The Globalization of Cultural Eutrophication in the Coastal Ocean: Causes and Consequences

Frontiers in Marine Science, Год журнала: 2020, Номер 7

Опубликована: Авг. 17, 2020

Coastal eutrophication caused by anthropogenic nutrient inputs is one of the greatest threats to health coastal estuarine and marine ecosystems worldwide. To better understand manage this threat, we compared six contrasting that are subjected a range riverine freshwater (buoyancy) nutrients address (i) impacts on ecosystem services; (ii) how traits minimize or amplify these impacts; (iii) synergies among pressures (nutrient enrichment, over fishing, development, climate-driven in particular); (iv) management ecosystems. Globally, ~ 24% N released watersheds estimated reach Our comparative assessment revealed terms spatial extent habitat degradation, Chesapeake Bay ranks number followed rank order northern Gulf Mexico, Baltic Sea, Great Barrier Reef, East China Sea Adriatic Sea; increases loading are, will continue be, exacerbated with other including development sea surface temperature, acidification rainfall; when defined quantitative ranges primary production, trophic status not useful for relating impacts. While managed reductions point source from sewage treatment plants increasingly successful, controlling diffuse sources remains challenging problem. Thus, it likely severity increase absence effectively enforced, ecosystem-based both nitrogen phosphorus. This requires sustained, integrated research monitoring, as well repeated assessments These must be informed guided ongoing collaborations scientists, politicians, managers public.

Язык: Английский

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Persistent eutrophication and hypoxia in the coastal ocean

Cambridge Prisms Coastal Futures, Год журнала: 2023, Номер 1

Опубликована: Янв. 1, 2023

Abstract Coastal eutrophication and hypoxia remain a persistent environmental crisis despite the great efforts to reduce nutrient loading mitigate associated damages. Symptoms of this have appeared spread rapidly, reaching developing countries in Asia with emergences Southern America Africa. The pace changes underlying drivers not so clear. To address gap, we review up-to-date status mechanisms global coastal oceans, upon which examine trajectories over 40 years or longer six model systems varying socio-economic development statuses different levels histories eutrophication. Although these share common features eutrophication, site-specific characteristics are also substantial, depending on regional setting level social-economic along policy implementation management. Nevertheless, ecosystem recovery generally needs greater reduction pressures compared that initiated degradation becomes less feasible achieve past norms time anthropogenic ecosystems. While qualitative causality between consequences is well established, quantitative attribution remains difficult especially when consider social economic because ecosystems subject multiple influences cause–effect relationship often non-linear. Such relationships further complicated by climate been accelerating few decades. knowledge gaps limit our mechanistic understanding human-coastal ocean nexus identified, essential for science-based making. Recognizing lessons from management practices, advocate better, more efficient indexing system an advanced earth modeling framework optimal modules human dimensions facilitate evaluation effective restoration actions.

Язык: Английский

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Copernicus Ocean State Report, issue 6

Journal of Operational Oceanography, Год журнала: 2022, Номер 15(sup1), С. 1 - 220

Опубликована: Авг. 31, 2022

Statement of main outcome: This section presents a satellite-based map potential eutrophic and oligotrophic areas in the European Seas for year 2020, together with time series eutrophication past 23 years (1998-2020) averaged over Exclusive Economic Zones (EEZs) each country.The were generated on basis comparison per-pixel chlorophyll-a data from remote sensing reporting corresponding climatological 90th percentile (P90) established 20-year baseline (1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017).The results showed few scattered areas, while extensive coastal shelf waters indicate status.The distributions point to localities that should be watch determine situ nutrient levels whether trend is sustained into future.The at EEZ level low percentages across area some remarkable high events occurring first decade study period, followed by an overall reduction 2013 onwards.Furthermore, several countries, indicator was often nil or never exceeded 1% area.Results are then compared those Sustainable Development Goal (SDG, set United Nations General Assembly) 14 global satellite-derived (target 14.1).

Язык: Английский

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Biogeochemical functioning of the Baltic Sea

Earth System Dynamics, Год журнала: 2022, Номер 13(1), С. 633 - 685

Опубликована: Март 31, 2022

Abstract. Location, specific topography, and hydrographic setting together with climate change strong anthropogenic pressure are the main factors shaping biogeochemical functioning thus also ecological status of Baltic Sea. The recent decades have brought significant changes in First, rising nutrient loads from land second half 20th century led to eutrophication spreading hypoxic anoxic areas, for which permanent stratification water column limited ventilation deep-water layers made favourable conditions. Since 1980s Sea been continuously decreasing. This, however, has so far not resulted improvements oxygen availability deep regions, revealed a slow response time system reduction land-derived loads. Responsible that is low burial efficiency phosphorus at conditions its remobilization sediments when oxic anoxic. This results stoichiometric excess available organic-matter production, promotes growth N2-fixing cyanobacteria turn supports eutrophication. assessment reviews published knowledge on In content, paper covers aspects related carbon, nitrogen, (C, N, P) external loads, their transformations coastal zone, production (eutrophication) remineralization (oxygen availability), role turnover C, P. addition that, this focuses marine CO2 system, structure microbial community, contaminants processes. comprehensive allowed identifying gaps future research needs field biogeochemistry

Язык: Английский

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Nitrogen fixation: A poorly understood process along the freshwater‐marine continuum

Limnology and Oceanography Letters, Год журнала: 2021, Номер 7(1), С. 1 - 10

Опубликована: Окт. 29, 2021

Although N2 fixation is a major component of the global N cycle and has been extensively studied in open-ocean terrestrial ecosystems, rates ecological dynamics remain virtually unknown for inland coastal aquatic ecosystems (lakes, wetlands, rivers, streams, estuaries) that connect marine biomes. This due to diversity these habitats, as well traditional paradigm were low nonexistent, therefore not important, ecosystems. We identify three research themes advance understanding fixation: 1) biological diazotrophs variability rates, 2) stoichiometry fixation, 3) upscaling from genes Coordinating across areas will limnology oceanography by fully integrating into local scales.

