Biogeochemical extremes and compound events in the ocean

Nature, Journal Year: 2021, Volume and Issue: 600(7889), P. 395 - 407

Published: Dec. 15, 2021

Language: Английский

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Changing Biogeochemistry of the Southern Ocean and Its Ecosystem Implications

Frontiers in Marine Science, Journal Year: 2020, Volume and Issue: 7

Published: July 31, 2020

The Southern Ocean plays a critical role in regulating global climate as major sink for atmospheric carbon dioxide (CO2), and ocean biogeochemistry by supplying nutrients to the thermocline, thereby influencing primary production export. Biogeochemical processes within regulate regional biological uptake, primarily through iron supply, support ecosystem functioning over range of spatial temporal scales. Here we assimilate existing knowledge present new data examine biogeochemical cycles iron, nutrients, their key drivers responses to, roles in, contemporary environmental change. Projected increases coupled with light availability phytoplankton increased near-surface stratification longer ice-free periods, are very likely increase export around Antarctica. Biological uptake is whole, whilst there greater uncertainty projections Sub-Antarctic basin-wide changes species composition, well consequences. Phytoplankton, zooplankton, higher trophic level organisms microbial communities strongly influenced biogeochemistry, particular nutrient supply acidification. In turn, these exert important controls on storage export, recycling redistribution, benthic-pelagic coupling. described this paper summarised graphical abstract. Climate-mediated coming decades impact production, sea-air CO2 exchange beyond vast critically region.

Language: Английский

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Global Drivers on Southern Ocean Ecosystems: Changing Physical Environments and Anthropogenic Pressures in an Earth System

Frontiers in Marine Science, Journal Year: 2020, Volume and Issue: 7

Published: Dec. 15, 2020

The manuscript assesses the current and expected future global drivers of Southern Ocean (SO) ecosystems. Atmospheric ozone depletion over Antarctic since 1970s, has been a key driver, resulting in springtime cooling stratosphere intensification polar vortex, increasing frequency positive phases Annular Mode (SAM). This increases warm air-flow East Pacific sector (Western Peninsula) cold air flow West sector. SAM as well El Niño Oscillation events also affect Amundsen Sea Low leading to either or negative sea ice anomalies west east sectors, respectively. strengthening westerly winds is linked shoaling deep warmer water onto continental shelves, particularly Atlantic sectors. Air ocean warming led changes cryosphere, with glacial sheet melting both opening up new free areas biological productivity, but seafloor disturbance by icebergs. increased correlated salinity decrease surface 100 m. Such processes could increase availability iron, which currently limiting primary production much SO. Increasing CO 2 one most important SO anthropogenic likely marine ecosystems coming decades. While levels many pollutants are lower than elsewhere, persistent organic (POPs) plastics have detected SO, concentrations enhanced migratory species. With traffic weakening barriers risk establishment non-indigenous species increased. continued recovery hole creates uncertainty reversal trends, especially light abrupt transition from record high low extent spring 2016. rate change physical certain impact Marine Ecosystem Assessment (MEASO) region near will wide range impacts across ecosystem.

Language: Английский

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The State and Future of Antarctic Environments in a Global Context

Annual Review of Environment and Resources, Journal Year: 2019, Volume and Issue: 44(1), P. 1 - 30

Published: Oct. 10, 2019

Antarctica and the Southern Ocean comprise a critical part of Earth System. Their environments are better understood than ever before, yet region remains poorly considered among international agreements to improve state global environment. In situation owes isolated regional regulation within Antarctic Treaty System, in dated notion that well conserved relatively free from human impact. Here we review growth knowledge anthropogenic pressures on them. We show region's unusual diversity is facing substantial local globally mediated pressure, par with globally. environmental management being challenged keep pace change. Much benefit can be derived consideration resource context agreements.

