Limnology and Oceanography最新文献

{"title":"Vertical structures of marine heatwaves and their impacts on primary production in the South China Sea","authors":"Jingjing Zheng, Peng Xiu, Lili Zeng, Guimei Liu, Xueming Zhu, Shan Gao, Xuanliang Ji, Zhijie Li","doi":"10.1002/lno.70511","DOIUrl":"https://doi.org/10.1002/lno.70511","url":null,"abstract":"Marine heatwaves (MHWs) are extreme warm‐water events that can strongly perturb marine ecosystems. Although MHWs are known to extend into subsurface and deep waters, their vertical structures and biogeochemical consequences remain poorly quantified. Here, we use a physical‐biogeochemical model to characterize the vertical structures of MHWs in the South China Sea (SCS) and to assess their impacts on primary production (PP). Four distinct types of vertical structure of MHWs (shallow, sub‐reversed, sub‐intensified and deep MHWs) are identified. Deep MHWs are the most common, accounting for nearly 50% of events. Shallow and sub‐reversed MHWs are generally short‐lived and confined to the upper ocean, whereas sub‐intensified and deep MHWs persist longer and penetrate deeper. Heat budget analysis indicates that air–sea heat flux primarily drives the formation of shallow, sub‐reversed, and deep MHWs, while vertical processes dominate the maintenance of sub‐intensified MHWs. Distinct MHW structures modify vertical stratification and nutrient transport, producing spatially and vertically heterogeneous PP responses across the mixed layer and the euphotic zone. Over the past two decades, the occurrence area, duration, and total intensity of all four MHW types increased significantly, and associated PP anomalies exhibited a declining trend. This decline is largely attributable to strengthened mixed‐layer stratification and reduced mixed‐layer PP, with subsurface processes contributing little to the long‐term trend.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"35 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Community metabolism generates chemical legacies that alter coral physiology","authors":"Laurel C. Diaz, Keanu Rochette‐Yu Tsuen, Kiran Reed, Craig E. Nelson, Nyssa J. Silbiger","doi":"10.1002/lno.70513","DOIUrl":"https://doi.org/10.1002/lno.70513","url":null,"abstract":"Coral reefs are among the world's most diverse ecosystems and contribute substantially to ocean productivity and the carbon budget. Disturbances are shifting reefs to altered community states, yet how these new communities indirectly alter organismal physiology by modifying the local biogeochemical environment remains largely unknown. We investigated this biogeochemical feedback in a 25‐d mesocosm experiment in Mo'orea, French Polynesia. We exposed the common coral <jats:italic>Porites rus</jats:italic> to the biogeochemical environments generated by three distinct communities representative of recent benthic states in this system: coral‐, macroalgae‐, and crustose coralline algae‐enriched relative to a seawater‐only control. While net community production was similar among communities, net community calcification was lowest in the macroalgae‐enriched state. Across treatments, community metabolism drove changes in the organic and inorganic carbon pool, with net community production increasing both pH and dissolved organic carbon. Using structural equation modeling, we tested how these community‐generated chemical legacies propagated through coral physiology. Elevated pH increased chlorophyll <jats:italic>a</jats:italic> content, which increased endosymbiont density, tissue biomass, gross photosynthesis, and respiration through a series of indirect pathways. Dissolved organic carbon had no detectable effect on downstream corals at 25 d. These results reveal a mechanistic pathway linking disturbance‐driven shifts in benthic communities to coral performance. Altered community metabolism modifies local carbon chemistry, which reshapes symbiont physiology and ultimately influences host metabolic function. By identifying the pathways through which community states engineer their chemical environment, this study provides a framework for predicting coral performance and ecosystem trajectories as reefs transition away from coral‐enriched states.