Nano- and microplastics: Do they impact fish health and welfare?

We have been able to, successfully, cultivate skin and corneal cells from salmon. The cells are viable at least for one week in culture dishes. We have performed exposure studies using nano- and microparticles made from polystyrene, silica, graphene and gold - and done uptake studies. In addition, we have studied uptake of both inactivated and live bacteria (causing skin ulcers in salmon) (Moritella viscosus and Vibrio salmonicida) - these were also taken up by the skin cells. All in all, the skin epithelial cells seem capable to ingest bot inorganic and organic particles. The reported co-infection issues (microbes unknown) is mitigated. The plan forward is to assess the trancriptomic and proteomic response by the cells after particle exposure.

The current proposal addresses the impact of NPs and MPs on fish health and welfare by introducing a systems biology approach. This ensures knowledge far beyond the current know how – which is fairly fragmented – and especially the fact that most of the previous studies have concerned millimeter-sized plastics and not tinier particles. The current proposal is tailored to answer fundamental questions: a) whether there is a discrimination between different plastic polymers (polystyrene, polyethylene, polypropylene, Teflon) with regards to uptake, b) presence of any plastic polymer-specific biological effects and c) whether wounded fish especially suffer from uptake of NPs and MPs. Thus, the potential for new knowledge is huge and impacts are expected in the fields of plastics pollution of sub millimeter particles. This study will seed similar studies on other species both in lower and higher taxa. For example, the methods applied here can likely be transferred to other fish species, thus there will be higher awareness on the environmental impacts of NPs and MPs on other fish species and other ecosystems/food webs – as well as to food to consumers. We foresee that, based on the current approach and its topicality, there will made other proposals to EU and RCN in the future. If successful, the project will provide a systems biology approach to study: 1) uptake mechanism in fish keratinocytes by high-end nanoscopy, 2) transcriptomic response, 3) metabolism by cells exposed to NPs and MPs, and to 4) correlation between plastic type and impacts. Furthermore, we will study how different particles are handled by fish keratinocytes in fish infected by fish lice causing wounds. RRI will be implemented throughout the project.