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1.
Sci Rep ; 14(1): 7240, 2024 03 27.
Artículo en Inglés | MEDLINE | ID: mdl-38538671

RESUMEN

A key control on the magnitude of coastal eutrophication is the degree to which currents quickly transport nitrogen derived from human sources away from the coast to the open ocean before eutrophication develops. In the Southern California Bight (SCB), an upwelling-dominated eastern boundary current ecosystem, anthropogenic nitrogen inputs increase algal productivity and cause subsurface acidification and oxygen (O 2 ) loss along the coast. However, the extent of anthropogenic influence on eutrophication beyond the coastal band, and the physical transport mechanisms and biogeochemical processes responsible for these effects are still poorly understood. Here, we use a submesoscale-resolving numerical model to document the detailed biogeochemical mass balance of nitrogen, carbon and oxygen, their physical transport, and effects on offshore habitats. Despite management of terrestrial nutrients that has occurred in the region over the last 20 years, coastal eutrophication continues to persist. The input of anthropogenic nutrients promote an increase in productivity, remineralization and respiration offshore, with recurrent O 2 loss and pH decline in a region located 30-90 km from the mainland. During 2013 to 2017, the spatially averaged 5-year loss rate across the Bight was 1.3 mmol m - 3 O 2 , with some locations losing on average up to 14.2 mmol m - 3 O 2 . The magnitude of loss is greater than model uncertainty assessed from data-model comparisons and from quantification of intrinsic variability. This phenomenon persists for 4 to 6 months of the year over an area of 278,40 km 2 ( ∼ 30% of SCB area). These recurrent features of acidification and oxygen loss are associated with cross-shore transport of nutrients by eddies and plankton biomass and their accumulation and retention within persistent eddies offshore within the SCB.


Asunto(s)
Ecosistema , Eutrofización , Nitrógeno , Oxígeno , Plancton
2.
Sci Rep ; 13(1): 22148, 2023 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-38092878

RESUMEN

Climate change is increasing drought severity worldwide. Ocean discharges of municipal wastewater are a target for potable water recycling. Potable water recycling would reduce wastewater volume; however, the effect on mass nitrogen loading is dependent on treatment. In cases where nitrogen mass loading is not altered or altered minimally, this practice has the potential to influence spatial patterns in coastal eutrophication. We apply a physical-biogeochemical numerical ocean model to understand the influence of nitrogen management and potable wastewater recycling on net primary productivity (NPP), pH, and oxygen. We model several theoretical management scenarios by combining dissolved inorganic nitrogen (DIN) reductions from 50 to 85% and recycling from 0 to 90%, applied to 19 generalized wastewater outfalls in the Southern California Bight. Under no recycling, NPP, acidification, and oxygen loss decline with DIN reductions, which simulated habitat volume expansion for pelagic calcifiers and aerobic taxa. Recycling scenarios under intermediate DIN reduction show patchier areas of pH and oxygen loss with steeper vertical declines relative to a "no recycling" scenario. These patches are diminished under 85% DIN reduction across all recycling levels, suggesting nitrogen management lowers eutrophication risk even with concentrated discharges. These findings represent a novel application of ocean numerical models to investigate the regional effects of idealized outfall management on eutrophication. Additional work is needed to investigate more realistic outfall-specific water recycling and nutrient management scenarios and to contextualize the benefit of these management actions, given accelerating acidification and hypoxia from climate change.