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"51 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elevated B‐vitamins within a temperate estuary: Strong spatiotemporal dynamics and links to microbial plankton communities","authors":"Meriel J. Bittner, Catherine C. Bannon, Elden Rowland, Gregor Luetzenburg, Erin M. Bertrand, Lasse Riemann, Ryan W. Paerl","doi":"10.1002/lno.70508","DOIUrl":"https://doi.org/10.1002/lno.70508","url":null,"abstract":"B‐vitamins are organic cofactors required by prokaryotic and eukaryotic planktonic cells; their availability impacts aquatic microbial communities and associated biogeochemistry. Despite their ecological importance, B‐vitamin dynamics and their relationships to plankton composition in estuaries are unclear, limiting our understanding of estuary biology in general as well as how B‐vitamins are distributed in marine systems. Here, we simultaneously quantified multiple B‐vitamins and their vitamers (vitamin related compounds, e.g., precursors for de novo synthesis) in particulate and dissolved phases. Alongside, we characterized the prokaryotic and eukaryotic microbial communities across freshwater to polyhaline zones of the Neuse River Estuary (NRE), North Carolina, USA from summer to fall. We found notable autochthonous B‐vitamin production in the estuary, and the mid‐estuary emerged as a zone of increased levels of B‐vitamins fueled by algal growth. B‐vitamin and vitamer concentrations were highly dynamic on short time scales (weeks) and we identified two specific dynamic modes. Moderate concentration changes likely driven by production/consumption and sporadic rapid concentration peaks presumably driven by shifts in plankton community composition. We identified vitamin B <jats:sub>1</jats:sub> , B <jats:sub>12</jats:sub> , psB <jats:sub>12</jats:sub> (pseudocobalamin), and B <jats:sub>3</jats:sub> as key explanatory variables for change in prokaryotic and eukaryotic NRE plankton, revealing B‐vitamins as important compounds for resolving variability of plankton communities in estuaries. Our study provides insights into the dynamic concentrations of B‐vitamins and vitamers across zones of estuaries and provides new evidence of B‐vitamin influence upon plankton community composition.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"226 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Depth-dependent metabolic stratification identifies the oxic deep chlorophyll maximum as a global biogeochemical hotspot","authors":"Satheeswaran Thangaraj,&nbsp;David A. Hutchins,&nbsp;Jun Sun","doi":"10.1002/lno.70501","DOIUrl":"10.1002/lno.70501","url":null,"abstract":"<p>The deep chlorophyll maximum (DCM) is an important feature of the marine photic zone where carbon fixation, nutrient transformations and particle-associated export can be enhanced, collectively influencing marine productivity, biogeochemical cycling and carbon sequestration. However, how microbial metabolism in this layer differs from that in the overlying surface layer (SL) remains poorly characterized. Using depth-resolved metagenomes from the Western Pacific Ocean, validated against global Tara Oceans datasets, we show that the DCM is strongly stratified metabolically even though its taxonomic composition differs only modestly from the SL, revealing a pronounced decoupling of function from taxonomy. Surface communities were enriched in light-driven carbon fixation pathways that consume 3–3.5 adenosine triphosphate (ATP) per CO₂ fixed, whereas DCM communities were enriched in pathways requiring only 1–2 ATP—the reductive tricarboxylic acid cycle and the dicarboxylate/4-hydroxybutyrate cycle—consistent with an energetic niche axis between light-rich surface and light-limited subsurface waters. Fully oxygenated DCM waters (~ 190 <i>μ</i>mol O₂ L⁻¹) contained gene inventories associated with nitrification, denitrification, and sulfur oxidation, together with methane metabolism–associated genes, potentials conventionally restricted to oxygen-minimum zones. These gene suites were consistently enriched at the DCM across all major ocean basins. Methane assimilation showed the same energetic pattern, with the ATP-expensive serine cycle dominating the SL and the lower-cost ribulose monophosphate route enriched in the DCM. Because warming intensifies stratification and is projected to deepen and sharpen DCM features, the metabolic organization of this layer is likely to become more, not less, important to upper-ocean biogeochemistry.