Journal of Experimental Marine Biology and Ecology最新文献

{"title":"Properties of diurnal vertical migration by the harmful red-tide dinoflagellate Karenia selliformis in relation to salinity conditions","authors":"Tomoyuki Shikata ,&nbsp;Saho Kitatsuji ,&nbsp;Koki Yuasa","doi":"10.1016/j.jembe.2025.152145","DOIUrl":"10.1016/j.jembe.2025.152145","url":null,"abstract":"<div><div>Many harmful red-tide flagellates accumulate at a certain depth amid diurnal vertical migration (DVM). Here, to identify the DVM properties of <em>Karenia selliformis</em>, a dinoflagellate species that causes huge harmful red tides, we examined DVM under salinity gradients and growth after rapid salinity changes in the laboratory. Seawater with a salinity of 33 psu was placed as the bottom layer and water with one of three different salinities (17, 25, or 33 psu) was placed as the upper layer in a cylindrical aquarium, and time-course variations in the dinoflagellate's vertical distribution were monitored as well as cell morphology and photosynthetic parameters. We found that <em>K. selliformis</em> displayed DVM only when the upper layer salinity was 33 psu. The ascent period was longer and the descent was less synchronized than in other red-tide flagellates, indicating that this dinoflagellate has a strong surface accumulation habit. When the upper layer salinity was lower, <em>K. selliformis</em> accumulated at the halocline (18 psu) or surface (25 psu) throughout the day. Morphology and a photosynthetic parameter of cells accumulated at 18 psu were different and dividing cells were few in comparison with the other salinity conditions. Our growth experiment revealed that <em>K. selliformis</em> could not acclimatize to salinities below 15 psu, and cells that had acclimatized to ≥20 psu quickly acclimatized and grew even when transferred to 33 psu. These results suggest that <em>K. selliformis</em> can ascend to the lowest salinity layer where it can survive, but its ability to descend decreases.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"593 ","pages":"Article 152145"},"PeriodicalIF":1.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate-related sediment load has severe impacts on the early life-stages of commercially important high-latitude kelp species","authors":"Veronica Farrugia Drakard ,&nbsp;Jordan A. Hollarsmith ,&nbsp;Michael S. Stekoll","doi":"10.1016/j.jembe.2025.152128","DOIUrl":"10.1016/j.jembe.2025.152128","url":null,"abstract":"<div><div>Kelp are likely to experience significant impacts due to ongoing climate change. Changes in sediment load as a result of glacial melt will have a major influence on coastal systems over the coming decades. Bull kelp (<em>Nereocystis luetkeana</em>) and ribbon kelp (<em>Alaria marginata</em>) are both species of commercial and ecological importance. In this study, fertile specimens were collected from Juneau, Alaska. Spores produced were cultivated over 30 days in four sediment treatments: 0 g/L, 0.21 g/L, 0.42 g/L, and 0.84 g/L. Sediment was obtained from the Mendenhall Glacier watercourse in Juneau, Alaska, and was mostly between 63 μm and 2 mm grain size. Germination and growth of both species were lower in sediment treatments at and above 0.42 g/L, although <em>A. marginata</em> appeared to be resilient to low levels of sediment load. Sediment levels at 0.42 g/L and above negatively impacted germination in <em>A. marginata</em>, while germination in <em>N. luetkeana</em> was negatively impacted by all sediment-added treatments. In terms of gametophyte size, <em>A. marginata</em> gametophytes at 20 days were largest in the control, smaller in the 0.21 g/L and 0.42 g/L treatments, and smaller still in the 0.84 g/L treatment. <em>N. luetkeana</em> gametophytes at 20 days were larger in the control treatment than in other treatments. Gametophyte density in both species was negatively impacted by all sediment treatments. Sediment load from late fall through early spring, when kelp gametophytes are present on the benthos, may have severe implications for the persistence and survival of wild kelp populations in glaciated regions.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"592 ","pages":"Article 152128"},"PeriodicalIF":1.