Language: Английский

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Effects of ocean acidification on Antarctic marine organisms: A meta‐analysis

Ecology and Evolution, Journal Year: 2020, Volume and Issue: 10(10), P. 4495 - 4514

Published: April 16, 2020

Southern Ocean waters are among the most vulnerable to ocean acidification. The projected increase in CO2 level will cause changes carbonate chemistry that likely be damaging organisms inhabiting these waters. A meta-analysis was undertaken examine vulnerability of Antarctic marine biota occupying south 60°S This showed acidification negatively affects autotrophic organisms, mainly phytoplankton, at levels above 1,000 μatm and invertebrates 1,500 μatm, but positively bacterial abundance. sensitivity phytoplankton influenced by experimental procedure used. Natural, mixed communities were more sensitive than single species culture a decline chlorophyll concentration, productivity, photosynthetic health, as well shift community composition μatm. Invertebrates reduced fertilization rates increased occurrence larval abnormalities, decreased calcification shell dissolution with any Assessment fish macroalgae limited number studies available. Overall, this analysis indicates many susceptible thereby change their contribution ecosystem services future. Further required address poor spatial coverage, lack or ecosystem-level studies, largely unknown potential for acclimate and/or adapt changing conditions.

Language: Английский

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Status, Change, and Futures of Zooplankton in the Southern Ocean

Frontiers in Ecology and Evolution, Journal Year: 2022, Volume and Issue: 9

Published: June 17, 2022

In the Southern Ocean, several zooplankton taxonomic groups, euphausiids, copepods, salps and pteropods, are notable because of their biomass abundance roles in maintaining food webs ecosystem structure function, including provision globally important services. These groups consumers microbes, primary secondary producers, prey for fishes, cephalopods, seabirds, marine mammals. providing link between production, higher trophic levels these taxa influence energy flows, biological production biomass, biogeochemical cycles, carbon flux web interactions thereby modulating functioning ecosystems. Additionally, Antarctic krill ( Euphausia superba ) various fish species harvested by international fisheries. Global local drivers change expected to affect dynamics key species, which may have potentially profound wide-ranging implications Ocean ecosystems services they provide. Here we assess current understanding dominant metazoan within other euphausiid, copepod, salp pteropod species. We provide a systematic overview observed potential future responses changing functional relationships impact them. To support assessments conservation management strategies, also identify priorities research.

Language: Английский

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Larval dispersal in a changing ocean with an emphasis on upwelling regions

Ecosphere, Journal Year: 2020, Volume and Issue: 11(1)

Published: Jan. 1, 2020

Abstract Dispersal of benthic species in the sea is mediated primarily through small, vulnerable larvae that must survive minutes to months as members plankton community while being transported by strong, dynamic currents. As climate change alters ocean conditions, dispersal these will be affected, with pervasive ecological and evolutionary consequences. We review impacts oceanic changes on larval transport, physiology, behavior. then discuss implications for population connectivity recruitment evaluate life history strategies affect susceptibility effects their patterns, understanding selective regimes a future ocean. find physical oceanographic impact transporting different directions or inhibiting movements changing environmental factors, such temperature, pH , salinity, oxygen, ultraviolet radiation, turbidity, survival alter Reduced distance may make local adaptation more likely well‐connected populations high genetic variation reduced success lower fishery stocks. Increased spur increasing diversity among previously disconnected well likelihood range expansions. hypothesize planktotrophic (feeding), calcifying, weakly swimming specialized adult habitats most affected change. also propose adaptive value retentive behaviors decrease where transport trajectories follow envelopes increase drive toward increasingly unsuitable conditions. Our holistic framework, combined knowledge regional conditions traits, can used produce powerful predictions expected consequences connectivity, expansion, recruitment. Based our findings, we recommend studies take view incorporating biological rather than solely focusing oceanography physiology. Genetic paleontological techniques examine altered ocean, museum collections expedition records inform modern‐day shifts.

