This study estimated the concentration of microplastics (i.e. plastics measuring less than 5mm; reported in unit of items/kg d.w.) in shoreline and seabed sediments in the Narragansett Bay, Rhode Island, USA, during 2020-09-25 to 2021-06-03. Microplastics in the shoreline sediments were collected using a metal spoon while those in the seabed sediments were collected using a Van Veen grab sampler. Data on sediment dry weight (reported in unit of g) and individual counts of microplastic fibers, fragments and films are provided. This dataset contains the results from all 76 shoreline and 7 seabed sediment samples, in a spreadsheet format.

This study estimated the load of surface microplastics (i.e. plastics less than 5mm, reported in unit of pieces/m^3) in the surface waters from the Northwest Pacific, the Bering Sea, and the Chukchi Sea from 2017-07-28 to 2017-10-01. Microplastics data were collected using manta net aboard R/V Xuelong. This dataset contains the results from all 13 surface net tows, in a spreadsheet format. Tows were conducted for 20 min at an average cruising speed of 3 knots.

This study was carried out to estimate the microplastics (i.e. plastics measuring less than 5mm, reported in unit of pieces/m^3) concentration in four coastal areas of the Mediterranean Sea, namely, Saronikos Gulf, Ligurian Sea, Gulf of Lion, and Gabes Gulf. Microplastics data was collected from 2018-09-05 to 2019-11-20 using manta net. This dataset contains the results from all 71 surface net tows, in a spreadsheet format.

This study estimated the concentration of microplastics (i.e. plastics measuring less than 5mm) in seawater (reported in unit of items/m3), and sediments (reported in unit of items/kg d.w.), in the Hangzhou Bay, China during 2020-09-11 to 2020-11-21. Microplastics in the seawater were collected using a plankton net while those in the sediment were collected using a sediment grab sampler. Data on hydrologic conditions in the study area were also collected. These include water depth (reported in unit of m), seawater temperature (reported in unit of oC), seawater dissolved oxygen (reported in unit of mg/L), seawater pH, and seawater salinity (reported in unit of ‰). This dataset contains the results from all 26 seawater, and 26 sediment samples, in a spreadsheet format.

This study was carried out to estimate the microplastics (i.e. plastics measuring less than 5mm, reported in unit of pieces kg-1 d.w.) concentration in deep sea sediments in the northeast Atlantic Ocean margins. Microplastics data was collected from 2019-08-03 to 2019-08-19 using a remotely operated vehicle aboard RV Celtic Explorer. This dataset contains the results from all 40 sampling efforts, in a spreadsheet format.

This study estimated the abundance of microplastics (i.e., plastics measuring less than 5mm) on marine turtle nesting beaches during 2018-08-04 to 2020-01-24. Samples were collected with metallic trowel. Sand samples were collected from 209 sites spanning six oceans and 39 countries by a global network of marine turtle scientists. Microplastics were extracted through stacked sieves, visually identified, and a sub-sample verified via Fourier-transform infrared spectroscopy. Microplastic particles were counted and weighed, which in combination with the dry sand sample weight and volume, allowed multiple units of measure to be calculated: Plastic weight per kg of dry sediment (g kg-1), plastic particle number per kg of dry sediment (particle kg-1), and plastic particle number per m-3 of dry sediment (particle m-3). Plastic particles were also categorized into five types: industrial plastic pellets, foams, fragments, sheetlike user plastics and threadlike user plastics. This dataset contains the results from all 209 samples in a spreadsheet format.

This study was carried out to estimate the microplastics (i.e. plastics measuring less than 5mm, reported in unit of pieces/m^3) concentration along a latitudinal gradient in the Atlantic Ocean. Microplastics data was collected from 2015-11-01 to 2015-11-28 aboard RV Polarstern. Ocean water was pumped onboard the vessel via the bow water system to collect microplastics samples. This dataset contains the results from all 76 sampling stations, in a spreadsheet format.

This dataset contains surface microplastics (i.e., plastics measuring less than 5mm, reported in unit of pieces/m^3) concentration in the global ocean collected by the Oceaneye Association. Microplastics data was collected from 2011-08-31 to 2021-10-05 using manta nets by several trained volunteer groups and Citizen Scientists. This dataset contains the results from all 802 sampling efforts, in a spreadsheet format.

This study estimated the concentration of microplastics (i.e. plastics measuring less than 5mm; reported in unit of items/kg d.w) in beach sediments along the Thoothukudi coast, Gulf of Mannar region, India, during 2021-01-03 to 2021-06-08. Microplastics in the sediments were collected using a shovel. This dataset contains the results from all 36 sediment samples, in a spreadsheet format.

This study estimated the concentration of surface microplastics (i.e. plastics measuring less than 5 mm; reported in unit of particles/L) in the Maowei Sea, a semi-closed mariculture bay in China. The data was collected on 2017-10-11 using a 5L stainless steel sampler. This dataset contains the results from all 23 surface water samples, in a spreadsheet format.