Recommended best practices for plastic and litter ingestion studies in marine birds: Collection, processing, and reporting

Abstract

Marine plastic pollution is an environmental contaminant of significant concern. There is a lack of consistency in sample collection and processing that continues to impede meta-analyses and large-scale comparisons across time and space. This is true for most taxa, including seabirds, which are the most studied megafauna group with regards to plastic ingestion research. Consequently, it is difficult to evaluate the impacts and extent of plastic contamination in seabirds fully and accurately, and to make inferences about species for which we have little or no data. We provide a synthesized set of recommendations specific for seabirds and plastic ingestion studies that include best practices in relation to sample collection, processing, and reporting, as well as highlighting some “cross-cutting” methods. We include guidance for how carcasses, regurgitations, and pellets should be handled and treated to prevent cross-contamination, and a discussion of what size class of microplastics can be assessed in each sample type. Although we focus on marine bird samples, we also include standardized techniques to remove sediment and biological material that are generalizable to other taxa. Lastly, metrics and data presentation of ingested plastics are briefly reviewed in the context of seabird studies.

Message in a belly : Plastic pathways in Fulmars

“…Tanaka et al (2019) show, that plastics ingested by fulmars and albatrosses contain UV-stabilizers, flame retardants and styrene oligomers, similar to those found in our PTX001 and PS material. Polyethylene and polypropylene were also the most common plastic types encountered.…”

“…All marine bird and mammal species that have been included, are listed in the Online Supplement Table 1. The species numbers for fish and invertebrates were taken from WoRMS (2019). Species numbers differ slightly from previous reviews mainly because of continuous changes in accepted taxonomy.…”

“…Another type of potential risk, closely related to entanglement is the incorporation of plastics in seabird nests. An overview has been recently published by Jagiello et al (2019) and a website has been launched in 2019 offering the general public to record cases of seabird entanglement or plastic in nests (www.birdsanddebris.com). To study the incidence of entanglement, background data on non-affected individuals in a population are necessary but is usually difficult to obtain.…”

“…The applicability of these studies for wild marine organisms, ingesting degraded, post-consumer plastics, remains unclear. Tanaka et al (2019) analysed plastic pieces ingested by procellariform seabirds, including fulmars from the Faroe Islands, and found several plastic additives such as UV stabilizers, styrene oligomers, and flame retardants in the plastics. Herzke et al (2016) studied the uptake of chemicals in fulmars and found that ingested amounts of plastics were not correlated with the occurrence of POPs in liver and muscle tissue.…”

Polymer types ingested by northern fulmars (Fulmarus glacialis) and southern hemisphere relatives

“…For visual impressions, graphs are presented as stacked columns either for numbers or mass. As mass of plastic is considered more important in terms of potential harm (Van Franeker et al 2011 ; Provencher et al 2019 ) and is used in the framework of monitoring of plastics in fulmars (OSPAR 2015 ), most graphs depict composition mass percentages. However, all underlying data (numbers and mass) are provided in Online Supplement Table 3 .…”