3.
Harmful Algae ; 126: 102435, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37290883

RESUMEN

Pseudo-nitzschia species with the ability to produce the neurotoxin domoic acid (DA) are the main cause of harmful algal blooms (HABs) along the U.S. West Coast, with major impacts on ecosystems, fisheries, and human health. While most Pseudo-nitzschia (PN) HAB studies to date have focused on their characteristics at specific sites, few cross-regional comparisons exist, and mechanistic understanding of large-scale HAB drivers remains incomplete. To close these gaps, we compiled a nearly 20-year time series of in situ particulate DA and environmental observations to characterize similarities and differences in PN HAB drivers along the California coast. We focus on three DA hotspots with the greatest data density: Monterey Bay, the Santa Barbara Channel, and the San Pedro Channel. Coastwise, DA outbreaks are strongly correlated with upwelling, chlorophyll-a, and silicic acid limitation relative to other nutrients. Clear differences also exist across the three regions, with contrasting responses to climate regimes across a north to south gradient. In Monterey Bay, PN HAB frequency and intensity increase under relatively nutrient-poor conditions during anomalously low upwelling intensities. In contrast, in the Santa Barbara and San Pedro Channels, PN HABs are favored under cold, nitrogen-rich conditions during more intense upwelling. These emerging patterns provide insights on ecological drivers of PN HABs that are consistent across regions and support the development of predictive capabilities for DA outbreaks along the California coast and beyond.


Asunto(s)
Diatomeas , Floraciones de Algas Nocivas , Humanos , Ecosistema , California , Ácido Kaínico
4.
Ther Adv Urol ; 15: 17562872231177779, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37275300

RESUMEN

Background: Percutaneous tibial nerve stimulation (PTNS) is widely used in the treatment of neurogenic detrusor overactivity (NDO) in multiple sclerosis (MS); however, controlled studies are still lacking.Objective:: To assess effectiveness of PTNS in MS patients with NDO unresponsive to pharmacological and behavioural therapies. Methods: MS patients with NDO were enrolled. Inclusion criteria were NDO not responding to pharmacological and behavioural therapies. Exclusion criteria were the presence of relevant comorbidities and urinary tract infections. Patients were evaluated using 3-day bladder diaries and validated questionnaires at baseline, after 4 weeks of educational therapy and after 12 PTNS sessions. The primary outcome measure was the percentage of patients considered responders after the behavioural therapy and after the PTNS in a historical controlled fashion (definition of 'responder' was reduction ⩾50% of urgency episodes). Results: A total of 33 patients (26 women, 7 men) were enrolled. Two patients dropped out for reasons not related to the protocol. Two out of 31 patients (6.5%) and 21/29 (72.4%) were considered responders at visits 1 and 2, respectively. In PTNS responders, a statistically significant improvement in both bladder diary results and standardized questionnaire scores was recorded, compared with that obtained with behavioural therapy alone. No serious adverse events were reported. Conclusion: This historically controlled study suggests that PTNS may be effective in improving NDO in MS patients.

5.
EJVES Vasc Forum ; 59: 8-14, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37213485

RESUMEN

Objective: Little is known about the cardiovascular changes after TEVAR and regarding the impact on aortic stiffness for different stent graft generations specifically, following changes in device design. The present study evaluated the stent graft induced aortic stiffening of two generations of the Valiant thoracic aortic stent graft. Methods: This was an ex vivo porcine investigation using an experimental mock circulatory loop. Thoracic aortas of young healthy pigs were harvested and connected to the mock circulatory loop. At a 60 bpm heart rate and stable mean arterial pressure, baseline aortic characteristics were obtained. Pulse wave velocity (PWV) was calculated before and after stent graft deployment. Paired and independent sample t tests or their non-parametric alternatives were performed to test for differences where appropriate. Results: Twenty porcine thoracic aortas were divided into two equal subgroups, in which a Valiant Captivia or a Valiant Navion stent graft was deployed. Both stent grafts were similar in diameter and length. Baseline aortic characteristics did not differ between the subgroups. Mean arterial pressure values did not change after either stent graft, while pulse pressures increased statistically significantly after Captivia (mean 44 ± 10 mmHg to 51 ± 13 mmHg, p = .002) but not after Navion. Mean baseline PWV increased after both Captivia (4.4 ± 0.6 m/s to 4.8 ± 0.7 m/s, p = .007) and Navion (4.6 ± 0.7 m/s to 4.9 ± 0.7 m/s, p = .002). There was no statistically significant difference in the mean percentage increase in PWV for either subgroup (8 ± 4% vs. 6 ± 4%, p = .25). Conclusion: These experimental findings showed no statistically significant difference in the percentage increase of aortic PWV after either stent graft generation and confirm that TEVAR increases aortic PWV. As a surrogate for aortic stiffness, this calls for further improvements in future thoracic aortic stent graft designs regarding device compliance.

