CLiP Belize Microplastics in sediment 2019

This dataset contains 2 csv file. BelizeSedimentMicroplastics.csv file reports data on microplastic abundance in sediment expressed in number of particles for 5g sediment. Sediment was collected at six locations in Belize between May and June 2019, but only four were analysed for microplastics due to time restrictions (only PSA reported for the two sites left). The file also reports information on blank used for calculations, grab GPS coordinates, deployment time and the particulate size analysis (PSA) of the sediment. BelizeSedimentMicroplastics_FTIR.csv contains the profile of a ATR-FT-IR spectrum analysis of a plastic particle (>5mm). A READ-ME text file contains the legend of the columns of the csv file. A .zip file contains the picture of the plastic particle analysed with ATR-FT-IR. The Commonwealth Litter Project (CLiP) supported Belize to take action on plastics entering the oceans. The assessment of microplastics in sediment was part of the action plan to define scientific baselines for future monitoring purposes and comparison. Samples were acquired deploying a small Van Veen grab (Duncan and Associates, UK, sampled area 0.025 square metre). Sediment grabs were subsampled with a steel spoon into sample jars for microplastics and PSA. Samples were then frozen (-18 degrees Celsius). A control jar was left exposed to the atmosphere during the subsampling to investigate background contamination. The samples were dried and homogenised, chemically digested with 30 percent KOH:NaClO solution for 3 days at 50 degrees Celsius. Samples were then filtered, stained with Red Nile dye and a digital image was acquired through a microscope. Number of particles was counted and corrected for blank samples. ATR-FT-IR is the attenuated total reflection Fourier Transform infrared spectroscopy. A Thermo Fisher Scientific Nicolet iS5 ATR-FTIR with an OMNIC software (version 9.9.473) was used to analyse one piece of plastic and polymer composition was identified based on the percentage match of IR spectra to a polymer library (optimal spectra match above 70 %). ATR-FTIR spectra are collected in the range 4000 – 650 1/cm at a resolution of 4 1/cm. Particulate size analysis was performed measuring the weight of the sample and of its gravel, sand and mud components. The percentage of the three components over the total weight was also measured.