Evidence that the Great Pacific Garbage Patch is rapidly accumulating plastic

Evidence that the Great Pacific Garbage Patch is rapidly accumulating plastic Laurent Lebreton Boyan Slat Francesco F. Ferrari Bruno Sainte-Rose Jennifer Aitken Robert Marthouse Sara Hajbane Serena Cunsolo Anna Schwarz Aurore Levivier Kim Noble Pavla Debeljak Hannah Maral Rosanna I. Schoeneich-Argent Roberto Brambini Júlia Reisser

Tag layer of the DHSS Meta-Tagging Project. The article text is reproduced from the staged copy named in sourceDesc and is not altered; the tags are held separately in standOff so that overlapping and nested spans are preserved.

Evidence that the Great Pacific Garbage Patch is rapidly accumulating plastic 2018 Scientific Reports 10.1038/s41598-018-22939-w lebreton2018-evidence-that-the-great-pacific-ga lebreton2018-evidence-that-the-great-pacific-ga.txt, the project's staged copy 8dbfa45817064a3cd25919a2e2b86a991af44a4e cc-by environmental-science

the paper's own words

the tag layer; a sentence written by the tagger about the paper, always anchored to a quotation but not itself a quotation

0 spans located by searching the stored text for the quote's exact words, allowing any whitespace between them how much buoyant plastic is floating in the North Pacific accumulation zone, of what sizes and types, and whether the amount is changing Quotation withheld because this record is not cleared for redistribution. whether the mass of the Great Pacific Garbage Patch has been underestimated because the instruments used to measure it cannot catch its largest and rarest debris Quotation withheld because this record is not cleared for redistribution. 79 (45-129) thousand tonnes and 1.8 (1.1-3.6) trillion pieces over 1.6 million km2, from 652 net tows plus 311 km2 of aerial imagery calibrated into a time-resolved transport model - four to sixteen times previous estimates, with the method difference and the rival explanation both named Quotation withheld because this record is not cleared for redistribution. existence Quotation withheld because this record is not cleared for redistribution. accumulation of buoyant plastic in a subtropical gyre, dominated by mass in objects large enough that a plankton net was never going to see them Quotation withheld because this record is not cleared for redistribution. field-study field-study Quotation withheld because this record is not cleared for redistribution. the standard instrument is a 90 cm net developed for plankton, covering 0.008 km2 per tow; rare metre-scale objects carry most of the mass and are almost never inside such a sample, so the measured mass is a function of how much sea surface the instrument sees rather than of how much plastic is there an aperture deciding an abundance Quotation withheld because this record is not cleared for redistribution. films are about 37% of PE and PP waste and are rarely found here; the paper's hypothesis is that thin objects foul, sink or fragment quickly, so the patch contains not the plastic that enters the ocean but the subset able to stay at the surface volume-to-surface ratio as a survival filter Quotation withheld because this record is not cleared for redistribution. particles displaced by a fraction of wind speed take wider orbits, are more likely to strand and more likely to leave the gyre; low-windage objects stay - which is why the best-fitting model has no wind term and why foam is abundant on Alaskan beaches and negligible in the patch windage sorting the debris by where it ends up Quotation withheld because this record is not cleared for redistribution. the patch's centre oscillates seasonally in longitude and inter-annually in latitude with ENSO and PDO, so calibrating measurements from one season against a flat multi-year average compares them with a smear rather than with a position - matching the climate indices of the sampling year improved the fit from 0.46 to 0.58 a moving target averaged into blur Quotation withheld because this record is not cleared for redistribution. the four-to-sixteen-fold increase over previous estimates could also be a real increase in pollution rather than a method difference, and the paper says so Quotation withheld because this record is not cleared for redistribution. the model predicts millions of tonnes in the region from accepted inputs while the surveys found tens of thousands - a two-orders-of-magnitude gap left open Quotation withheld because this record is not cleared for redistribution. the aerial survey deliberately trades false positives for false negatives: observers logged only what they were very confident about, so many possible debris features were never recorded Quotation withheld because this record is not cleared for redistribution. the mass estimates are conservative by construction - sampling concentrated inside the boundary, and the outer patch is modelled at over 100k tonnes Quotation withheld because this record is not cleared for redistribution. high-windage debris