6.
J Urol ; 209(3): 513-514, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36562682
7.
J Urol ; 209(1): 109-110, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36263699
8.
Int J Numer Method Biomed Eng ; 39(4): e3594, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-35340129

RESUMEN

Thoracic endovascular aortic repair (TEVAR) is widespread in clinical practice for treating aortic diseases but it has relevant systemic complications, such as increase of the cardiac workload due to post-TEVAR aortic stiffening, and local issues such as re-entry tears due to the tissue damage caused by endograft interaction. The present study aims to elucidate these aortic biomechanical mechanisms by coupling ex vivo and in silico analysis. By ex vivo tests, the pulse wave velocity before and after TEVAR is measured. Uni-axial tensile tests are performed to measure regional mechanical response of tissue samples, supplied as input data for the in silico analysis. Numerical analysis is finally performed to compute the wall stress induced by the stent-graft deployment and the arterial pressurization. The ex vivo results highlight an increase of baseline PWV by a mean .78 m/s or 12% after TEVAR with a 100 mm stent-graft (p <.013). In the in silico analysis, the average von Mises stress in the landing zone increases of about 15% and 20% using, respectively stent-graft with radial oversizing of 10% and 20%. This work shows the effectiveness of integrated framework to analyze the biomechanical post TEVAR mechanisms. Moreover, the obtained results quantify the effect of prosthesis selection on the stiffening of the aorta after TEVAR and on the local increase of the aortic wall stress that is proportional to the stent-graft oversizing.


Asunto(s)
Aneurisma de la Aorta Torácica , Implantación de Prótesis Vascular , Procedimientos Endovasculares , Porcinos , Animales , Prótesis Vascular , Implantación de Prótesis Vascular/métodos , Reparación Endovascular de Aneurismas , Aorta Torácica/cirugía , Fenómenos Biomecánicos , Análisis de la Onda del Pulso , Procedimientos Endovasculares/métodos , Stents , Aorta/cirugía , Aneurisma de la Aorta Torácica/cirugía , Resultado del Tratamiento , Diseño de Prótesis
9.
Harmful Algae ; 118: 102296, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36195423

RESUMEN

Pseudo-nitzschia species are one of the leading causes of harmful algal blooms (HABs) along the western coast of the United States. Approximately half of known Pseudo-nitzschia strains can produce domoic acid (DA), a neurotoxin that can negatively impact wildlife and fisheries and put human life at risk through amnesic shellfish poisoning. Production and accumulation of DA, a secondary metabolite synthesized during periods of low primary metabolism, is triggered by environmental stressors such as nutrient limitation. To quantify and estimate the feedbacks between DA production and environmental conditions, we designed a simple mechanistic model of Pseudo-nitzschia and domoic acid dynamics, which we validate against batch and chemostat experiments. Our results suggest that, as nutrients other than nitrogen (i.e., silicon, phosphorus, and potentially iron) become limiting, DA production increases. Under Si limitation, we found an approximate doubling in DA production relative to N limitation. Additionally, our model indicates a positive relationship between light and DA production. These results support the idea that the relationship with nutrient limitation and light is based on direct impacts on Pseudo-nitzschia biosynthesis and biomass accumulation. Because it can easily be embedded within existing coupled physical-ecosystem models, our model represents a step forward toward modeling the occurrence of Pseudo-nitzschia HABs and DA across the U.S. West Coast.


