%, respectively. A review of studies conducted in Mediterranean coastal lagoons highlighted a lack of direct integrated analysis of sediment features and the biotic components. We suggest that, especially in organic-enriched coastal lagoons, monitoring programs should primarily investigate and consider the cohesive fraction of sediments in order to allow a better assessment of benthic-sediment relationships and ecological quality of the system.
The effect of human trampling on the abundance of small invertebrates inhabiting rocky shallow bo... more The effect of human trampling on the abundance of small invertebrates inhabiting rocky shallow bottoms was studied at Asinara Island MPA. To this aim we have conducted two experiments. The first was a quantitative study and tested the hypothesis that small invertebrates are more abundant at no-entry locations than at the location visited by tourists through time (before, during and after tourist season). The second was a manipulative experiment and tested the hypothesis that the abundance of small invertebrates is indirectly related to experimental trampling intensities. The effect due to tourist visitation was not highlighted on overall assemblages, suggesting that present seasonal tourist load at the MPA does not cause a significantly negative effect on the zoobenthic community studied. Although tourists exhibited trampling activity at the visited location, none of taxa examined showed a significant lower abundance during and strictly after the end of seasonal tourism peak in the visited location, rather than at control locations. However, results obtained with the second experiment suggested that the effects of different experimental trampling intensities on small invertebrates were variable among taxa. The experimental trampling caused immediate declines in the density of tanaids, nematodes, acari, bivalves, gammarids, echinoderms, isopods, and harpacticoids. For some of these taxa a recovery in abundance was observed within one month.
In this paper, two benthic habitats have been investigated in a fully protected site and two cont... more In this paper, two benthic habitats have been investigated in a fully protected site and two control sites at the Tavolara-Punta Coda Cavallo marine protected area (MPA) (NE Sardinia). Overall, a protection effect on the benthic assemblages was highlighted in the shallow subtidal (5 m deep) rather than at intertidal algal turf habitat. Structure of assemblages at the shallow subtidal habitat is different in the fully protected site vs. controls, while this was not true for the intertidal habitat. At the subtidal, this finding is probably linked to indirect effects due to an increase of consumers in the protected site (e.g., sea urchins), while the lack of direct impacts in the intertidal at control sites is indicative of very similar assemblages. Cover of encrusting algae was significantly higher at the subtidal protected site suggesting a possible higher grazing pressure. Possible causes underlying the inconsistency of results obtained between habitats include the possibility that trophic cascade effects have a different influence at different heights on the shore. The need to estimate the interconnection among benthic habitats through trophic links is also highlighted to provide an estimate of the vulnerability to protection of various habitats.
Marine protected areas (MPAs) represent a potentially useful management tool to preserve biodiver... more Marine protected areas (MPAs) represent a potentially useful management tool to preserve biodiversity. Protection effectiveness was investigated at Tavolara-Capo Coda Cavallo MPA by comparing assemblages of rocky shores at a location ÔAÕ level of protection (island), with those at two locations at ÔBÕ level of protection (one on an island and one on the mainland coast) and two at ÔCÕ level of protection (one on an island and one on the mainland coast). Results did not indicate significant differences in structure of intertidal assemblages among locations under different levels of protection (ÔAÕ, ÔBÕ and ÔCÕ). Protection was not found to be a significant source of variation to low-shore assemblages investigated. In contrast, assemblages seemed to be more dependent on the geographical location within the MPA. Results have important implications for conservation of marine coastal assemblages and would indicate that inclusion of representative assemblages within systems of marine protected areas should target rocky shores both on the mainland and on islands.
... MARCO CURINI-GALLETTI Dipartimento di Zoologia e Antropologia Biologica, Corso Margherita di ... more ... MARCO CURINI-GALLETTI Dipartimento di Zoologia e Antropologia Biologica, Corso Margherita di Savoia 15, I ... ALBERTO CASTELLI Dipartimento di Scienze dell&#x27;Uomo e dell&#x27;Ambiente, Via Volta 6, I ... Vilanova i la Geltni, Barcelona Portopalo, Ragusa Vigo Porto Torres Ancona ...
