Foraging preferences influence microplastic ingestion by six marine fish species from the Texas Gulf Coast

This study evaluated the influence of foraging preferences on microplastic ingestion by six marine fish species from the Texas Gulf Coast. A total of 1381 fish were analyzed and 42.4% contained ingested microplastic, inclusive of fiber (86.4%), microbead (12.9% %), and fragment (< 1.0%) forms. Despite a substantial overlap in diet, ordination of ingested prey items clustered samples into distinctive species groupings, reflective of the foraging gradient among species. Orthopristis chrysoptera displayed the lowest overall frequency of microplastic ingestion and the most distinctive ordination grouping, indicating their selective invertebrate foraging preferences. Cluster analysis of O. chrysoptera most closely classified microplastic with the ingestion of benthic invertebrates, whereas the ingestion of microplastic by all other species most closely classified with the ingestion of vegetation and shrimp. O. chrysoptera, as selective invertebrate foragers, are less likely to ingest microplastics than species exhibiting generalist foraging preferences and methods of prey capture.

Colleen A. Peters, Peyton A. Thomas, Kaitlyn B. Rieper, Susan P. Bratton, Marine Pollution Bulletin, Available online 11 July 2017, In Press

The article

The adverse effects of virgin microplastics on the fertilization and larval development of sea urchins

Highlights

• Toxicity of virgin PS and HDPE particles and their leachates was investigated.
• Virgin microplastics are toxic to sea urchin embryo through the leaching of chemicals.
• Our results highlight the necessity to wash or weather virgin microplastics before toxicity testing.

Concepción Martínez-Gómez, Víctor M. León, Susana Calles, Marina Gomáriz-Olcina, A. Dick Vethaak, Marine Environmental Research, Available online 30 June 2017, In Press

The article

Inter-annual variation in the density of anthropogenic debris in the Tasman Sea

An increasing number of studies highlight the risk of plastic pollution in the marine environment. However, systematic longitudinal data on the distribution and abundance of plastic debris remain sparse. Here we present the results of a two-year study of plastic pollution within the Tasman Sea, contrasted with a further year of data from the same region, in order to document how the density of debris varies across years in this area. Surface net tows were collected between Hobart, Tasmania and Sydney, Australia during the spring of 2013 and 2014 and compared with a subset of data from autumn 2012 from the same region. Substantial inter-annual variation in mean plastic abundance was observed over the three year period, ranging from to 248.04–3711.64 pieces km− 2, confirming the need for multiple years of sampling to fully estimate the extent of, and trends in, plastic pollution.

Osha-Ann Rudduck, Jennifer L. Lavers, Andrew M. Fischer, Silke Stuckenbrock, Paul B. Sharp, Richard B. Banati, Marine Pollution Bulletin, Available online 8 July 2017, In Press

The article

Long-term toxicity of surface-charged polystyrene nanoplastics to marine planktonic species Dunaliella tertiolecta and Artemia franciscana

Plastic pollution has been globally recognized as a critical issue for marine ecosystems and nanoplastics constitute one of the last unexplored areas to understand the magnitude of this threat. However, current difficulties in sampling and identifying nano-sized debris make hard to assess their occurrence in marine environment. Polystyrene nanoparticles (PS NPs) are largely used as nanoplastics in ecotoxicological studies and although acute exposures have been already investigated, long-term toxicity on marine organisms is unknown. Our study aims at evaluating the effects of 40 nm PS anionic carboxylated (PS-COOH) and 50 nm cationic amino-modified (PS-NH2) NPs in two planktonic species, the green microalga Dunaliella tertiolecta and the brine shrimp Artemia franciscana, respectively prey and predator. PS NP behaviour in exposure media was determined through DLS, while their toxicity to microalgae and brine shrimps evaluated through 72 h growth inhibition test and 14 d long-term toxicity test respectively. Moreover, the expression of target genes (i.e. clap and cstb), having a role in brine shrimp larval growth and molting, was measured in 48 h brine shrimp larvae. A different behaviour of the two PS NPs in exposure media as well as diverse toxicity to the two planktonic species was observed. PS-COOH formed micro-scale aggregates (Z-Average > 1 μm) and did not affect the growth of microalgae up to 50 μg/ml or that of brine shrimps up to 10 μg/ml. However, these negatively charged NPs were adsorbed on microalgae and accumulated (and excreted) in brine shrimps, suggesting a potential trophic transfer from prey to predator. On the opposite, PS-NH2-formed nano-scale aggregates (Z-Average < 200 nm), caused inhibition of algal growth (EC50 = 12.97 μg/ml) and mortality in brine shrimps at 14 d (LC50 = 0.83 μg/ml). Moreover, 1 μg/ml PS-NH2 significantly induced clap and cstb genes, explaining the physiological alterations (e.g. increase in molting) previously observed in 48 h larvae, but also suggesting an apoptotic pathway triggered by cathepsin L-like protease in brine shrimps upon PS-NH2 exposure. These findings provide a first insight into long-term toxicity of nanoplastics to marine plankton, underlining the role of the surface chemistry in determining the behaviour and effects of PS NPs, in terms of adsorption, growth inhibition, accumulation, gene modulation and mortality. The use of long-term end-point has been identified as valuable tool for assessing the impact of nanoplastics on marine planktonic species, being more predictable of real exposure scenarios for risk assessment purposes.