Asunto(s)
Diatomeas , Neurotoxinas , Calibración , Diatomeas/metabolismo , Ecosistema , Humanos , Hierro/metabolismo , Ácido Kaínico/análogos & derivados , Neurotoxinas/metabolismo , Nitrógeno/metabolismo , Océanos y Mares , Fósforo/metabolismo , Silicio/metabolismo
10.
Energy Fuels ; 36(19): 12010-12020, 2022 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-36250135

RESUMEN

Hydrothermal liquefaction (HTL) can thermochemically transform sewage sludge into a biocrude with high energy content, high chemical complexity, and high O and N content. The development of an efficient upgrading process for such complex feedstocks necessitates detailed knowledge of the molecular composition and the specific heteroatom-containing compounds to understand and optimize the hydrotreating reactions. In this study, we present the upgrading of sewage sludge-derived HTL biocrude via a two-stage hydrotreatment process and perform advanced chemical characterization of the feedstock, intermediate, and final upgraded products with gas chromatography-mass spectrometry (GC-MS) and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). We show that hydrotreatment significantly improves the quality of the oil, primarily succeeding in cracking the heavy molecules and removing the sulfur- and oxygen-containing components. FTICR-MS analysis shows that the HTL biocrude has a high concentration of fatty acid amides that readily lose their oxygen and nitrogen during hydrotreating and are converted into saturated hydrocarbons, whereas the aromatic OxNy compounds are converted into N1 and N2 classes, which are more resistant to hydrotreating. We also demonstrate that the upgraded HTL oil can be successfully blended with intermediate refinery streams, such as vacuum gas oil (VGO), for further co-processing to in-spec fuels in conventional processes. This provides an alternative route to introduce renewable carbon in existing fossil-based refineries.

11.
Artículo en Inglés | MEDLINE | ID: mdl-35886092

RESUMEN

BACKGROUND: In water polo, more physical and performance variables are related to a performance in a match. The aim of our work was therefore: (a) to evaluate the relationships between anthropometric characteristics and performance tests and performance in a match in young male water polo players; (b) to propose new guidelines for match analysis. METHODS: Multiple regression analysis was used to study the results in anthropometric evaluations (height, body mass, chest circumference, arm span, non-dominant arm length) and performance tests (push-up, chin-up, shuttle swim test, sprint swim 10 m, eggbeater kick, 100 m swimming) and two coaches' evaluations of two friendly matches using new guidelines. A total of 130 subjects (age: 15.6 ± 0.9 years) were involved in the study. RESULTS: In this study, we proposed a new performance model based on multiple regression analysis (r = 0.85, r2 = 0.73, adjusted r2 = 0.57) and described by the following equation: Coach's Evaluation = 151.6 + (-0.016 × height) + (0.6 × body mass) + (-0.82 × chest) + (-0.59 × arm span) + (0.75 × non dominant arm length) + (-0.037 × push up) + (0.17 × chin up) + (5.87 × shuttle swim test) + (-2.2 × 10 m sprint swim) + (0.05 × eggbeater kick) + (-0.35 × 100 m swimming). Inter-observer values were: CV: -3.9%, ICC: 0.82, ES: 0.1. Intra-observer: CV: -4.1%, ICC: 0.96, ES: 0.06. CONCLUSIONS: The relationships between anthropometric and performance variables and the match analysis have been statistically described. The equation found can be used to predict the overall performance of a player and permits evaluations of how much the improvement in one of the qualities can affect the players' overall performance. Moreover, the new method for match analysis we have proposed showed a good reliability and can be used for new studies on water polo.


Asunto(s)
Rendimiento Atlético , Deportes Acuáticos , Adolescente , Humanos , Masculino , Análisis de Regresión , Reproducibilidad de los Resultados , Natación
12.
Biosensors (Basel) ; 12(6)2022 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-35735511

RESUMEN

Wearables are valuable solutions for monitoring a variety of physiological parameters. Their application in cardiorespiratory monitoring may significantly impact global health problems and the economic burden related to cardiovascular and respiratory diseases. Here, we describe a soft biosensor capable of monitoring heart (HR) and respiratory (RR) rates simultaneously. We show that a skin-interfaced biosensor based on fiber optics (i.e., the smart patch) is capable of estimating HR and RR by detecting local ribcage strain caused by breathing and heart beating. The system addresses some of the main technical challenges that limit the wide-scale use of wearables, such as the simultaneous monitoring of HR and RR via single sensing modalities, their limited skin compliance, and low sensitivity. We demonstrate that the smart patch estimates HR and RR with high fidelity under different respiratory conditions and common daily body positions. We highlight the system potentiality of real-time cardiorespiratory monitoring in a broad range of home settings.


