Pub Date : 2025-12-30DOI: 10.1016/j.aquabot.2025.103988
Iraj Baloch , Mehran Loghmani , Amir Ghazilou
This study predicts changes in the potential distribution of seagrass beds in the Persian Gulf under climate change scenarios (SSP1–2.6, SSP3–7.0, and SSP5–8.5) by 2100, using MaxEnt ecological modeling. Model performance was robust, with a mean AUC greater than 0.79. The current suitable habitat covers approximately 71,714 km². Under SSP1–2.6, suitable habitat contracts to 57,424 km². The SSP3–7.0 and SSP5–8.5 scenarios predict severe losses, reducing suitable habitat to 1492 km² and 10,797 km², respectively, accompanied by substantial fragmentation and core habitat loss. Key environmental drivers of seagrass suitability include positive responses to temperature, pH, iron, and photosynthetically active radiation, while nitrate, salinity, and cloud fraction exhibited negative effects. Climate change and biotic velocity analyses indicated a prospective southward shift of seagrass habitats. These findings highlight the vulnerability of the seagrass ecosystems in the Persian Gulf.
{"title":"Predicted changes in potential distribution of seagrass beds in the Persian Gulf driven by climate change","authors":"Iraj Baloch , Mehran Loghmani , Amir Ghazilou","doi":"10.1016/j.aquabot.2025.103988","DOIUrl":"10.1016/j.aquabot.2025.103988","url":null,"abstract":"<div><div>This study predicts changes in the potential distribution of seagrass beds in the Persian Gulf under climate change scenarios (SSP1–2.6, SSP3–7.0, and SSP5–8.5) by 2100, using MaxEnt ecological modeling. Model performance was robust, with a mean AUC greater than 0.79. The current suitable habitat covers approximately 71,714 km². Under SSP1–2.6, suitable habitat contracts to 57,424 km². The SSP3–7.0 and SSP5–8.5 scenarios predict severe losses, reducing suitable habitat to 1492 km² and 10,797 km², respectively, accompanied by substantial fragmentation and core habitat loss. Key environmental drivers of seagrass suitability include positive responses to temperature, pH, iron, and photosynthetically active radiation, while nitrate, salinity, and cloud fraction exhibited negative effects. Climate change and biotic velocity analyses indicated a prospective southward shift of seagrass habitats. These findings highlight the vulnerability of the seagrass ecosystems in the Persian Gulf.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103988"},"PeriodicalIF":2.6,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Seaweed strandings are recurrent in the eastern Seine Bay (English Channel) and may strongly affect nutrient dynamics at the sediment–water interface. This study investigated whether nitrogen released from decaying stranded seaweeds contributes to nitrogen availability for benthic Ulva during summer, using a combined approach of 19 months of in situ monitoring and an in vitro experiment. Variation in δ15N in Ulva (δ15NUlva) was observed, with lower values (<7 ‰) in spring and higher values (>9 ‰) in summer. In spring, low δ15NUlva values and the positive correlation between concentrations of dissolved inorganic nitrogen (DIN) in intertidal seawater and the River Orne’s flow indicate a terrigenous nitrogen origin, mainly from agricultural fertilizers. In summer, concentrations of dissolved organic nitrogen (DON) and ammonium increased in both intertidal and interstitial waters. Significant positive correlations were found between δ15NUlva, the extent of algal wracks, and DON concentrations, the latter also increasing with the extent of wracks. These relationships suggest that, in summer, when riverine nitrogen inputs are minimal, decaying stranded seaweeds constitute an endogenous nitrogen source for benthic seaweeds. This hypothesis was supported by a controlled experiment showing an increase in δ15N in Ulva thalli after 9 days of culture in seawater enriched with algal leachate. Such endogenous nitrogen recycling supports the growth of opportunistic Ulva, which dominate summer strandings and negatively affect coastal water quality assessments under the European Water Framework Directive. These findings highlight the importance of accounting for seaweed strandings in strategies and management actions aimed at improving coastal water quality.
