Microplastic contamination is a growing threat facing marine ecosystems, of which a prominent source is the fibres from synthetic clothing. Ingestion and egestion (excretion) of microfibres, and whether these have short-term effects on behaviours such as feeding rate, have yet to be studied in many organisms, especially non-bivalve filter feeders. To determine if a common, filter feeding, intertidal invertebrate can ingest microfibres, we studied the acorn barnacle (Balanus glandula Darwin 1854). We collected B. glandula from four locations near Bamfield, British Columbia, Canada, exposed half of them to a high concentration (~70,000 microfibres/L) of brightly coloured polyester microfibres for 24 h in unfiltered seawater (while the other half received a non-exposure treatment), and measured the feeding rates of the barnacles before and after the exposure. An average of 1.2 ± 1.9 fibres per barnacle were present in the gastrointestinal tracts of the plastic treatment group before depuration, and 0.3 ± 0.6 fibres per barnacle were found in the corresponding control group. Prior to depuration, 50% of the 20 barnacles in the plastic treatment ingested at least one microfibre, while a 15% ingestion rate was observed in the control group. There was no detectable short-term effect of microfibre ingestion on feeding rate. A 48-h post plastic exposure depuration period was used to evaluate whether microplastics were egested. No difference in egestion was found between those assessed directly after exposure and those that underwent depuration. Furthermore, a low depuration rate of 0.05 microfibres per 48 h suggests that barnacles may require longer than 48 h to egest microfibres. If representative, these results indicate that acorn barnacles ingested few microfibres even when exposed at very high concentrations, which supports the idea that they are at low risk for microplastic contamination and would not be a suitable indicator species.

微塑料污染是海洋生态系统面临的日益严重的威胁，其中一个突出的来源是来自合成服装的纤维。微纤维的摄入和消化（排泄），以及它们是否对摄食率等行为有短期影响，还有待在许多生物体中进行研究，尤其是非双壳类滤食性动物。以确定是否一个共同的，过滤器馈送，潮间无脊椎动物可以摄取的微纤维，我们研究橡子藤壶（藤壶glandula达尔文1854）。我们从加拿大不列颠哥伦比亚省 Bamfield 附近的四个地点收集了腺体 B.在未过滤的海水中将其中一半暴露于高浓度（~70,000 微纤维/L）的鲜艳聚酯微纤维中 24 小时（而另一半接受了非暴露处理），并测量了暴露前后藤壶的摄食率。在净化前，塑料治疗组的胃肠道中平均每只藤壶存在 1.2±1.9 根纤维，在相应的对照组中发现每只藤壶平均有 0.3±0.6 根纤维。在净化之前，塑料处理中的 20 只藤壶中有 50% 摄入了至少一种微纤维，而 15%在对照组中观察到摄入率。没有检测到微纤维摄入对喂食率的短期影响。塑料暴露后 48 小时的净化期用于评估微塑料是否被排出。在暴露后直接评估的人和经过净化的人之间没有发现消化方面的差异。此外，每 48 小时 0.05 条微纤维的低净化率表明藤壶可能需要超过 48 小时才能排出微纤维。如果具有代表性，这些结果表明，即使暴露在非常高的浓度下，橡子藤壶也摄入了很少的微纤维，这支持了这样的观点，即它们受到微塑料污染的风险很低，不会是合适的指示物种。