Structure and Functionality of the Mesozooplankton Community in a Coastal Marine Environment: Portofino Marine Protected Area (Liguria)

This research is part of the LTER (Long-Term Ecological Research) project, a network of terrestrial, freshwater, transitional water and marine sites, on which ecological research is conducted on a multi-decade scale. LTER studies ecosystems, their dynamics and evolution, the relationships between biodiversity and ecological functionality, water quality, productivity, the role of resource availability, the effects of pollution and climate change. The research focuses on the study of the variability of zooplankton groups in the Portofino marine protected area, in Punta Faro. The samplings were carried out in the years 2018\u20132019, and the results were compared with the values of the years 2003\u20132005, interesting from a meteorological climatic and biological point of view. The plankton community of the Punta Faro system was analyzed by means of a modeling approach to obtain information on the functionality and health status of the system and to verify whether this has undergone any alterations in the last decade. The analyses carried out show a clear difference between the three-year period 2003\u20132005 and the two-year period 2018\u20132019, highlighting how environmental changes, such as the increase in temperature, have led to higher costs of system functioning in the last two years. The mesozooplankton community has changed both in terms of abundance of organisms and in terms of organization and functionality

Composición de la materia orgánica particulada en un sistema periantártico semi-cerrado: el Estrecho de Magallanes

The elemental and biochemical composition of particulate organic matter (POM) was investigated in the Straits of Magellan during February-March 1991. Twenty-two stations were selected in order to identify different areas of the Magellan ecosystem from a trophic point of view. The Strait of Magellan can be divided into three subsystems characterized by different hydrological and geomorphological conditions. Seston concentrations were mostly constrained by physical events, particularly the influence of oceanic and land run-off water inputs and the strong vertical mixing and resuspension events. POM composition displayed quali-quantitative differences between the three areas. In the first subsystem, influenced by Pacific waters, the low seston and POM concentrations and the high POC/Chl-a ratio values indicated the general predominance of the detrital and heterotrophic fractions. In the second subsystem, characterized by superficial stratification, higher seston and organic matter concentrations and lower values of POC/Chl-a ratio were found, indicating that this subsystem was influenced by an active autotrophic component. Shallow waters with intense tidal regime and strong vertical mixing characterized the third subsystem, connected to the Atlantic Ocean, which displayed an increasing importance of the inorganic fraction (values of the POC/TSM ratio lower than in the other systems). Moreover, the third subsystem showed higher values of the RNA/DNA ratio, possibly indicating that resuspension events may enhance the metabolic state of the organic particles mainly dominated by heterotrophic components.Se estudió la composición elemental y bioquímica de la POM (materia orgánica particulada) en el Estrecho de Magallanes durante el periodo febrero-marzo de 1991. Se eligieron 22 estaciones a fin de identificar diferentes áreas del ecosistema magallánico desde un punto de vista trófico. De acuerdo con las características hidrológicas y geomorfológicas dicho Estrecho se puede dividir en 3 subsistemas. Las concentraciones de seston estuvieron condicionadas, principalmente, por los fenómenos físicos y, en particular, por los aportes oceánicos y terrestres, por la mezcla vertical y por los fenómenos de resuspensión. La composición de la materia orgánica particulada (POM) mostró diferencias cualitativas y cuantitativas en las tres áreas. En el primer subsistema, influenciado por las aguas del Océano Pacífico, las bajas concentraciones de seston y POM y los altos valores de la relación POC/clorofila a indicaron una predominancia general de las fracciones detrítica y heterótrofa. En el segundo subsistema, caracterizado por una estratificación superficial, se encontraron altas concentraciones de seston y de materia orgánica y bajos valores de la relación POC/clorofila a, señalando una influencia de la componente autótrofa activa. El tercer subsistema, conectado con el Océano Atlántico y caracterizado por aguas poco profundas y por un régimen mareal intenso y una fuerte mezcla vertical, mostró un importante aumento de la fracción inorgánica (valores de la relación POC/TSM más bajos que en los otros dos subsistemas). Por otra parte, el tercer subsistema mostró altos valores de la relación RNA/DNA, indicando que posiblemente el estado metabólico de las partículas orgánicas (dominadas principalmente por componentes heterótrofas) estaría influenciado por fenómenos de resuspensión

The driving forces of the biotic processes along an offshore gradient in the Ligurian basin (Portofino Promontory) during 2008