{"title":"Seaweed strandings as a nitrogen source for benthic algae: Evidence from in situ and in vitro experiments in the English Channel","authors":"Stéphanie Lemesle , Anne-Marie Rusig , Pascal Claquin , Isabelle Mussio","doi":"10.1016/j.aquabot.2025.103986","DOIUrl":"10.1016/j.aquabot.2025.103986","url":null,"abstract":"<div><div>Seaweed strandings are recurrent in the eastern Seine Bay (English Channel) and may strongly affect nutrient dynamics at the sediment–water interface. This study investigated whether nitrogen released from decaying stranded seaweeds contributes to nitrogen availability for benthic <em>Ulva</em> during summer, using a combined approach of 19 months of <em>in situ</em> monitoring and an <em>in vitro</em> experiment. Variation in δ<sup>15</sup>N in <em>Ulva</em> (δ<sup>15</sup>N<sub><em>Ulva</em></sub>) was observed, with lower values (<7 ‰) in spring and higher values (>9 ‰) in summer. In spring, low δ<sup>15</sup>N<sub><em>Ulva</em></sub> values and the positive correlation between concentrations of dissolved inorganic nitrogen (DIN) in intertidal seawater and the River Orne’s flow indicate a terrigenous nitrogen origin, mainly from agricultural fertilizers. In summer, concentrations of dissolved organic nitrogen (DON) and ammonium increased in both intertidal and interstitial waters. Significant positive correlations were found between δ<sup>15</sup>N<sub><em>Ulva</em></sub>, the extent of algal wracks, and DON concentrations, the latter also increasing with the extent of wracks. These relationships suggest that, in summer, when riverine nitrogen inputs are minimal, decaying stranded seaweeds constitute an endogenous nitrogen source for benthic seaweeds. This hypothesis was supported by a controlled experiment showing an increase in δ<sup>15</sup>N in <em>Ulva</em> thalli after 9 days of culture in seawater enriched with algal leachate. Such endogenous nitrogen recycling supports the growth of opportunistic <em>Ulva</em>, which dominate summer strandings and negatively affect coastal water quality assessments under the European Water Framework Directive. These findings highlight the importance of accounting for seaweed strandings in strategies and management actions aimed at improving coastal water quality.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103986"},"PeriodicalIF":2.6,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-17DOI: 10.1016/j.aquabot.2025.103984
Maria Cecilia S. Lima , Thomaz Henrique A. Lima , Marcus V. Loss Sperandio , Gilvan Takeshi Yogui , João Silva , Karine M. Magalhães
Oil spills represent a significant threat to seagrasses as hydrocarbons can impair photosynthetic processes and plant functioning, although physiological responses may vary depending on the spill and environmental conditions This study investigates the physiological responses of Halophila baillonii when exposed to the water-soluble fraction (WSF) of crude oil. Photosynthetic pigment composition, maximum quantum yield (Fv/Fm), and oxidative stress indicators malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) were analyzed after short-term exposure. A significant increase in chlorophyll a and b concentrations and variations in carotenoid levels were detected, while photochemical efficiency and oxidative stress indicators were maintained. These findings suggest that the species dynamically adjusts its pigment composition to optimize light capture and mitigate oxidative stress, demonstrating physiological plasticity. Its ability to tolerate WSF exposure highlights the species' short-term resilience to hydrocarbon pollution. Future studies should investigate the effects of long-term exposure to different oil types, such as boat fuel, and the recovery mechanisms of seagrasses.
{"title":"Effect of petrochemical contaminants on the photosynthetic physiology on the seagrass Halophila baillonii Ascherson","authors":"Maria Cecilia S. Lima , Thomaz Henrique A. Lima , Marcus V. Loss Sperandio , Gilvan Takeshi Yogui , João Silva , Karine M. Magalhães","doi":"10.1016/j.aquabot.2025.103984","DOIUrl":"10.1016/j.aquabot.2025.103984","url":null,"abstract":"<div><div>Oil spills represent a significant threat to seagrasses as hydrocarbons can impair photosynthetic processes and plant functioning, although physiological responses may vary depending on the spill and environmental conditions This study investigates the physiological responses of <em>Halophila baillonii</em> when exposed to the water-soluble fraction (WSF) of crude oil. Photosynthetic pigment composition, maximum quantum yield (Fv/Fm), and oxidative stress indicators malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) were analyzed after short-term exposure. A significant increase in chlorophyll <em>a</em> and <em>b</em> concentrations and variations in carotenoid levels were detected, while photochemical efficiency and oxidative stress indicators were maintained. These findings suggest that the species dynamically adjusts its pigment composition to optimize light capture and mitigate oxidative stress, demonstrating physiological plasticity. Its ability to tolerate WSF exposure highlights the species' short-term resilience to hydrocarbon pollution. Future studies should investigate the effects of long-term exposure to different oil types, such as boat fuel, and the recovery mechanisms of seagrasses.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103984"},"PeriodicalIF":2.6,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-17DOI: 10.1016/j.aquabot.2025.103985
Sukanta Ankure , Subrata Mondal , Saikat Naskar
Druse-type Calcium oxalate (CaOx) crystals are commonly found in mangroves, yet their functional role remains unclear. To explore their significance, seedlings of Bruguiera gymnorhiza were grown under varying dilutions of brackish water. Growth responses were maximised. at moderate salinity, but the abundance of CaOx crystals continued to rise with increasing substrate salinity, whereas soluble salt concentrations remained constant. Measurements of salinity along with Na⁺, K⁺, and Ca²⁺ from fresh leaf extracts (soluble salts) and acid-digested leaf extracts (total salts) showed that a substantial fraction of salts was immobilised through CaOx crystal formation, primarily involving Ca²⁺, followed by Na⁺ and K⁺. In naturally growing Bruguiera gymnorhiza, Ceriops decandra, and Rhizophora mucronata, total salt content increased gradually from top to basal leaves, while soluble salt remained relatively constant. Leaf thickness, an approximate proxy for succulence within a species, increased toward basal nodes and correlated positively with the number of CaOx crystals. The Ca–Na ratio derived from CaOx crystals and total salts showed significant variation, though with an uncertain effect size. A moderate negative relationship was detected between Specific Leaf Area (SLA) with both total salt content and CaOx crystal abundance. Collectively, these findings suggest that CaOx formation in mangrove leaves acts as a functional trait that maintains cellular homeostasis, thereby enhancing fitness under salinity stress.
