Marine aquaculture can deliver 40% lower carbon footprints than freshwater aquaculture based on feed, energy and biogeochemical cycles

Nature Food, Journal Year: 2024, Volume and Issue: 5(7), P. 615 - 624

Published: June 21, 2024

Language: Английский

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Contrasting trends of the ocean CO2 sink and pH in the Agulhas current system and the Mozambique Basin, South-Western Indian Ocean (1963-2023).

Deep Sea Research Part II Topical Studies in Oceanography, Journal Year: 2025, Volume and Issue: 220, P. 105459 - 105459

Published: Jan. 17, 2025

Language: Английский

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Nitrate‐Driven Eutrophication Supports High Nitrous Oxide Production and Emission in Coastal Lagoons

Journal of Geophysical Research Biogeosciences, Journal Year: 2025, Volume and Issue: 130(4)

Published: April 1, 2025

Abstract Under current circumstances, coastal lagoons are net emitters of nitrous oxide (N 2 O) to the atmosphere. We hypothesize that widespread nitrogen‐driven eutrophication will enhance N O production and emissions from lagoons. Here, we quantified spatial temporal patterns sediment‐water water‐air fluxes in three large eutrophic Europe. Annual sediment ranged between −0.3 ± 0.3 (summer) 10.6 2.0 μmol m −2 d −1 (spring). In spring, conspicuous effluxes were mainly supported by high nitrate concentrations (89–202 μM) incomplete denitrification. summer, a small influx was related limitation (0–9 μM), potentially leading demand for The comparable with benthic fluxes, indicating main source hypereutrophic Curonian Lagoon had largest emission at 4.9 2.1 , while less Oder Vistula emitted 2.5 1.0 0.7 respectively. Our observations, combined earlier measurements worldwide, revealed lagoon median (Q1–Q3) 14.2 (2.7–29.8) Gg yr which is about 48% higher than previous estimates. Eutrophication driven nitrogen inputs thus significant driver globally.

Language: Английский

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High‐Resolution Variability of the Ocean Carbon Sink

Global Biogeochemical Cycles, Journal Year: 2024, Volume and Issue: 38(8)

Published: Aug. 1, 2024

Abstract Measurements of the surface ocean fugacity carbon dioxide ( f CO 2 ) provide an important constraint on global sink, yet gap‐filling products developed so far to cope with sparse observations are relatively coarse (1° × 1° by 1 month). Here, we overcome this limitation using a novel combination machine learning‐based methods and target transformations estimate associated sea‐air fluxes F globally at resolution 8‐day 0.25° (8D) over period 1982 through 2022. Globally, method reconstructs accuracy similar that low‐resolution (∼19 μatm), but improves it in coastal ocean. Although uptake differs little, 8D product captures 15% more variance . Most increase comes from better‐represented subseasonal scale variability, which is largely driven better‐resolved variability winds, also contributed The high‐resolution capable capturing signal short‐lived regional events such as hurricanes. For example, reveals was least 25 μatm lower wake Hurricane Maria (2017), result complex interplay between decrease temperature, entrainment carbon‐rich waters, primary production. By providing new insights into role higher frequency variations sink underlying processes, fills gap.

Language: Английский

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Nitrogen cycling in China marginal seas: Progress and challenges

Marine Chemistry, Journal Year: 2024, Volume and Issue: 265-266, P. 104421 - 104421

Published: June 12, 2024

Language: Английский

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Ebullition drives high methane emissions from a eutrophic coastal basin

Geochimica et Cosmochimica Acta, Journal Year: 2024, Volume and Issue: 384, P. 1 - 13