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144863859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increasing tidal inundation does not buffer heat stress effects: Implications for benthic ecosystem responses to climate change","authors":"Simon D. Thomas,&nbsp;Ines Bartl,&nbsp;Simon F. Thrush","doi":"10.1016/j.jembe.2025.152130","DOIUrl":"10.1016/j.jembe.2025.152130","url":null,"abstract":"<div><div>Intertidal soft sediments are on the frontline of climate change effects, subject to increasing atmospheric heatwave intensity alongside rising sea levels. Longer inundation periods can keep sediments more saturated with water, potentially providing a thermal buffer against atmospheric heatwaves and creating refugia for resident communities and the ecosystem functions they produce. To assess this effect, we set up a field experiment to simulate a heat stress event along a gradient of inundation time on an intertidal flat using open top heat chambers. We examined how heat stress and inundation interact to influence sediment temperature, and how this in turn affects CO₂ flux, a proxy for ecosystem metabolism, and its relationship to key ecological covariates. We found that in ambient conditions, maximum sediment temperature decreased with increasing inundation. However, under heat stress, this relationship reversed, with maximum sediment temperature increasing with inundation, suggesting that more saturated sediments conduct heat more efficiently and promote higher temperatures under prolonged heat stress. Despite this temperature anomaly, the effect of heat stress on ecosystem metabolism remained consistent across the inundation gradient, indicating that increasing inundation time does not provide refugia from heat stress, nor does the elevated temperature anomaly amplify metabolic responses. Resilience mechanisms such as functional redundancy and compensatory interactions in sediment communities may have buffered against temperature variability, therefore maintaining function under heat stress. Our findings highlight the complex interactions between heat stress and inundation and suggest that sea level rise will not provide straightforward thermal refugia for soft sediment ecosystem function.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"592 ","pages":"Article 152130"},"PeriodicalIF":1.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144902756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal response of respiration and thermal tolerance of PSII to sea surface temperature variation in two foundation seaweed species","authors":"Rosalie J. Harris ,&nbsp;Callum Bryant ,&nbsp;Pieter A. Arnold ,&nbsp;Andrew P. Scafaro ,&nbsp;Andrea Leigh ,&nbsp;Melinda A. Coleman ,&nbsp;Adrienne B. Nicotra","doi":"10.1016/j.jembe.2025.152129","DOIUrl":"10.1016/j.jembe.2025.152129","url":null,"abstract":"<div><div>Amidst escalating sea surface temperatures, comprehending how marine organisms acclimate to temperature fluctuations is paramount. This understanding is not only needed to anticipate the ecological ramifications of future climatic conditions, but also forms the cornerstone of our efforts to effectively restore and safeguard these invaluable marine habitats. The mechanisms of acclimation in seaweed physiology in response to seasonal shifts in temperature have not yet been sufficiently explored. Here, we examined the physiological responses of two foundational seaweeds, <em>Ecklonia radiata</em> and <em>Phyllospora comosa</em>, to seasonal sea surface temperature (SST) variation. Our approach combined a fluorophore O₂-sensor system to measure respiration and chlorophyll fluorescence to assess critical heat thresholds (<em>T</em>_crit) with PSII. By measuring <em>T</em>_crit and respiration across a full year, we explored the metabolic costs and some of the trade-offs in seaweed acclimation and examined whether a higher <em>T</em>_crit entails a greater respiratory carbon cost, or, whether respiration acclimates as SST increases, reducing metabolic expenses. Our findings reveal significant seasonal shifts in <em>T</em>_crit, for both species. For metabolic activity, <em>Phyllospora</em> exhibited temporally stable respiration, indicating homeostatic regulation, while <em>Ecklonia</em> demonstrated potential energy deficits during warmer months. These findings are likely linked to the species' habitat differences, with <em>Phyllospora</em> occupying variable and extreme intertidal environments, and <em>Ecklonia</em> residing in more stable subtidal habitats. The relationship between the predicted temperature at maximum respiration (<em>T</em>_max) and <em>T</em>_crit indicated a coupling between thermal stability of respiration and photosynthesis within seaweeds. Our approach has uncovered important connections between thermal tolerance and respiration, providing new insights into seaweed physiology which offer a foundation for future research and conservation strategies under global warming.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"592 ","pages":"Article 152129"},"PeriodicalIF":1.