{"title":"Exploring calcium oxalate crystals as a functional trait for salt tolerance in mangrove Rhizophoraceae","authors":"Sukanta Ankure , Subrata Mondal , Saikat Naskar","doi":"10.1016/j.aquabot.2025.103985","DOIUrl":"10.1016/j.aquabot.2025.103985","url":null,"abstract":"<div><div>Druse-type Calcium oxalate (CaOx) crystals are commonly found in mangroves, yet their functional role remains unclear. To explore their significance, seedlings of <em>Bruguiera gymnorhiza</em> were grown under varying dilutions of brackish water. Growth responses were maximised. at moderate salinity, but the abundance of CaOx crystals continued to rise with increasing substrate salinity, whereas soluble salt concentrations remained constant. Measurements of salinity along with Na⁺, K⁺, and Ca²⁺ from fresh leaf extracts (soluble salts) and acid-digested leaf extracts (total salts) showed that a substantial fraction of salts was immobilised through CaOx crystal formation, primarily involving Ca²⁺, followed by Na⁺ and K⁺. In naturally growing <em>Bruguiera gymnorhiza</em>, <em>Ceriops decandra</em>, and <em>Rhizophora mucronata</em>, total salt content increased gradually from top to basal leaves, while soluble salt remained relatively constant. Leaf thickness, an approximate proxy for succulence within a species, increased toward basal nodes and correlated positively with the number of CaOx crystals. The Ca–Na ratio derived from CaOx crystals and total salts showed significant variation, though with an uncertain effect size. A moderate negative relationship was detected between Specific Leaf Area (SLA) with both total salt content and CaOx crystal abundance. Collectively, these findings suggest that CaOx formation in mangrove leaves acts as a functional trait that maintains cellular homeostasis, thereby enhancing fitness under salinity stress.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103985"},"PeriodicalIF":2.6,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-10DOI: 10.1016/j.aquabot.2025.103983
Ying Wang , Yi-tong Du , Nora Fung-Yee Tam
The present study examined the combined effects of polybrominated diphenyl ethers (PBDEs, represented by 2,2’,4,4’-tetrabromodiphenyl ether, BDE-47) and tidal flooding regimes on the growth, antioxidative enzymes (superoxide dismutase, SOD; peroxidase, POD; catalase, CAT) and non-enzymatic antioxidants (total polyphenols and extractable condensed tannins) in Kandelia obovata (Ko) seedlings. Greenhouse experiments were conducted with one-year-old Ko seedlings, which were exposed to three tidal frequencies (no tidal flooding, every two-day tidal flooding and every day tidal flooding) and five BDE-47 levels (0, 0.1, 1, 5, 10 mg kg−1 dry weight). Results showed that Ko tolerated BDE-47 up to 10 mg kg−1 dry weight, with no significant differences in tissue biomass or chlorophyll contents vs. control. Daily tidal flooding (highest frequency) promoted growth (higher biomass and leaf number) and increased the activity of three key antioxidant enzymes (SOD, POD, CAT) in roots and leaves, relative to the less frequent flooding. Notably, 10 mg kg−1 BDE-47 reduced total polyphenols and extractable condensed tannins in roots and leaves, with no significant differences among tidal regimes. In conclusions, our findings confirmed that the tolerance of Ko to combined BDE-47 and tidal flooding stress was mediated by a clear mechanistic link: Enzymatic antioxidants (SOD, POD, CAT) adapt to tidal-induced oxidative stress, while non-enzymatic antioxidants (total polyphenols and extractable condensed tannins) mitigate BDE-47 damage. These findings offer critical insights into mangrove adaptive strategies under co-occurring stresses, informing conservation and restoration of mangrove ecosystems facing tidal dynamics and pollution.
