S'Ena Arrubia lagoon, western Sardinia

Generally, through the LOICZ model application to the lagoon, it is observed that there is prevalence of nutrient storing processes rather than that of nutrient mobilisation. Nitrogen fixation always prevailed over denitrification. The productive processes in the lagoon thus seem to be prevalent over most of the year. These results confirm that S’Ena Arrubia Lagoon is to be considered an autotrophic system as far as the net total metabolism is concerned

Dominancia de las cianobacterias en lagunas mediterráneas hipertróficas: el caso de la laguna de Cabras (Cerdeña, Italia)

An intense proliferation of cyanobacteria in Cabras Lagoon was investigated over a period of two years (July 2007 to June 2009). The influence of environmental and meteorological parameters in the lagoon on temporal variations in cyanobacteria orders was assessed. For 17 months, Chroococcales was the only cyanobacterial order observed in the lagoon. Cyanobium-type cells (Reynolds functional group Z) were the most abundant phytoplankton taxon during this period. In the following months, drastic changes in the cyanobacteria assemblages occurred simultaneously with constant, intense rainfall that led to a sudden drop in the lagoon’s salinity. The succession of autumn–winter Oscillatoriales (Planktothrix sp. and Pseudanabaena catenata; Reynolds functional group S1) and late spring growth of Nostocales (Aphanizomenon gracile, Aphanizomenon aphanizomenoides, and Anabaenopsis circularis; Reynolds functional group H1) was monitored. Canonical Correspondence Analysis was carried out to quantify the influence of environmental variables, and indicated strong relationships between Chroococcales and salinity, Oscillatoriales and higher values of SRP and the DIN/SRP ratio, and Nostocales and lower nutrient concentrations, the DIN/SRP ratio and salinity.Durante dos años (julio 2007-junio 2009) se monitoreó una proliferación intensa de cianobacterias en la laguna de Cabras, así como los parámetros ambientales y climáticos que determinaron sus variaciones temporales. Durante 17 meses, Chroococcales fue el único orden de cianobacterias en la laguna, del cual células similares a Cyanobium (grupo funcional Z según Reynolds) fueron las más importantes en cuanto a abundancia. En los meses siguientes, las cianobacterias sufrieron cambios drásticos, que ocurrieron simultáneamente con lluvia constante e intensa que dio lugar a una caída brusca de la salinidad de la laguna. Se monitoreó también la sucesión de Oscillatoriales en otoño-invierno (Planktothrix sp. and Pseudanabaena catenata; grupo funcional S1 según Reynolds) y el crecimiento en primavera de Nostocales (Aphanizomenon gracile, Aphanizomenon aphanizomenoides, y Anabaenopsis circularis; grupo funcional H1 según Reynolds). Análisis de Correspondencia Canónica permitieron cuantificar la influencia de las variables ambientales, indicando una estrecha relación entre Chroococcales y salinidad, Oscillatoriales y altos niveles de SRP y proporción DIN/SRP, y Nostocales y bajos niveles de nutrientes, proporción DIN/SRP y salinidad

Indice per la valutazione della qualità ecologica dei bacini artificiali mediterranei (MedPTI) a partire dalla composizione del fitoplancton: documento presentato al Ministero dell’Ambiente e della tutela del territorio e del mare

Secondo la Direttiva 2000/60/CE (WFD, Water Framework Directive), la valutazione della qualità ecologica dei corpi idrici deve essere ottenuta con l’uso di indici numerici costruiti a partire dai parametri biologici, confrontando il valore assunto nel sito in esame con quello di un sito di riferimento, attraverso il calcolo di un quoziente di qualità ecologica (Ecological quality ratio, EQR). L’indice qui proposto è stato sottoposto alla procedura di intercalibrazione, per ottenere i valori dell’indice corrispondenti alle condizioni di riferimento e ai limiti tra le classi di qualità e quindi il rispettivo EQR

A Numerical index for evaluating phytoplankton response to changes in nutrient levels in deep Mediterranean reservoirs