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144863860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature does not seem to affect nematocyst size in the upside-down jellyfish Cassiopea","authors":"Min Kang Ling ,&nbsp;Nicholas Wei Liang Yap ,&nbsp;Danwei Huang","doi":"10.1016/j.jembe.2025.152126","DOIUrl":"10.1016/j.jembe.2025.152126","url":null,"abstract":"<div><div>The effects of ocean warming on jellyfish blooms have garnered considerable attention, but few studies have investigated the effects of rising seawater temperatures on changes in jellyfish physiology, in particular nematocyst development. Our study examines the differences in the sizes (length, width, length/width ratio) and volumes of two types of nematocysts (a-isorhiza and medium-sized birhopaloids) in the polyps of a tropical coastal jellyfish (<em>Cassiopea</em> sp.) when grown at different temperatures (28 °C, 30 °C and 32 °C) over four weeks. Surprisingly, exposing <em>Cassiopea</em> polyps to higher temperatures did not significantly change the sizes and volumes of both a-isorhiza and birhopaloid nematocysts. Additionally, sizes and volumes of both types of nematocysts also did not exhibit any identifiable trends across time after exposure to their respective treatment temperatures. Interactions between temperature and time were recorded for both a-isorhiza and birhopaloid sizes, while interactions between temperature and time were recorded for a-isorhiza volumes only in the 30 °C treatment. Our findings suggest that rising seawater temperatures pose minimal effects on <em>Cassiopea</em> sp. nematocyst sizes, enabling them to thrive in the face of rising ocean temperatures. Future studies should be carried out at higher treatment temperatures to determine if the limited impact of temperature on nematocyst size and volume will persist beyond 32 °C.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"592 ","pages":"Article 152126"},"PeriodicalIF":1.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gamma (γ)-aminobutyric acid (GABA) improves feeding, growth rate, and growth hormone of the sea cucumber Apostichopus japonicus at high stocking density","authors":"Ruihuan Tian,&nbsp;Qiuzhen Song,&nbsp;Guo Wu,&nbsp;Xiang Li,&nbsp;Xiyuan Huang,&nbsp;Yunjie Yang,&nbsp;Huiyan Wang,&nbsp;Chong Zhao","doi":"10.1016/j.jembe.2025.152131","DOIUrl":"10.1016/j.jembe.2025.152131","url":null,"abstract":"<div><div>Gamma (γ)-aminobutyric acid (GABA) is a critical neuromodulator in behavioral and growth regulation of organisms. The present study showed that feeding behavior significantly reduced when individuals were cultured in a high-density stocking environment, and that dietary GABA significantly ameliorated the effect of high density on feeding behavior. We further found that high density significantly reduced the protease activity and defecation rate of sea cucumbers, indicating a suppressed digestion. No significant difference was found in the protease activity and defecation rate between individuals fed with dietary GABA and those fed without dietary GABA at high density, suggesting that dietary GABA did not improve digestion. Additionally, cortisol level significantly increased when the density of stocking increased, and dietary GABA did not relieve the elevated cortisol level.</div><div>The growth rate directly affects the efficiency of sea cucumber aquaculture. The specific growth rate (SGR) and the level of growth hormone significantly reduced, while the coefficient of variation (CV) increased significantly at high density. These results revealed the inhibited growth performance at high density was potentially linked to reduced growth hormone level. We further found that dietary GABA improved the SGR and the level of growth hormone, but had no significant effect on individual growth difference of sea cucumbers cultured in high density.</div><div>In conclusion, this study demonstrates that dietary GABA enhances growth rate by increasing feeding behavior and growth hormone level, but not by improving digestive capacity and stress hormone level. We suggest GABA serve as a feed supplement to partially mitigate growth suppression in high-density aquaculture of sea cucumbers.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"592 ","pages":"Article 152131"},"PeriodicalIF":1.