</p>","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"71 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pyrosome fecal pellet production: Implications for grazing and carbon export","authors":"Grace F. Cawley,&nbsp;Stephanie A. Matthews,&nbsp;Natalia Llopis-Monferrer,&nbsp;Minerva Padilla Villa,&nbsp;Katherine Barbeau,&nbsp;Moira Décima","doi":"10.1002/lno.70506","DOIUrl":"10.1002/lno.70506","url":null,"abstract":"<p>This study quantifies the fecal pellet production and pellet sinking rates of the pyrosome <i>Pyrosoma atlanticum</i> in the Southern California Current across a range of conditions, from the productive nearshore to the oligotrophic offshore. Fecal pellet production rates averaged 1310 ± 76 pellets h⁻¹, resulting in the production of up to 390,380 pellets h⁻¹ m⁻² in locations with high densities of 298 ind. m⁻². Fecal pellet mean size was 354 ± 111 <i>μ</i>m, and sinking rates of fresh pellets averaged 47 ± 38 m d⁻¹, while aged pellets had lower rates averaging 31 ± 28 m d⁻¹. We estimate ingestion rates of 55.5 ± 9.5 mg C m⁻² d⁻¹ in the offshore and 41.1 ± 8.28 mg C m⁻² d⁻¹ in nearshore coastal waters. Based on pellet production rates, colony abundance, carbon content per pellet, and literature values of assimilation efficiencies, we estimate that pyrosomes consume the carbon equivalent of ~ 30% of net primary production in offshore waters and 1–26% in coastal waters. We present novel measurements of biogenic silica in pyrosome fecal pellets, indicating that pyrosomes can directly remove 0.5–4% of the euphotic zone-integrated diatom standing stock, with higher rates in nearshore environments. Direct observation of fecal pellets showed unassimilated diatom chains, confirming direct consumption. Our results suggest that pyrosomes contribute to both carbon and silica export, important processes to constrain for understanding biogeochemistry in the region.</p>","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"71 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lno.70506","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148979614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Dissolved organic carbon variance attribution shifts with prior environmental states and historical water-quality context along a eutrophication–marine exchange gradient","authors":"Yuquan Zhao,&nbsp;Shigeru Tabeta","doi":"10.1002/lno.70503","DOIUrl":"10.1002/lno.70503","url":null,"abstract":"<p>Reliable environmental attribution of coastal dissolved organic carbon (DOC) variability is important for interpreting carbon processing and fate under climate change. Yet attribution commonly relies on contemporaneous relationships or a single lag structure, leaving uncertain whether variable rankings remain robust across different spans of prior system history. We analyzed quarterly observations (total nitrogen, total phosphorus, chlorophyll <i>a</i>, pheophytin, water temperature, pH, dissolved oxygen, salinity, and water clarity) from 1981 to 2021 across Tokyo Bay. Regional vector autoregressive models and forecast-error variance decomposition quantified DOC forecast uncertainty attributed to DOC itself and the measured variables. We compared a one-quarter model using the preceding state with a four-quarter model using the previous four states; the one-quarter model was also fitted to 1981–2001 and 2002–2021. Attribution shifted from nutrient–phytoplankton prominence in the north to more distributed thermal, hydrographic, optical, and algal-degradation contributions southward. Including four rather than one prior quarter increased the environmental share by 15.6–24.3 percentage points, while chlorophyll a attribution rose from 6.4% to 17.5% in the north. Historical patterns diverged: the environmental share decreased by 35.3 percentage points in the north but increased by 4.6 and 9.4 points in the central and southern bays, respectively. These model-based allocations do not establish causal control but show that attribution depends on the span of prior system history represented and varies across regions and historical contexts. The findings provide a foundation for evaluating the temporal robustness of environmental attribution and guiding process-based observations in changing coastal systems.