Asunto(s)
Tecnología de Fibra Óptica , Frecuencia Respiratoria , Frecuencia Cardíaca/fisiología , Humanos , Monitoreo Fisiológico , Respiración , Frecuencia Respiratoria/fisiología
13.
J Clin Med ; 11(10)2022 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-35628977

RESUMEN

Metastatic lesions compromise the mechanical integrity of vertebrae, increasing the fracture risk. Screw fixation is usually performed to guarantee spinal stability and prevent dramatic fracture events. Accordingly, predicting the overall mechanical response in such conditions is critical to planning and optimizing surgical treatment. This work proposes an image-based finite element computational approach describing the mechanical behavior of a patient-specific instrumented metastatic vertebra by assessing the effect of lesion size, location, type, and shape on the fracture load and fracture patterns under physiological loading conditions. A specific constitutive model for metastasis is integrated to account for the effect of the diseased tissue on the bone material properties. Computational results demonstrate that size, location, and type of metastasis significantly affect the overall vertebral mechanical response and suggest a better way to account for these parameters in estimating the fracture risk. Combining multiple osteolytic lesions to account for the irregular shape of the overall metastatic tissue does not significantly affect the vertebra fracture load. In addition, the combination of loading mode and metastasis type is shown for the first time as a critical modeling parameter in determining fracture risk. The proposed computational approach moves toward defining a clinically integrated tool to improve the management of metastatic vertebrae and quantitatively evaluate fracture risk.

14.
Eur J Vasc Endovasc Surg ; 63(4): 567-577, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35283000

RESUMEN

OBJECTIVE: Increased aortic stiffness (AoS) has been recognised as a risk factor in the development of cardiovascular disease. The aim of this systematic review and meta-analysis was to assess the impact of aortic repair on AoS. DATA SOURCES: PubMed, Scopus, and Web of Science were searched systematically for relevant studies evaluating the consequences of endovascular and open aortic repair on AoS. REVIEW METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) statement was followed to perform the research process. Papers containing data on AoS before and after both thoracic (TEVAR) and abdominal (EVAR) endovascular repair, as well as open surgical repair (OSR), were included for detailed evaluation. A fixed effects model was used to perform analysis. The Newcastle-Ottawa Scale was calculated for each included study. RESULTS: The first article cluster comprised 367 papers. After removal of duplicates and the adoption of inclusion/exclusion criteria, 14 articles remained, 13 of which were selected for meta-analysis. Ten studies analysed EVAR and three analysed TEVAR. Five of the selected papers were case control studies, with OSR adopted in four of these as the EVAR comparator. Several graft types were used in the endovascular group. AoS increased after TEVAR and EVAR, in terms of pulse wave velocity (PWV), even though several spatial levels and measurement modalities were adopted. No differences were described after OSR, although no pooled data could be analysed. CONCLUSION: EVAR and TEVAR both demonstrated a significant increase in AoS measurement (PWV). Although the heterogeneity and the low number of available studies limit the strength of the results, this review highlights the potential deleterious endograft role in the cardiovascular system although further studies are needed to achieve robust evidence. Further studies are needed to improve the mutual interaction between aorta and endograft, minimising their impact on the native aortic wall properties.


Asunto(s)
Aneurisma de la Aorta Abdominal , Implantación de Prótesis Vascular , Procedimientos Endovasculares , Rigidez Vascular , Aorta/cirugía , Aneurisma de la Aorta Abdominal/cirugía , Implantación de Prótesis Vascular/efectos adversos , Procedimientos Endovasculares/efectos adversos , Procedimientos Endovasculares/métodos , Humanos , Análisis de la Onda del Pulso , Factores de Riesgo , Resultado del Tratamiento
15.
J Sports Med Phys Fitness ; 62(4): 485-491, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33871237