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144996623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Methods for precipitating plasma proteins for stable isotope analysis of elasmobranch blood","authors":"Alexander M. Rubin ,&nbsp;Sunita R. Shah Walter ,&nbsp;John A. Mohan ,&nbsp;Aaron B. Carlisle","doi":"10.1016/j.jembe.2025.152127","DOIUrl":"10.1016/j.jembe.2025.152127","url":null,"abstract":"<div><div>Stable isotope analysis can provide insight into the ecology of elasmobranchs across spatiotemporal scales, with metabolically active tissues, such as blood plasma, providing information on recent diet. However, the stable isotopic composition of plasma can be challenging to interpret because plasma is a systemic transport tissue containing many dissolved constituents in variable amounts. Previous efforts to selectively remove plasma constituents known to confound isotopic interpretation have limited effectiveness, leading to the current practice of analyzing whole plasma. Here we propose an alternative method of targeting proteins within plasma by solvent-based protein precipitation, and evaluate the effectiveness of ethanol and acetonitrile to isolate the protein fraction of plasma. We tested a commercially-prepared bovine serum albumin standard as well as to plasma from wild Sandbar Sharks and compare the carbon and nitrogen stable isotopic composition and C:N of untreated plasma to precipitated protein. We observed no change in the stable isotope composition or C:N in bovine serum albumin samples, indicating protein precipitation itself does not introduce a stable isotopic or elemental bias. Protein isolation of Sandbar Shark plasma resulted in a statistically-significant decrease in δ¹³C values and increase in C:N compared to untreated plasma. No significant effect was observed on δ¹⁵N values. Our results for precipitated proteins are not consistent with a simple loss of lipids and urea from whole plasma, and suggest a heterogenous composition of plasma. We find that protein precipitation provides a reproducible and promising method of isolating a specific and informative fraction of plasma for stable isotope studies.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"592 ","pages":"Article 152127"},"PeriodicalIF":1.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144913460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exposure to a gradient of freshwater pulses duration mimicking frequent floodings reveals species-specific vulnerability thresholds in an assemblage of key benthic molluscs","authors":"Valentine Loiseau ,&nbsp;Piero Calosi ,&nbsp;David Drolet ,&nbsp;Mathieu Cusson ,&nbsp;Yanick Gendreau","doi":"10.1016/j.jembe.2025.152120","DOIUrl":"10.1016/j.jembe.2025.152120","url":null,"abstract":"<div><div>Estuarine communities provide many ecosystem services and are highly vulnerable to global changes. Detrimental changes in land use and intense rainfall events increase the frequency and intensity of flooding, causing abrupt changes in estuarine conditions. As a result, marine organisms are more often exposed to freshwater conditions for several days after flooding. While estuarine organisms are able to thrive under fluctuating salinities, their responses to intense and prolonged hypoosmotic stress may differ. Understanding these responses is crucial as salinity variability is key to species distribution. Changes in hydrological regimes are occurring much faster in high latitudes environments, yet subarctic estuarian communities are rarely studied. Our study investigates the sensitivity of three key marine benthic macroinvertebrates inhabiting subarctic estuaries (<em>Littorina saxatilis</em>, <em>Macoma balthica</em> and <em>Mytilus</em> spp.) to different durations of freshwater exposure. In laboratory conditions, molluscs were exposed during six weeks to a gradient of 12 freshwater pulse durations, ranging from 0 to 9 d, interspersed with 24 h of exposure to sea water. Mortality and shell growth, as well as energy content for <em>Mytilus</em> spp., were compared after two, four and six weeks of exposure using linear mixed models and break-point analyses. All three species demonstrated tolerance to short-duration freshwater pulses (less than 2 d) repeated over several weeks. <em>Littorina saxatilis</em> exhibited the highest vulnerability, with mortality increasing under freshwater pulses longer than 2 d after two weeks. <em>Macoma balthica</em> displayed a comparable threshold but only after four weeks. <em>Mytilus</em> spp. displayed the greatest tolerance, with a threshold only detectable after six weeks of exposure and increasing mortality in treatments with freshwater pulses longer than 5 d. In addition, shell growth decreased with increasing duration of freshwater pulse only in <em>L. saxatilis</em> while it was not affected in <em>M. balthica</em> and <em>Mytilus</em> spp. Energy content in <em>Mytilus</em> spp. varied according to pulse duration and time, with the highest energy content being detected in the longer freshwater exposure periods, suggesting complex physiological responses to hypoosmotic stress. Altogether, our study indicates the existence of highly species-specific differences in freshwater vulnerability among marine benthic macroinvertebrates inhabiting subarctic estuaries. Our findings highlight the importance of using gradients of stress scenarios to identify ecologically relevant thresholds, helping in the prediction and management of extreme climate events like river floods on estuarine communities. Our study provides valuable recommendations for dam management and biodiversity conservation in estuarine ecosystems.