{"title":"Combined effects of tidal regimes and polybrominated diphenyl ether BDE-47 (a persistent organic chemical) on growth, enzymatic and non-enzymatic antioxidants in Kandelia obovata","authors":"Ying Wang , Yi-tong Du , Nora Fung-Yee Tam","doi":"10.1016/j.aquabot.2025.103983","DOIUrl":"10.1016/j.aquabot.2025.103983","url":null,"abstract":"<div><div>The present study examined the combined effects of polybrominated diphenyl ethers (PBDEs, represented by 2,2’,4,4’-tetrabromodiphenyl ether, BDE-47) and tidal flooding regimes on the growth, antioxidative enzymes (superoxide dismutase, SOD; peroxidase, POD; catalase, CAT) and non-enzymatic antioxidants (total polyphenols and extractable condensed tannins) in <em>Kandelia obovata</em> (Ko) seedlings. Greenhouse experiments were conducted with one-year-old Ko seedlings, which were exposed to three tidal frequencies (no tidal flooding, every two-day tidal flooding and every day tidal flooding) and five BDE-47 levels (0, 0.1, 1, 5, 10 mg kg<sup>−1</sup> dry weight). Results showed that Ko tolerated BDE-47 up to 10 mg kg<sup>−1</sup> dry weight, with no significant differences in tissue biomass or chlorophyll contents vs. control. Daily tidal flooding (highest frequency) promoted growth (higher biomass and leaf number) and increased the activity of three key antioxidant enzymes (SOD, POD, CAT) in roots and leaves, relative to the less frequent flooding. Notably, 10 mg kg<sup>−1</sup> BDE-47 reduced total polyphenols and extractable condensed tannins in roots and leaves, with no significant differences among tidal regimes. In conclusions, our findings confirmed that the tolerance of Ko to combined BDE-47 and tidal flooding stress was mediated by a clear mechanistic link: Enzymatic antioxidants (SOD, POD, CAT) adapt to tidal-induced oxidative stress, while non-enzymatic antioxidants (total polyphenols and extractable condensed tannins) mitigate BDE-47 damage. These findings offer critical insights into mangrove adaptive strategies under co-occurring stresses, informing conservation and restoration of mangrove ecosystems facing tidal dynamics and pollution.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103983"},"PeriodicalIF":2.6,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145747820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-05DOI: 10.1016/j.aquabot.2025.103982
Meiying Wang, Ming Jiang, Yuanchun Zou, Wenguang Zhang, Yu An, Bo Liu
Flooding regimes critically regulate the growth, distribution, and composition of wetland plants, with depth and duration being key determinants. Bolboschoenus planiculmis, a perennial sedge species, serves as the primary tuber food source for Leucogeranus leucogeranus in the Momoge National Nature Reserve (MNNR) in northeastern China. This study aimed to investigate the effects of flooding depth and duration on this species, as well as its recovery performance following flood recession. A controlled pot experiment simulated 20-, 40-, and 60-day submergence periods under water depths of 0, 10, 30, and 50 cm, followed by 20 days of de-submergence. The results showed that increased flooding depths (30–50 cm) had detrimental effects on the performance of B. planiculmis. As flooding duration increased, the suppression of biomass accumulation became progressively more severe at deeper water depths (30 and 50 cm) compared to shallower ones (0 and 10 cm). All response variables after recovery were significantly affected by flooding depth, duration, and their interactions. Post-recovery biomass showed no significant differences between the 0 and 10 cm treatments across all durations. However, deeper flooding (30–50 cm) combined with prolonged submergence (40–60 days) severely impaired growth recovery. These findings highlight the vulnerability of B. planiculmis to prolonged deep flooding and underscore the importance of maintaining shallow water depths (≤10 cm) during the sprouting period to preserve its population. Such hydrological management is critical for sustaining Siberian crane foraging habitats.