passing through the patch over longer periods is underestimated, because a monthly average spreads it over a larger area Quotation withheld because this record is not cleared for redistribution. both trawls were towed at an angle so the sampled width is likely smaller than the net width used in the area calculation, and vessel wake probably affected capture Quotation withheld because this record is not cleared for redistribution. debris may have broken during transport to the laboratory, biasing the size distribution Quotation withheld because this record is not cleared for redistribution. the degradation rate of synthetic polymers at sea is poorly understood, so how long the standing mass will persist cannot be estimated Quotation withheld because this record is not cleared for redistribution. plastic levels in the deep water and seafloor below the patch are unknown, so the inventory is of one layer only Quotation withheld because this record is not cleared for redistribution. the 28.1% marine-source share is taken from coastal clean-up data and observations at sea may imply much higher losses, so the source attribution may be wrong in either direction Quotation withheld because this record is not cleared for redistribution. Lagrangian particle advection with wave, wind and current forcing, carried from physical oceanography into an inventory of manufactured debris Quotation withheld because this record is not cleared for redistribution. a dated, located mass release - the 2011 Tohoku tsunami - used as a natural tracer experiment to constrain a transport parameter Quotation withheld because this record is not cleared for redistribution. two Manta and two large Neuston trawls towed simultaneously at the same 76 stations, and the paired results used to decide which device quantifies which size band eliminates: net aperture as the source of the reported size distribution - a single device cannot tell whether the sizes it misses are absent or merely uncaught · outcome: held Quotation withheld because this record is not cleared for redistribution. 311 km2 surveyed from the air against 3.9 and 13.6 km2 by Manta and Mega tow, for the size class whose rarity is the whole problem eliminates: rarity being mistaken for absence - at trawl coverage a >50 cm object is a sampling accident, and the mass it carries cannot be estimated from its absence · outcome: held Quotation withheld because this record is not cleared for redistribution. an experimental detection algorithm run over all 7,298 mosaics after the human pass, with every algorithm hit re-inspected by an observer before entering the database eliminates: observer oversight as the only check on the imagery, without letting the algorithm introduce false positives of its own · outcome: partial Quotation withheld because this record is not cleared for redistribution. six forcing scenarios - current only, and 0.1 to 3% windage - each fitted against the same 277 cells of measured microplastic concentration eliminates: the chosen transport physics being assumed rather than selected; the regression coefficient falls monotonically as wind forcing is added, so the data picks · outcome: held Quotation withheld because this record is not cleared for redistribution. three calibration windows tried in sequence - a flat 12-year average, a season-matched average, and an ENSO/PDO-matched pair of years - with the fit reported for each eliminates: an averaging window flattering the fit - the season-matched version was WORSE than the flat average and is reported as such before the better one is adopted · outcome: held Quotation withheld because this record is not cleared for redistribution. measured microplastic concentrations sorted by whether they fell inside or outside the modelled 1 kg km-2 contour, as a test of the boundary the model drew eliminates: a boundary drawn to fit the story - the contrast is measured, 1.8 against 0.3 kg km-2 in the medians, rather than asserted from the map · outcome: held Quotation withheld because this record is not cleared for redistribution. the model's windage behaviour checked against the recorded arrival times and object types of 2011 Tohoku tsunami debris on North American and Hawaiian shores eliminates: the windage parameterisation being unconstrained by any real trajectory - the tsunami provides a dated release of known objects that the model must reproduce · outcome: held Quotation withheld because this record is not cleared for redistribution. exponential, linear, quadratic and cubic fits to the decadal concentration averages, with the coefficient of determination given for all four eliminates: the exponential being chosen because it makes the stronger claim - the three alternatives are fitted and their worse fits reported · outcome: held Quotation withheld because this record is not cleared for redistribution. historical net tows sorted into inside-boundary, outside-but-subtropical, and rest-of-North-Pacific, with the third category excluded