Published: Sept. 1, 2024

The production of methane in coastal sediments and its release to the water column is intensified by anthropogenic eutrophication bottom hypoxia, it still uncertain whether emissions atmosphere will be enhanced. Here, we assess seasonal variations dynamics a eutrophic, seasonally euxinic basin (Scharendijke, Lake Grevelingen). In-situ benthic chamber incubations reveal high rates from sediment (74 – 163 mmol m−2 d−1) during monthly measurements between March October 2021. Comparison these in-situ total fluxes calculated diffusive point towards major role for ebullition. In spring fall, when was oxic, microbial removal dissolved occurred aerobically water. summer, contrast, accumulated concentrations up 67 μmol L−1 below oxycline. Shifts δ13C–CH4 δD-CH4 higher values abundant presence oxidizing bacteria around oxycline, likely through both aerobic anaerobic pathways, with latter possibly linked iron oxide reduction. lower above oxycline indicate that bubble dissolution contributed methane. Methane were observed all seasons highest, measured (1.2 upon onset mixing at end summer. events measurement water-air model calculations flux form bubbles, which bypass filter. suggest potential year-round ebullitive 30 120 d−1. We conclude eutrophic systems may much than previously thought because

Language: Английский

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Aotearoa New Zealand’s marine carbon cycle in a changing climate – Current understanding and future directions

New Zealand Journal of Marine and Freshwater Research, Journal Year: 2025, Volume and Issue: unknown, P. 1 - 44

Published: Feb. 13, 2025

The marine system plays a critical role in the global climate cycle, as major control of atmospheric carbon dioxide (CO2). Marine primary production (photosynthesis) and remineralisation organic (respiration, degradation) determine amount CO2 sequestered sediments deep-water environments on century to millennial timescales. stocks fluxes cycle are susceptible change impacts other anthropogenic activities that modify key processes. Oceanographic studies Aotearoa New Zealand's Exclusive Economic Zone (NZ EEZ) Territorial Seas over past decades have provided broad knowledge across complex dynamic seascape, but there remain fundamental gaps limit identification response present future threats. In particular, several areas EEZ been under-sampled currently insufficient data establish baselines variability for cycle. We recommend new observational technologies ocean modelling applications be fully developed utilised enable development robust predictive capability our ocean's human-induced perturbations. Future focus oceanic nature-based solutions accelerate uptake will require improved NZ's EEZ.

Language: Английский

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Sunlight drives the abiotic formation of nitrous oxide in fresh and marine waters

Science, Journal Year: 2025, Volume and Issue: 387(6739), P. 1198 - 1203

Published: March 13, 2025

Nitrous oxide (N 2 O) is a potent greenhouse gas and the main stratospheric ozone-depleting agent, yet its sources are not well resolved. In this work, we experimentally show N O production pathway previously considered in budgets, which name photochemodenitrification. Sunlight induces substantial consistent under oxic abiotic conditions fresh marine waters. We measured photochemical rates using isotope tracers determined that nitrite substrate nitrate can also contribute after being photoreduced to nitrite. Additionally, was strongly correlated radiation dose. Photochemodenitrification exceeded biological surface Although overlooked, process may considerably global emissions through occurrence

Language: Английский

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Surface CO2 partial pressure and air–sea CO2 flux on the China side of the South Yellow Sea based on multiple-year underway measurements during 2005–2011 and comparison with results for 2011–2018

Progress In Oceanography, Journal Year: 2025, Volume and Issue: 234, P. 103466 - 103466

Published: March 16, 2025

Language: Английский

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Diazotrophs: An Overlooked Sink of N₂O

Geophysical Research Letters, Journal Year: 2025, Volume and Issue: 52(6)

Published: March 18, 2025

Abstract The ocean is the second‐largest source of greenhouse gas nitrous oxide (O). However, its role as an O sink severely overlooked. fixation by diazotrophs has lately been proposed a new pathway consumption. We investigated diazotrophic consumption and examined anthropogenic influence on dynamics in coastal northeastern Arabian Sea, hotspot emissions. Our findings reveal that relatively unperturbed waters, unlike anthropogenically perturbed are modest net (98 29 saturation), contrary to previous reports. remains active waters contrast fixation. additionally provide evidence absence control incubations leads incorrect rate estimates, further implying oceanic dark carbon rates might be overestimated. suggest not only directly sequesters but may correspond 0.3 Tg C global primary production.

Language: Английский

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