This paper proposes a new ecological index based on phytoplankton (MedPTI) as suggested by the European Directive 2000/60/CE, Water Framework Directive (WFD). The index is a useful tool to verify the impacts of eutrophication in Mediterranean reservoirs belonging to different categories of the WFD. Multiple data sets were employed to develop the MedPTI index. The calibration data set included data collected from 30 Sardinian reservoirs in 1994. A list of 44 selected taxa was obtained and used for index calculation. A second dataset including 48 averaged annual values from 10 reservoirs was used. Results showed good correlation between MedPTI and concentration of total phosphorus, which was the limiting nutrient in these reservoirs. The trophic classifications determined using the index agreed with the results from the OECD probabilistic model on the same series of data. Finally, the index was included in an international exercise to compare the definition of reference conditions and quality class boundaries against indices used in other Mediterranean countries

Indice per la valutazione della qualit? ecologica dei bacini artificiali mediterranei (MedPTI) a partire dalla composizione del fitoplancton

No abstract availableIndici per la valutazione della qualit? ecologica dei laghi. Indice per la valutazione della qualit? ecologica dei bacini artificiali mediterranei (MedPTI) a partire dalla composizione del fitoplancto

Chamaepinnularia thermophila (Bacillariophyceae) : synonymy with Navicula tongatensis Hustedt and update of its geographic distribution and ecology

Abstract Chamaepinnularia thermophila is a small and poorly known diatom species. After the first description from a hot spring in Guadalupe in 1952, its presence appeared to be limited to a few other springs of the French Antilles. The objective of this study is to report new information on aspects of taxonomy, distribution and ecology of this species. Accurate analysis under light and scanning electron microscope of the material collected on different substrates (cobbles, macrophytes and fine sediments) from a thermo-mineral spring of Sardinia (Italy) allowed us to document the first record of the species in the Mediterranean area. Furthermore, the comparison with Navicula tongatensis from Hustedt's original material, carried out because of their similarity, revealed identical morphological characteristics suggesting their consequent synonymy. Based on the information available in the literature and our data, C. thermophila is a rare species present mainly in tropical areas, in thermal springs with alkaline pH, medium to high conductivity and low to moderate nutrient content. The occurrence of the species at sites with very different environmental characteristics seems unusual, but it could indicate a broader ecological range. This study contributes to the standardization of the nomenclature used for this species so far and provides the first framework on its global geographic distribution and ecology

Water quality evaluation in Mediterranean Lagoons using the Multimetric Phytoplankton Index (MPI): study cases from Sardinia

1 - Water quality in four Sardinian lagoons (western Mediterranean Sea) was assessed using the Multimetric Phytoplankton Index (MPI), which is consistent with the EU Water Framework Directive. The index was developed using data on phytoplankton abundances, species structure and chlorophyll a concentrations in Venice Lagoon, Italy. 2 - The aim of this study was to test the MPI on a larger geographical scale and across a range of lagoon types. Therefore, it was applied to assess water quality in the Cabras, S’Ena Arrubia, Santa Giusta and Calich lagoons in Sardinia. These lagoons are all “choked”, but exhibit a range of sizes and morphometric features. They are directly affected by human activity within the lagoons themselves, such as fisheries, aquaculture and the construction of dams and canals, and are indirectly affected by anthropogenic activities in their catchments, including intensive agriculture, industrial activity and urban development. 3 - The data used in the present study were collected monthly over a period of 4 years (Calich, Santa Giusta and S’Ena Arrubia) to 7 years (Cabras). Samples were collected at three stations at each of the Cabras, Santa Giusta and Calich lagoons, and at two stations at the S’Ena Arrubia Lagoon, providing a total of 220 samples. 4 - The water quality in three of the four lagoons investigated (Cabras, S’Ena Arrubia and Calich) was classified as bad using the MPI. Among these three, water in Cabras Lagoon exhibited the worst condition. Water quality in Santa Giusta Lagoon was classified as poor using the MPI. 5 - Although we present preliminary results that require further verification, the index appears to be a useful tool for assessing the ecological status of typical Mediterranean lagoons

Identificación de especies de Chattonella (Raphidophyceae) presentes en muestras de fitoplancton recogidas durante un monitoreo de larga duración en la Laguna de Santa Giusta (Cerdeña, Italia)