E. Bergami, S. Pugnalini, M.L. Vannuccini, L. Manfra, C. Faleri, F. Savorelli, K.A. Dawson, I. Corsi, Aquatic Toxicology, Aquatic Toxicology, Volume 189, August 2017, Pages 159–169

The article

The Impacts of Biofilm Formation on the Fate and Potential Effects of Microplastic in the Aquatic Environment

In the aquatic environment, Microplastic (MP; < 5 mm) is a cause of concern due to its persistence and potential adverse effects on biota. Studies on microlitter impacts are mostly based on virgin and spherical polymer particles as model MP. However, in pelagic and benthic environments, surfaces are always colonized by microorganisms forming so-called biofilms. The influence of such biofilms on the fate and potential effects of MP presents a current knowledge gap. Here, we review the physical interactions of early microbial colonization on plastic surfaces and their reciprocal influence on the weathering processes and vertical transport as well as sorption and release of contaminants by MP. Possible ecological consequences of biofilm formation on MP, such as trophic transfer of MP particles and potential adverse effects of MP, are virtually unknown. However, the evidence is accumulating that by modifying the physical properties of the particles, the biofilm-plastic interactions have the capacity to influence the fate and impacts MP may have. There is an urgent research need to better understand these interactions and increase ecological relevance of current laboratory testing by simulating field conditions where microbial life is a key driver of the biogeochemical processes.

Christoph D. Rummel, Annika Jahnke, Elena Gorokhova, Dana Kühnel, and Mechthild Schmitt-Jansen, Environ. Sci. Technol. Lett., 2017, 4 (7), pp 258–267

Interactions between polystyrene microplastics and marine phytoplankton lead to species-specific hetero-aggregation

To understand the fate and impacts of microplastics (MP) in the marine ecosystems, it is essential to investigate their interactions with phytoplankton as these may affect MP bioavailability to marine organisms as well as their fate in the water column. However, the behaviour of MP with marine phytoplanktonic cells remains little studied and thus unpredictable. The present study assessed the potential for phytoplankton cells to form hetero-aggregates with small micro-polystyrene (micro-PS) particles depending on microalgal species and physiological status. A prymnesiophycea, Tisochrysis lutea, a dinoflagellate, Heterocapsa triquetra, and a diatom, Chaetoceros neogracile, were exposed to micro-PS (2 μm diameter; 3.96 μg L−1) during their growth culture cycles. Micro-PS were quantified using an innovative flow-cytometry approach, which allowed the monitoring of the micro-PS repartition in microalgal cultures and the distinction between free suspended micro-PS and hetero-aggregates of micro-PS and microalgae. Hetero-aggregation was observed for C. neogracile during the stationary growth phase. The highest levels of micro-PS were “lost” from solution, sticking to flasks, with T. lutea and H. triquetra cultures. This loss of micro-PS sticking to the flask walls increased with the age of the culture for both species. No effects of micro-PS were observed on microalgal physiology in terms of growth and chlorophyll fluorescence. Overall, these results highlight the potential for single phytoplankton cells and residual organic matter to interact with microplastics, and thus potentially influence their distribution and bioavailability in experimental systems and the water column.

Marc Long, Ika Paul-Pont, Hélène Hégaret, Brivaela Moriceau, Christophe Lambert, Arnaud Huvet, Philippe Soudant, Environmental Pollution, Volume 228, September 2017, Pages 454–463

The article

Occurrence and effects of plastic additives on marine environments and organisms: A review

Plastics debris, especially microplastics, have been found worldwide in all marine compartments. Much research has been carried out on adsorbed pollutants on plastic pieces and hydrophobic organic compounds (HOC) associated with microplastics. However, only a few studies have focused on plastic additives. These chemicals are incorporated into plastics from which they can leach out as most of them are not chemically bound. As a consequence of plastic accumulation and fragmentation in oceans, plastic additives could represent an increasing ecotoxicological risk for marine organisms. The present work reviewed the main class of plastic additives identified in the literature, their occurrence in the marine environment, as well as their effects on and transfers to marine organisms. This work identified polybrominated diphenyl ethers (PBDE), phthalates, nonylphenols (NP), bisphenol A (BPA) and antioxidants as the most common plastic additives found in marine environments. Moreover, transfer of these plastic additives to marine organisms has been demonstrated both in laboratory and field studies. Upcoming research focusing on the toxicity of microplastics should include these plastic additives as potential hazards for marine organisms, and a greater focus on the transport and fate of plastic additives is now required considering that these chemicals may easily leach out from plastics.

Ludovic Hermabessiere, Alexandre Dehaut, Ika Paul-Pont, Camille Lacroix, Ronan Jezequel, Philippe Soudant, Guillaume Duflos, Chemosphere, Volume 182, September 2017, Pages 781–793

The article