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"591 ","pages":"Article 152120"},"PeriodicalIF":1.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144588350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diversity, non-additive effects, and functional redundancy drive sponge community filtration in a shallow, tropical ecosystem","authors":"Mark J. Butler IV","doi":"10.1016/j.jembe.2025.152122","DOIUrl":"10.1016/j.jembe.2025.152122","url":null,"abstract":"<div><div>A central question in ecology concerns the role of biodiversity in maintaining ecosystem function and, as a corollary in ecological conservation, how much diversity can be lost before ecological processes are affected? The answer is complicated by functional redundancy and non-additive effects in speciose systems, and by definitions of biodiversity that span the scales of biological organization. Sponge communities provide a tractable model for exploring this dilemma across different measures of diversity, given the myriad and powerful ways that their filter-feeding shapes the biogeochemical processes, pelagic-to-benthic coupling, and microbial water column composition of tropical coastal waters. Mirroring conditions in other ecosystems, coastal sponge communities are also undergoing degradation and loss of diversity that portends the loss of ecosystem function. In this study, sponge biodiversity was manipulated in flow-through mesocosms to test the independent effects of various levels of biodiversity (i.e., species richness, size, life history traits, microbiome abundance type) on the effects of sponge community filtration on seawater chemistry and bacterioplankton. Species-rich sponge assemblages generally reshaped water column properties to a greater degree than monocultures, reaching an asymptote when ∼50 % of the species were present. Species identity and community assemblage also had substantial, idiosyncratic effects on various aspects of ecosystem function from nitrogen dynamics to plankton composition. These results provide a compelling demonstration of how biodiversity in its various guises can drive ecosystem processes – to a point, after which functional redundancy and complex interspecies interactions obscure the relationship.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"591 ","pages":"Article 152122"},"PeriodicalIF":1.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144662143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Toxic impact of aluminium on the natural phytoplankton community during spring in the Atlantic sector of the Southern Ocean","authors":"C. Demasy ,&nbsp;A. Singh ,&nbsp;S. Samanta ,&nbsp;T.J. Ryan-Keogh ,&nbsp;A.N. Roychoudhury","doi":"10.1016/j.jembe.2025.152119","DOIUrl":"10.1016/j.jembe.2025.152119","url":null,"abstract":"<div><div>The natural Southern Ocean phytoplankton community plays a pivotal role in both the marine trophic chain and global climate regulation. Previous studies and models have primarily focused on the individual effects of iron (Fe) on phytoplankton, often overlooking the potential toxic impact of aluminium (Al) and its interactive effects with Fe and cobalt (Co). Here, a series of controlled incubations involving the addition of trace metals (Al, Fe, and Co) were conducted to evaluate the potential effects of these elements in the Polar Frontal Zone and the Marginal Ice Zone. The findings revealed that the introduction of 1 nM of Al prompted a reduction in biomass of the entire natural community, coupled with a decrease in the photosynthetic efficiency (F_v/F_m) and an increase of the absorption cross-section of photosystem II (σ_PSII). A similar toxic impact of Al addition was observed at both sites, however, the level of cell activity and presence of other micronutrients (Fe, Co) attenuated the toxicity to some extent. Despite its connotations, Al toxicity is not considered an immediate threat to the sub-Antarctic phytoplankton community, however, the scenario could differ in regions where increased lithogenic input is likely.</div></div>","PeriodicalId":50197,"journal":{"name":"Journal of Experimental Marine Biology and Ecology","volume":"591 ","pages":"Article 152119"},"PeriodicalIF":1.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144605382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}