07 nov. 2017 - Laura Fantozzi

20171107 Seminario Fantozzi

The biogeochemical cycling of mercury

Presenta: Laura Fantozzi

CNR Istituto per lo Studio degli Ecosistemi

Mercury (Hg) is one of the most investigated natural elements and potential contaminants in the world and in the Mediterranean area in particular. It is considered a priority pollutant due to its unique properties and adverse effects on human health and environment, and is a major driving force for international action. Differently to other metals, the atmosphere is the central pathway of distribution for Hg. It evaporates easily and exists in the atmosphere almost in the gaseous phase (>95%). In this form, called gaseous elemental mercury (GEM), it is very stable, with a residence time in air of 6-24 months. As a result, Hg can travel long distances, and persists in environments where it circulates between air, water, sediments, soil, and living organisms. Its organic form, methylmercury (MeHg), readily bioaccumulates and biomagnifies, causing neurological, immunological, and cardiovascular problems at high levels. Human exposure to MeHg is mainly through the consumption of contaminated fish, and is a concern even in relatively pristine environments, as Hg can be readily transported through the atmosphere. It is of even greater concern in areas that have high background levels of Hg, as is the case in the Mediterranean area, due to its distinct climatic, meteorological, geomorphological, and anthropogenic framework. Atmospheric Hg enter marine and fresh waters by wet and dry deposition mostly as inorganic Hg (Hg(II)). Hg(II) can be reduced by biological and photochemical processes to volatile dissolved forms (90% elemental Hg), named Dissolved Gaseous Mercury (DGM), that are readily re-emitted. The removal of these volatile forms ultimately reduces the pool of Hg that could be converted to MeHg and bioaccumulated in marine and fresh water food webs. Water surfaces contribute more than 53% of global Hg emissions that comes from natural processes and sources. In particular, in the Mediterranean area the aquatic evasion represents the largest natural source of Hg into the atmosphere (60-77 t/year). The purpose of this seminar is to give an insight to the cycling of Hg in the aquatic environment and at the air-water interface. In particular, the formation and distribution of DGM, air-water Hg flux, and the contribution of the eukaryotic and prokaryotic microorganisms to the production of DGM in aquatic systems will be discussed.

click to download notice of seminar

26 ott. 2017 - Silvana Halac

20171026 Seminario Halac

Various study approaches of microbiological proliferation and their relationship with environmental factors at San Roque reservoir (Córdoba, Argentina)

Presenta: Silvana Halac

Instituto Nacional del Agua, Centro de la Región Semiárida, INA-CIRSA.
Centro de Investigaciones en Ciencias de la Tierra, CICTERRA,
Consejo Nacional de Investigaciones Científicas y Técnicas, CONICET, Argentina

San Roque reservoir (SRr; Córdoba, Argentina) is the main source of drinking water to Cordoba city. It presents an advanced eutrophic state with records of recurrent cyanobacteria blooms (e.g. Microcystis aerouginosa, Dolichospermum sp.) and presence of cyanotoxins (e.g.; microcystins –MCs and anatoxins), as well as occurrence of pathogenic bacteria (e.g. Escherichia coli, Enterococcus spp. --STC).
Because a monthly uninterrupted monitoring was carried out since 1999, a wide base data was achieved. Many questions raised from the observed patterns, e.g.: a.-Which are the main factors triggering the cyanobacterial blooms and regulating cyanotoxins (mainly MCs) production in ESR? b.-Are cyanobacterial blooms promoting pathogenic bacteria proliferation? c.- Is neighboring human population being health affected by chronic MCs exposure?
In order to asses these events, different types of studies were carried out, among which are: a.- Microcosms experiments carried out with natural cyanobacterial populations isolated from SRr and with different addition Fe treatments b.-Interaction experiments between cyanobacteria cultures and pathogenic bacteria strains isolated from ESr. c.- Assessment of chronic exposure to MCs in a SRr neighboring population through out blood and immunological analysis, surveys and water quality determinations.
Moreover, SRr paleolimnological studies started to be done recently, with the aim of studying the eutrophication process in a broader range of time.

click to download notice of seminar

24 ott. 2017 - Alessandro Balestrieri e Andrea Mosini

20171024 Seminario BalestrieriMosini

Into the wilderness: l'espansione della martora nel Parco nazionale della Val Grande

