Zhuyin Tong, Jiayu Guo, Yikai Liu, Lizhen Lin, Jixin Chen, Xin Liu, Bangqin Huang, Edward A. Laws, Wupeng Xiao
{"title":"Novel sequential modeling framework improves phytoplankton biomass predictions in response to multiple environmental stressors","authors":"Zhuyin Tong, Jiayu Guo, Yikai Liu, Lizhen Lin, Jixin Chen, Xin Liu, Bangqin Huang, Edward A. Laws, Wupeng Xiao","doi":"10.1002/lol2.70031","DOIUrl":"10.1002/lol2.70031","url":null,"abstract":"<p>Understanding the impacts of multiple environmental stressors on phytoplankton biomass is crucial for predicting marine ecosystem responses under global climate change. This study employed a sequential modeling framework integrating principal component analysis, generalized additive models, and artificial neural networks to improve predictions of phytoplankton chlorophyll <i>a</i> concentrations in the Taiwan Strait. Analyzing a decadal dataset, we found that a 2°C rise in sea surface temperature and a 0.2 pH decline will each lead to an 11.3% reduction in chlorophyll <i>a</i> biomass, whereas nitrogen enrichment is expected to increase it by only 2.8%. The combined effects of these stressors will result in an 18.3% reduction, with the most significant declines occurring in high-chlorophyll areas during algal blooms. Compared to simpler models, our approach improved accuracy by reducing overestimation biases, particularly under acidification scenarios, highlighting the need for advanced, multivariate models in forecasting phytoplankton dynamics under global changes.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"10 4","pages":"587-596"},"PeriodicalIF":5.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.70031","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Caleb J. Robbins, William J. Matthaeus, Rebecca A. Eckert, Elliot Bastias, Allyn K. Dodd, Jérémy Jabiol, David W. P. Manning, Andrew S. Mehring, Ada Pastor
{"title":"Revisiting k: Time-varying stream litter breakdown rates","authors":"Caleb J. Robbins, William J. Matthaeus, Rebecca A. Eckert, Elliot Bastias, Allyn K. Dodd, Jérémy Jabiol, David W. P. Manning, Andrew S. Mehring, Ada Pastor","doi":"10.1002/lol2.70029","DOIUrl":"10.1002/lol2.70029","url":null,"abstract":"<p>Litter decomposition is usually modeled with the negative exponential model, which assumes constant proportional mass loss. We assessed this assumption and its interpretive consequences using 145 stream litter mass loss time series and process-based simulations. Relatively simple (two to three parameters) models allowing time-varying decay rates produced more accurate predictions and were generally more parsimonious. Decomposition trajectories strongly deviated from constant decay for at least 50% of the time series, with the shape influenced by the degree of decomposition covered by a time series. Finally, simulations and empirical evidence suggested that the degree of decomposition covered can interact with time-varying decay rates and leachability to bias estimates of breakdown rates (<i>k</i>) from negative exponential models, obfuscating comparisons within and across studies. Considering alternative models could accelerate understanding and prediction of litter decomposition dynamics by enabling investigation of time-explicit decomposition dynamics and more precise modeling when warranted.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"10 4","pages":"576-586"},"PeriodicalIF":5.0,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.70029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144133625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Leonie Esters, Jan Kleint, Torben Gentz, Anna Rutgersson, Marcus B. Wallin, Hiroki Iwata, Antonin Verlet-Banide, Erik Sahlée
{"title":"Confirming existing parameterizations for methane gas transfer velocity in lakes based on direct and high-frequent methods","authors":"Leonie Esters, Jan Kleint, Torben Gentz, Anna Rutgersson, Marcus B. Wallin, Hiroki Iwata, Antonin Verlet-Banide, Erik Sahlée","doi":"10.1002/lol2.70028","DOIUrl":"10.1002/lol2.70028","url":null,"abstract":"<p>Freshwater systems are important sources of atmospheric methane (CH<sub>4</sub>). However, estimated emissions are associated with high uncertainties due to limited knowledge about the temporal variability in emissions and their associated controls, such as air–water gas transfer velocity. Here, we determined the gas transfer velocity of CH<sub>4</sub> based on a novel measurement setup that combines simultaneous eddy covariance flux measurements with continuously monitored CH<sub>4</sub> water- and air-side