Prior heatwave exposure improves hypoxia tolerance in a typical freshwater fish species

Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology, Journal Year: 2025, Volume and Issue: unknown, P. 111803 - 111803

Published: Jan. 1, 2025

Language: Английский

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Vertical structure of subsurface marine heatwaves in a shallow nearshore upwelling system

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: Feb. 21, 2025

Language: Английский

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Climate change and variability drive increasing exposure of marine heatwaves across US estuaries

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: March 6, 2025

Marine heatwaves (MHWs) are among the greatest threats to marine ecosystems, and while substantial advances have been made in oceanic MHWs, little is known about estuarine MHWs. Utilizing a temperature dataset spanning over two decades 54 stations distributed across 20 estuaries United States National Estuarine Research Reserve System, we present comprehensive analysis of MHW characteristics trends. Long-term climate-change-driven warming driving more frequent MHWs along East Coast, if trends continue, this region will be state for ~ 1/3 year by end century. In contrast, vast majority West Coast showed no trends, highlighting potential future thermal refugia. The was strongly influenced climate variability through enhancement/suppression during different phases modes, suggesting long-term predictability potential. These results can provide guidance management actions planning these critical environments.

Language: Английский

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Freshwater faces a warmer and saltier future from headwaters to coasts: climate risks, saltwater intrusion, and biogeochemical chain reactions

Biogeochemistry, Journal Year: 2025, Volume and Issue: 168(2)

Published: March 10, 2025

Abstract Alongside global climate change, many freshwater ecosystems are experiencing substantial shifts in the concentrations and compositions of salt ions coming from both land sea. We synthesize a risk framework for anticipating how change increasing pollution saltwater intrusion will trigger chain reactions extending headwaters to tidal waters. Salt ‘chain reactions,’ where chemical products one biogeochemical reaction influence subsequent ecosystem responses. Different impact drinking water quality, ecosystems, infrastructure, energy food production. Risk factors include salinity sources due amplification pulses interaction precipitation variability human activities. Depending on other factors, retention can range 2 90% across watersheds globally. retained interacts with cycles along flowpaths contributes ‘fast’ ‘slow’ associated temporary acidification long-term alkalinization freshwaters, impacts nutrient cycling, CO , CH 4 N O, greenhouse gases, corrosion, fouling, scaling deoxygenation, contaminant mobilization freshwater-marine continuum. also carbon cycle quantity quality organic matter transported coasts. identify double wide services. Our salinization is based analyses of: (1) temporal trends tributaries freshwaters Chesapeake Bay freshening mainstem over 40 years changes streamflow, sea level rise, watershed pollution; (2) loads major rivers Eastern U.S. increased riverine exports coastal waters sometimes 100-fold greater than forest reference conditions; (3) varying ion concentration-discharge relationships at Geological Survey (USGS) sites U.S.; (4) empirical between specific conductance Na + Cl − SO 2− Ca 2+ Mg K USGS (5) dissolved (DOC) different (6) original experiments demonstrating composition, nutrients metals, alkalinization, oxidation–reduction potentials, deoxygenation non-tidal The activities altering sources, transport, storage, reactivity entire helps anticipate, prevent, manage growing water, health, aquatic life, agriculture,

Language: Английский

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Pacific‐Arctic Ocean Acidification: Decadal Trends and Drivers

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

Published: April 1, 2025

Abstract This study presents the first regional‐scale analysis to quantify decadal trends and drivers of surface ocean acidification (OA) across highly sensitive Pacific‐Arctic Region (PAR) using a consistent trend methodology. From 1993 2021, Southern PAR acidified at rates comparable global average, with declining by 0.018 units aragonite saturation state decreasing 0.063 , primarily driven anthropogenic uptake. In contrast, Bering Strait exhibited slower acidification, 0.011 0.020 —substantially lower than previously reported—likely due increased primary productivity. The Northern experienced most rapid acidification: decreased 0.028 0.078 Beaufort Gyre acidifying 2–4 times faster mean. change was rising atmospheric significant freshening linked sea ice melt riverine input, which reduced ocean's buffering capacity. Continued warming will likely exacerbate in regions transitioning from multi‐year seasonal ice. While local processes such as productivity can temporarily counteract OA, whether they offset levels remains unclear. underscores importance biogeochemical models that integrate climatic biological feedbacks, enabling accurate forecasts OA changes their impacts on marine ecosystems. These findings highlight urgent need for sustained monitoring PAR, where accelerating threaten critical

Language: Английский

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Impacts of riverine heatwaves on rates of ecosystem metabolism in the United States

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

Published: April 11, 2025

Abstract Rivers produce and decompose large amounts of carbon globally due, in part, to high rates gross primary production (GPP) ecosystem respiration (ER), collectively known as metabolism. Water temperature is a major driver metabolism, in‐stream temperatures are increasing globally, including extreme events called heatwaves. This study used published estimates daily GPP ER from 48 stream river locations the United States examine how metabolism responds riverine During low‐severity heatwaves, increase proportionally, resulting no net difference. However, during severe declined up 82% while increased 47%, greater heterotrophy (ER > GPP). While rivers were typically heterotrophic outside heatwave conditions, these results suggest that become stronger sources dioxide.

