Microplastics pollution after the removal of the Costa Concordia wreck: First evidences from a biomonitoring case study

Microplastics (MPs) represent a matter of growing concern for the marine environment. Their ingestion has been documented in several species worldwide, but the impact of specific anthropogenic activities remains largely unexplored. In this study, MPs were characterized in different benthic fish sampled after 2.5 years of huge engineering operations for the parbuckling project on the Costa Concordia wreck at Giglio Island. Fish collected in proximity of the wreck showed a high ingestion of microplastics compared to both fish from a control area and values reported worldwide. Also the elevated percentage of nylon, polypropylene lines and the presence of polystyrene are quite unusual for marine organisms sampled in natural field conditions, thus supporting the possible relationship of ingested microplastics with maritime operations during wreck removal. On the other hand, the use of transplanted mussels revealed a lower frequency of ingested MPs, and did not discriminate differences between the wreck and the control area. Some variations were observed in terms of typology and size of particles between surface- and bottom-caged mussels highlighting the influence of a different distribution of MPs along the water column. In conclusion, this study demonstrated that MPs pollution in the area of Costa Concordia was more evident on benthonic environment than on seawater column, providing novel insights on the possibility of using appropriate sentinel organisms for monitoring specific anthropogenic sources of MPs pollution in the marine environment.

Carlo Giacomo Avio, Lara Roberta Cardelli, Stefania Gorbi and al., Environmental Pollution, Volume 227, August 2017,  Pages 207–214

The article

Quantification and characterization of microplastics in blue mussels (Mytilus edulis): protocol setup and preliminary data on the contamination of the French Atlantic coast

Microplastics (MPs) constitute a main environmental issue due to their threat to marine organisms and so far to humans. The lack of a fast standard protocol in MP isolation and identification from living organisms bring to challenge for the science. In this paper, an optimized protocol using potassium hydroxide 10% (KOH 10%; m/v) for digestion of mussel soft tissues (Mytilus edulis) and multi-steps of sedimentation has been developed. Efficiency higher than 99.9% of organic and mineral matter elimination was shown by application on mussels sampled on the French Atlantic coast. The identification of MPs was performed by FTIR microscopy straight on the filter and the whole analysis can be compatible with a routine goal. Fourteen MPs of four different chemical natures were found and identified in 5 pools of 3 sampled mussels. Their size ranged from 30 to 200 μm. Further investigations are now needed to evaluate the potential risk of such particles within this marine bivalve species and other filter feeders.

Nam Ngoc Phuong, Aurore Zalouk-Vergnoux, Abderrahmane Kamari,Catherine Mouneyrac, Frederic Amiard, Laurence Poirier, Fabienne Lagarde, Environ Sci Pollut Res (April 2017), online first, pages 1-10

The article

Microplastics en route: Field measurements in the Dutch river delta and Amsterdam canals, wastewater treatment plants, North Sea sediments and biota

Environmental contamination by plastic particles, also known as ‘microplastics’, brings synthetic materials that are non-degradable and biologically incompatible into contact with ecosystems. In this paper we present concentration data for this emerging contaminant in wastewater treatment plants (WWTPs) and freshwater and marine systems, reflecting the routes via which these particles can travel and the ecosystems they potentially impact along their path. Raw sewage influents, effluents and sewage sludge from seven municipal WWTPs in the Netherlands contained mean particle concentrations of 68–910 L− 1, 51–81 L− 1 and 510–760 kg− 1 wet weight (ww), respectively (particle sizes between 10 and 5000 μm). Even after treatment, wastewater constitutes a source of microplastic pollution of surface waters, and via biosolids applications in farming and forestry, plastic retained in sewage sludge can be transferred to terrestrial environments. The WWTPs investigated here had a mean microplastics retention efficiency of 72% (s.d. 61%) in the sewage sludge. In the receiving waters of treated and untreated wastewaters, we detected high microplastic levels in riverine suspended particulate matter (1400–4900 kg− 1 dry weight (dw)) from the Rhine and Meuse rivers. Amsterdam canal water sampled at different urban locations contained microplastic concentrations (48–187 L− 1), similar to those observed in wastewater that is emitted from sewage treatment facilities in the area. At least partial settling of the particles occurs in freshwater as well, as indicated by microplastics in urban canal sediments (< 68 to 10,500 particles kg− 1 dw). Microplastics in suspension in the water column have the potential to be discharged into the sea with other riverine suspended particulates. We report microplastic concentrations from 100 up to 3600 particles kg− 1 dry sediment collected at 15 locations along the Dutch North Sea coast. The high microplastic enrichment in marine sediments compared to most literature data for seawater at the surface supports the hypothesis of a seabed sink for these materials. Marine species are heavily exposed to plastic particles. Body residues between 10 and 100 particles g− 1 dw were measured in benthic macroinvertebrate species inhabiting the Dutch North Sea coast: filter-feeding mussels and oysters (species for human consumption) as well as other consumers in the marine food chain.

H.A. Leslie, S.H. Brandsma, M.J.M. van Velzen, A.D. Vethaak, Environment International, Available Environment International, Volume 101, April 2017, Pages 133–142

The article

Development and optimization of a standard method for extraction of microplastics in mussels by enzyme digestion of soft tissues

The authors compared procedures for digestion of mussel soft tissues and extraction of microplastics. Complete tissue digestion was achieved with 1M NaOH, 35% HNO3, and protease at 9.6 UHb/mL (unit hemoglobin per mL); but use of HNO3 caused unacceptable destruction of some microplastics. Recovery of microplastics spiked into mussels was similar (93 ± 10%) for NaOH and enzyme digestions. The authors recommend use of industrial enzymes based on digestion efficiency, microplastic recovery, and avoidance of caustic chemicals.