The marine coastal area of the Portofino Promontory, located in the North-East side of the Ligurian basin (Mediterranean Sea), has been studied since 1980’s to identify its main ecological characteristics. The large physical, chemical and biological dataset available for this site (LTER sites) represents a powerful tool for the reliable reconstruction of seasonal cycles and allow the differentiation of regular and recurrent patterns from occasional and exceptional events. This long-term monitoring reveled an increases in the average monthly temperature along the water column in the last 10 years compare with the previous decade (1985-1995), with a high inter-annual variability and some specific episodic occurrence of thermal anomalies. The physical features of the water column seems to have a strict relation with the phytoplankton biomass fluctuations. A detailed study of 2008 intended to analyze a wider area, in order to compare the driving forces influencing the development of biotic process along an offshore gradient

LTER-AMP-Portofino (Mar Ligure): variabilità stagionale ed interannuale delle forzanti meteo-climatiche, delle variabili fisico-chimiche e biologiche del comparto pelagico

L’area marina costiera antistante il Promontorio di Portofino è stata inserita nella rete ILTER – International Long Term Ecological Research dal 2007, grazie ai numerosi studi ecologici che si susseguono nell’area dagli anni ’80, ed in particolare dal 1999, quando è iniziata la raccolta sistematica delle principali variabili fisiche e chimico-biologiche lungo la colonna d’acqua e delle principali forzanti meteo-climatiche. L’analisi dei dati ha messo in evidenza un incremento della temperatura media lungo la colonna d’acqua negli ultimi anni rispetto al decennio precedente (1985-1995) ed in particolare un progressivo aumento della temperatura superficiale nelle stagioni primaverili ed autunnali, che ha portato ad un ampliamento del periodo caldo. L’area di studio è inoltre caratterizzata da una forte variabilità interannuale: sono state registrate importanti anomalie termiche nell’estate 2003 e nei periodi autunnali e primaverili del 2006-2007 con temperature superficiali più elevate rispetto alla media del periodo, dovute a due importanti anomalie termiche atmosferiche. Negli ultimi anni, le precipitazioni annuali sono sempre al di sotto della media climatica, ad eccezione del 2002, con conseguente modificazione della struttura termo-alina dell’area di studio. Le variabilità riscontrate si riflettono sui popolamenti planctonici, modificando le risposte delle comunità, in particolare nel periodo tardo primaverile. L’area conserva, comunque, le caratteristiche oligotrofiche tipiche del Mar Ligure: infatti, pur mostrando una evidente variabilità interannuale, la biomassa planctonica media nello strato superficiale continua a rimanere bassa, con una tendenza a diminuire negli ultimi anni

Phaeocystis antarctica unusual summer bloom in stratified antarctic coastal waters (Terra Nova Bay, Ross Sea)

This study focuses on the potential explanations for a Phaeocystis antarctica summer bloom occurred in stratified waters of Terra Nova Bay (TNB) - which is part of the Antarctic Special Protected Area (n.161) in the Ross Sea - trough a multi-parameter correlative approach. Many previous studies have highlighted that water column stratification typically favors diatom dominance compared to the colonial haptophyte P. antarctica, in the Ross Sea, and this correlation has often been used to explain the historic dominance of diatoms in TNB. To explore the spatial and temporal progression of P. antarctica bloom in coastal waters, four stations were sampled three times each between December 31, 2009 and January 13, 2010. Taxonomic and pigment composition of phytoplankton communities, macro-nutrient concentrations and various different indices, all indicated the relative dominance of P. antarctica. Cell abundances revealed that P. antarctica contributed 79% of total cell counts in the upper 25 m and 93% in the lower photic zone. Similarly, a strong correlation was observed between Chl-a and the Hex:Fuco pigment ratio, corroborating the microscopic analyses. Recent studies have shown that iron can trigger colonial P. antarctica blooms. Based on the Hex:Chl-c3 proxy for iron limitation in P. antarctica, we hypothesize that anomalously higher iron fluxes were responsible for the unusual bloom of colonial P. antarctica observed in TNB

Applicazione in GRASS per l\u2019identificazione di aree idonee alla realizzazione di nuovi impianti di itticoltura offshore