Language: Английский

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Hydrological and climate impacts on river characteristics of pahang river basin, Malaysia

Heliyon, Journal Year: 2023, Volume and Issue: 9(11), P. e21573 - e21573

Published: Nov. 1, 2023

The climate, geomorphological changes, and hydrological elements that have occurred all influenced future flood episodes by increasing the likelihood intensity of extreme weather occurrences like precipitation events. River bank erosion is a natural geomorphic process occurs in channels. As modifications sizes channel shapes are made to transport discharge, sediment abounds from stream catchment, floods triggered dramatically. aim this study analyze flood-sensitive regions along Pahang Basin determine how climate river changes would an impact on flooding based hydrometeorological data information characteristics. divided into three stages, namely upstream, middle stream, downstream River. main primary characteristics, such as Sinuosity Index, Dominant Slope Range Entrenchment Ratio collected important inputs statistical analysis process. analyses, HACA, PCA, Linear Regression applied classification. result showed areas demonstrated worst affected anthropogenic factors. Rainfall distribution one factors contributed disaster. There strong correlations between Index (SI) water level, which indicates at both planform best management practices towards sustainability application outcomes been obtained after geometry, local rainfall pattern Basin.

Language: Английский

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Contrasting trends in water quality between adjacent ocean‐ and river‐dominated estuaries: Evidence for marsh porewaters as a source of nutrient enrichment?

Limnology and Oceanography, Journal Year: 2023, Volume and Issue: 68(9), P. 2040 - 2058

Published: July 17, 2023

Abstract Degradation of estuarine water quality during the Anthropocene has largely resulted from discharges nutrients leading to eutrophication. Recently, upstream management practices have led comparatively reduced nutrient input into estuaries. Concurrently, climate cycles and impacts associated with anthropogenic warming can affect long‐term conditions observed within Using monitoring data adjacent southeastern U.S. estuaries, we show that decadal‐scale trends in concentrations phytoplankton standing stock differ between two connected systems. These contrasting appear result differences oceanic influence, extent vegetated marsh, watershed size, degradation. In minimally impacted, ocean‐dominated North Inlet estuary, document increasing ammonium chlorophyll a (Chl ), while adjacent, river‐dominated Winyah Bay, ammonium, Chl are more variable but do not increased over same time period. Surprisingly, total nitrogen exhibits opposite pattern: temporal stability Bay. We hypothesize sea level rise change driven complex set interactions salt marsh porewaters tidal pumping, spillover marshes creeks Inlet. this mechanism is less evident as driver concentrations, likely due outsized effect narrow fringing platform. The degree which operates other vary range, degradation warrants further study.

Language: Английский

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Hypoxia Tolerance of Two Killifish Species

Integrative and Comparative Biology, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 5, 2024

Hypoxia tolerance in aquatic ectotherms involves a suite of behavioral and physiological responses at the organismal, tissue, cellular levels. The current study evaluated two closely related killifish species (Fundulus heteroclitus, Fundulus majalis) to evaluate acute moderate severe hypoxia. Routine metabolic rate loss equilibrium were assessed, followed by analysis skeletal muscle markers oxidative damage proteins (2,4-DNPH), lipids (4-HNE), DNA (8-OHdG), hypoxia signaling (HIF1α, HIF2α), energy state (p-AMPK: AMPK), protein degradation (Ubiquitin, LC3B, Calpain 2, Hsp70). Both had similar reduction low PO2. However, F. heteroclitus was more hypoxia-tolerant based on lower PO2 which there equilibrium, perhaps due part oxygen demand all tensions. Despite differences between species, molecular largely insensitive hypoxia, few species. Thus, depression observed whole animal level appears limit perturbations both during treatments.

Language: Английский

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River Discharge Mediates Extent of Phytoplankton and Harmful Algal Bloom Habitat in the Columbia River Estuary (USA) During North Pacific Marine Heat Waves

Estuaries and Coasts, Journal Year: 2022, Volume and Issue: 46(1), P. 166 - 181

Published: Oct. 24, 2022

Language: Английский

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