</p>","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"71 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lno.70503","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148979616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 length of winter influences the dissolved oxygen dynamics in a large ice-covered dimictic lake","authors":"Lidi Shi,&nbsp;Mathew Wells,&nbsp;Joelle Young","doi":"10.1002/lno.70505","DOIUrl":"10.1002/lno.70505","url":null,"abstract":"<p>In dimictic lakes, under-ice dissolved oxygen (DO) is shaped by stratification and mixing, oxygen consumption, and late-winter algal production, which can increase upper-water DO as light availability rises. Despite growing interest in these dynamics, late-winter DO remains poorly documented due to inherent dangers of sampling on thin ice. To address this, we analyzed 6 yr of high-frequency temperature and DO data from Lake Simcoe (2015–2017 and 2022–2024), a large dimictic lake in Ontario, Canada. Our observations indicate that under-ice DO at the lake bottom decreased in early winter due to hypolimnetic oxygen demand. However, the DO increased in the upper-water column, leading to near-surface supersaturation in the winters with longer snow-free ice cover. The net result is that after ice-off, the depth-averaged DO levels were usually higher than at the start of winter, and thus set the initial DO for spring, with volumetrically averaged DO ranging from 12.6 to 14.5 mg L⁻¹ over the 6 yr. After the onset of summer stratification, hypolimnetic oxygen demand reduced bottom DO in late summer to 4.0–5.1 mg L⁻¹. As the hypolimnetic summer oxygen demands were similar for 6 yr, the years with higher initial spring DO levels and a shorter stratification period had higher DO at the end of summer stratification. These findings highlight the important but understudied role of late winter DO dynamics in shaping seasonal oxygen budgets and underscore the need to monitor these processes due to the rapid shifts in ice quality and duration in many ice-covered dimictic lakes.</p>","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"71 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lno.70505","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148979615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Genomic adaptation of the water flea Daphnia to elevated temperatures: Insights from power plant-heated lakes","authors":"Shaolin Xu,&nbsp;Justyna Wolinska,&nbsp;Marcin Krzysztof Dziuba,&nbsp;Slawek Cerbin,&nbsp;Markus Möst,&nbsp;Luc De Meester","doi":"10.1002/lno.70498","DOIUrl":"10.1002/lno.70498","url":null,"abstract":"<p>Global warming increasingly threatens freshwater biodiversity, highlighting the need to understand how key ecological interactors, such as the zooplankton water flea <i>Daphnia</i>, genetically adapt to rising temperatures. Although local thermal adaptation has been documented in <i>Daphnia</i>, the underlying genomic changes remain poorly resolved. Here, we examined genomes of <i>Daphnia cucullata</i> (a member of the <i>D. longispina</i> complex) from five lakes artificially warmed for six decades by cooling water from power plants (increase of about 2–4°C), and from seven adjacent, control (i.e., unheated) lakes. Heated-lake and unheated-lake populations showed pronounced genomic divergence. Using a Hidden Markov Model framework, we identified highly differentiated genomic intervals (HDGIs) between the two groups, which were significantly enriched near 188 thermal-adaptation candidate genes, supporting a polygenic basis of thermal adaptation. Contrary to previous studies on the <i>D. longispina</i> complex that identified hybridization as a key driver of local adaptation, we found no evidence for adaptive introgression in the heated lakes, despite the presence of <i>D. cucullata</i> × <i>D. galeata</i> hybrids. Adaptive potential, measured as cumulative allelic richness across the set of differentiated loci overlapping or located near thermal adaptation candidate genes, was high across all populations. Strikingly, shifts of formerly rare alleles toward intermediate frequencies have led to a higher genetic diversity at adaptive loci in heated-lake than in unheated-lake populations. Our results identify specific loci associated with thermal adaptation in <i>D. cucullata</i>, demonstrate that adaptation has occurred independently of hybridization, and underscore the importance of standing genetic variation in local populations for adaptive evolution to warming.