Microplastic in a macro filter feeder: Humpback whale Megaptera novaeangliae.

Marine filter feeders are exposed to microplastic because of their selection of small particles as food source. Baleen whales feed by filtering small particles from large water volumes. Macroplastic was found in baleen whales before. This study is the first to show the presence of microplastic in intestines of a baleen whale (Megaptera novaeangliae). Contents of its gastrointestinal tract were sieved, dissolved in 10% potassium hydroxide and washed. From the remaining dried material, potential synthetic polymer particles were selected based on density and appearance, and analysed by Fourier transform infrared (FTIR) spectroscopy. Several polymer types (polyethylene, polypropylene, polyvinylchloride, polyethylene terephthalate, nylon) were found, in varying particle shapes: sheets, fragments and threads with a size of 1mm to 17cm. This diversity in polymer types and particle shapes, can be interpreted as a representation of the varying characteristics of marine plastic and the unselective way of ingestion by M. novaeangliae.

Guidance for the prognostic risk assessment of nanomaterials in aquatic ecosystems.

Our understanding of the environmental fate and effects of engineered nanomaterials (ENMs) is in a state of fast transition. Recent scientific developments open new and powerful perspectives to define a framework for the prognostic risk assessment of ENMs in aquatic ecosystems. This requires abandoning the reductionist's approach of mechanistic analysis on particle or cellular scales and calls for engineering solutions that deal with uncertainties by applying assessment factors and probabilistic approaches. An ecological risk assessment (ERA) framework for ENMs is similar to that for other classes of substances, in that it requires clear protection goals based on ecosystem services, evidence-based concepts that link exposure to effects, and a transparent tiered effect assessment. Here, we discuss approaches to assess exposure and effects of ENMs. This includes recent developments in ENP fate modeling that greatly expanded the potential of prognostic exposure assessments. For the effect assessment, we advise a cost-effective screening based on principles of read-across as a conservative first tier. The feasibility of using species sensitivity distributions as a higher tier option is discussed. Controlled model ecosystem field experiments are proposed as a highest experimental tier, and are required for the calibration of the lower tiers. An outlook to unify information from various tiers by experimental work, fate modeling, and effect modeling as cost-effective prognostic tools for the ERA of ENMs is provided.

Effects of nanopolystyrene on the feeding behavior of the blue mussel (Mytilus edulis L.).

As the industrial production of nanoplastic and the degradation of microplastic into smaller particles at sea increase, the potential amount of nanoplastics in the marine environment rises. It has been reported that mussels uptake 100-nm polystyrene (PS) beads; to date, however, the effects of this uptake on the organism are unknown. In the present study, the authors investigated the effects of 30-nm PS on the feeding behavior of the blue mussel (Mytilus edulis) by exposing the organism to different nano PS and different algae (Pavlova lutheri) concentrations. The state of nano PS aggregation in the exposure medium was assessed using dynamic light scattering. In all treatments that contained nano PS, M. edulis produced pseudofeces. The total weight of the feces and pseudofeces increased with increasing nano PS and increasing algae concentration. Furthermore, M. edulis reduced its filtering activity when nano PS was present but still caused a decrease in the apparent nano PS concentration in the water. The presence of nano PS around the foot of M. edulis after the bioassay confirmed that the organism removed nano PS from the water. Chronic effect studies are therefore needed to investigate the effects of nanoplastics in M. edulis and possible consequences for its predators, including humans.