Chattonella species in a Mediterranean lagoon (Santa Giusta Lagoon, Sardinia, Italy) were identified by applying a molecular approach to fixed natural phytoplankton samples collected over the last two decades. Like the other raphidophytes, Chattonella cells are naked and lose their shape when fixed, making species identification difficult on the basis of their morphological characteristics. Employing species-specific primers (oBTG-005-F, oBTG-027-R, oBTG-028-R) for the amplification of the ITS-5.8S rDNA region, we established the occurrence of C. subsalsa in fixed natural phytoplankton samples collected in coincidence with fish death events. Additionally, we established the presence of the recently discovered C. cf. subsalsa Adriatic genotype by analysing cellular cultures obtained from the same lagoon in 2013. This is the second worldwide record of C. cf. subsalsa Adriatic genotype. Our results revealed that the species-specific primers oBTG-005-F and oBTG-028-R distinguished this new genotype only when present singularly. This study provides valuable data that increase knowledge of C. subsalsa genotypes and of the long-term occurrence of Chattonella blooms in a transitional ecosystem through the use of samples up to 20 years old.Se identificaron especies de Chattonella mediante la aplicación de técnicas moleculares en muestras naturales de fitoplancton. Las muestras fueron recogidas y fijadas durante las últimas dos décadas en una laguna litoral mediterránea (Laguna de Santa Giusta, Cerdeña, Italia). Al igual que otras rafidoficeas, las células de Chattonella no poseen teca y, por lo tanto, pierden su forma cuando se fijan lo que dificulta la identificación basada en características morfológicas. Con el uso de cebadores específicos a nivel de especie (OBTG-005-F, OBTG-027-R, OBTG-028-R) diseñados para la amplificación de la región ITS- 5.8S rDNA, se detectó la presencia de C. subsalsa en las muestras recogidas en periodos coincidentes con eventos de muerte de peces. A través del análisis de los cultivos celulares obtenidos de la misma laguna en el año 2013, se identificó la presencia, por segunda vez a nivel mundial, del recientemente descubierto genotipo Adriático de C. cf. subsalsa. Los resultados revelaron que los cebadores oBTG-005-F y oBTG-028-R amplifican este nuevo genotipo sólo cuando está presente individualmente. En este estudio se presentan datos relevantes para el conocimiento de los genotipos de C. subsalsa y sobre la presencia recurrente de proliferaciones de especies de Chatonella en un ecosistema de transición a través de la utilización de muestras recogidas durante los últimos veinte años y analizadas hoy en día

Identification of Chattonella (Raphidophyceae) species in long-term phytoplankton samples from Santa Giusta Lagoon, Italy

none7noChattonella species in a Mediterranean lagoon (Santa Giusta Lagoon, Sardinia, Italy) were identified by applying a molecular approach to fixed natural phytoplankton samples collected over the last two decades. Like the other raphidophytes, Chattonella cells are naked and lose their shape when fixed, making species identification difficult on the basis of their morphological characteristics. Employing species-specific primers (oBTG-005-F, oBTG-027-R, oBTG-028-R) for the amplification of the ITS-5.8S rDNA region, we established the occurrence of C. subsalsa in fixed natural phytoplankton samples collected in coincidence with fish death events. Additionally, we established the presence of the recently discovered C. cf. subsalsa Adriatic genotype by analysing cellular cultures obtained from the same lagoon in 2013. This is the second worldwide record of C. cf. subsalsa Adriatic genotype. Our results revealed that the species-specific primers oBTG-005-F and oBTG-028-R distinguished this new genotype only when present singularly. This study provides valuable data that increase knowledge of C. subsalsa genotypes and of the long-term occurrence of Chattonella blooms in a transitional ecosystem through the use of samples up to 20 years oldopenStacca D.; Satta C.T.; Casabianca S.; Penna A.; Padedda B.M.; Sechi N.; Lugliè A.Stacca, D.; Satta, C. T.; Casabianca, Silvia; Penna, Antonella; Padedda, B. M.; Sechi, N.; Lugliè, A

Banca dati di serie storiche relative alle concentrazioni di azoto nelle deposizioni atmosferiche, nei laghi e nei corsi d\u27acqua

