Influence of amino acids on bacterioplankton production, biomass and community composition at Ocean Station Papa in the subarctic Pacific

Elementa Science of the Anthropocene, Journal Year: 2023, Volume and Issue: 11(1)

Published: Jan. 1, 2023

Bacterioplankton play a central role in carbon cycling, yet their relative contributions to production and removal can be difficult constrain. As part of the Export Processes Ocean from RemoTe Sensing (EXPORTS) program, this study identifies potential influences bacterioplankton community dissolved organic matter (DOM) composition on cycling at Station Papa August 2018. Surface (5–35 m) rates stocks spanned 2- 3-fold range over 3-week cruise correlated positively with DOM degradation state, estimated using mole proportion total amino acids. When was more degraded, 16S rRNA gene amplicon data revealed less diverse significant contribution members Flavobacteriaceae family. Over course 7–10 d, as quality improved (became degraded) productivity increased, responding became diverse, increased SAR86, SAR11 AEGEAN-169 clades. The mean for mixed layer, depth-integrated demand (gross production) 5.2 mmol C m−2 d−1, representing 60% net primary production, where difference between than sinking flux 50 m. concentrations (cruise average 58.5 µM C) did not exhibit systematic change period. Therefore, we hypothesize that supplied gross values were greater provided necessary account excess production. These findings highlight Papa, site high recycling.

Language: Английский

---

Inorganic and organic nutrients in tropical–subtropical Western Pacific coral reef waters

Coral Reefs, Journal Year: 2024, Volume and Issue: 43(4), P. 1053 - 1069

Published: July 8, 2024

Language: Английский

---

Sponge species from New Zealand may transform and degrade dissolved organic matter

Journal of Experimental Marine Biology and Ecology, Journal Year: 2025, Volume and Issue: 585, P. 152092 - 152092

Published: Feb. 28, 2025

Language: Английский

---

Photooxidation removes biologically recalcitrant dissolved organic carbon released by the macroalga Sargassum natans

Limnology and Oceanography Letters, Journal Year: 2025, Volume and Issue: unknown

Published: April 3, 2025

Abstract Macroalgae are important primary producers in the coastal ocean, and they release a large fraction of their net production as dissolved organic carbon (DOC). It is assumed that much this DOC recalcitrant results sequestration amounts carbon. We lack sufficient knowledge about bioavailability material role other sinks such photooxidation. conducted dark remineralization photooxidation experiments on derived from an abundant brown macroalga quantified amended was remineralized by both processes. The ranged 14% to 99% significantly negatively correlated with its phenolic content. Upon exposure light, biologically compounds were quickly oxidized CO 2 , indicating sink for macroalgal DOC. These especially macroalgae cultivation being considered sequester atmospheric .

Language: Английский

---

Multi‐Elemental Tracers in the Amerasian Basin Reveal Interlinked Biogeochemical and Physical Processes in the Arctic Ocean Upper Halocline

Global Biogeochemical Cycles, Journal Year: 2025, Volume and Issue: 39(4)

Published: April 1, 2025

Abstract The physical and biogeochemical properties of the western Arctic Ocean are rapidly changing, resulting in cascading shifts to local ecosystems. nutrient‐rich Pacific water inflow through Bering Strait is modified on Chukchi East Siberian shelves by brine rejection during sea ice formation, a strong halocline (called Upper Halocline Layer (UHL)) that separates cold relatively fresh surface layer from warmer more saline (and nutrient‐poor) Atlantic‐derived below. Biogeochemical signals entrained into UHL result Waters sediment river influence shelf. In this synthesis, we bring together data 2015 U.S. GEOTRACES program implement multi‐tracer (dissolved particulate trace elements, radioactive stable isotopes, macronutrients, dissolved gas/atmospheric tracers) approach assess relative shelf sediments, rivers, seawater contribution Amerasian halocline. For each element, characterized their behavior as mixing dominated (e.g., dCu, dGa), shelf‐influenced dFe, dZn), or combination both dBa, dNi). Leveraging framework, assessed sources sinks contributing elemental distributions: sediments dZn, dCd, dHg), riverine sources, organic carbon), scavenging particles originating dMn, dV, etc.). Additionally, synthesized results isotopic atmospheric tracers yielded tracer age estimates for ranging between 1 2 decades spatial gradient consistent with cyclonic circulation.

