Plastic fish: assessing the scale, chemical properties and biological effects of petrochemical plastics and bioplastics on aquaculture fish

一次性塑料是我们日常生活的一部分，但我们并不完全了解它们对动物福利的影响。生物基塑料，称为生物塑料，作为传统石化塑料的更环保的替代品销售。然而，我们需要确保这些生物塑料及其分解产物在消费时是安全的。这个跨学科项目由三个大学部门（卡迪夫大学，生物科学，化学和工程学院）组成，由行业主导的问题驱动，将评估石化和生物塑料对养殖鱼类的化学特性和生物影响。环境塑料的总质量超过地球上所有鱼类的质量。这在多个层面上都令人担忧;鱼类是最丰富的脊椎动物物种，是人类蛋白质的主要来源，水产养殖是全球增长最快的食品部门。如果可持续地进行，养鱼可以为人类提供最低碳的动物蛋白质来源。污染是威胁受管理鱼类种群的福利及其未来可持续性的一个关键因素。受管理鱼类种群中塑料污染的规模在很大程度上是未知的，现在必须解决这个问题。在鱼类和人体组织中检测到塑料颗粒，表明塑料是人类食物链的一部分，因此我们必须评估这种普遍存在的污染物如何影响鱼类福利。我们的试验数据表明，不含化学添加剂的塑料通过降低抗病能力和延长感染时间来影响鱼类福利。然而，这可能只是“冰山一角”，因为大多数塑料也含有化学添加剂，如增塑剂和热稳定剂，塑料可以作为环境毒素的海绵，在消费时可能会造成更多的损害。解决塑料污染的一个新兴战略是开发生物塑料。虽然生物塑料目前仅占塑料年产量的1%，但它们作为石化塑料的替代品被广泛销售。生物塑料被公开宣传为生态友好和可生物降解的，但对其环境适应性的研究非常有限，以前的降解研究（在不现实的情况下进行）显示降解程度很小。但是，即使生物塑料确实比石化塑料降解得更快，它们也可能矛盾地产生更高比例的持久性微米和纳米塑料。此外，生物塑料含有与石化塑料相同的化学添加剂，因此我们必须评估它们在水生环境中释放这些化学物质和吸附其他化学污染物的效率。同样，我们必须了解生物塑料和相关添加剂在动物食用时的功能影响。该项目有三个关键目标，直接与BBSRC在动物健康方面的战略重点保持一致，特别是管理动物的福利，数据驱动的生物学和可以为公共政策提供信息的研究。首先，我们将评估英国水产养殖鱼类种群中塑料污染的规模。其次，结合石化塑料中普遍存在的添加剂和环境毒素，我们将评估这些塑料的化学性质及其对养殖鱼类的生物影响，重点是生长，代谢和抗病性。然后，认识到评估替代塑料解决方案的紧迫性，我们将测试生物塑料在暴露和消费时的化学性质和生物效应。在实施该项目时，我们将直接向政府机构和水产养殖业通报鱼类种群中塑料污染的规模和相关影响，以支持塑料使用和减少废物的政策。通过评估生物塑料的环境适应性，未来的公共宣传计划可以帮助防止潜在的绿色清洗。

Disposable plastics are an everyday part of our lives but we do not fully understand their impacts on animal welfare. Biobased plastics, termed bioplastics, are marketed as a more envrionmentally friendly alternative to traditional petrochemical plastics. We need to be sure, however, that these bioplastics and their breakdown products are safe when consumed. This interdisciplinary project between three university departments (Cardiff University, Schools of Biosciences, Chemistry and Engineering), driven by industry-led questions, will assess the chemical properties and biological impacts of petrochemical and bioplastics on farmed fish.The combined mass of environmental plastic exceeds the mass of all fish on the planet. This is concerning on multiple levels; fish comprise the most abundant vertebrate species, they are a major source of protein for humans and aquaculture is the fastest growing food sector globally. If practiced sustainably, fish culturing can provide the lowest carbon source of animal protein for human populations. A key factor that threatens the welfare of managed fish stocks and their future sustainability is pollution. The scale of plastic pollution within managed fish stocks is largely unknown and this must be addressed now. Plastic particles have been detected in fish and human tissues demonstrating that plastics are part of the human food chain, so we must assess how this pervasive pollutant is impacting fish welfare. Our pilot data has shown that plastics without chemical additives impact fish welfare by reducing disease resistance and prolonging infections. However, this may just be 'the tip of the iceberg', as most plastics also have chemical additives, such as plasticisers and thermal stabilisers, and plastics can act as sponges for environmental toxins potentially causing more damage when consumed. An emerging strategy in addressing plastic pollution is the development of bioplastics. While bioplastics currently only constitute 1% share of annual plastic production, they are widely marketed as an alternative to petrochemical plastics. Bioplastics are openly advertised as eco-friendly and biodegradable, yet research on their environmental suitability is extremely limited and previous degradation studies (conducted under unrealistic scenarios) show minimal degradation. But even if bioplastics do degrade faster than petrochemical plastics, they might paradoxically generate higher rates of persistent micro and nanoplastics. Furthermore, bioplastics contain the same chemical additives as petrochemical plastics, so we must assess how efficient they are at releasing these chemicals and adsorbing other chemical pollutants within aquatic environments. Likewise, we must understand the functional impacts of bioplastics, and the associated additives, when they are consumed by animals. This project has three key objectives, which directly align with BBSRC strategic priorities on animal health, specifically welfare of managed animals, data driven biology and research that can inform public policy. Firstly, we will assess the scale of plastic pollution within aquaculture fish stocks across the UK. Secondly, in association with prevalent additives and environmental toxins that petrochemical plastics contain, we will assess the chemical properties of these plastics as well as their biological impacts on farmed fish with an emphasis on growth, metabolism, and disease resistance. Then, recognising the urgency to assess alternative plastic solutions, we will test the chemical properties and biological effects of bioplastics, when exposure and consumption occurs. In delivering this project, we will directly inform government agencies and aquaculture about the scale and associated effects of plastic pollution in fish stocks to support policies on plastic use and waste mitigation. By assessing the environmental suitability of bioplastics, future public outreach programmes can help prevent potential greenwashing.