Laboratory Methods to Improve Quantification of Microplastic Ingestion by Marine Organisms Under Climate Change Stressors

Human impacts on the environment pose serious threats to the planet’s oceans. This thesis presents methods to quantify microplastic ingestion by marine organisms under ocean warming and acidification. First, a study utilizing a novel high-throughput screening device with CO2 concentration and temperature gradients was completed to quantify microplastic ingestion by copepod, Tisbe biminiensis, under multiple temperature and CO2 levels. Due to limitations in the methods of that study, three additional methods were developed: (i) a low-cost customizable climate-change incubator capable of regulating temperature and CO2 for larger volumes and longer exposures; (ii) a fluorescent microplastic dyeing method enabling tracking of different microplastic types and shapes in exposure studies; and (iii) a digestible fluorescent microplastic coating method enabling enumeration of microplastic ingestion. The methods developed here enable screening impacts of multiple stressors, and improve realism in microplastic experiments, to properly depict future ocean conditions and their subsequent effects on marine life.