{"title":"Increased flooding depth and duration limit post-submergence recovery of Bolboschoenus planiculmis","authors":"Meiying Wang, Ming Jiang, Yuanchun Zou, Wenguang Zhang, Yu An, Bo Liu","doi":"10.1016/j.aquabot.2025.103982","DOIUrl":"10.1016/j.aquabot.2025.103982","url":null,"abstract":"<div><div>Flooding regimes critically regulate the growth, distribution, and composition of wetland plants, with depth and duration being key determinants. <em>Bolboschoenus planiculmis</em>, a perennial sedge species, serves as the primary tuber food source for <em>Leucogeranus leucogeranus</em> in the Momoge National Nature Reserve (MNNR) in northeastern China. This study aimed to investigate the effects of flooding depth and duration on this species, as well as its recovery performance following flood recession. A controlled pot experiment simulated 20-, 40-, and 60-day submergence periods under water depths of 0, 10, 30, and 50 cm, followed by 20 days of de-submergence. The results showed that increased flooding depths (30–50 cm) had detrimental effects on the performance of <em>B. planiculmis</em>. As flooding duration increased, the suppression of biomass accumulation became progressively more severe at deeper water depths (30 and 50 cm) compared to shallower ones (0 and 10 cm). All response variables after recovery were significantly affected by flooding depth, duration, and their interactions. Post-recovery biomass showed no significant differences between the 0 and 10 cm treatments across all durations. However, deeper flooding (30–50 cm) combined with prolonged submergence (40–60 days) severely impaired growth recovery. These findings highlight the vulnerability of <em>B. planiculmis</em> to prolonged deep flooding and underscore the importance of maintaining shallow water depths (≤10 cm) during the sprouting period to preserve its population. Such hydrological management is critical for sustaining Siberian crane foraging habitats.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103982"},"PeriodicalIF":2.6,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145747821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wetlands are critical for maintaining landscape connectivity and biodiversity across scales, yet the spatial drivers of functional connectivity in aquatic plants, particularly in inland freshwater wetlands, remain poorly understood. This study examines the genetic diversity and landscape factors influencing functional connectivity in Schoenoplectus californicus across freshwater wetlands in the Mexican highlands. We genotyped 380 individuals of S. californicus at nine microsatellite loci from 12 freshwater wetlands in Central-Western Mexico (states of Michoacán, Guanajuato, Jalisco, and an external population in Tlaxcala), covering the most important wetlands where the species occurs in the region. We observed low observed heterozygosity (average Ho = 0.280 ± 0.019; average uHE = 0.717 ± 0.009), high inbreeding levels (average FIS = 0.57 ± 0.090), and evidence of genetic bottlenecks in small wetlands (< 50 ha). Contemporary migration rates were asymmetric; Lake Cuitzeo acts as a genetic source for nearby wetlands (e.g., Yuriria, Pátzcuaro, Zirahuén). Multi-scale landscape analyses using population genetic graphs and landscape elements revealed that forest cover facilitates gene flow at broad scales (> 2 km, p < 0.05), while urban areas significantly reduce connectivity (> 1.5 km, p < 0.05). These results underscore the importance of assessing functional connectivity in wetland networks to guide conservation efforts, particularly by preserving forest corridors that maintain genetic resilience in increasingly human-dominated landscapes.
湿地对于维持景观连通性和跨尺度生物多样性至关重要，但水生植物功能连通性的空间驱动因素，特别是内陆淡水湿地，仍然知之甚少。本研究探讨了墨西哥高原淡水湿地加利福尼亚Schoenoplectus californicus的遗传多样性和景观因素对其功能连通性的影响。我们从墨西哥中西部12个淡水湿地（Michoacán州、瓜纳华托州、哈利斯科州和特拉斯卡拉的一个外部种群）的9个微卫星位点对380个加利福尼亚加利福尼亚小蠊个体进行了基因分型，覆盖了该地区最重要的湿地。我们观察到低杂合度（平均Ho = 0.280 ± 0.019；平均uHE = 0.717 ± 0.009），高近交水平（平均FIS = 0.57 ± 0.090），以及小湿地遗传瓶颈的证据（< 50 ha）。当代移民率是不对称的；奎策奥湖是附近湿地（如Yuriria、Pátzcuaro、zirahuachan）的遗传源。利用种群遗传图谱和景观要素进行的多尺度景观分析表明，森林覆盖促进了大尺度的基因流动（> 2 km, p <； 0.05），而城市显著降低了连通性（> 1.5 km, p <； 0.05）。这些结果强调了评估湿地网络功能连通性对指导保护工作的重要性，特别是通过保护森林走廊，在日益以人类为主导的景观中保持遗传弹性。
