This data repository contains the following files. General descriptions of file contents are provided after the file name, and column names and contents are provided after the list of files.

Files in the Resource

Foam_dimensions.csv - This file contains 154 measurements of the long dimensions (mm) of individual pieces of foamed plastic visually identified in sediment samples. There are 3 columns of data.
FTIR_IDs.csv - This file contains information about 136 putative plastic pieces randomly selected for ATR-FTIR analysis. The file contains 11 columns:
TransectsSurfaceLitter.csv - This file contains information about transect locations, lengths, large and small surface litter counts by date. The file contains 30 columns and 11 rows (including 1 header row).
LargeByItem.txt - This tab-delimited text file contains information about large litter (>5 cm in long dimension) on the beach surface. Each row is 1 piece of litter, with columns including the date, transect, distance from water, substrate, object type, material, dimensions, mass (if recorded), UNEP litter code and UNEP litter form. This file contains 12 columns and 592 rows (including 1 header row).
SmallByItem.txt - This tab-delimited text file contains information about small litter (<5 cm in long dimension) collected on the beach surface. Each row is 1 piece of litter, with columns including the date, transect, distance from water, substrate, object type, material, dimensions, mass, UNEP litter code and UNEP litter form. This file contains 12 columns and 73 rows (including 1 header row).
SedimentLitterSamples.csv - This file contains information about the 79 sediment litter samples, including date, transect, location, depth sieved, and materials within the sample. There are also notes. This file contains 22 columns and 80 rows (including 1 header row).

Foam_dimensions.csv columns

Date (MM/DD/YY)
Location (transect name and mid or back beach position)
Long_Dimension_mm (mm).
FTIR_IDs.csv
Date_analyzed contains the date analyzed by FTIR (MM/DD/YY)
Date_collected contains the date the sample was collected (MM/DD/YY)
Location contains the transect name (B01 to B09) and the position along the transect (mid, back, or 10m)
Pellet_or_Not indicates whether the item was a pellet or not.
FTIR_Num gives a unique number to each item with respect to the data analyzed, date collected, location, and pellet or not. These numbers can be used to associate the individual spectra in the repository with the data in this table. In the spectra files, pellets are referred to as nurdles.
Color contains the color as described by the FTIR analyst.
Object description contains information as recorded by the FTIR analyst.
Long_dimension_mm contains the long dimension in mm. NM indicates that dimensions were not measured.
Middle_dimension_mm contains the middle dimension in mm. NM indicates that dimensions were not measured.
Area_mm2 contains the product of the long and middle dimensions in square mm.
Final_ID contains the final identification based on visual examination and OpenSpecy matches as described in the methods.  ABS is acrylonitrile butadiene styrene. EP is ethylene polypropylene. HDPE is high density polyethylene. LDPE is low density polyethylene. PE is polyethylene. PP is polypropylene. PVC is polyvinyl chloride.

TransectsSurfaceLitter.csv columns

Transect contains the transect name (B01-B10).
N_Back_of_Sand contains the GPS coordinate for latitude of the back of the sand for each transect, as measured on May 17-19, 2021.
W_Back_of_Sand contains the GPS coordinate for longitude of the back of the sand for each transect, as measured on May 17-19, 2021.
N_Water contains the GPS coordinate for latitude of the water line for each transect, as measured on May 17-19, 2021.
W_Water contains the GPS coordinate for longitude of the water line for each transect, as measured on May 17-19, 2021.
Length_0517-19 contains the length in m of the transects on May 17-19, 2021.
Length_0601 contains the length in m of the transects on June 1, 2021.
Length_0622 contains the length in m of the transects on June 22, 2021.
Length_0709 contains the length in m of the transects on July 9, 2021.
Length_0730 contains the length in m of the transects on July 30, 2021.
Length_0809 contains the length in m of the transects on August 9, 2021.
Length_0824 contains the length in m of the transects on August 24, 2021.
Length_0913 contains the length in m of the transects on September 13, 2021.
Large_0517-19 contains the total count of large (>50 mm) per transect on May 17-19, 2021.
Large_0601 contains the total count of large (>50 mm) per transect on June 1, 2021.
Large_0622 contains the total count of large (>50 mm) per transect on June 22, 2021.
Large_0709 contains the total count of large (>50 mm) per transect on July 9, 2021.
Large_0730 contains the total count of large (>50 mm) per transect on July 30, 2021.
Large_0809 contains the total count of large (>50 mm)) per transect on August 9, 2021.
Large_0824 contains the total count of large (>50 mm) per transect on August 24, 2021.
Large_0913 contains the total count of large (>50 mm) per transect on September 13, 2021.
Small_0517-19 contains the total count of small (<50 mm) per transect on May 17-19, 2021.
Small_0601 contains the total count of small (<50 mm) per transect on June 1, 2021.
Small_0622 contains the total count of small (<50 mm) per transect on June 22, 2021.
Small_0709 contains the total count of small (<50 mm) per transect on July 9, 2021.
Small_0730 contains the total count of small (<50 mm) per transect on July 30, 2021.
Small_0809 contains the total count of small (<50 mm) per transect on August 9, 2021.
Small_0824 contains the total count of small (<50 mm) per transect on August 24, 2021.
Small_0913 contains the total count of small (<50 mm) per transect on September 13, 2021.
Location_notes contains visual identifiers of the location of each transect, as recorded May 17-19, 2021.