Language: Английский

---

Variation in chemical composition of dissolved organic matter during the winter to spring transition in the northern Barents Sea

Marine Chemistry, Journal Year: 2025, Volume and Issue: unknown, P. 104517 - 104517

Published: April 1, 2025

Language: Английский

---

Unravelling the Effects of Climate Extremes and Land Use on Greenhouse Gas Emissions in the Yangtze River Riparian: Soil Columns Experiments

Ecohydrology, Journal Year: 2025, Volume and Issue: 18(3)

Published: April 1, 2025

ABSTRACT River riparian basins play a crucial role in mitigating greenhouse gas (GHG) emissions through carbon sequestration and nitrogen sinks. However, increased ecological stresses led to the release of CO 2 , CH 4 N O. This study aimed investigate how extreme temperatures, water levels, moisture content, land use changes soil composition influence GHG corridor recommend mitigation techniques. It was carried out at Yangtze Riparian zone, China, using column testing. used The results showed that temperatures caused highest CO₂ (29–45%), CH₄ (24–43%) N₂O (27–33%). due accelerated organic carbon/nitrogen decomposition. Conversely, control wet–dry cycles absorbed (1–3%), (3–10%) O (1–21%) by improving aeration, oxygen availability, structure, stable table low temperature change. Grasses areas also improved Highest levels had lowest concentrations level. Adaptive wet‐dry cycles, grass cover better management can restore areas, maintain moisture, balance mitigate climate change quality. Dissolved matter fluorescence (DOMFluor) components are essential for dynamics, aquatic biome safety, nutrient cycling zones. recommends implementing restoration practices, managing afforestation, regulating monitoring tables address Future policies should focus on promoting resilient ecosystems.

Language: Английский

---

Occurrence and distribution of per- and polyfluoroalkyl substances (PFAS) in tidal salt marsh creeks

Marine Pollution Bulletin, Journal Year: 2025, Volume and Issue: 216, P. 117932 - 117932

Published: April 14, 2025

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous global contaminants where the ocean plays a critical role in PFAS cycling. Large estuarine systems conduits for anthropogenic contaminants, but little is known regarding small tidal creek systems. Surface waters from seven creeks were analyzed 16 target including legacy replacement PFAS. Mean total ranged 139.4 to 12,293.8 ng/L terrestrial influenced upland sampling sites 33.9-176.3 mouth sites. Nine negatively correlated with salinity positively DOC (p < 0.05), indicating that source of predominantly terrestrial. also had strong positive relationship percent impervious surface (R2 = 0.99), importance human land use influencing occurrence. Results this study will inform future investigations their dynamics at land-sea interface.

Language: Английский

---

A global database of dissolved organic matter (DOM) measurements in coastal waters (CoastDOM v1)

Published: Sept. 27, 2023

Abstract. The measurements of dissolved organic carbon (DOC), nitrogen (DON), and phosphorus (DOP) are used to characterize the matter (DOM) pool important components biogeochemical cycling in coastal ocean. Here, we present first edition a global database (CoastDOM v1; available at https://figshare.com/s/512289eb43c4f8e8eaef) compiling previously published unpublished DOC, DON, DOP collected waters. These data complemented by hydrographic such as temperature salinity and, extent possible, other variables (e.g., Chlorophyll-a, inorganic nutrients) system total alkalinity). Overall, CoastDOM v1 includes observations from all continents however, most were Northern Hemisphere, with clear gap water DOM Southern Hemisphere. included 1978 2022 consist 62339 points for 20360 DON 13440 DOP. number decreases progressively sequence DOC > DOP, reflecting both differences maturity analytical methods greater focus on aquatic science community. shows that average concentration waters (average (standard deviation; SD): 182 (314) µmol C L−1; median: 103 L−1), is 13-fold than concentrations (SD): 13.6 (30.4) N 8.0 which was itself 39-fold 0.34 ± 1.11 P 0.18 L−1). This dataset will be useful identify spatial temporal patterns facilitate reuse studies aimed better characterising local processes, closing nutrient budgets, estimating carbon, phosphorous pools, well identifying baseline modelling future changes

Language: Английский

---

Kelp dissolved organic carbon release is seasonal and annually enhanced during senescence

Journal of Phycology, Journal Year: 2024, Volume and Issue: 60(4), P. 980 - 1000

Published: July 19, 2024

Macroalgae influence local and global biogeochemical cycles through their production of dissolved organic carbon (DOC). Yet, data remain scarce annualized estimates are typically based on high growth periods without considering seasonal variability. Although the mechanisms active exudation passive leakage need clarifying, ecophysiological stress is known to enhance DOC release. Therefore, from seasonally senescent macroalgae may be overlooked. This study focuses annual kelp Saccharina japonica var. religiosa (class Phaeophyceae) Oshoro Bay, Hokkaido, Japan. Three years (2020-2022) were collected analyzed, with least squares mean release rates established for (n = 88) across 16 incubation experiments (t ≥ 4 d, samples ≥1 · d

Language: Английский

---