Plastic monitoring dataset:

To assess the amount of plastic present in the field 
that could pose a threat to mangroves by covering pneumatophores, 
we quantified the presence of plastic with a size larger than 1 cm 
(the diameter of a pneumatophore). This was done in two fractions: 

(1) the amount of relatively mobile plastic covering the forest floor, 
measured in terms of the percentage of forest floor covered by plastic waste, 
and the number of items per m2 of forest floor. 
(2) The amount and the burial depth of immobilized plastic that is trapped 
in the upper layers of the mangrove sediment.

The mobile and immobile plastic fractions were monitored in three zones 
across eight mangrove fringes during a series of field campaigns in 2018 and 2019. 
Eight mangrove stands were selected as replicates for this study, 
all of which consisted primarily of Avicennia spp. (Avicennia alba and Avicennia marina).


ID = sampling station ID
Date = date of sample collection
season = the season after which the sampling campaign has been conducted. (eg. March 2018: sampling campaign at the end of the wet season. Plastic that is collected during the monitoring is expected to have been deposited there during the wet season)
site_name = descriptive name of the site, often incorporating the nearest village
Site_lon = longitude of mangrove stand in WGS84
Site_lat = latitude of mangrove stand in WGS84
Zone = the zone at which the sampling station is located:
	- fringe_sea: seafront of the mangrove fringe
	- fringe_land: landward side on top of the sediment ridge in the mangrove fringe (if there is a sediment ridge)
	- basin: mangrove basin, forest interior
Sediment_type = sediment type (sand or mud) 
Items_quadrat(0.25m2) = the number of plastic items found within the quadrat at a sampling station (0.5 * 0.5 m)
#items_per_m2 = extrapolated number of plastic items to a number of plastic items per square metre
Estimated_plastic_coverage_(%) = the estimated percentage of forest floor inside the quadrat covered by plastic (estimations were done by the same person in the field)
Plastic_coverage_pic_qntfd(%) = percentage of quadrat covered by plastic items manually digitized with imageJ from quadrat pictures. NOTE for muddy sites this is an underestimation of plastic cover as the plastic items were very poorly visible in the pictures due to biofouling and canopy shade
Total_items_per_core = number of plastic items retrieved from a core taken at the same sampling station as the quadrat
Items_per_depth = the number of plastic items found at a certain depth inside the core
Depth_of_items_in_core_(cm) = the depth at which each plastic item was found inside the core
total_depth_core_(cm) = the depth of the sediment column that was collected with the core