La gestione della fascia costiera \ue8 un processo complesso che cerca di integrare lo sfruttamento dell\u2019area con il mantenimento di una buona qualit\ue0 ambientale. Trattandosi di un problema spaziale complesso pu\uf2 essere ben affrontato mediante strumenti GIS. Questo lavoro presenta un approccio applicato all\u2019itticoltura offshore, sviluppando una procedura con GRASS per l\u2019identificazione delle aree idonee all\u2019installazione di nuovi impianti, applicata al caso della Regione Liguria. La selezione dei siti si \ue8 basata sulla definizione di due principali criteri che ne determinano l\u2019idoneit\ue0 per l\u2019attivit\ue0 proposta (\u201caree non idonee\u201d e \u201caree potenzialmente idonee\u201d) e di condizioni concernenti la zona studio. La procedura ha permesso di ottenere la mappa finale con la perimetrazione delle aree idonee, tramite la realizzazione intermedia delle mappe dei criteri. Sono state identificate circa trenta zone idonee lungo la costa ligure, principalmente localizzare a ponente; a levante si trovano quelle di maggiore estensione. La procedura \ue8 stata verificata confrontando le aree individuate con la posizione degli impianti gi\ue0 esistenti. I risultati di questo lavoro dimostrano come questa procedura permette di individuare le aree idonee in modo semplice, rapido, efficiente ed efficace. Con opportune modifiche la procedura pu\uf2 essere applicata a qualunque sistema marino costiero e pu\uf2 essere adattata ad altre attivit\ue0 della zona costiera. Questo lavoro \ue8 inoltre una solida base per lo sviluppo futuro di un Sistema di Supporto alle Decisioni Spaziali che restituisca scenari alternativi per i portatori di interesse al fine di individuare la migliore scelta decisionale

Formation of ionospheric irregularities over Southeast Asia during the 2015 St. Patrickˈs Day storm

We investigate the geospace response to the 2015 St. Patrickˈs Day storm leveraging on instruments spread over Southeast Asia (SEA), covering a wide longitudinal sector of the low-latitude ionosphere. A regional characterization of the storm is provided, identifying the peculiarities of ionospheric irregularity formation. The novelties of this work are the characterization in a broad longitudinal range and the methodology relying on the integration of data acquired by Global Navigation Satellite System (GNSS) receivers, magnetometers, ionosondes, and Swarm satellites. This work is a legacy of the project EquatoRial Ionosphere Characterization in Asia (ERICA). ERICA aimed to capture the features of both crests of the equatorial ionospheric anomaly (EIA) and trough (EIT) by means of a dedicated measurement campaign. The campaign lasted from March to October 2015 and was able to observe the ionospheric variability causing effects on radio systems, GNSS in particular. The multiinstrumental and multiparametric observations of the region enabled an in-depth investigation of the response to the largest geomagnetic storm of the current solar cycle in a region scarcely reported in literature. Our work discusses the comparison between northern and southern crests of the EIA in the SEA region. The observations recorded positive and negative ionospheric storms, spread F conditions, scintillation enhancement and inhibition, and total electron content variability. The ancillary information on the local magnetic field highlights the variety of ionospheric perturbations during the different storm phases. The combined use of ionospheric bottomside, topside, and integrated information points out how the storm affects the F layer altitude and the consequent enhancement/suppression of scintillations.Published12211–122331A. Geomagnetismo e Paleomagnetismo2A. Fisica dell'alta atmosfera1IT. Reti di monitoraggio e Osservazioni5IT. Osservazioni satellitariJCR Journalope

Marine pelagic ecosystems: the West Antarctic Peninsula

The marine ecosystem of the West Antarctic Peninsula (WAP) extends from the Bellingshausen Sea to the northern tip of the peninsula and from the mostly glaciated coast across the continental shelf to the shelf break in the west. The glacially sculpted coastline along the peninsula is highly convoluted and characterized by deep embayments that are often interconnected by channels that facilitate transport of heat and nutrients into the shelf domain. The ecosystem is divided into three subregions, the continental slope, shelf and coastal regions, each with unique ocean dynamics, water mass and biological distributions. The WAP shelf lies within the Antarctic Sea Ice Zone (SIZ) and like other SIZs, the WAP system is very productive, supporting large stocks of marine mammals, birds and the Antarctic krill, Euphausia superba. Ecosystem dynamics is dominated by the seasonal and interannual variation in sea ice extent and retreat. The Antarctic Peninsula is one among the most rapidly warming regions on Earth, having experienced a 28C increase in the annual mean temperature and a 68C rise in the mean winter temperature since 1950. Delivery of heat from the Antarctic Circumpolar Current has increased significantly in the past decade, sufficient to drive to a 0.68C warming of the upper 300 m of shelf water. In the past 50 years and continuing in the twenty-first century, the warm, moist maritime climate of the northern WAP has been migrating south, displacing the once dominant cold, dry continental Antarctic climate and causing multi-level responses in the marine ecosystem. Ecosystem responses to the regional warming include increased heat transport, decreased sea ice extent and duration, local declines in icedependent Ade´lie penguins, increase in ice-tolerant gentoo and chinstrap penguins, alterations in phytoplankton and zooplankton community composition and changes in krill recruitment, abundance and availability to predators. The climate/ecological gradients extending along theWAPand the presence of monitoring systems, field stations and long-term research programmes make the region an invaluable observatory of climate change and marine ecosystem response