</p>","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"71 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lno.70498","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148979656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Zooplankton reliance on autochthonous and allochthonous resources across mountain lakes revealed through essential amino acid δ13C analysis","authors":"Christopher B. Wall,&nbsp;Alexi C. Besser,&nbsp;Celia C. Symons,&nbsp;Seth D. Newsome,&nbsp;Jonathan B. Shurin","doi":"10.1002/lno.70496","DOIUrl":"10.1002/lno.70496","url":null,"abstract":"<p>Terrestrial subsidies shape aquatic ecosystem structure and function, serving as important energy channels for consumers when phytoplankton and other autochthonous resources are limited. Despite this, quantifying the assimilation of allochthonous nutrients by aquatic consumers can be challenging. Here, we show terrestrial plants, benthic algae, and particulate organic matter have distinct essential amino acid (AA_ESS) carbon isotope (δ¹³C) fingerprints across eight freshwater habitats in California's eastern Sierra Nevada Mountains, which enabled us to quantify the relative contributions of autochthonous and allochthonous resources to zooplankton. We found in-water production accounted for the majority (70–98%) of AA_ESS assimilated by zooplankton, with low but variable zooplankton allochthony (2–30%) across zooplankton taxa and habitats. Assimilation of terrestrial plant-derived AA_ESS differed among zooplankton groups, with the lowest assimilation in Calanoida (7%), intermediate assimilation in a pooled &gt; 350 <i>μ</i>m zooplankton fraction (10%) and Cladocera (17%), and highest in Neocopepoda (calanoids and cyclopoids; 24%). Zooplankton allochthony also positively correlated with elevation and negatively correlated with chlorophyll <i>a</i> concentrations, indicating geographic factors and primary production are strong predictors of terrestrial plant-derived AA_ESS use by lacustrine zooplankton in mountain lakes. These findings suggest there is interspecific variation in the mechanisms employed by zooplankton to access terrestrial carbon pools and illustrate an inverse relationship between primary production and allochthonous support of zooplankton. Our work exemplifies the power of AA_ESS δ¹³C fingerprinting in quantifying energy channel utilization in freshwater ecosystems and emphasizes the predominance of autochthonous nutrition to zooplankton in alpine and montane lakes.</p>","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"71 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lno.70496","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148979655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Model predicts coastal paralytic shellfish toxicity in mussels from in situ phytoplankton concentrations","authors":"Sylvain Gaillard,&nbsp;David K. Ralston,&nbsp;V. Monica Bricelj,&nbsp;Roman Marin III,&nbsp;Bruce Keafer,&nbsp;Dennis J. McGillicuddy Jr.,&nbsp;Donald M. Anderson","doi":"10.1002/lno.70502","DOIUrl":"10.1002/lno.70502","url":null,"abstract":"<p>Harmful algal blooms (HABs) of <i>Alexandrium catenella</i> occur annually in the Gulf of Maine, leading to accumulation of paralytic shellfish toxins (PSTs) in bivalve mollusks and closure of harvesting areas. State monitoring programs in the region rely on weekly shellfish sampling and toxin analysis, requiring extensive effort with limited temporal resolution. With the development of autonomous in situ detection devices such as the Environmental Sample Processor (ESP), this study aimed to model shellfish toxicity using ESP-derived <i>A</i>. <i>catenella</i> counts to complement traditional monitoring programs using mussels (<i>Mytilus edulis</i>). We developed a one-compartment model of PST accumulation using <i>A. catenella</i> concentrations from nearshore ESP deployments. Multi-year and multi-site data were used to test four approaches for estimating mussel toxin uptake and depuration parameters, that is, local, global, or fixed literature values. When compared with direct PST measurements in nearby shellfish, the models achieved high correlations (<i>R</i>² = 0.69–0.90), with no false negatives. Model fit varied mainly with toxin uptake parameters and was influenced by <i>Alexandrium</i> concentrations. The impact of other environmental and biological factors on uptake and depuration parameters remained elusive, likely due to the mussels' physiological plasticity, spatial or hydrographic separation between ESP and toxicity measurements, and microhabitat conditions. This ESP-based model offers a simple, effective tool for translating offshore, automated cell counts into daily shellfish toxicity estimates and is promising for improvement of monitoring capacity in remote or under-sampled areas. Incorporation of this approach into physical–biological models and application in early warning systems with other biosensors remain to be tested.</p>","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"71 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lno.70502","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148979657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}