Aquatic BotanyPub Date : 2025-11-01Epub Date: 2025-05-26DOI: 10.1016/j.aquabot.2025.103903
James E. Kaldy , Cayla Sullivan , Angel Dieppa , Evelyn Huertas , Mark Reiss , Izabela Wojtenko , Julia Perzley , Ivelisse Cappielo Cosme , Marco Orizondo Lugo
{"title":"Preliminary assessment of a nutrient pollution indicator for application to tropical seagrasses of Puerto Rico","authors":"James E. Kaldy , Cayla Sullivan , Angel Dieppa , Evelyn Huertas , Mark Reiss , Izabela Wojtenko , Julia Perzley , Ivelisse Cappielo Cosme , Marco Orizondo Lugo","doi":"10.1016/j.aquabot.2025.103903","DOIUrl":"10.1016/j.aquabot.2025.103903","url":null,"abstract":"<div><div>Seagrass health is often used as an indicator of water quality and plant tissue nitrogen content has long been used as an indicator of nitrogen availability, but it is not a sensitive early indicator of nutrient over enrichment. A critical characteristic for an early indicator is that it can detect increased nutrient availability before seagrasses die. The seagrass nutrient pollution indicator (NPI) integrates leaf tissue nitrogen content and leaf areal mass to track nutrient loading. We assess the underlying assumptions associated with the NPI metric and explore the application of the metric to three tropical seagrasses <em>Thalassia testudinum</em>, <em>Halodule wrightii</em>, and <em>Halophila stipulacea</em>. In June 2022 we sampled ten seagrass sites across three embayments in Puerto Rico. We used water column and sediment nutrient measurements, seagrass stable isotope analyses (%N and δ<sup>15</sup>N) and we made morphological measurements (leaf areal mass, mg dry weight cm <sup>−2</sup>) to evaluate the NPI relative to anticipated environmental gradients. <em>T. testudinum</em> sheath material, <em>H. wrightii</em> and <em>H. stipulacea</em> met the assumptions of the NPI method, suggesting that the NPI metric may be applied to these tropical species. Jobos Bay sites had isotopically light δ<sup>15</sup>N values suggesting that either local N fixation or import of allochthonous N fixation are dominant sources. In Guánica Bay, heavy δ<sup>15</sup>N values suggest either wastewater inputs or internal recycling of N are the dominant source. Additional research is required, but the evidence suggests that with further development and validation the NPI metric with δ<sup>15</sup>N could be appropriate for tropical seagrass species.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"201 ","pages":"Article 103903"},"PeriodicalIF":1.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168251","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}
Aquatic BotanyPub Date : 2025-11-01Epub Date: 2025-06-02DOI: 10.1016/j.aquabot.2025.103914
Celeste A. Diaz-Licona , Nadine Schubert , Vladimir González-Gamboa , Fernando Tuya , Juan Carlos Azofeifa-Solano , Cindy Fernández-García
{"title":"Rhodolith beds in the Eastern Tropical Pacific: Habitat structure and associated biodiversity","authors":"Celeste A. Diaz-Licona , Nadine Schubert , Vladimir González-Gamboa , Fernando Tuya , Juan Carlos Azofeifa-Solano , Cindy Fernández-García","doi":"10.1016/j.aquabot.2025.103914","DOIUrl":"10.1016/j.aquabot.2025.103914","url":null,"abstract":"<div><div>Rhodolith beds (RBs) are globally distributed marine benthic habitats and recognized biodiversity hotspots of conservation interest. However, considerable regions of the world’s oceans remain unknown in terms of the presence, distribution, structure, and associated biodiversity of such habitats. In the Eastern Tropical Pacific (ETP), even basic information about these habitats is still extremely scarce. To fill this gap, we characterized the habitat structure and associated biodiversity of four shallow-water RBs at Cocos Island, Costa Rica. Specifically, information regarding rhodolith structural attributes (size, morphology, and CaCO<sub>3</sub> content), as well as habitat characteristics (rhodolith nodule density, biomass and CaCO<sub>3</sub> standing stocks) were collected. Moreover, the diversity and abundance of associated organisms, including macroalgae, invertebrates and fishes, were determined. Our study shows that Cocos Island harbors dense RBs (1100 to >4500 nodules