RESUMEN

BACKGROUND: We intended to verify through time-motion analysis the characteristics of the sequences of actions in terms of occurrence during water polo matches: number, duration, and possible relationships with technical-tactical aspects. METHODS: Water polo matches played at the 18th FINA World Championships 2019, Gwangju, South Korea, were chosen for examination, and the analysis involved both single actions and Trains of Actions (ToAs). A ToA is a sequence of actions that occurs during the match without actual game interruption. RESULTS: A total of 1261 game actions were evaluated in the 17 matches analyzed. In 89% of cases the actions occurred in ToAs while in 11% of cases they took place as single actions. On average, each match included 74.4±5.3 actions; of these, only 7.9±3.4 (CI at 95%: lower bound 6.1 and upper bound 9.6) were single actions while 66.2±5.5 occurred in sequences (ToA2=29.6±9.0%; ToA3=26.1±9.7%; ToA4=16.5±10.6%). The winning team performed on average more actions than the losing one (42.1±6.1 vs. 32.0±6.4; effect size: 1.67; P value: 0.001). The ToAs had different compositions, from 2 to 18 actions, and then very different durations, from about 1 minute up to 8 minutes. 66% of goals were scored after ToAs and 34% after single actions. CONCLUSIONS: The study of ToAs provides useful information on the physiological demand of the game, which may help to plan and organize physical training making it as specific as possible. The description of ToAs can help coaches to better define the game scenario and understand which technical and tactical measures are needed to improve game organization.


Asunto(s)
Rendimiento Atlético , Deportes Acuáticos , Rendimiento Atlético/fisiología , Ejercicio Físico , Humanos , Masculino , República de Corea
16.
Ther Adv Urol ; 13: 17562872211058243, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34868350

RESUMEN

OBJECTIVES: To evaluate the role of preoperative abdominal straining in predicting de novo overactive bladder (OAB) and voiding dysfunction in female patients undergoing suburethral taping by trans-obturator approach (TVT-O) for uncomplicated stress urinary incontinence (SUI). METHODS: Data from patients who underwent TVT-O surgery for SUI were retrospectively analyzed. Inclusion criteria included: history of pure SUI. Exclusion criteria included previous surgery for urinary incontinence, pelvic radiation, pelvic surgery within the last 3 months, and anterior or apical pelvic organ prolapse (POP) ⩾ +1 cm. Voiding dysfunction has been defined through symptoms and or urodynamics (UDS) signs. Accordingly, patients were divided into group A and group B according to the presence of abdominal straining during UDS. Patients were observed clinically and with UDS at a 3-year follow-up. RESULTS: A total of 192 patients underwent TVT-O surgery for uncomplicated SUI. Preoperative abdominal straining was identified in 60/192 patients (Group A: 31.2% vs Group B: 68.8%). Qmax was not different in the two groups (Group A: 19.5 vs Group B: 20.5 mL/s, p = 0.76). Demographics was similar for the two groups regarding age, parity. At 3-year follow-up, voiding dysfunction was reported in Group A: 9 and Group B: 8 patients (p = 0.056), de novo OAB was significantly reported in Group A: 23 and Group B: 26 patients (p = 0.007). CONCLUSION: Preoperative abdominal straining was found to be related to a significant incidence of de novo OAB. A significant correlation was not assessed for postoperative voiding dysfunction. Further studies may better define the impact of preoperative abdominal straining.

17.
Nat Clim Chang ; 11(11): 973-981, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34745348

RESUMEN

Projections of climate change impacts on marine ecosystems have revealed long-term declines in global marine animal biomass and unevenly distributed impacts on fisheries. Here we apply an enhanced suite of global marine ecosystem models from the Fisheries and Marine Ecosystem Model Intercomparison Project (Fish-MIP), forced by new-generation Earth system model outputs from Phase 6 of the Coupled Model Intercomparison Project (CMIP6), to provide insights into how projected climate change will affect future ocean ecosystems. Compared with the previous generation CMIP5-forced Fish-MIP ensemble, the new ensemble ecosystem simulations show a greater decline in mean global ocean animal biomass under both strong-mitigation and high-emissions scenarios due to elevated warming, despite greater uncertainty in net primary production in the high-emissions scenario. Regional shifts in the direction of biomass changes highlight the continued and urgent need to reduce uncertainty in the projected responses of marine ecosystems to climate change to help support adaptation planning.

