Organic matter degradation causes enrichment of organic pollutants in hadal sediments

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: April 10, 2023

Burial of persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) in deep-sea sediments contributes to 60% their historical emissions. Yet, empirical data on occurrence the deep-ocean is scarce. Estimates POP sink are therefore uncertain. Hadal trenches, representing deepest part ocean, hotspots for carbon burial and decomposition. POPs favorably partition carbon, making trenches likely significant sinks contaminants. Here we show that PCBs occur both hadal (7720-8085 m) non-hadal (2560-4050 sediment Atacama Trench. PCB concentrations normalized dry weight were similar across sites while those increased exponentially inert fraction degraded sediments. We suggest unique deposition dynamics elevated turnover increase places Earth.

Language: Английский

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Distribution of microplastics in bathyal- to hadal-depth sediments and transport process along the deep-sea canyon and the Kuroshio Extension in the Northwest Pacific

Marine Pollution Bulletin, Journal Year: 2023, Volume and Issue: 199, P. 115466 - 115466

Published: Oct. 7, 2023

Understanding microplastic (MP) behavior in oceans is crucial for reducing marine plastic pollution. However, the complex process underlying MP transportation to deep seafloor remains unknown despite sea being considered its major sink. We focused on distribution Sagami Bay (adjacent highly populated areas of Japan), plate triple junction connected through Trough, and abyssal plain immediately below Kuroshio Extension. observed highest number MPs stations, more than previously reported. The polymer types aspect ratio stations significantly differed from those bathyal/hadal stations. study suggests that accumulated open ocean surface layer sink plains it, while land sources accumulate bathyal depth are transported hadal near coast turbidity currents along submarine canyon.

Language: Английский

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Effects of increasing hydrostatic pressures on marine microbial enzymatic activities

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 15, 2025

Abstract High hydrostatic pressure is characteristic of the deep ocean and presumed to influence microbial functions viability. However, marine processes are typically measured only at atmospheric (0.1 MPa), limiting our understanding effects on activities microbes that sink as part biological carbon pump well those reside in ocean. To test functions, we extracellular enzymatic activities—the first step organic matter remineralization—of a moderate piezophile (Photobacterium profundum SS9), communities waters sediments from shallow abyssal (5,500 m) depths their cell-free enzymes (<0.2 µm). Activities were 0.1-100 MPa assess across nearly full range oceanic depths. P. SS9 show varying effects, considerable stimulation optimal (28 MPa) near complete inhibition (100 MPa). Pressure for diverse protein- carbohydrate-degrading phosphorus-acquiring among pelagic benthic communities. The most common effect partial activity reduction, indicating dampening initial remineralization increasing pressures. retention higher pressures was occasionally observed even surface-originating assemblages, functionality down hadal potential piezotolerance. These variable must be considered when quantifying degradation rates sinking deposited particulate

Language: Английский

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Disentangling Effects of Sea Surface Temperature and Water Depth on Hydroxylated Isoprenoid GDGTs: Insights From the Hadal Zone and Global Sediments

Geophysical Research Letters, Journal Year: 2023, Volume and Issue: 50(15)

Published: Aug. 8, 2023

Abstract Hydroxylated isoprenoid glycerol dialkyl tetraethers (OH‐GDGTs) preserved in marine sediments are thought to be controlled by sea surface temperature (SST). However, water depth may also exert a significant influence on OH‐GDGTs. Here, we investigated sedimentary OH‐GDGTs the Kermadec and Atacama trench regions (2,560–9,560 m depth). Sedimentary hadal trenches were dominated OH‐GDGT‐0 (72 ± 8%), potentially reflecting an adaption of source organisms ambient cold deep water. This result, combined with global data set, revealed that predominance is ubiquitous phenomenon deep‐sea sediments, leading considerable underestimation RI‐OH′‐derived SSTs. By considering both SST effects, developed more accurate OH‐GDGT‐based paleothermometers for shallow ocean, encompassing full‐ocean‐depth range. Our findings highlight importance accounting effect provide improved tools reconstructing paleo‐SSTs.

