Kelly Eleanor R M, Trujillo José E, Setiawan Alvin, Pether Steve, Burritt David, Allan Bridie J M
Department of Marine Science, University of Otago, New Zealand.
Department of Marine Science, University of Otago, New Zealand.
Mar Pollut Bull. 2024 Jun;203:116438. doi: 10.1016/j.marpolbul.2024.116438. Epub 2024 May 14.
Microorganisms quickly colonise microplastics entering the ocean, forming a biofilm that, if ingested, is consumed with the microplastics. Past research often neglects to expose fish to biofouled microplastics, opting only for clean microplastics despite the low likelihood that fish will encounter clean microplastics. Here, we investigate the physiological impacts of biofouled polyethylene microplastic (300-335 μm) exposure in juvenile fish. Intermittent flow respirometry, antioxidant enzyme activity, and lipid peroxidation were investigated after fish were exposed to clean, biofouled, or no microplastic beads. Fish exposed to biofouled microplastics had a wider aerobic scope than those exposed to clean microplastics while antioxidant enzyme and lipid peroxidation levels were higher in clean microplastics. Clean microplastic exposure indicated higher fitness costs, potentially due to a nutritional advantage of the biofilm or varying bioavailability. These findings highlight the importance of replicating natural factors in exposure experiments when predicting the impacts of increasing pollutants in marine systems.
微生物会迅速在进入海洋的微塑料上定殖，形成生物膜，若被摄入，生物膜会与微塑料一同被消耗。过去的研究常常忽略让鱼类接触被生物污染的微塑料，尽管鱼类遇到清洁微塑料的可能性很低，但仍只选择清洁微塑料进行实验。在此，我们研究了暴露于被生物污染的聚乙烯微塑料（300 - 335微米）对幼鱼生理的影响。在幼鱼暴露于清洁、被生物污染或无微塑料珠的环境后，我们对其进行了间歇流呼吸测定、抗氧化酶活性和脂质过氧化的研究。暴露于被生物污染微塑料的鱼类比暴露于清洁微塑料的鱼类具有更宽的有氧代谢范围，而清洁微塑料中的抗氧化酶和脂质过氧化水平更高。暴露于清洁微塑料表明有更高的健康成本，这可能是由于生物膜的营养优势或不同的生物可利用性。这些发现凸显了在预测海洋系统中污染物增加的影响时，在暴露实验中复制自然因素的重要性。