concentrations. Measurements were conducted during a 10-d campaign in a freshwater lake in mid-Sweden. The gas transfer velocity fell within the range of existing wind-speed-based parameterizations derived for carbon dioxide in other lakes. For wind speeds below 4 m s<sup>−1</sup>, the gas transfer velocity for CH<sub>4</sub> followed parameterizations predicting faster gas exchange, while for wind speeds above 5 m s<sup>−1</sup>, it aligned with those predicting relatively lower gas exchange. This pattern can be explained by ebullition. Extending the wind speed range for such combined eddy covariance measurements with continuously monitored CH<sub>4</sub> water- and air-side concentrations would improve model reliability.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"10 4","pages":"566-575"},"PeriodicalIF":5.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.70028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Samuel B. Fey, Emma E. Campbell, Hannah E. Kuder, Danny Gibson, Asher K. Smith, Hannah S. Meier, Tamara J. Layden, Angela L. Strecker
{"title":"Resolving the environmental factors that determine pond thermal refuge quality","authors":"Samuel B. Fey, Emma E. Campbell, Hannah E. Kuder, Danny Gibson, Asher K. Smith, Hannah S. Meier, Tamara J. Layden, Angela L. Strecker","doi":"10.1002/lol2.70032","DOIUrl":"10.1002/lol2.70032","url":null,"abstract":"<p>Cold thermal refuges may mitigate detrimental effects of future climate warming; yet, pond ecosystems have been largely omitted from thermal refuge research despite being globally numerous and providing critical ecosystem services. We create a formal definition for pond thermal refuge quality, then operationalize this definition by measuring the thermal characteristics and environmental attributes of ponds near Mount St. Helens (Washington, USA) to determine the environmental features that promote or hinder pond thermal refuges. Our results reveal substantial variation in thermal refuge quality between ponds and indicate that within-pond thermal refuges are a distinct metric from pond surface temperature. Denser floating surface vegetation promoted thermal refuges during summer conditions, while floating surface vegetation, water clarity, and canopy cover were associated with reduced mean pond temperatures during summer and heatwave conditions. These findings help identify ponds with high conservation value and suggest actionable steps for heightening the quality of pond thermal refuges.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"10 5","pages":"702-711"},"PeriodicalIF":5.0,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aslopubs.onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.70032","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144097308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Vulnerability to ocean acidification of marine calcifying organisms cannot be predicted from the mineral type in their shells","authors":"Gerald Langer, Patrizia Ziveri","doi":"10.1002/lol2.70020","DOIUrl":"10.1002/lol2.70020","url":null,"abstract":"<p>This essay challenges the assumption that the vulnerability of marine calcifiers to ocean acidification (OA) can be inferred from the calcium carbonate polymorph (two different polymorphs of a crystal have the same chemical composition but a different crystal structure) in their shells. Anthropogenic carbon dioxide (CO<sub>2</sub>) emissions have led to both an increase in atmosphere/surface ocean carbon dioxide concentrations and a decrease in ocean pH, a phenomenon termed OA (Caldeira and Wickett <span>2005</span>; Doney et al. <span>2009</span>). The alteration of calcium carbonate (CaCO<sub>3</sub>) chemistry of seawater (also termed carbonate chemistry, carbonate system, carbon system, and C-system) includes associated parameters, for example, the saturation state of seawater (omega) with respect to CaCO<sub>3</sub> minerals such as aragonite and calcite, commonly referred to as omega aragonite and omega calcite, respectively (Zeebe and Wolf-Gladrow <span>2001</span>). Aragonite is a metastable polymorph of CaCO<sub>3</sub> and is more soluble than calcite (Morse et al. <span>1980</span>). At ALOHA station Hawaii, omega aragonite decreased from 3.7 in 1990 to 3.6 in 2007, and omega calcite decreased from 5.8 in 1990 to 5.6 in 2007 (Doney et al. <span>2009</span>). In 1973, omega aragonite was 4.25, and omega calcite 6.4 (Doney et al. <span>2009</span>). Omega values above 1 indicate supersaturation (no dissolution of the respective mineral), and values below 1 indicate undersaturation (dissolution of the respective mineral, Zeebe and Wolf-Gladrow <span>2001</span>). In the Southern Ocean, surface waters might permanently experience omega aragonite values below 1, that is, become corrosive for aragonite, by the year 2100, with winter-time undersaturation reached as early as 2030 (Orr et al. <span>2005</span>; McNeil and Matear <span>2008</span>).