Revealing the risk of macroplastic ingestion to marine wildlife. Really!

When the hysteria and alarmism about microplastic is not enough anymore!

We at least 5 decades of experience with and research of floating macroplastic in our oceans. What is really new? If I am not mistaken, then over the past several decades numerous countries have improved on preventing macroplastics to enter the oceans. Maybe more clean up and prevention efforts are necessary, but no hubris please.

How good is the model that was being used? What was the inductive bias (presumption) for this research? I am afraid high! Plastophobia is a serious disorder. This seems to be very hypothetical research.

All we know for sure is that marine wildlife is not even close to extinction due to plastic!

How much plastic do these researchers consume on a daily basis?

From the significance and abstract:

"Significance

Plastic ingestion is a known cause of mortality across taxa, yet the quantitative risk plastic ingestion poses is still poorly understood. Based on data from more than 10,000 necropsies, we estimate the likelihood of mortality due to the gastrointestinal load of various plastic materials—hard, soft, rubber, and fishing debris—for seabirds, marine mammals, and sea turtles. We find that 6 to 405 pieces of ingested macroplastic (or a volume between 0.044 and 39.89 cm3/cm body length) lead to a 90% chance of mortality in these marine species. Importantly, the amount varies depending on plastic types ingested and taxon. Our findings can be used to better understand the mortality risk of macroplastic pollution and inform future risk assessment frameworks.

Abstract

Plastic ingestion has been documented in nearly 1,300 marine species, including every seabird family, marine mammal family, and sea turtle species. Acute mortality, due to obstruction, perforation, or torsion of the gastrointestinal (GI) tract, has been confirmed via necropsy in all three taxa; however, quantitative risk assessment for macroplastic ingestion poses unique challenges, with risk more dependent on probability of discrete events involving diverse plastic types rather than cumulative exposure models (e.g., LC50).
We model mortality risk associated with macroplastic ingestion in seabirds, marine mammals, and sea turtles, using data from more than 10,000 necropsies reported in the academic literature and stranding network databases.

Employing an adapted Weibull Accelerated Failure Time model, we assess the relationship between the GI load (pieces and volume/animal length) of different plastic types—hard, soft, rubber, or fishing debris—and likelihood of plastic-induced mortality. Overall, 35% of seabirds, 12% of marine mammals, and 47% of sea turtles ingested plastic, and 1.6%, 0.7%, and 4.4% died from plastic, respectively.

When modeling plastic together, a 90% chance of mortality was associated with 23 pieces (0.098 cm3/cm) in seabirds, 29 pieces (39.89 cm3/cm) in marine mammals, and 405 pieces (5.52 cm3/cm) in sea turtles (377 for juveniles).

The plastic types that posed the greatest risks were rubber for seabirds, soft plastics and fishing debris for marine mammals, and hard and soft plastics for sea turtles.
This research furthers scientific understanding of the likelihood of mortality from plastic ingestion and can inform monitoring, risk assessments, and management frameworks."

Revealing the risk of macroplastic ingestion to marine wildlife | PNAS (no public access, commentary)

I presume this commentary refers to the study below.

NEWS: Groundbreaking Research Identifies Lethal Dose of Plastics for Seabirds, Sea Turtles and Marine Mammals: “It’s Much Smaller Than You Might Think”  "Less Than Three Sugar Cubes of Plastic Can Kill a Seabird, According to Comprehensive New Analysis"

A quantitative risk assessment framework for mortality due to macroplastic ingestion in seabirds, marine mammals, and sea turtles

Fig. 2 Curves showing probability of mortality based on the amount of macroplastic in the GI tracts of seabirds.