... Simple associations included a positive relationship of both Ficopomatus enigmaticus and Coro... more ... Simple associations included a positive relationship of both Ficopomatus enigmaticus and Corophium sextonae, patchily distributed along the shores, with sediment sorting (σ), an index of sediment selection due to hydrodynamic energy. ...
La ricerca qui descritta si è svolta nell'area marina protetta (AMP) dell'Isola dell'Asinara e ha... more La ricerca qui descritta si è svolta nell'area marina protetta (AMP) dell'Isola dell'Asinara e ha cercato di valutare l'effetto del calpestio sulla comunità zoobentonica associata ad alghe dell'infralitorale superiore di fondo roccioso. E' stato condotto un esperimento multifattoriale di simulazione del calpestio: in due cale "no entry, no take" sono state scelte 6 aree e, 3 intensità di calpestio sperimentale (0, 60 e 120 calpestii per quadrato di 20x20 cm), sono state attribuite a random nelle aree. I prelievi sono stati compiuti con cilindri di plastica (diametro 40 mm) e un raschietto metallico; sono stati raccolti 2 campioni per quadrato. Il materiale è stato fissato in formalina. In laboratorio sono state separate le due componenti mediante adeguati setacci; gli animali raccolti sono stati identificati e contati. Dall'analisi delle similarità risulta che, per entrambe le componenti, vi è differenza significativa tra i controlli e le aree dove è stato effettuato il calpestio (ANOSIM macrofauna p=0,4% R=0,45, meiofauna p=0,5% R=0,50). Inoltre dai confronti a coppie tra i livelli di calpestio risulta una differenza significativa tra i controlli e le due intensità di calpestio (60 e 120), mentre non vi è differenza significativa tra questi ultimi due trattamenti. Sebbene non si possa fare nessuna previsione sulla resilienza della comunità, questi risultati suggeriscono che sia la macrofauna sia la meiofauna siano estremamente vulnerabili a questo tipo di disturbo.
Caulerpa racemosa (Forsskål) J. Agardh è una specie lessepsiana altamente invasiva e le conoscenz... more Caulerpa racemosa (Forsskål) J. Agardh è una specie lessepsiana altamente invasiva e le conoscenze sull'effetto della sua diffusione sui popolamenti zoobentonici in Mediterraneo sono molto scarsi. Lo scopo di questo studio è quello di valutare l'effetto immediato della rimozione di ...
L'istituzione delle Aree Marine Protette (AMP) consente adeguate misure di conservazione dell'amb... more L'istituzione delle Aree Marine Protette (AMP) consente adeguate misure di conservazione dell'ambiente marino. Tuttavia l'efficacia di tale protezione dovrebbe essere verificata attraverso programmi di monitoraggio, utilizzando specie che siano facili da identificare e analizzare in maniera non distruttiva. In tale contesto è stata individuata Patella ferruginea, che risulta essere l'invertebrato marino più minacciato del Mediterraneo occidentale. L'obiettivo dello studio è quello di stimare i livelli di diversità genetica e flusso genico di alcune popolazioni di P. ferruginea dell'AMP dell'Isola dell'Asinara. È stato prelevato il materiale biologico di 10 esemplari da 3 diversi siti, tramite escissione di piccole quantità di tessuto muscolare, seguendo un protocollo da noi sperimentato sulla specie P. ulyssiponensis. Tale protocollo assicura la sopravvivenza degli esemplari campionati. L'analisi genetica è stata condotta effettuando la genotipizzazione di un subcampione di individui per ciascun sito utilizzando la tecnica ISSR (Inter-Simple Sequence Repeat). I risultati ottenuti indicano una notevole uniformità genetica tra gli individui appartenenti a ciascun sito, contrapposta ad una moderata eterogeneità genetica tra gli individui appartenenti ai tre siti. Questi fatti suggeriscono inoltre che P. ferruginea possa aver subito erosione genetica negli anni passati in relazione alla sua raccolta, e che i livelli di flusso genico non siano elevati anche su piccola scala geografica.
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