Language: Английский

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The Impact of Zooplankton Calcifiers on the Marine Carbon Cycle

Global Biogeochemical Cycles, Journal Year: 2023, Volume and Issue: 37(6)

Published: May 15, 2023

Abstract Shelled pteropods and planktic foraminifers are calcifying zooplankton that contribute to the biological carbon pump via sinking of their calcareous shells. However, importance for regional global plankton biomass fluxes is not well understood. Here, we modeled annual patterns pteropod foraminifer total (TC) inorganic (TIC) export over top 200 m using five species distribution models (SDMs). An extended version MARine Ecosystem DATa (MAREDAT) abundance observations was used estimate both groups. We found hotspots mean in high Northern latitudes upwelling systems, hemispheres tropics foraminifers. This largely agrees with previously observed distributions. For groups, temperature strongest environmental correlate, followed by chlorophyll‐a. standing stocks 52 Tg TC (48 57 TC) 0.9 (0.6 1.1 foraminifers, respectively. translates TIC 14 yr −1 (9 22 ) shells 11 (3 27 tests. These results similar previous estimates but approximately a factor ten lower pteropods. Pteropods 0.2%–3.2% 0.1%–3.8% surface carbonate fluxes. Including coccolithophore fluxes, this leaves 40%–60% unaccounted for. Our figures likely lower‐bound due sampling data characteristics uncertainty associated organism growth rates.

Language: Английский

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El Niño-Related Thermal Stress Coupled With Upwelling-Related Ocean Acidification Negatively Impacts Cellular to Population-Level Responses in Pteropods Along the California Current System With Implications for Increased Bioenergetic Costs

Frontiers in Marine Science, Journal Year: 2018, Volume and Issue: 5

Published: Dec. 12, 2018

Understanding the interactive effects of multiple stressors on pelagic mollusks associated with global climate change is especially important in highly productive coastal ecosystems upwelling regime, such as California Current System (CCS). Due to temporal overlap between a marine heatwave, an El Niño event, and springtime intensification upwelling, pteropods CCS were exposed co-occurring increased temperature, low Ωar pH, deoxygenation. The variability natural gradients during NOAA's WCOA 2016 cruise provided unique opportunity for synoptic study chemical biological interactions. We investigated situ drivers their interactions across cellular, physiological, population levels. Oxidative stress biomarkers used assess pteropods' cellular status antioxidant defenses. Ocean acidification (OA) induced significant activation oxidative biomarkers, indicated by levels lipid peroxidation (LPX), but antioxidative activity defense might be insufficient against stress. Thermal combination additively increases level LPX toxicity, while food availability can mediate negative effect. On physiological level, we found synergistic interaction deoxygenation thermal (Ωar: T, O2:T). temperature was main driver abundance distribution, being strong secondary importance. additive suggest effect at level. Our clearly demonstrates are master variables explaining responses, cautioning use single parameter statistical analyses. High quantities polyunsaturated fatty acids susceptible because peroxidation, resulting loss reserves structural damage cell membranes, potential mechanism extreme pteropod sensitivity OA. Accumulation requires metabolic compensation, implying energetic trade-offs under combined OA early-warning signal thereby providing new insights into factors that set limits species' tolerance drivers.

Language: Английский

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Biological Impact of Ocean Acidification in the Canadian Arctic: Widespread Severe Pteropod Shell Dissolution in Amundsen Gulf

Frontiers in Marine Science, Journal Year: 2021, Volume and Issue: 8

Published: March 11, 2021

Increasing atmospheric CO 2 , cold water temperatures, respiration, and freshwater inputs all contribute to enhanced acidification in Arctic waters. However, ecosystem effects of ocean (derived from anthropogenic and/or natural sources) the Ocean are highly uncertain. Zooplankton samples oceanographic data were collected August 2012–2014 again 2017 investigate pelagic sea snail, Limacina helicina a biological indicator presence potential impact acidified waters Canadian Beaufort Sea. Between 2012 2014 L. abundance ranged <1 1942 Ind. m –2 with highest abundances occurring at stations on Shelf 2012. The majority individuals (66%) located between 25 100 depth, corresponding upper halocline Pacific origin. In both 2017, >85% assessed ( n = 134) Amundsen Gulf region displayed shell dissolution advanced levels occurred stations. severity was not significantly different despite larger that less prone dissolution, higher food availability can provide some physiological benefits 2014. Corrosive conditions widespread time sampling aragonite undersaturation (Ω ar < 1) primarily depths >150 m. observed first whorl shells strongly indicating damage initiated during larval stage growth May or early June when ice is still present. Evidence modification present 2014, likely supported by abundant relative 2017. proportion damaged coastal embayments offshore than other temperate locations exposure corrosive spatially region, periods extreme enough population.

Language: Английский

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