Language: Английский

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Hidden dangers: High levels of organic pollutants in hadal trenches

Water Research, Journal Year: 2024, Volume and Issue: 251, P. 121126 - 121126

Published: Jan. 10, 2024

Language: Английский

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Metagenome-assembled genomes of deep-sea sediments: changes in microbial functional potential lag behind redox transitions

ISME Communications, Journal Year: 2024, Volume and Issue: 4(1)

Published: Jan. 1, 2024

Abstract Hadal sediments are hotspots of microbial activity in the deep sea and exhibit strong biogeochemical gradients. But although these gradients widely assumed to exert selective forces on hadal communities, actual relationship between biogeochemistry, functional traits, community structure remains poorly understood. We tested whether conditions select for microbes based their genomic capacity respiration carbohydrate utilization via a metagenomic analysis over 153 samples from Atacama Trench region (max. depth = 8085 m). The obtained 1357 non-redundant genomes were affiliated with about one-third all known phyla, more than half belonging unknown genera. This indicated that capability withstand extreme hydrostatic pressure is phylogenetically widespread trait inhabited by diverse lineages. Although composition changed gradually sediment depth, changes not driven selection respiratory or degradation oxic nitrogenous zones, except case anammox bacteria nitrifying archaea. However, did communities ferruginous zone, where aerobic nitrogen respiring declined exponentially (half-life 125–419 years) replaced subsurface communities. These results highlight delayed response imposed redox zonation gradual shaped high-resilience slow growth seafloor.

Language: Английский

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Differential use of multiple food sources at a bathyal benthic ecosystem in the central Sagami Bay revealed by amino acid nitrogen isotopic compositions

Progress in Earth and Planetary Science, Journal Year: 2025, Volume and Issue: 12(1)

Published: Jan. 15, 2025

Abstract The nitrogen isotopic composition ( δ 15 N) of amino acids can be used to estimate the trophic position organisms with high precision compared bulk tissue analyses, and shed light on potential food sources webs. Sagami Bay, Japan, is located at tectonic plate boundary have complex bottom topography, making multiple organic matter bathyal deep-sea ecosystems. Here, we applied this method benthic animals (meiofauna, macrofauna, megafauna) living 1430 m deep in central Japan. N value phenylalanine Phe ) reflects primary producers was organisms, while difference between glutamic acid Glu shifts source consumer thus (TP Glu/Phe ). data obtained were interpreted together previously reported values from foraminifera same site for a holistic understanding web. positions Bay ranged mostly 2.2 3.6, except hydrozoans (up 4.3). Organisms similar sometimes exhibited different TP values. observed varied greatly among (− 8.3‰ 21.1‰), suggesting wide variety exhibiting Given location study part basin, various terrestrial, planktic, coastal, upper bathyal, perhaps chemosynthetic origins expected accumulate become available organisms. Furthermore, cross-plot 13 C values, another indicator source, suggested that macro–megafauna examined rely than metazoan meiofauna foraminifera, which particulate sediments. Despite habitat, these two size classes may belong independent webs due differences feeding ecology.

Language: Английский

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Prophage-encoded chitinase gene supports growth of its bacterial host isolated from deep-sea sediments

The ISME Journal, Journal Year: 2025, Volume and Issue: 19(1)

Published: Jan. 1, 2025

Language: Английский

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Bioturbation in the hadal zone

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Feb. 18, 2025

The hadal zone, >6 km deep, remains one of the least understood ecosystems on Earth. We address bioturbational structures in sediment cores from depths exceeding 7.5 km, collected during IODP Expedition 386 Japan Trench. Micro-CT imaging 20 core sections allowed to identify biogenic sedimentary (incipient trace fossils) and their colonization successions within gravity flow deposits. Their frequency, consequent changes substrate consistency, oxygenation organic matter delivery remineralization controlled endobenthic colonization. gravity-flow beds show recurring bioturbation successions: initial is characterized by deposit-feeding such as Phycosiphon, Nereites Artichnus generating typically cm thick intensively bioturbated fabrics. final stage comprises slender spiral, lobate deeply penetrating straight ramifying burrow systems Gyrolithes, Pilichnus Trichichnus, interpreted include burrows microbe farming chemosymbiotic invertebrates. main factor precluding soupy substrate. Organic degradation post-event upward expansion anoxic zone drive change deposit feeding microbe-dependent strategies.

Language: Английский

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Element cycling and microbial life in the hadal realm

Trends in Microbiology, Journal Year: 2024, Volume and Issue: 32(11), P. 1045 - 1048

Published: July 31, 2024

Language: Английский

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