Ana I. Catarino, Richard Thompson, William Sanderson, Theodore B. Henry, Environmental Toxicology and Chemistry, October 2016, 5 pages, In press

The article

Leachate from microplastics impairs larval development in brown mussels

Microplastic debris is a pervasive type of contaminant in marine ecosystems, being considered a major threat to marine biota. One of the problems of microplastics is that they can adsorb contaminants in extremely high concentrations. When released from the particle, these contaminants have the potential to cause toxic effects in the biota. So far, reports of toxic effects are mostly linked with the direct exposure of organisms through ingestion of contaminated microplastics. There is little information on the toxicity of leachates from microplastics to marine organisms. In this study, we conducted experiments to evaluate the toxicity of leachates from virgin and beached plastic pellets to embryo development of the brown mussel (Perna perna). We compared the efficiency of two test procedures, and evaluated the toxicity of beached pellets collected in a coastal marine protected area. We observed that mussel embryo is sensitive to leachate from both virgin and beached pellets. However, the toxicity of the leachate from beached pellets was much higher than that of virgin pellets. We suggest contaminants adsorbed onto the surface of beached pellets were responsible for the high toxicity of leachate from beached pellets, while the toxicity of leachate from virgin pellets was mainly due to plastic additives. Our results suggest microplastic debris may be harmful even if ingestion is not the only or main pathway of interaction of marine organisms with contaminated plastic debris.

Pablo Pena Gandara e Silva, Caio Rodrigues Nobre, Pryscila Resaffe, Camilo Dias Seabra Pereira, Felipe Gusmão, Water Research, Volume 106, 1 December 2016, Pages 364–370

The article

Microplastics Affect the Ecological Functioning of an Important Biogenic Habitat

Biological effects of microplastics on the health of bivalves have been demonstrated elsewhere, but ecological impacts on the biodiversity and ecosystem functioning of bivalve-dominated habitats are unknown. Thus, we exposed intact sediment cores containing European flat oysters (Ostrea edulis) or blue mussels (Mytilus edulis) in seawater to two different densities (2.5 or 25 μg L–1) of biodegradable or conventional microplastics in outdoor mesocosms. We hypothesized that filtration rates of the bivalves, inorganic nitrogen cycling, primary productivity of sediment dwelling microphytobenthos, and the structure of invertebrate benthic assemblages would be influenced by microplastics. After 50 days, filtration by M. edulis was significantly less when exposed to 25 μg L–1 of either type of microplastics, but there were no effects on ecosystem functioning or the associated invertebrate assemblages. Contrastingly, filtration by O. edulis significantly increased when exposed to 2.5 or 25 μg L–1 of microplastics, and porewater ammonium and biomass of benthic cyanobacteria decreased. Additionally the associated infaunal invertebrate assemblages differed, with significantly less polychaetes and more oligochaetes in treatments exposed to microplastics. These findings highlight the potential of microplastics to impact the functioning and structure of sedimentary habitats and show that such effects may depend on the dominant bivalve present.

Dannielle Senga Green, Bas Boots, Nessa E. O’Connor, and Richard Thompson, Environ. Sci. Technol., 2017, 51 (1), pp 68–77

Impact of bisphenol A (BPA) on early embryo development in the marine mussel Mytilus galloprovincialis: Effects on gene transcription

Bisphenol A (BPA), a monomer used in plastic manufacturing, is weakly estrogenic and a potential endocrine disruptor in mammals. Although it degrades quickly, it is pseudo-persistent in the environment because of continual inputs, with reported concentrations in aquatic environments between 0.0005 and 12 μg/L. BPA represents a potential concern for aquatic ecosystems, as shown by its reproductive and developmental effects in aquatic vertebrates.

In invertebrates, endocrine-related effects of BPA were observed in different species and experimental conditions, with often conflicting results, indicating that the sensitivity to this compound can vary considerably among related taxa. In the marine mussel Mytilus galloprovincialis BPA was recently shown to affect early development at environmental concentrations. In this work, the possible effects of BPA on mussel embryos were investigated at the molecular level by evaluating transcription of 13 genes, selected on the basis of their biological functions in adult mussels. Gene expression was first evaluated in trocophorae and D-veligers (24 and 48 h post fertilization) grown in physiological conditions, in comparison with unfertilized eggs. Basal expressions showed a general up-regulation during development, with distinct transcript levels in trocophorae and D-veligers. Exposure of fertilized eggs to BPA (10 μg/L) induced a general upregulation at 24 h pf, followed by down regulation at 48 h pf. Mytilus Estrogen Receptors, serotonin receptor and genes involved in biomineralization (Carbonic Anydrase and Extrapallial Protein) were the most affected by BPA exposure. At 48 h pf, changes in gene expression were associated with irregularities in shell formation, as shown by scanning electron microscopy (SEM), indicating that the formation of the first shelled embryo, a key step in mussel development, represents a sensitive target for BPA. Similar results were obtained with the natural estrogen 17β-estradiol. The results demonstrate that BPA and E2 can affect Mytilus early development through dysregulation of gene transcription.

Teresa Balbi, Silvia Franzellitti, Rita Fabbri, Michele Montagna, Elena Fabbri, Laura Canesi, Environmental Pollution, Volume 218, November 2016, Pages 996–1004

The article