{"title":"Forested landscape promotes functional connectivity of California bulrush (Schoenoplectus californicus) in threatened freshwater wetlands","authors":"Efraín Noriega-Rico , Tatiana Lobato-de Magalhães , Yessica Rico","doi":"10.1016/j.aquabot.2025.103980","DOIUrl":"10.1016/j.aquabot.2025.103980","url":null,"abstract":"<div><div>Wetlands are critical for maintaining landscape connectivity and biodiversity across scales, yet the spatial drivers of functional connectivity in aquatic plants, particularly in inland freshwater wetlands, remain poorly understood. This study examines the genetic diversity and landscape factors influencing functional connectivity in <em>Schoenoplectus californicus</em> across freshwater wetlands in the Mexican highlands. We genotyped 380 individuals of <em>S. californicus</em> at nine microsatellite loci from 12 freshwater wetlands in Central-Western Mexico (states of Michoacán, Guanajuato, Jalisco, and an external population in Tlaxcala), covering the most important wetlands where the species occurs in the region. We observed low observed heterozygosity (average <em>Ho</em> = 0.280 ± 0.019; average <em>uH</em><sub><em>E</em></sub> = 0.717 ± 0.009), high inbreeding levels (average <em>F</em><sub><em>IS</em></sub> = 0.57 ± 0.090), and evidence of genetic bottlenecks in small wetlands (< 50 ha). Contemporary migration rates were asymmetric; Lake Cuitzeo acts as a genetic source for nearby wetlands (e.g., Yuriria, Pátzcuaro, Zirahuén). Multi-scale landscape analyses using population genetic graphs and landscape elements revealed that forest cover facilitates gene flow at broad scales (> 2 km, <em>p</em> < 0.05), while urban areas significantly reduce connectivity (> 1.5 km, <em>p</em> < 0.05). These results underscore the importance of assessing functional connectivity in wetland networks to guide conservation efforts, particularly by preserving forest corridors that maintain genetic resilience in increasingly human-dominated landscapes.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103980"},"PeriodicalIF":2.6,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145600384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-26DOI: 10.1016/j.aquabot.2025.103972
Aarin Conrad Allen , Danielle C. Sattelberger , Justin E. Campbell , Jeremy J. Kiszka
The Florida manatee (Trichechus manatus latirostris) is known to consume at least sixty species of aquatic macrophytes, but seagrass dominates their diet. In recent years, however, harmful algal blooms (HABs) have caused major seagrass declines, particularly in the Indian River Lagoon (IRL), Florida. Recent studies suggest that manatees in the IRL have undergone a significant dietary shift from a seagrass- to a macroalgae-dominated diet over the past ∼50 years. Therefore, there is a need to understand the nutritional and energetic consequences of such a dietary shift. This study compared the macronutrients carbon (C), nitrogen (N), and phosphorus (P), and proximate composition (acid detergent fiber [ADF], ash, crude fat, crude protein, total digestible nutrients [TDN], and total nonstructural carbohydrates [TNC]) of ten known forage items consumed by manatees in the IRL. Here, we aimed to: 1) quantify macronutrient and elemental stoichiometry (C:N:P) of items consumed by manatees, 2) evaluate the proximate composition of forage resources, and 3) investigate the seasonal (wet vs. dry) variation in macronutrient and proximate compositions. Results indicate that a macroalgae-rich diet provides readily digestible energy but contains significantly less fiber, and exhibits altered nutritional balances compared to seagrass. Such a dietary transition may compromise hindgut fermentation efficiency, disrupt symbiotic microbiota, and exacerbate malnutrition risks to manatees in Florida.