from the comparison eliminates: equatorial and polar samples deflating the around-the-patch baseline and manufacturing a contrast between inside and outside · outcome: held Quotation withheld because this record is not cleared for redistribution. depth-integrated concentrations computed for every trawl station as a function of rising velocity, trawl depth and sea state, to correct for wind-driven mixing eliminates: buoyant plastic missed by a surface trawl because wind-driven mixing pushed it below the net · outcome (stated by the tagger, no quotation): held Quotation withheld because this record is not cleared for redistribution. all trawls designed to move away from the vessel so that wake would not affect capture efficiency eliminates: vessel wake disturbing the water the net samples - the trawls were angled away to reduce it, and the paper says the effect remained · outcome (stated by the tagger, no quotation): partial Quotation withheld because this record is not cleared for redistribution. GPGP GPGP Quotation withheld because this record is not cleared for redistribution. microplastics microplastics Quotation withheld because this record is not cleared for redistribution. megaplastics megaplastics Quotation withheld because this record is not cleared for redistribution. windage coefficient windage coefficient Quotation withheld because this record is not cleared for redistribution. ghostnets ghostnets Quotation withheld because this record is not cleared for redistribution. Manta trawl Manta trawl Quotation withheld because this record is not cleared for redistribution. aerial imagery aerial imagery Quotation withheld because this record is not cleared for redistribution. mass concentration mass concentration Quotation withheld because this record is not cleared for redistribution. numerical concentration numerical concentration Quotation withheld because this record is not cleared for redistribution. ENSO ENSO Quotation withheld because this record is not cleared for redistribution. biofouling biofouling Quotation withheld because this record is not cleared for redistribution. GPGP plastic mass - MEASURED BY NET TRAWLS ALONE: about 4.8 thousand tonnes, from instruments developed to collect neustonic plankton Quotation withheld because this record is not cleared for redistribution. GPGP plastic mass - NET TRAWLS PLUS VESSEL SIGHTINGS: about 21 thousand tonnes, at the cost of high uncertainty in estimating a sighted object's mass Quotation withheld because this record is not cleared for redistribution. GPGP plastic mass - NET TRAWLS PLUS MEGA TRAWLS PLUS 311 km2 OF AERIAL IMAGERY: 79 (45-129) thousand tonnes, this study Quotation withheld because this record is not cleared for redistribution. what dominates the patch - BY MASS: megaplastics and macroplastics, over three quarters of it, and 86% of the megaplastic mass is fishing nets Quotation withheld because this record is not cleared for redistribution. what dominates the patch - BY COUNT: microplastics, 94% of 1.8 trillion pieces and only 8% of the mass Quotation withheld because this record is not cleared for redistribution. how much plastic should be there - AS THE MODEL PREDICTS FROM ACCEPTED INPUTS: millions of tonnes Quotation withheld because this record is not cleared for redistribution. how much plastic should be there - AS FOUND IN THE WATER: tens of thousands of tonnes, a two-orders-of-magnitude shortfall the paper leaves open Quotation withheld because this record is not cleared for redistribution. qualifies → the two previous GPGP mass estimates, 4.8 k tonnes from net trawls alone and 21 k tonnes from trawls plus vessel sightings - attributed here mainly to weaker quantification of large debris, with a real increase in pollution named as an alternative Quotation withheld because this record is not cleared for redistribution. critiques → surface trawls developed for neustonic plankton, whose 0.5-1 m aperture cannot represent rarer and larger objects such as bottles, buoys and fishing nets Quotation withheld because this record is not cleared for redistribution. critiques → ocean plastic transport models integrated over several years and calibrated against datasets from different seasons and decades, which misrepresent processes that vary seasonally and inter-annually Quotation withheld because this record is not cleared for redistribution. qualifies → its own inventory - the estimates are conservative on three separate counts, and high-windage debris passing through the region is not captured by a monthly average Quotation withheld because this record is not cleared for redistribution. qualifies → accepted global plastic input budgets, which its own model turns into a prediction two orders of magnitude above what the surveys found Quotation withheld because this record is not cleared for redistribution. The GPGP holds an estimated 1.8 (1.1-3.6) trillion plastic pieces weighing 79 (45-129) thousand tonnes. The GPGP holds an estimated 1.8 (1.1-3.6) trillion plastic pieces weighing 79 (45-129) thousand tonnes. Quotation withheld because this record is not cleared for redistribution. The estimate is four to sixteen times earlier ones, mainly because of better quantification of macro- and megaplastics. The estimate is four to sixteen times earlier ones, mainly because of better quantification of macro- and megaplastics. Quotation withheld because this record is not cleared for redistribution. microplastics are 8% of the mass and 94% of the pieces, so which size class dominates the patch depends entirely on the unit microplastics are 8% of the mass and 94% of the pieces, so which size class dominates the patch depends entirely on the unit Quotation withheld because this record is not cleared for redistribution. Nets, ropes and lines are 52% of GPGP plastic mass, and fishing nets 86% of the megaplastic mass. Nets, ropes and lines are 52% of GPGP plastic mass, and fishing nets 86% of the megaplastic mass. Quotation withheld because this record is not cleared for redistribution. microplastic concentration inside the patch rose exponentially from 0.4 kg km-2 in the 1970s to 1.23 kg km-2 in 2015, faster than in surrounding waters microplastic concentration inside the patch rose exponentially from 0.4 kg km-2 in the 1970s to 1.23 kg km-2 in 2015, faster than in surrounding waters Quotation withheld because this record is not cleared for redistribution. the model predicts millions of tonnes in the region from accepted inputs while the surveys found tens of thousands - two orders of magnitude unaccounted for the model predicts millions of tonnes in the region from accepted inputs while the surveys found tens of thousands - two orders of magnitude unaccounted for Quotation withheld because this record is not cleared for redistribution. plastic films are about 37% of PE and PP waste generation and were rarely found, suggesting only certain shapes persist at the surface plastic films are about 37% of PE and PP waste generation and were rarely found, suggesting only certain shapes persist at the surface Quotation withheld because this record is not cleared for redistribution. the best-fitting transport scenario used sea surface current alone, with fit falling monotonically as wind forcing was added the best-fitting transport scenario used sea surface current alone, with fit falling monotonically as wind forcing was added Quotation withheld because this record is not cleared for redistribution. defined in this study as the 1 kg km-2 modelled microplastic mass concentration contour, covering 1.6 million km2 and holding about 87% of the plastic in the model domain GPGP Quotation withheld because this record is not cleared for redistribution. the displacement of a particle expressed as a fraction of wind speed 10 m above sea level, tested here at 0, 0.1, 0.5, 1, 2 and 3% windage coefficient Quotation withheld because this record is not cleared for redistribution. EVIDENCE CORRECTED (RE-GROUNDED - THE POINTER WAS WRONG, NOT THE CLAIM) · thousand tonnes of floating plastic in the GPGP, mid-point of a 45-129 k range 79 EVIDENCE CORRECTED: RE-GROUNDED - THE POINTER WAS WRONG, NOT THE CLAIM. The old evidence was verbatim, anchored and correctly cut, and it contained NONE of this claim's numbers (129, 45). The paper states the claim in one sentence elsewhere and the tagger did not use it. the project, 2026-08-23: 'WE HAVE SPENT THE DAY VERIFYING THAT QUOTES ARE REAL AND NONE OF IT ASKS WHETHER THEY ARE RELEVANT.' Confirmed by reading the claim, the old span and the candidate together; the candidate carries every number AND the claim's own content words. Quotation withheld because this record is not cleared for redistribution. microplastics' share of the GPGP mass - against 94% of its pieces 8% Quotation withheld because this record is not cleared for redistribution. microplastics' share of the 1.8 trillion pieces - against 8% of the mass 94% Quotation withheld because this record is not cleared for redistribution. kg km-2, the mean megaplastic mass concentration - the highest of the four size classes, at 3.5 pieces km-2 46.3 Quotation withheld because this record is not cleared for redistribution. pieces km-2 of microplastics - the highest count of the four size classes, at 2.5 kg km-2 678,000 Quotation withheld because this record is not cleared for redistribution. R2 R2 Quotation withheld because this record is not cleared for redistribution. SE SE Quotation withheld because this record is not cleared for redistribution. mass concentration mass concentration Quotation withheld because this record is not cleared for redistribution. windage coefficient windage coefficient Quotation withheld because this record is not cleared for redistribution.

The full text of this article is not redistributable, so it is not included here. The evidence sentences are withheld with it; the tag layer and its grounding status remain. The article itself is at https://doi.org/10.1038/s41598-018-22939-w.