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Marine plastic pollution is a global issue, with microplastics (1 μm–5 mm) dominating the measured plastic count1,2. Although microplastics can be found throughout the oceanic water column3,4, most studies collect microplastics from surface waters (less than about 50-cm depth) using net tows5. Consequently, our understanding of the microplastics distribution across ocean depths is more limited. Here we synthesize depth-profile data from 1,885 stations collected between 2014 and 2024 to provide insights into the distribution and potential transport mechanisms of subsurface (below about 50-cm depth, which is not usually sampled by traditional practices3,6) microplastics throughout the oceanic water column. We find that the abundances of microplastics range from 10−4 to 104 particles per cubic metre. Microplastic size affects their distribution; the abundance of small microplastics (1 μm to 100 μm) decreases gradually with depth, indicating a more even distribution and longer lifespan in the water column compared with larger microplastics (100 μm to 5,000 μm) that tend to concentrate at the stratified layers. Mid-gyre accumulation zones extend into the subsurface ocean but are concentrated in the top 100 m and predominantly consist of larger microplastics. Our analysis suggests that microplastics constitute a measurable fraction of the total particulate organic carbon, increasing from 0.1% at 30 m to 5% at 2,000 m. Although our study establishes a global benchmark, our findings underscore that the lack of standardization creates substantial uncertainties, making it challenging to advance our comprehension of the distribution of microplastics and its impact on the oceanic environment. 

ABSTRACT Sister taxa that have diverged and persisted in sympatry have likely been exposed to the same general environmental changes throughout their evolutionary history and may thus exhibit similar phylogeographies. Here, we compare the phylogeographic patterns of two sister species of isopods (genusTylos) that have broadly overlapping distributions but distinct habitat preferences in the supralittoral zone of Chile. The dynamic geoclimatic history of this region during the Quaternary has been implicated in shaping the evolutionary histories of other coastal taxa.Tylos spinulosusis found in sandy beaches at latitudes ~27°–30° S, whereasTylos chilensishas been found in rocky shores at ~27°–33° S and at ~39°–42° S. We sampled both species across their ranges (collectively from 20 localities) and obtained sequences from at least one mitochondrial gene for 95 T. chilensisand 41 T. spinulosus. We used phylogenetics and population genetics methods to analyze four single‐gene and one concatenated datasets: 12S rDNA (n = 130); 16S rDNA (n = 31); Cytochrome oxidase subunit I (n = 28); Cytochrome b (n = 24); concatenation of the four genes (n = 24). Both species show high levels of isolation of local populations, consistent with expectations from their limited autonomous dispersal potential. However, they exhibit strikingly different mitochondrial phylogeographic patterns.Tylos chilensisshows evidence of multiple relatively deep divergence events leading to geographically restricted lineages that appear to have persisted over multiple glaciations. Surprisingly, one lineage ofT. chilensiswas found in geographically distant localities, suggesting the possibility of human‐mediated dispersal.Tylos spinulosusappears to have undergone a relatively recent bottleneck followed by a population/range expansion. Differences in life histories and habitat preferences or stochasticity may have contributed to these striking phylogeographic differences. Finally, the high levels of differentiation and isolation among populations indicate that they are highly vulnerable to extirpation. We discuss threats to their persistence and recommendations for their conservation. 

The global distribution of primary production and consumption by humans (fisheries) is well-documented, but we have no map linking the central ecological process of consumption within food webs to temperature and other ecological drivers. Using standardized assays that span 105° of latitude on four continents, we show that rates of bait consumption by generalist predators in shallow marine ecosystems are tightly linked to both temperature and the composition of consumer assemblages. Unexpectedly, rates of consumption peaked at midlatitudes (25 to 35°) in both Northern and Southern Hemispheres across both seagrass and unvegetated sediment habitats. This pattern contrasts with terrestrial systems, where biotic interactions reportedly weaken away from the equator, but it parallels an emerging pattern of a subtropical peak in marine biodiversity. The higher consumption at midlatitudes was closely related to the type of consumers present, which explained rates of consumption better than consumer density, biomass, species diversity, or habitat. Indeed, the apparent effect of temperature on consumption was mostly driven by temperature-associated turnover in consumer community composition. Our findings reinforce the key influence of climate warming on altered species composition and highlight its implications for the functioning of Earth’s ecosystems. 

Abstract Marine plastic debris floating on the ocean surface is a major environmental problem. However, its distribution in the ocean is poorly mapped, and most of the plastic waste estimated to have entered the ocean from land is unaccounted for. Better understanding of how plastic debris is transported from coastal and marine sources is crucial to quantify and close the global inventory of marine plastics, which in turn represents critical information for mitigation or policy strategies. At the same time, plastic is a unique tracer that provides an opportunity to learn more about the physics and dynamics of our ocean across multiple scales, from the Ekman convergence in basin-scale gyres to individual waves in the surfzone. In this review, we comprehensively discuss what is known about the different processes that govern the transport of floating marine plastic debris in both the open ocean and the coastal zones, based on the published literature and referring to insights from neighbouring fields such as oil spill dispersion, marine safety recovery, plankton connectivity, and others. We discuss how measurements of marine plastics (bothin situand in the laboratory), remote sensing, and numerical simulations can elucidate these processes and their interactions across spatio-temporal scales.