{"title":"Nutritional composition of forage resources consumed by Florida manatees (Trichechus manatus latirostris) vulnerable to seagrass decline in the Indian River Lagoon","authors":"Aarin Conrad Allen , Danielle C. Sattelberger , Justin E. Campbell , Jeremy J. Kiszka","doi":"10.1016/j.aquabot.2025.103972","DOIUrl":"10.1016/j.aquabot.2025.103972","url":null,"abstract":"<div><div>The Florida manatee (<em>Trichechus manatus latirostris</em>) is known to consume at least sixty species of aquatic macrophytes, but seagrass dominates their diet. In recent years, however, harmful algal blooms (HABs) have caused major seagrass declines, particularly in the Indian River Lagoon (IRL), Florida. Recent studies suggest that manatees in the IRL have undergone a significant dietary shift from a seagrass- to a macroalgae-dominated diet over the past ∼50 years. Therefore, there is a need to understand the nutritional and energetic consequences of such a dietary shift. This study compared the macronutrients carbon (C), nitrogen (N), and phosphorus (P), and proximate composition (acid detergent fiber [ADF], ash, crude fat, crude protein, total digestible nutrients [TDN], and total nonstructural carbohydrates [TNC]) of ten known forage items consumed by manatees in the IRL. Here, we aimed to: 1) quantify macronutrient and elemental stoichiometry (C:N:P) of items consumed by manatees, 2) evaluate the proximate composition of forage resources, and 3) investigate the seasonal (wet vs. dry) variation in macronutrient and proximate compositions. Results indicate that a macroalgae-rich diet provides readily digestible energy but contains significantly less fiber, and exhibits altered nutritional balances compared to seagrass. Such a dietary transition may compromise hindgut fermentation efficiency, disrupt symbiotic microbiota, and exacerbate malnutrition risks to manatees in Florida.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103972"},"PeriodicalIF":2.6,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dwarf shoots of the Mediterranean seagrass Posidonia oceanica, referred to as “Posidonia bonsai”, described in shallow hydrothermal vents, showed markedly reduced size and altered phenology, that were attributed to the extreme environmental conditions associated with ocean acidification and H2S emissions of these vent systems. Here we report new records of Posidonia “bonsai” from CO2 vent off the Ischia Island and non-vent areas with normal pH conditions at Ischia, and Ustica islands and at Palinuro. At Ustica and Palinuro, bonsai shoots we found exclusively on rocky bottoms, while at Ischia they occurred on the dead P. oceanica matte, both within vent systems and in control areas. Bonsai shoots exhibited a reduced number of leaves, significantly shorter leaf length and width, resulting in a drastic reduction of total leaf surface area (84–95 % lower) and biomass (82–97 % lower) compared to nearby regular-sized shoots. In addition, bonsai shoots lacked the typical annual cycle of leaf sheath thickness observed in normal shoots (lepidochronological cycle), as previously observed in bonsai from other sites. The high number of sheaths recorded per rhizome length, suggests high leaf production and turnover. The occurrence of bonsai shoots on dead matte at the meadow margins and in small clearings, or behind regular terminal shoots on creeping rhizomes in hard bottoms, leads to hypothesize that Posidonia bonsai represents a novel growth and colonization strategy, probably trigged by stressful conditions, not limited to ocean acidification, and point out the remarkable phenotypic plasticity of this seagrass.
{"title":"Posidonia bonsai: Dwarf morphotypes of Posidonia oceanica in CO2 vents and non-vents areas suggest a novel growth strategy","authors":"Maria Cristina Gambi , Caterina Iacono , Antonino Miccio , Valentina Esposito , Gabriele Procaccini , Lazaro Marín-Guirao","doi":"10.1016/j.aquabot.2025.103981","DOIUrl":"10.1016/j.aquabot.2025.103981","url":null,"abstract":"<div><div>Dwarf shoots of the Mediterranean seagrass <em>Posidonia oceanica</em>, referred to as “Posidonia bonsai”, described in shallow hydrothermal vents, showed markedly reduced size and altered phenology, that were attributed to the extreme environmental conditions associated with ocean acidification and H<sub>2</sub>S emissions of these vent systems. Here we report new records of Posidonia “bonsai” from CO<sub>2</sub> vent off the Ischia Island and non-vent areas with normal pH conditions at Ischia, and Ustica islands and at Palinuro. At Ustica and Palinuro, bonsai shoots we found exclusively on rocky bottoms, while at Ischia they occurred on the dead <em>P. oceanica</em> matte, both within vent systems and in control areas. Bonsai shoots exhibited a reduced number of leaves, significantly shorter leaf length and width, resulting in a drastic reduction of total leaf surface area (84–95 % lower) and biomass (82–97 % lower) compared to nearby regular-sized shoots. In addition, bonsai shoots lacked the typical annual cycle of leaf sheath thickness observed in normal shoots (lepidochronological cycle), as previously observed in bonsai from other sites. The high number of sheaths recorded per rhizome length, suggests high leaf production and turnover. The occurrence of bonsai shoots on dead matte at the meadow margins and in small clearings, or behind regular terminal shoots on creeping rhizomes in hard bottoms, leads to hypothesize that <em>Posidonia</em> bonsai represents a novel growth and colonization strategy, probably trigged by stressful conditions, not limited to ocean acidification, and point out the remarkable phenotypic plasticity of this seagrass.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"204 ","pages":"Article 103981"},"PeriodicalIF":2.6,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-20DOI: 10.1016/j.aquabot.2025.103971
L. Kamaitytė-Bukelskienė , Z. Sinkevičienė , D. Naugžemys , J. Butkuvienė
The present study examined the phenotypic and genetic differences between Najas marina L. s.s. and Najas major All. in the south-eastern Baltic region, testing reliable diagnostic markers. The key questions included species distribution patterns, the most distinctive morphological traits, the impact of ecological conditions on morphology, and the effectiveness of ISSR markers in evaluating genetic diversity and structure. The results were contrasted with those obtained from ITS and rbcL markers. We highlighted the potential and limitations of diagnostic tools used for by integrating morphological and molecular methods, and environmental data. Samples for the study were collected from diverse aquatic habitats in Lithuania, Latvia, and Poland, chosen based on herbarium data and literature. Morphological measurements and DNA extraction were performed using the freshly collected samples. Results show that morphological markers, specifically leaf widths, have significant diagnostic value for distinguishing Najas marina from Najas major. Therefore, assist in environmental management planning and ecological assessments as easy to use marker. Our results also show that ISSR markers produce distinct population structures confirming clear separation between Najas marina and Najas major, and underscoring the interspecific plasticity potentially related to specific environmental factors across sites. We confirmed that, currently, two species of the subgenus Najas coexist in separate waterbodies within the south-eastern Baltic region. We also argue that morphological markers are usually adequate for these species when considering morphological plasticity due to environmental properties. However, the use of barcoding markers or markers such as PCR ISSR are preferable when both species are growing sympatrically.