m<sup>−2</sup>) with substantial carbonate stocks (14–22 kg m<sup>−2</sup>), which provide habitats for a wide array of species (158 recorded species). This study adds 58 new records of RB-associated species to previously published records for the island, which increases the total number of species to 316, including 51 species endemic to the ETP and four species categorized as vulnerable by the IUCN. Our results also indicate that community composition and abundance of organisms vary among RBs, likely due to differences in rhodolith morphologies and sizes and/or local environmental conditions. Further research efforts are warranted to identify the drivers for these differences, as well as expanding studies towards other RBs at Cocos Island and in the ETP in general.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"201 ","pages":"Article 103914"},"PeriodicalIF":1.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144211830","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}
Aquatic BotanyPub Date : 2025-11-01Epub Date: 2025-07-03DOI: 10.1016/j.aquabot.2025.103923
Qingfeng Zhang , Nora Kainz , Gabriel Ferreira , Michael Kühl , Kasper Elgetti Brodersen
{"title":"Effects of increasing temperature on NO, N2O and H2S production and dynamics within epiphytic seagrass leaf biofilms","authors":"Qingfeng Zhang , Nora Kainz , Gabriel Ferreira , Michael Kühl , Kasper Elgetti Brodersen","doi":"10.1016/j.aquabot.2025.103923","DOIUrl":"10.1016/j.aquabot.2025.103923","url":null,"abstract":"<div><div>Leaf epiphytes have potential to reduce seagrasses nighttime O<sub>2</sub> supply leading to microbial production of greenhouse gases and phytotoxins that may be harmful to the plant. However, it remains unknown how global warming affects anaerobic processes like denitrification and sulfate reduction in the seagrass phyllopshere during darkness. We used electrochemical microsensors to measure gradients of O<sub>2</sub>, NO, N<sub>2</sub>O and H<sub>2</sub>S in the leaf microenvironment of heavily epiphyte-covered seagrass (<em>Zostera marina</em> L.) during darkness as a function of temperature at 14 and 24 °C. Increasing seawater temperature stimulated phytotoxic H<sub>2</sub>S production and accumulation within anoxic seagrass phyllospheres in darkness, which can be harmful to the plant as H<sub>2</sub>S readily diffuses through the thin cuticle of seagrass leaves. The seagrass phyllosphere also exhibited production of NO, which was diffusing into the plant as measured in the basal leaf meristem, as well as the potent greenhouse gas N<sub>2</sub>O during darkness. Increased temperature and reduced O<sub>2</sub> availability in the water-column, e.g., during marine heatwaves in eutrofied waters, can thus induce hostile chemical conditions in the seagrass phyllosphere that potentially can be detrimental for the plant’s performance and ecological function. The phyllosphere dynamics of NO and N<sub>2</sub>O displayed limited response to increasing seawater temperatures as compared to H<sub>2</sub>S, but the N<sub>2</sub>O production in epiphyte-covered seagrass leaves and subsequent emission to the surrounding seawater could have implications for the role of seagrass meadows in greenhouse gas mitigation.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"201 ","pages":"Article 103923"},"PeriodicalIF":1.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144588285","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}
Aquatic BotanyPub Date : 2025-11-01Epub Date: 2025-07-17DOI: 10.1016/j.aquabot.2025.103924
Jens P. Beets , Kara J. Foley , Benjamin P. Sperry , Andrew W. Howell , Robert J. Richardson
