| Sede | Verbania |
| Tipologia di contributo | Progetto |
| Tipologia di progetto | Progetti di ricerca internazionali |
| Titolo | Assessing microplastic abundance and distribution in Lake Maggiore using native and invasive freshwater mussels: a case study exploitation to improve bio-monitoring methodologies. |
| Acronimo | microPA-LKM |
| Abstract ITA | Non disponibile |
| Abstract ENG | The project has two complementary purposes:
1) Answering the local request to assess the abundance and distribution of microplastic in the coastal area of Lake Maggiore in agreement with the monitoring needs of the CIPAIS (Commission for the Protection of Italian-Swiss Waters) 2) a more general one aimed at contributing new knowledge to help optimization of survey protocols by bioaccumulators.
To match both aims, the project includes the analysis of wild mussels (field assessment) and the laboratory exposure of mussels taken in the wild and standardized under laboratory conditions. |
| Descrizione estesa ITA | Non disponibile |
| Descrizione estesa ENG | 1) Field assessment:
Sampling:
Sampling strategy represents a challenge in designing a representative and adequately replicated monitoring scheme. Patchiness of microplastics in different spatial and temporal scales may lead to variable amounts within mussels. The extent to which these factors change microplastic abundance or type in the environment varies with sampling sites. Therefore, sampling time and sites should be variable factors considered during the investigation. Environmental factors, changing with local shore shape and season (e.g., wind, currents, rainfall, temperature, human activity) may affect microplastic distribution.
Therefore, we planned the following sampling strategy taking into account the above mentioned variables.
To improve representativeness, sampling will be performed in 6 sites representative of different levels of anthropogenic impact and characterized by different habitat features on two seasonal periods, autumn 2019 and spring 2020 (theoretically corresponding to the minimum and maximum lake water levels). Since the type of substrate can influence both the distribution of mussels and that of microplastics, sampling will be carried out in A) 3 sites with slightly sloping shores and predominantly muddy soft substrate and B) 3 sites with steep slopes and mixed substrate (rock, stones, boulders with small patches of soft sediment included between the hard substrates).
Lake Maggiore is presently hosting four native species (Unio elongatulus, Anodonta anatina, A. cygnea and A. exulcerata) and three invasive bivalves (Sinanodonta woodiana, Corbicula fluminea, Dreissena polymorpha). To avoid impoverishing the local populations of Anodonta, rarer than Unio. the project will only compare the most abundant native Unio elongatulus with the two most abundant invasive species (Corbicula fluminea, Dreissena polymorpha). In each site a representative number of specimens will be collected and pooled to obtain a representative sample for each of the 3 target species.
Sample preservation and processing: To minimize the risk of samples contamination, specimens will be identified visually for species assignment and preserved immediately after collection according the procedures agreed with the JRC researchers involved in the analytical task.
Sample processing will be designed according the suggestions of the researchers of the Nanobiotechnology laboratory involved in the analytical procedure, taking into account the requirements that must be fulfilled for each analytical approach. The total body burden of microplastics in mussels goes beyond ingestion. Besides uptake through the gut and across the gills, microplastics adhere to mussel's soft tissue (mantle, gonad, adductor, visceral tissue and foot) can further contribute to microplastic presence within individuals. Since the dissection of the organs can be a source of contamination, as a first step the whole tissues will be analysed to verify the mussel’s bioaccumulation capacities. As a second step, mussel dissection will be eventually performed to specifically target the critical organs and/or to compare organ specific accumulation rates.
Number of samples to be analysed: 36
Analytical methods: Current methods for microplastic identification involve visual sorting (with the aid of polarized light microscopy), Nile Red staining, Fourier transformed infrared spectrometry (FT-IR), attenuated total reflectance (ATR), Raman spectrometry, pyrolysis-gas chromatography combined with mass spectroscopy (Pyr-GC-MS), high temperature gel-permeation chromatography (HT-GPC) with IR detection, SEM-EDS, thermal extraction desorption gas chromatography mass spectrometry (TED-GC-MS) and liquid extraction. Since no single method is able to obtain the physical (size, shape and colour) and chemical (polymer type) characteristics of particles in a single step, the combination of several parallel approaches will be applied after discussion with the researchers of the Nanobiotechnoloy Lab. Extraction procedure will be defined accordingly. Procedural blanks will be carried out to monitor contamination and correct empirical data.
2) Laboratory exposure:
The exposure in standard laboratory conditions is indispensable for measuring crucial parameters for the evaluation of the efficiency of biological models and analytical procedures, for the interpretation of monitoring data and for the large-scale extrapolation of local data.
Wild mussels collected in Lake Maggiore will be cleaned of epibionts, measured by a digital caliper (length, width, eight) and tagged for individual identification. Before experimental exposure, mussels will be acclimated in a 10 x 8 m artificial pond, 1.5-m deep (provided with daily water renewal) for at least 1 week to recover from transport stressors. A stock of approximately 50 specimens of each species (Unio elongatulus, Corbicula fluminea, Dreissena polymorpha) will be acclimatized for 2 weeks in three large flow-through maintenance tanks, each containing ca. 150 L of filtered (1 μm). Lake Maggiore water at 15±1°C, which will be entirely turned over about once a day. A low- pressure air blower will be used to maintain aeration. Mussels will be fed a commercial shellfish diet every day. Water inflow will be stopped for 1−2 h during feeding.
The exposure experiments will be carried out in 2 L glass beakers filled with filtered (0,45 μm) lake water and/or dechlorinated tap water at a constant temperature of 15±1°C and a 12 h light-dark illumination regime. The animals for the exposure experiments will be randomly selected from the maintenance tanks. As the three model species vary widely in size, to obtain comparable results, the number of specimens per beaker will be calculated to obtain the same animal biomass: water volume ratio. For each species three beakers will receive the artificial plastic beds treatment and one beaker will serve as unexposed negative control. Experiment duration and biomass:water volume ratio will be planned in order to avoid feeding the animals during exposure. Based on previous preliminary experiments, exposure times can be tentatively planned at 3, 6, 12 and 24 h, and the number of specimens/beaker at 3 Unio elongatulus, 5 Corbicula fluminea, 10 Dreissena polymorpha. |
| Rilevanza scientifica e risultati ITA | I primi risultati sono stati pubblicati: 2. Facchetti, S.V., La Spina, R., Fumagalli, F., Riccardi, N., Gilliland, D., Ponti, J. 2020. Detection of Metal-Doped Fluorescent PVC Microplastics in Freshwater Mussels. Nanomaterials, 10, 2363; doi:10.3390/nano10122363 |
| Rilevanza scientifica e risultati ENG | First results are published: Facchetti, S.V., La Spina, R., Fumagalli, F., Riccardi, N., Gilliland, D., Ponti, J. 2020. Detection of Metal-Doped Fluorescent PVC Microplastics in Freshwater Mussels. Nanomaterials, 10, 2363; doi:10.3390/nano10122363 |
| Coordinatore | Nicoletta Riccardi |
| Referente IRSA | Nicoletta Riccardi |
| Periodo di attivita | 2019-2021 |
| Data | 2020-16-12 |
| Fonte di finanziamento ITA | Commissione per la Protezione delle Acque Italo-Svizzere |
| Fonte di finanziamento ENG | Commissione per la Protezione delle Acque Italo-Svizzere |
