Uncovering the Hidden Dangers of Microplastic Pollution in Lake Ecosystems: Effects of Ingestion on Talitrid Amphipods

Abstract

Microplastic (MP) contamination is a globally recognised issue in aquatic environments, and recently, there has been an increase in investigations focusing on lake contamination, revealing significant amounts of dispersed MPs. However, our understanding of the ingestion and effects of MPs on organisms living in lake ecosystems remains limited. This study aims to develop an effective protocol for assessing the ingestion of MPs by the talitrid amphipod Cryptorchestia garbinii, with the goal of verifying and evaluating the biological effects following ingestion. Individuals sampled from the shores of Lake Albano were exposed to four different polymers, namely low-density polyethylene (PE), polyethylene terephthalate (PET), polyester (PES), and polypropylene (PP), under laboratory conditions. To deliver MPs through the diet, we decided to employ DECOTABs (DEcomposition and COnsumption TABlets) which have been successfully used as a food source in aquatic toxicity tests. At the end of the experiments, we employed the solvatochromic and fluorescent dye Nile red to detect and quantify the MPs present in the digestive tube contents of the animals. The results clearly demonstrate the ingestion of the supplied polymers through the tabs, validating this method of exposure as effective. Furthermore, the measurement of glucose, glycogen, and lipid levels reveals that within 24 h of ingestion, MPs had an impact on the macromolecules involved in the energy metabolism of C. garbinii. This research underscores the suitability of this species as a model organism for studying MP uptake and its effects.

Small Microplastics: A yet Unknown Threat in the Svalbard (Norway) Region

“…This characteristic, and their trophic role (primary consumers, detritivores, and polyphages) in aquatic environments, make them particularly suitable as bioindicators in toxicity tests [55]. MPs ingestion was documented in several marine species [56][57][58], and studies tested the MPs toxicity and genotoxicity on them at a lab scale [59][60][61][62].…”

“…To globally assess MPs impacts, the analyses also address the microbe-plastic interactions ("plastisphere") and the microbiome of bioindicators, since microbes are sentinels of environmental changes [81]. To investigate the effects of the ingested SMPs and related pollutants on the sampled benthic organisms, a set of biomarkers, including the body's biochemical composition and energy allocation, such as glucose, glycogen, and lipid levels, as already developed [59], antioxidant enzymes (catalase and SOD), detoxifying enzymes (glutathione S-transferases), and reactive oxygen species (ROS), will be analyzed. The whole-animal transcriptomic response in the selected species will be examined, and changes in gene transcription will be used to detect environmental stress related to the SMPs' presence and uptake.…”