In the Water Framework Directive (Directive 2000/60/EC), hydrographic basins are the management units, implicitly assuming that water body pollution is due to sources within the catchments. However some pollutants may reach a river basin from distant sources, by long-range atmospheric transport. Besides many micropollutants, nitrogen is the most relevant pollutant that can reach a water body in relevant quantity by atmospheric transport. In this deliverable we (1) discuss the importance of atmospheric deposition of nitrogen, (2) estimate the nitrogen quantity that reaches through atmospheric deposition one specific lake in one of the InHabit study regions, namely Lake Maggiore in Piedmont, and compare the results with published data on other lakes in Sardinia, (3) provide long-term data on nitrogen concentration in both atmospheric deposition and water bodies in both InHabit study regions (Sardinia and Piedmont), to be used in a further deliverable to test the statistical significance of temporal changes and to model catchment responses. In the first part, the topic is discussed in a general way and an overview is given to the distribution of nitrogen deposition in Italy using data collected by another EU-funded projects, namely the LIFE project "FutMon" (Further Development and Implementation of an EU-level Forest Monitoring System). In part 2, nitrogen inputs from human population and atmosphere are calculated for Lake Maggiore in 2007. Lake Maggiore is not an InHabit lake, but is very close (less than 1 km) to the InHabit Mergozzo Lake. The evaluation on the complete N budget of InHabit lakes is not possible within this project because monitoring data covering the inflow streams are not collected within the project, and because the hydrology of some lakes, like Lake Sirio, is strongly influenced by submersed inflows. However, as regards the two nitrogen sources, the general pattern described for Lake Maggiore can be extended to other lakes, to explore the relative importance of nitrogen atmospheric input in one of the study areas, the Piedmont region. LIFE 08 ENV/IT/000314 ‐ INHABIT Deliverable I2d5 3 For what concern Sardinia, nitrogen budget was calculated in the 1990\u27s for some man-made lakes, and the results were published. We selected in particular lakes Medio Flumendosa and Mulargia, two reservoirs in central Sardinia, the catchments of which are interested by human activities at different degree. The results show that, in spite of the population living in the catchment, the atmospheric deposition corresponds to the triple of the nitrogen input from population that reaches the Lake Maggiore in 2007. Lake Maggiore catchment is located in the area most affected by the deposition of nitrogen. An attempt was also done to compare nitrogen deposition on lake catchments in Sardinia with the amount of nitrogen reaching the lakes through their inlets. The results are very preliminary, but the amounts were comparable. The results obtained on these lakes cannot be directly transferred to the InHabit lakes, even if they were obtained on lakes very close to the InHabit sites. These results are simply used to underline the relative importance of atmospheric deposition of nitrogen compounds versus local and/or specific sources. The third part of this deliverable include a collection of nitrogen data series to be used for subsequent elaboration. Long-term data were collected for 2 lakes, 18 streams rivers and 7 deposition sampling stations in Piedmont, where nitrogen deposition is more relevant. In this dataset we only collected nitrogen concentrations from streams and river data relatively close to the InHabit study lakes, i.e. in the Orco/Chiusella and Ticino river basins, the formers being close to lakes Serr?, Candia and Viverone, and the latter including lakes Morasco and Mergozzo. Streams were also selected in order to have minimal human disturbance: only small villages and mainly forested watershed, with extensive agriculture. In Sardinia, where nitrogen deposition is markedly lower, 3 lakes and 2 deposition sampling stations were considered. No stream nitrogen data series was collected in Sardinia. This is mainly to due the low number of long-term data series available, and the different nature of river catchments LIFE 08 ENV/IT/000314 ‐ INHABIT Deliverable I2d5 4 in Sardinia. In effect in Sardinia almost completely forested watershed are rare, and the streams draining them were not systematically analyzed for long periods, as priority was given to more polluted rivers and streams. However, notwithstanding the different number of sites available in the two regions, the collected data are sufficient for trend analysis and for comparing the two study regions.Nella Direttiva Quadro sulle Acque (Direttiva 2000/60/EC), le unit? di gestione dei corpi idrici sono i bacini idrografici, e questa scelta assume