LargeByItem.txt columns

Date (MM/DD/YY)
Transect contains the transect name (B01-B10).
DistWater_m contains the item's distance from the water line in meters.
surface contains the surface substrate on which the item was found (e.g., gravel, sand, vegetation, brick-cobble)
object_type contains the description of the item as recorded in the field.
material contains the category of the dominant material as recorded in the field. If there were two dominant materials, they are separated by a slash.
LongestDim_cm is the longest dimension of the item in centimeters, as measured in the field.
IntermedDim_cm is the length of the item perpendicular to the longest and shortest axis, in cm, as measured in the field.
ShortDim_cm is the length of the item's shortest dimension, measured perpendicular to the long dimension.
Mass_g is the item's mass as measured in the field, where recorded. The field scale had a minimum mass of 1 g, so items recorded as <1 g did not register on the scale.
Litter_code is based on the object type and material categories, following the use category of the UNEP/IOC guidelines in Cheshire, A., Adler, E., Barbière, J., Cohen, Y., Evans, S., Jarayabhand, S., Jeftic, L., Jung, R.- T., Kinsey, S., Kusui, E. T., Lavine, I., Manyara, P., Oosterbaan, L., Pereira, M. A., Sheavly, S., Tkalin, A., Wenneker, B., & Westphalen, G. (2009). UNEP/IOC Guidelines on Survey and Monitoring of Marine Litter (Regional Seas Reports and Studies No. 186). https://wedocs.unep.org/bitstream/handle/20.500.11822/13604/rsrs186.pdf?sequence=1& isAllowed=y "frag" was added after the UNEP code to denote items which were fragments and a use could not be determined.
Litter_form is the text description of the use category in the UNEP/IOC guidelines cited above. There are commas within some of these descriptors.  Parenthetical words in some descriptors were added by the researchers to clarify our reasoning.

SmallByItem.txt columns

Date (MM/DD/YY)
Transect contains the transect name (B01-B10).
DistWater_m contains the item's distance from the water line in meters.
surface contains the surface substrate on which the item was found (e.g., gravel, sand, vegetation, brick-cobble)
object_type contains the description of the item as recorded in the field.
material contains the category of the dominant material as recorded in the field.
LongestDim_cm is the longest dimension of the item in centimeters, as measured in the field.
IntermedDim_cm is the length of the item perpendicular to the longest and shortest axis, in cm, as measured in the field.
ShortDim_cm is the length of the item's shortest dimension, measured perpendicular to the long dimension.
Mass_g is the item's mass as measured in the field, where recorded. The field scale had a minimum mass of 1 g, so items recorded as <1 g did not register on the scale.
Litter_code is based on the object type and material categories, following the use category of the UNEP/IOC guidelines in Cheshire, A., Adler, E., Barbière, J., Cohen, Y., Evans, S., Jarayabhand, S., Jeftic, L., Jung, R.- T., Kinsey, S., Kusui, E. T., Lavine, I., Manyara, P., Oosterbaan, L., Pereira, M. A., Sheavly, S., Tkalin, A., Wenneker, B., & Westphalen, G. (2009). UNEP/IOC Guidelines on Survey and Monitoring of Marine Litter (Regional Seas Reports and Studies No. 186). https://wedocs.unep.org/bitstream/handle/20.500.11822/13604/rsrs186.pdf?sequence=1& isAllowed=y "frag" was added after the UNEP code to denote items which were fragments and a use could not be determined.
Litter_form is the text description of the use category in the UNEP/IOC guidelines cited above. There are commas within some of these descriptors.  Parenthetical words in some descriptors were added by the researchers to clarify our reasoning.

SedimentLitterSamples.csv columns

Date (MM/DD/YY)
Transect contains the transect name (B01-B10).
Location contains a descriptor of where along the transect the sample was taken.
DistWater_m contains the sample's distance from the water line in meters.
Quadrat_cm contains the size of the quadrat used for sampling, always reported as 55 cm by 55 cm.
SievedDepth_cm provides the depth of sand sieved in the field in cm.
NumQuadrats is the number of quadrats collected to comprise a sample. It is always 1.
RetainedVol_ml lists the approximate volume (to nearest 50 ml) retained on the 2 mm sieve in the field, after sieving and large rocks and sticks were manually removed.
Plastics_all is the sum of counts for plastics_pellets, plastics_other, and plastics_foam.
Plastics_pellets is the count of pieces identified visually as preproduction pellets.
Plastics_other is the count of pieces identified visually as plastics, but not pellets or foamed plastic.
Plastics_foam is the count of pieces identified visually as foamed plastic. 
Glass is the count of pieces identified visually as glass.
Brick is the count of pieces identified visually as brick.
Concrete is the count of pieces identified visually as concrete.
Asphalt is the count of pieces identified visually as ashpalt.
Ceramics is the count of pieces identified visually as ceramics.
Metal is the count of pieces identified visually as metal, but not visually aluminum.
Metal_Aluminum is the count of pieces identified visually as aluminum.
Other is the count of pieces identified visually as anthropogenic, but not belonging to the previous categories.
Other_ID contains descriptors of the other anthropogenic pieces where they were recorded. 
Notes contains other notes recorded in the field or lab, including whether the sample was selected for FTIR analysis.