</p><p>The large majority of CaCO<sub>3</sub> production in the modern ocean is regulated by calcite and aragonite formation by calcifying organisms (calcifiers) (Morse and Mackenzie <span>1990</span>). Many marine shell forming organisms indeed use either aragonite or calcite (or both) in their biominerals (Lowenstam <span>1981</span>). These shells might dissolve in undersaturated waters with detrimental consequences for the organism. Note that in supersaturated bulk seawater significant dissolution of biogenic calcium carbonate does occur, showing that undersaturated microenvironments must exist (Ziveri et al. <span>2023</span>; Sulpis et al. <span>2021</span>; Dean et al. <span>2024</span>; Kwon et al. <span>2024</span>). Dissolution of shells in these microenvironments might impact both calcifiers and grazers.</p><p>Aragonite dissolution can create conditions that slow down or even stop calcite dissolution in marine sediments (Sulpis et al. <span>2022</span>; van de Mortel et al. <span>2024</span>). This observation, however, does not suffice to assess the vulnerability of aragonitic compared ","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"10 4","pages":"448-452"},"PeriodicalIF":5.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.70020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143940630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shohei Watanabe, Erin P. Overholt, S. Geoffrey Schladow, Warwick F. Vincent, Craig E. Williamson
{"title":"Climate change and underwater light: Large-scale changes in ultraviolet radiation transparency associated with intensifying wet–dry cycles","authors":"Shohei Watanabe, Erin P. Overholt, S. Geoffrey Schladow, Warwick F. Vincent, Craig E. Williamson","doi":"10.1002/lol2.70021","DOIUrl":"10.1002/lol2.70021","url":null,"abstract":"<p>Ultraviolet radiation (UV) is the most energetic waveband of incident solar radiation and has wide-ranging effects in the aquatic environment. Our analysis of an 18-year record of underwater irradiance and related limnological variables in sub-alpine, ultra-oligotrophic Lake Tahoe revealed orders of magnitude changes in UV transparency associated with interannual climate perturbations. The large-scale shifts between years were caused by pronounced changes in the loading of allochthonous particulate matter and colored dissolved organic matter associated with regional dry–wet cycles, while autochthonous factors explained the seasonal variations in UV under average weather conditions. Water clarity in the photosynthetically available radiation (PAR) waveband showed less variation, resulting in large interannual differences in the UV : PAR ratio. Clearwater lakes are likely to experience increasingly large fluctuations in underwater UV and spectral irradiance due to ongoing climate change and precipitation extremes, with potential impacts on their ecosystem structure and function.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"10 4","pages":"485-494"},"PeriodicalIF":5.0,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.70021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143932427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elisa Calvo-Martin, Xosé Antón Álvarez-Salgado, María José Pazó Fernández, Vanesa Vieitez Dos Santos, J. Severino P. Ibánhez
{"title":"Drivers of dissolved organic matter processing in subterranean estuaries","authors":"Elisa Calvo-Martin, Xosé Antón Álvarez-Salgado, María José Pazó Fernández, Vanesa Vieitez Dos Santos, J. Severino P. Ibánhez","doi":"10.1002/lol2.70026","DOIUrl":"10.1002/lol2.70026","url":null,"abstract":"<p>Subterranean estuaries (i.e., seawater-fresh groundwater mixing zones at coastal aquifers) are highly reactive boundaries between continental groundwater and coastal surface seawater. Because particulate organic matter is retained in shallow sediments, internal microbial transformations rely on dissolved organic matter (DOM) supply and bioavailability. Here, we investigated DOM carbon content and optical characteristics in two nearby subterranean estuaries with contrasting oxygenation. Coastal organic carbon processing in the anoxic subterranean estuary resulted in the export of DOM enriched in recalcitrant compounds compared to the oxygenated one, which was a net sink of DOM. This contrasting behavior was not driven by opposite redox conditions but from the fast transfer of labile DOM and oxygen to the beach interior of the oxygenated subterranean estuary. There, heterotrophic processes, which rely almost exclusively on DOM, are enhanced, resulting in net DOM consumption prior discharge to surface waters.