Presentano: Alessandro Balestrieri e Andrea Mosini

Cooperativa Val Grande

L'abbandono dell'agricoltura e dell'allevamento nei territori montani ha determinato, in Europa, l'incremento della superficie delle aree boscate con un effetto positivo sulle specie forestali. Sulle Alpi la martora (Martes martes) potrebbe essere stata avvantaggiata dall'incremento della superficie forestale (ca. 50 % tra il 1960 e il 2000), ricolonizzando aree montane da cui era scomparsa nel XX secolo, espandendosi anche in aree di pianura. Il Parco nazionale della Val Grande è la più vasta area wilderness delle Alpi; l'abbandono delle pratiche agricole tradizionali alla fine della seconda guerra mondiale ha comportato la contrazione della superficie dei pascoli e delle aree coltivate dal 59% al 5% della superficie dell'Area Protetta. Il primo dato di presenza recente di martora nel Parco risale ad ottobre 2014. Con lo scopo di studiare la distribuzione di questa specie in relazione alla più diffusa faina (Martes foina), tra luglio e ottobre 2015 abbiamo condotto una ricerca su un'area di 42 km2, utilizzando il fototrappolaggio (N=27; 2163 notti-trappola) e il censimento genetico a partire da campioni fecali (N=112). La martora è stata osservata 6 volte (su di un totale di 945 video) in sole 4 località, mentre la faina è risultata presente in 21 siti, per un totale di 156 video. Utilizzando il metodo PCR-RFLP 12 feci sono state attribuite a M. martes e 82 a M. foina. I nostri risultati supportano l'ipotesi che la martora stia ricolonizzando l'area protetta; le modificazioni dell'habitat e la sua persecuzione avvenute nel secolo scorso, più che la competizione interspecifica, hanno probabilmente avuto un ruolo fondamentale nel delineare l'attuale distribuzione e abbondanza delle due specie del genere Martes.

click to download notice of seminar

17 ott. 2017 - Michaela M. Salcher

20171017 Seminario Salcher

Ecogenomics of genome-streamlined freshwater microbes

Presenta: Michaela M. Salcher

Limnological Station, University of Zurich, Switzerland

Freshwater microbes are centrally involved in chemical turnover processes, yet individual microbial populations greatly differ in their metabolic and ecological features. The most abundant microbes in the plankton of lakes are of conspicuously small size (cell volumes <0.1 μm3) and have reduced genomes (<1.5 Mb). Streamlining theory predicts that gene loss is caused by evolutionary selection driven by environmental factors, making these organisms superior competitors for limiting resources under oligotrophic conditions. Although such streamlined microbes numerically dominate in lakes, they are still poorly studied, mainly because of problems establishing axenic cultures. A newly developed isolation strategy allowed us to bring some of these oligotrophs in culture, e.g., members of the most abundant freshwater microbes, the acI Actinobacteria ('Ca. Nanopelagicales') and 'Ca. Methylopumilus planktonicus' (Betaproteobacteria). Whole genome sequencing and comparative population-genomics in combination with high-resolution monitoring identified a high degree of microdiversification in closely related genotypes. This ecotype diversification reflects a possible niche-specific adaptation and might be the reason for the observed high total population numbers in lakes.

click to download notice of seminar

05 ott. 2017 - Paolo Debernardi, Laura Garzoli e Elena Patriarca

20171005 Seminario Garzoli

Pipistrelli, protezione e gestione

Presentano: Paolo Debernardi, Laura Garzoli, Elena Patriarca

S.Te.P. Stazione Teriologica Piemontese

Il seminario, di carattere tecnico-scientifico, è mirato a incrementare la conoscenza dei chirotteri. Dopo una introduzione mirata a fornire nozioni biologiche di base e circa il ruolo dei pipistrelli come bioindicatori e fornitori di servizi ecosistemici, saranno illustrate le principali tecniche di rilievo e monitoraggio chirotterologico e le problematiche di protezione e gestione nei diversi ambienti. Enfasi verrà data agli aspetti legati al ruolo delle zone umide per la conservazione delle diverse specie e saranno presentati i risultati delle indagini effettuate sulla colonia di Myotis capaccinii, Myotis daubentonii, Myotis blythii e Myotis myotis dell'Isola Bella.
Il seminario è rivolto primariamente al personale che si occupa di gestione ambientale e di divulgazione naturalistica. Più in generale, l'iniziativa è aperta a tutti coloro che, a vario titolo, sono interessati alla conservazione e alla conoscenza della chirotterofauna.

click to download notice of seminar