Язык: Английский

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Intensification of harmful cyanobacterial blooms in a eutrophic, temperate lake caused by nitrogen, temperature, and CO2

The Science of The Total Environment, Год журнала: 2024, Номер 915, С. 169885 - 169885

Опубликована: Янв. 6, 2024

Warmer temperatures can significantly increase the intensity of cyanobacterial harmful algal blooms (CHABs) in eutrophic freshwater ecosystems. However, few studies have examined effects CO

Язык: Английский

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Cyanophage infections reduce photosynthetic activity and expression of CO2 fixation genes in the freshwater bloom-forming cyanobacterium Aphanizomenon flos-aquae

Harmful Algae, Год журнала: 2022, Номер 116, С. 102215 - 102215

Опубликована: Март 11, 2022

Cyanobacteria play a significant role in ecosystem functioning as photosynthetic and CO2 fixing microorganisms. Whether to what extent cyanophages alter these carbon energy cycles their cyanobacterial hosts is still poorly understood. In this study, we investigated changes activity (PSII), expression of genes associated with the light phase photosynthesis (psbA, petA, ndhK) metabolism (rbcL, zwf) well intracellular ATP NADHP concentrations freshwater bloom-forming filamentous cyanobacterium Aphanizomenon flos-aquae infected by cyanophage vB_AphaS-CL131. We found that PSII level rbcL genes, indicating potential for fixation, had decreased response adsorption DNA injection. During period viral replication assembly, performance gene remained at did not change significantly, lack transcriptional shutdown cyanophage. Combined, observations suggest although there little no interference between replication, host transcription cellular metabolism, A. underwent physiological state-shift toward lower efficiency cycling. This further cascading effect co-occurring non-infected members microbial community.

Язык: Английский

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Spatiotemporal patterns of N<sub>2</sub> fixation in coastal waters derived from rate measurements and remote sensing

Biogeosciences, Год журнала: 2021, Номер 18(5), С. 1857 - 1871

Опубликована: Март 18, 2021

Abstract. Coastal lagoons are important sites for nitrogen (N) removal via sediment burial and denitrification. Blooms of heterocystous cyanobacteria may diminish N retention as dinitrogen (N2) fixation offsets atmospheric losses We measured N2 in the Curonian Lagoon, Europe's largest coastal lagoon, to better understand factors controlling context seasonal changes phytoplankton community composition external inputs. Temporal patterns were primarily determined by abundance cyanobacteria, mainly Aphanizomenon flos-aquae, which became abundant after decline riverine nitrate inputs associated with snowmelt. Heterocystous dominated summer resulting strong correlations between chlorophyll a (Chl a) fixation. used regression models relating Chl a, along remote-sensing-based estimates derive lagoon-scale pelagic was found be significant component lagoon's budget based on comparisons previously derived fluxes inputs, sediment–water exchange, To our knowledge, this is first study ecosystem-scale combining remote sensing empirical rates a.

Язык: Английский

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Retracing cyanobacteria blooms in the Baltic Sea

Scientific Reports, Год журнала: 2022, Номер 12(1)

Опубликована: Июнь 27, 2022

Abstract In late summer, massive blooms and surface scums of cyanobacteria emerge regularly in the Baltic Sea. The bacteria can produce toxins add bioavailable nitrogen fixed from atmospheric to an already over-fertilized system. This counteracts management efforts targeted at improving water quality. Despite their critical role, controls on are not comprehensively understood yet. limits usability models-based bloom forecasts projections into our warming future. Here we discussion by combining, for first time, satellite estimates with output a high-resolution general ocean circulation model in-situ nutrient observations. We retrace origins conditions calculating trajectories respective parcels backwards time. attempt identify drivers development, find that originate manifest themselves predominantly offshore where more nutrient-depleted compared coastal environments.

Язык: Английский

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Simulated heat waves promote the growth but suppress the N2 fixation rates of Dolichospermum spp. and cyanobacterial communities in temperate lakes

Ecological Indicators, Год журнала: 2023, Номер 147, С. 109983 - 109983

Опубликована: Фев. 11, 2023

The intensity and duration of heat waves are expected to increase this century, occurrences considered favorable for harmful, bloom-forming freshwater cyanobacteria. Dinitrogen (N2) fixation is a major component nitrogen cycling in systems, yet little known with respect how diazotrophic (N2 fixing) cyanobacteria respond waves. Here, we quantified the effects elevated temperature fixed N enrichment on growth N2 rates Dolichospermum isolates from differing latitudes cyanobacterial communities four lakes across New York state, USA, during summer early fall. In culture experiments, temperatures ≥ 26℃ significantly reduced maximum sub-polar strains Finland relative those grown at 20 − 25℃, while strain isolated subtropical Australia grew faster 30℃ compared cooler temperatures. All strains, however, exhibited lower higher (29 30℃) (13-26℃). During ecosystem-based experiments comprised Nostocales other cyanobacteria, short-term (3–4 day) exposures mimicking (+3-6℃; 27-31℃) and/or (NH4+) caused significant net but also decline rates. Collectively, results indicate that loading can promote communities, they suppress diazotrophy, which generally regarded as eutrophic systems. Such reductions would or intensify limitation primary production summer, an outcome be exacerbated under future warming scenarios.

Язык: Английский

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