18.
Sci Adv ; 7(41): eabd7554, 2021 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-34623923

RESUMEN

The biomass and biogeochemical roles of fish in the ocean are ecologically important but poorly known. Here, we use a data-constrained marine ecosystem model to provide a first-order estimate of the historical reduction of fish biomass due to fishing and the associated change in biogeochemical cycling rates. The pre-exploitation global biomass of exploited fish (10 g to 100 kg) was 3.3 ± 0.5 Gt, cycling roughly 2% of global primary production (9.4 ± 1.6 Gt year−1) and producing 10% of surface biological export. Particulate organic matter produced by exploited fish drove roughly 10% of the oxygen consumption and biological carbon storage at depth. By the 1990s, biomass and cycling rates had been reduced by nearly half, suggesting that the biogeochemical impact of fisheries has been comparable to that of anthropogenic climate change. Our results highlight the importance of developing a better mechanistic understanding of how fish alter ocean biogeochemistry.

19.
Mar Pollut Bull ; 170: 112669, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34218030

RESUMEN

Time series were compiled of terrestrial nitrogen, phosphorus, carbon, iron, and silica fluxes to the Southern California Bight (SCB), a U.S. West Coast embayment (Sutula et al., 2021). Monitoring data and model output were used to construct a baseline of inputs from direct point source (PS) discharges of wastewater treatment (WWT) effluent (via ocean outfalls) and PS, non-point and natural sources from coastal rivers. The baseline covers 1971-2017 for large WWT plants discharging >50 million gallons per day (MGD) and 1997-2017 for small WWT plants and rivers. PS are the dominant nitrogen source, with contributions of 70% of the total annual freshwater discharge and 95% of nitrogen loads. WWT upgrades have reduced organic nitrogen loads by 73% since 1971. Inorganic nitrogen loads have generally held constant (35-40 Gg y-1) for the large WWT plants. This baseline represents a period prior to extensive wastewater and stormwater recycling that is increasing in the region.


Asunto(s)
Nitrógeno , Ríos , Carbono/análisis , Monitoreo del Ambiente , Nitrógeno/análisis , Fósforo/análisis , Aguas Residuales
20.
Proc Natl Acad Sci U S A ; 118(21)2021 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-34001604

RESUMEN

Global change is leading to warming, acidification, and oxygen loss in the ocean. In the Southern California Bight, an eastern boundary upwelling system, these stressors are exacerbated by the localized discharge of anthropogenically enhanced nutrients from a coastal population of 23 million people. Here, we use simulations with a high-resolution, physical-biogeochemical model to quantify the link between terrestrial and atmospheric nutrients, organic matter, and carbon inputs and biogeochemical change in the coastal waters of the Southern California Bight. The model is forced by large-scale climatic drivers and a reconstruction of local inputs via rivers, wastewater outfalls, and atmospheric deposition; it captures the fine scales of ocean circulation along the shelf; and it is validated against a large collection of physical and biogeochemical observations. Local land-based and atmospheric inputs, enhanced by anthropogenic sources, drive a 79% increase in phytoplankton biomass, a 23% increase in primary production, and a nearly 44% increase in subsurface respiration rates along the coast in summer, reshaping the biogeochemistry of the Southern California Bight. Seasonal reductions in subsurface oxygen, pH, and aragonite saturation state, by up to 50 mmol m-3, 0.09, and 0.47, respectively, rival or exceed the global open-ocean oxygen loss and acidification since the preindustrial period. The biological effects of these changes on local fisheries, proliferation of harmful algal blooms, water clarity, and submerged aquatic vegetation have yet to be fully explored.


Asunto(s)
Carbono/metabolismo , Ecosistema , Eutrofización , Fitoplancton/fisiología , Explotaciones Pesqueras , Humanos , Océanos y Mares , Oxígeno/metabolismo , Agua de Mar/química
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