本文研究了Najas marina L. s.s s和Najas major All的表型和遗传差异。在波罗的海东南部地区，检测可靠的诊断标记物。关键问题包括物种分布格局、最显著的形态特征、生态条件对形态的影响以及ISSR标记在评价遗传多样性和结构方面的有效性。结果与ITS和rbcL标记进行对比。我们强调了通过整合形态学和分子方法以及环境数据所使用的诊断工具的潜力和局限性。该研究的样本是从立陶宛、拉脱维亚和波兰不同的水生栖息地收集的，根据植物标本馆的数据和文献选择。使用新采集的样品进行形态学测量和DNA提取。结果表明，形态标记，特别是叶片宽度，对区分小红花和大红花具有重要的诊断价值。因此，辅助环境管理规划和生态评价成为易于使用的标志。我们的研究结果还表明，ISSR标记产生了不同的种群结构，证实了Najas marina和Najas major之间的明显分离，并强调了种间可塑性可能与不同地点的特定环境因素有关。我们证实，目前在波罗的海东南部地区的不同水体中共存着两种Najas亚属。我们还认为，当考虑到由于环境特性造成的形态可塑性时，形态标记通常足以用于这些物种。然而，当两种植物共生生长时，使用条形码标记或PCR ISSR等标记是可取的。
{"title":"Phenotypic and genetic variation of Najas marina and Najas major in the south-eastern Baltic region","authors":"L. Kamaitytė-Bukelskienė , Z. Sinkevičienė , D. Naugžemys , J. Butkuvienė","doi":"10.1016/j.aquabot.2025.103971","DOIUrl":"10.1016/j.aquabot.2025.103971","url":null,"abstract":"<div><div>The present study examined the phenotypic and genetic differences between <em>Najas marina</em> L. s.s. and <em>Najas major</em> All. in the south-eastern Baltic region, testing reliable diagnostic markers. The key questions included species distribution patterns, the most distinctive morphological traits, the impact of ecological conditions on morphology, and the effectiveness of ISSR markers in evaluating genetic diversity and structure. The results were contrasted with those obtained from ITS and <em>rbc</em>L markers. We highlighted the potential and limitations of diagnostic tools used for by integrating morphological and molecular methods, and environmental data. Samples for the study were collected from diverse aquatic habitats in Lithuania, Latvia, and Poland, chosen based on herbarium data and literature. Morphological measurements and DNA extraction were performed using the freshly collected samples. Results show that morphological markers, specifically leaf widths, have significant diagnostic value for distinguishing <em>Najas marina</em> from <em>Najas major</em>. Therefore, assist in environmental management planning and ecological assessments as easy to use marker. Our results also show that ISSR markers produce distinct population structures confirming clear separation between <em>Najas marina</em> and <em>Najas major</em>, and underscoring the interspecific plasticity potentially related to specific environmental factors across sites. We confirmed that, currently, two species of the subgenus <em>Najas</em> coexist in separate waterbodies within the south-eastern Baltic region. We also argue that morphological markers are usually adequate for these species when considering morphological plasticity due to environmental properties. However, the use of barcoding markers or markers such as PCR ISSR are preferable when both species are growing sympatrically.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"203 ","pages":"Article 103971"},"PeriodicalIF":2.6,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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