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"10 4","pages":"536-546"},"PeriodicalIF":5.0,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.70026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143920409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiwoon Park, Katherine R. Heal, Anitra E. Ingalls, Ryan D. Groussman, Zinka Bartolek, E. Virginia Armbrust, Randelle M. Bundy
{"title":"Efficient cobalamin uptake and cycling contribute to the lack of cobalamins in the surface cobalt-binding ligand pool in the North Pacific","authors":"Jiwoon Park, Katherine R. Heal, Anitra E. Ingalls, Ryan D. Groussman, Zinka Bartolek, E. Virginia Armbrust, Randelle M. Bundy","doi":"10.1002/lol2.70019","DOIUrl":"10.1002/lol2.70019","url":null,"abstract":"<p>Cobalt is a central component of cobalamins, which are nutrients essential for various metabolic processes in marine organisms. Dissolved cobalt in seawater is mostly bound to organic ligands, and the prevailing assumption to date is that these ligands are cobalamin-related compounds, yet the identity and impact of these ligands on cobalt bioavailability remain unknown. In this study, we examined cobalt ligand distributions and cobalamin cycling in surface waters across a North Pacific meridional transect. While we did not detect cobalamin derivatives in the dissolved cobalt ligand pool, the detection of transcripts associated with cobalamin synthesis and salvage pathways suggests that cobalamins may not be accumulating in seawater as cobalt-binding ligands and thus represent only a small fraction of the cobalt ligand pool in the North Pacific.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"10 4","pages":"547-556"},"PeriodicalIF":5.0,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.70019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143915593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Correction to “Greenhouse gas emissions from lakes and impoundments: Upscaling in the face of global change”","authors":"","doi":"10.1002/lol2.70022","DOIUrl":"10.1002/lol2.70022","url":null,"abstract":"<p>DelSontro, T., J. J. Beaulieu, and J. A. Downing. 2018. “Greenhouse Gas Emissions from Lakes and Impoundments: Upscaling in the Face of Global Change.” <i>Limnology and Oceanography Letters</i> 3: 64–75. https://doi.org/10.1002/lol2.10073.</p><p>In the abstract of this article, “CO<sub>2</sub>-equivalents” should have been stated as “C-CO<sub>2</sub>-equivalents.”</p><p>We apologize for this error.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"10 4","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.70022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143901581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The deep ocean as a major sink for terrestrial organic carbon","authors":"Hyekyung Park, Guebuem Kim","doi":"10.1002/lol2.70023","DOIUrl":"10.1002/lol2.70023","url":null,"abstract":"<p>Rivers transport ~200 Tg of particulate organic carbon (POC) to the global ocean annually, of which 30% is known to be buried in continental-shelf sediments. The fate of the remaining “missing” terrestrial POC (POC<sub>terr</sub>) remains uncertain, with proposed explanations including rapid remineralization or transport to the remote deep ocean. Here, based on δ<sup>13</sup>C and <sup>234</sup>Th tracers, we show that the vertical fluxes of POC<sub>terr</sub> to the deep sea (~2.7 Tg C yr<sup>−1</sup>) account for the “missing” portion in the northwestern Pacific marginal seas. The East China Sea and East/Japan Sea are ideal for testing this hypothesis, given substantial POC<sub>terr</sub> inputs and extensive shelf areas connected to a semi-enclosed deep sea. We found that sediment resuspension and the refractory nature of POC<sub>terr</sub> facilitate its effective transport to the deep sea, which serves as its major sink. These findings provide crucial insights into the fate of POC<sub>terr</sub> in the global ocean.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"10 4","pages":"557-565"},"PeriodicalIF":5.0,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.70023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143901582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}