Search results for "Reefs"
showing 10 items of 32 documents
A Triassic carbonate platform edge in the Sciacca zone: implications for the accretion of the Maghrebian chain in southwestern Sicily
2008
Mediterranean bioconstructions along the Italian coast
2018
Marine bioconstructions are biodiversity-rich, three-dimensional biogenic structures, regulating key ecological functions of benthic ecosystems worldwide. Tropical coral reefs are outstanding for their beauty, diversity and complexity, but analogous types of bioconstructions are also present in temperate seas. The main bioconstructions in the Mediterranean Sea are represented by coralligenous formations, vermetid reefs, deep-sea cold-water corals, Lithophyllum byssoides trottoirs, coral banks formed by the shallow-water corals Cladocora caespitosa or Astroides calycularis, and sabellariid or serpulid worm reefs. Bioconstructions change the morphological and chemicophysical features of prima…
Mediterranean rocky reefs in the Anthropocene: Present status and future concerns
2021
Global change is striking harder and faster in the Mediterranean Sea than elsewhere, where high levels of human pressure and proneness to climate change interact in modifying the structure and disrupting regulative mechanisms of marine ecosystems. Rocky reefs are particularly exposed to such environmental changes with ongoing trends of degradation being impressive. Due to the variety of habitat types and associated marine biodiversity, rocky reefs are critical for the functioning of marine ecosystems, and their decline could profoundly affect the provision of essential goods and services which human populations in coastal areas rely upon. Here, we provide an up-to-date overview of the statu…
Changes in fish communities due to benthic habitat shifts under ocean acidification conditions
2020
Ocean acidification will likely change the structure and function of coastal marine ecosystems over coming decades. Volcanic carbon dioxide seeps generate dissolved CO2 and pH gradients that provide realistic insights into the direction and magnitude of these changes. Here, we used fish and benthic community surveys to assess the spatio-temporal dynamics of fish community properties off CO2 seeps in Japan. Adding to previous evidence from ocean acidification ecosystem studies conducted elsewhere, our findings documented shifts from calcified to non-calcified habitats with reduced benthic complexity. In addition, we found that such habitat transition led to decreased diversity of associated …
Artificial Reefs in the Gulf of Castellammare (North-West Sicily): A Case Study
2000
Most of the plans for fish stock replenishment recently undertaken in Sicily have focused on the Gulf of Castellammare. Reasons for choosing this biotope for a restocking plan include the size of the Gulf (300 km2), the importance and traditional role of its fisheries and the existence of information describing the local marine environment. The Gulf of Castellammare is the widest bay in Sicily and fishing has always played a major role in the local economy. Today income from fishing complements that from tourism.
A new marker for sea surface temperature trend during the last centuries in temperate areas: Vermetid reef
2004
The presence of Vermetid reefs in temperate waters, their diffusion in the Mediterranean Sea, and the possibility of performing 14 C ages allowed the use of Vermetids as an indicator of sea level changes. We present new data on sea climate trend fluctuations that could be interpreted as Sea Surface Temperature (SST) variations, recorded on Vermetid (Dendropoma petraeum) reefs, by means of isotopic analysis. The isotopic records show positive values of the d 18 O relative to present-day values in the period between 1600 and 1850 AD; this deviation occurs in association with the climatic cooling event known as Little Ice Age (LIA). Subsequently, we can observe the warming trend that character…
Ocean acidification and elevated temperature negatively affect recruitment, oxygen consumption and calcification of the reef-building Dendropoma cris…
2019
Expected temperature rise and seawater pH decrease may affect marine organism fitness. By a transplant experiment involving air-temperature manipulation along a natural CO2 gradient, we investigated the effects of high pCO(2) (similar to 1100 mu atm) and elevated temperature (up to +2 degrees C than ambient conditions) on the reproductive success, recruitment, growth, shell chemical composition and oxygen consumption of the early life stages of the intertidal reef-building vermetid Dendropoma cristatum. Reproductive success was predominantly affected by temperature increase, with encapsulated embryos exhibiting higher survival in control than elevated temperature conditions, which were in t…
Biological diversity of the microbial film associated to the central-Mediterranean Dendropoma cristatum (Biondi, 1859) reefs.
2017
Microbial films may provide physical and bio-chemical cues which positively affect the settlement dynamic of a variety of benthic marine organisms, driving the development of ecosystems. Also for the Mediterranean intertidal reef-builder Dendropoma cristatum (Biondi, 1859), biofilm maturity has been found to enhance the settlement pattern. However, the microbial diversity associated with these bioconstructions has never been described. This study investigates the D. cristatum reef bacterial assemblage composition and temporal evolution in two localities in the northwest of Sicily. Biological diversity of the reef-associated biofilm and of 3 progressively older biofims obtained on artificial…
Rekomendācijas aizsargājamās jūras teritorijas "Rīgas līča rietumu piekraste" monitoringa metožu uzlabošanai
2021
Akmeņu sēkļi ir svarīgi jūras vides bioloģiskās daudzveidības un kvalitātes nodrošināšanai – tie ir mājvieta gan daudzām sēdošām un peldošām bentisko jūras dzīvnieku un aļģu sugām, gan nozīmīga nārsta vieta zivju sugām. Dažādu abiotisko faktoru ietekmē akmeņu sēkļos nereti veidojas mikrobiotopi vai atšķirīgi biotopu kompleksi, kas savas mozaīkveida struktūras, kā arī mainīgā dziļuma dēļ apgrūtina šo aizsargājamo jūras biotopu monitoringu. Šo apgrūtinājumu dēļ nepieciešams uzlabot monitoringa metožu efektivitāti un rekomendēt tādas monitoringa metodes, kas pietiekami atspoguļotu teritorijas bioloģisko daudzveidību. Galvenās rekomendācijas monitoringa uzlabošanai, būtu veikt monitoringu staci…
The Status of Coastal Benthic Ecosystems in the Mediterranean Sea: Evidence From Ecological Indicators
2020
The Mediterranean Sea is subject to multiple human pressures increasingly threatening its unique biodiversity. Spatially explicit information on the ecological status of marine ecosystems is therefore key to an effective maritime spatial planning and management, and to help the achievement of environmental targets. Here, we summarized scientific data on the ecological status of a selection of marine ecosystems based on a set of ecological indicators in more than 700 sites of the Mediterranean Sea. For Posidonia oceanica seagrass beds, rocky intertidal fringe, and coastal soft bottoms, more than 70% of investigated sites exhibited good to high ecological conditions. In contrast, about two-th…