{"title":"Growth patterns of three Hydrilla verticillata biotypes in the United States","authors":"Jens P. Beets , Kara J. Foley , Benjamin P. Sperry , Andrew W. Howell , Robert J. Richardson","doi":"10.1016/j.aquabot.2025.103924","DOIUrl":"10.1016/j.aquabot.2025.103924","url":null,"abstract":"<div><div>Hydrilla [<em>Hydrilla verticillata</em> (L.f. Royle)] is an invasive submersed plant first documented in the United States (US) in the 1950s. Until recently, only two distinct strains of hydrilla, hereafter referred to as biotypes, were recorded in the US with both belonging to the same clade and characterized as either ‘monoecious’ or ‘dioecious’. In 2016, a third genetically distinct biotype (‘clade C’) was identified in the lower Connecticut River, Connecticut. Trials were conducted at two geographically unique locations within North Carolina to compare growth and reproduction of hydrilla biotypes by climatic conditions. Nominal differences were observed in peak aboveground biomass, relative growth rate, or occurrence of these metrics among the three hydrilla biotypes, although the predicted peak biomass for dioecious hydrilla did not occur during the study period. Monoecious hydrilla exhibited lower peak belowground biomass than dioecious and clade C hydrilla despite its abundant subterranean turion production. Monoecious hydrilla exhibited 1.8X greater aboveground biomass 180 days after planting (Julian day 304) than clade C hydrilla. Clade C hydrilla produced 74 axillary turions per plant on Julian day 304, which equates to a 2.3X increase over monoecious hydrilla and 61.5X increase over dioecious hydrilla. Conversely, subterranean turion production was 4.7 and 7.1X higher in monoecious hydrilla and dioecious hydrilla than clade C hydrilla, respectively. These studies suggest the clade C hydrilla displays many phenological similarities to the other two biotypes in the US, but its prodigious axillary turion production poses concerning implications for potential to spread and persistence following management.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"201 ","pages":"Article 103924"},"PeriodicalIF":1.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144670767","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}
Aquatic BotanyPub Date : 2025-11-01Epub Date: 2025-06-01DOI: 10.1016/j.aquabot.2025.103913
Toshihiro Yamada
{"title":"Seagrass fossils from the lower Miocene Morozaki Group in Aichi Prefecture, central Japan","authors":"Toshihiro Yamada","doi":"10.1016/j.aquabot.2025.103913","DOIUrl":"10.1016/j.aquabot.2025.103913","url":null,"abstract":"<div><div>Two new seagrass fossils are reported from the upper lower Miocene Morozaki Group (18.0–17.6 Ma) of central Japan: <em>Thalassites morozakiensis</em> T. Yamada, sp. nov., and <em>Maresurculus aichiensis</em> T. Yamada, gen. et sp. nov. The former bears strap-shaped, eligulate leaves enclosed within a fibrous sheath, suggesting an affinity with the extant subfamily Hydrilloideae (Hydrocharitaceae). The latter is characterized by ligulate leaves shed without leaving a sheath on the stem, indicating a relationship to extant genera of Cymodoceaceae, such as <em>Amphibolis</em> and <em>Thalassodendron</em>. These fossils represent the first reliable records of seagrasses from the early Miocene, consistent with divergence-time estimates for marine Hydrilloideae and Cymodoceaceae based on molecular clocks. Additionally, they imply that seagrasses extended their range to higher latitudes than today during the late early Miocene, a period marked by global warming.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"201 ","pages":"Article 103913"},"PeriodicalIF":1.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144204533","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}
Aquatic BotanyPub Date : 2025-11-01Epub Date: 2025-07-01DOI: 10.1016/j.aquabot.2025.103921
Madison A. Lytle , Michael E. Wheeler
{"title":"Evidence of Halodule wrightii flower and seed production at its northern range extent in the western North Atlantic (USA)","authors":"Madison A. Lytle , Michael E. Wheeler","doi":"10.1016/j.aquabot.2025.103921","DOIUrl":"10.1016/j.aquabot.2025.103921","url":null,"abstract":"<div><div><em>Halodule wrightii</em> is a tropical, euryhaline, dioecious seagrass found in marine waters of the western Atlantic Ocean, ranging from Brazil and the Gulf of Mexico to its northern limit in North Carolina. For seagrasses, sexual reproduction can serve as a resilience mechanism, with seed banks supporting re-establishment and recovery following a stress event. However, environmental stress may limit sexual reproduction due to high energetic costs. <em>H. wrightii</em> in North Carolina was previously thought to rely exclusively on asexual reproduction, with no