implicitamente che gli inquinanti che raggiungono i corpi idrici siano prodotti nei loro bacini imbriferi. Tuttavia esistono anche inquinanti che possono raggiungere un bacino fluviale attraverso le deposizioni, dopo essere stati emessi nell?atmosfera a distanze anche considerevoli. Questo avviene per diversi microinquinanti di sintesi, ma anche per l?azoto, che pu? raggiungere i bacini fluviali in quantit? rilevanti (anche dell?ordine delle migliaia di tonnellate annue) attraverso le deposizioni atmosferiche. Questo deliverable si compone di tre parti: 1) una parte introduttiva sull?importanza dell?azoto nelle deposizioni, in particolare nell?Italia settentrionale e in Sardegna; 2) una stima della quantit? di azoto che pu? raggiungere, attraverso le deposizioni atmosferiche, un corpo idrico situato in una delle regioni di studio del progetto InHabit. La scelta ? caduta sul Lago Maggiore, in Piemonte, che non ? un lago inserito nel progetto InHabit, ma si trova in prossimit? del Lago di Mergozzo incluso nel progetto. La scelta di questo lago ? stata dettata dall?ampia disponibilit? di dati di monitoraggio per un periodo abbastanza lungo da permettere una stima della variazione temporale. Uno studio simile non ? possibile per i laghi InHabit, perch? il campionamento previsto dal progetto non comprende gli immissari; inoltre alcuni laghi (come il Sirio) hanno immissari subacquei di importanza relativa notevole. Tuttavia, i risultati emersi per il Lago Maggiore sono stati brevemente discussi anche per i laghi del progetto InHabit al termine della parte 2. Per quanto riguarda la Sardegna, sono stati rielaborati i risultati dei bilanci di bacino calcolati negli anni 1990 per due laghi artificiali della Sardegna centrale, il Lago Mulargia ed il Lago Medio Flumendosa, caratterizzati da un impatto antropico decisamente differente nei due rispettivi bacini imbriferi; 3) una raccolta di serie temporali delle concentrazioni dei composti azotati nelle deposizioni atmosferiche e nei corpi idrici di entrambe le regioni di studio del progetto InHabit (Piemonte e Sardegna), da usarsi in un successivo deliverable per verificare l?esistenza di variazioni temporali significative e per modellizzare il comportamento dell?azoto nei bacini imbriferi, se possibile. Sono stati ricercati dati che coprissero serie temporali abbastanza lunghe da permettere una successiva analisi dei trend con metodi statistici affidabili. I risultati della seconda parte hanno mostrato che l?azoto atmosferico che raggiunge il Lago Maggiore ? maggiore di quello derivante dalla popolazione nel 2007. Per quanto riguarda la Sardegna, sono stati rielaborati i bilanci di bacino calcolati negli anni 1991-92 per i laghi Mulargia e Medio Flumendosa. In entrambi i casi, la quantit? di azoto che raggiunge il bacino imbrifero attraverso le deposizioni atmosferiche ? superiore a quello che arriva ai laghi, nonostante i rilasci dovuti alle attivit? agricole e agli insediamenti umani. Il bacino imbrifero trattiene dunque una notevole quantit? d?azoto. ? verosimile che una parte notevole dell?azoto di origine atmosferica venga trattenuto dai suoli o intrappolato nelle culture, con le quali lascia poi il bacino stesso, o in alcuni casi demineralizzato, sfuggendo cos? nell?atmosfera. Nella terza parte sono state raccolte serie temporali delle concentrazioni di diversi composti dell?azoto in 2 laghi, 18 corsi d?acqua e 7 stazioni di campionamento delle deposizioni atmosferiche in Piemonte. Per quanto riguarda i corsi d?acqua, questi sono stati scelti sulla base di due criteri: il pi? importante ? il minimo impatto antropico. I bacini imbriferi dei torrenti scelti sono quasi completamente boscati, anche se nel bacino possono esservi piccoli insediamenti abitati e una limitata estensione di aree agricole. Inoltre i bacini considerati sono vicini ai siti InHabit, trovandosi nei bacini fluviali dell?Orco e del Chiusella (in prossimit? dei laghi Serr?, Candia e Viverone) o del Ticino (dove si trovano i laghi di Morasco e di Mergozzo). Per la Sardegna, dove le deposizioni di azoto sono meno elevate, sono stati raccolti i dati di 3 laghi e di due stazione di campionamento delle deposizioni atmosferiche. In questa regione non sono stati trovati dati adatti per i corsi d?acqua. Infatti in Sardegna i bacini completamente o prevalentemente boscati sono rari e i corsi d?acqua che li drenano non sono stati analizzati regolarmente per lunghi periodi, in quanto la priorit? del monitoraggio ambientale ? stata ovviamente data ai corsi d?acqua maggiormente compromessi, dove il carico di azoto di origine antropica ? pi? importante. Tuttavia, pur tenendo conto della differente mole di dati raccolta per le due Regioni, si ritiene che i dati raccolti siano sufficienti per un?analisi delle serie temporali e un confronto tra le due Regioni, che verr? effettuato in un successivo deliverable