confirmed reports of fully developed seeds and only a single historical account of flowering. Here, we report field observations of female and male flowers, fruits, and fully developed seeds in the sediment confirming that <em>H. wrightii</em> is capable of successful sexual reproduction at its northern range limit. These findings challenge prior assumptions and highlight the need for future research into the ecological and environmental factors influencing sexual reproduction (e.g. flower formation, timing of pollination, fruit development) and the role it plays in shaping genetic diversity in edge-of-range <em>H. wrigthii</em> populations.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"201 ","pages":"Article 103921"},"PeriodicalIF":1.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144534204","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}
Aquatic BotanyPub Date : 2025-11-01Epub Date: 2025-06-07DOI: 10.1016/j.aquabot.2025.103915
Yira Rodríguez-Jerez , Rita Sellares-Blasco , Maria F. Villalpando , Estefany Vargas-Pérez , Andreina Valdez-Trinidad , Someira Zambrano , Yasmin D. Evangelista , Sergio D. Guendulain-García , Aldo Croquer
{"title":"First report of Halophila stipulacea (Forsskål) Ascherson,1867 in the Dominican Republic, an invasive species that continues to expand across the Caribbean","authors":"Yira Rodríguez-Jerez , Rita Sellares-Blasco , Maria F. Villalpando , Estefany Vargas-Pérez , Andreina Valdez-Trinidad , Someira Zambrano , Yasmin D. Evangelista , Sergio D. Guendulain-García , Aldo Croquer","doi":"10.1016/j.aquabot.2025.103915","DOIUrl":"10.1016/j.aquabot.2025.103915","url":null,"abstract":"<div><div><em>Halophila stipulacea</em> (Forsskål) Ascherson,1867 is a seagrass species native to the Red Sea and the Persian-Indian Ocean, introduced 150 years ago into the Mediterranean Sea. <em>H. stipulacea</em> was first reported in the Caribbean in 2002; and in less than 15 years, it expanded across small island nations and Venezuela. Expected to continue expanding across its invasive range, monitoring programs aimed at spotting new geographic areas where <em>H. stipulacea</em> has successfully settled are vital. Here, we report for the first time an extensive meadow of <em>H. stipulacea</em> in Punta Salinas, Bani, Peravia Province, Dominican Republic (La Hispaniola). In November 2024, the species was spotted drifting inside Las Calderas Bay, and soon after, detected in a meadow located at the exposed side of Punta Salinas. After taxonomic confirmation, we conducted a survey during December 2024 to check for the presence of <em>H. stipulacea</em> meadows We observed a large <em>H. stipulacea</em> patch (1500 m) established on muddy sediments mixed with <em>Dictyota</em> spp., dead <em>Halimeda</em> spp. and other macroalgae. On average, the alien species covered 67.5 ± 36.7 %, whereas <em>Thalassia testudinum</em> covered < 5 % of the substrate. While the impacts of <em>H. stipulacea</em> in La Hispaniola remain unknown, our results confirm that <em>H. Stipulacea</em> continues to expand, successfully invading coastal habitats across the Caribbean region.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"201 ","pages":"Article 103915"},"PeriodicalIF":1.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144271130","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}
{"title":"Flowers from the sea: First record of seagrass flowers in the Arabian Gulf","authors":"Hung Manh Nguyen, Sajin Velakkandy, Aadil Yahiya Koothuparambil, Viliame Waqalevu, Elise Marquis","doi":"10.1016/j.aquabot.2025.103922","DOIUrl":"10.1016/j.aquabot.2025.103922","url":null,"abstract":"<div><div>The Arabian Gulf is home to three tropical seagrass species, <em>Halodule uninervis</em>, <em>Halophila ovalis</em> and <em>H. stipulacea</em>, which together cover an area of ∼ 6 % of the world’s seagrass distribution. To date, seagrass flowers and fruits have never been documented in this region. In March 2025, we conducted a sampling survey in four locations along Abu Dhabi’s coastline and here report for the first time on the presence of both flowers and fruits for <em>H. ovalis</em> in two studied sites, <em>H. stipulacea</em> flowers in another site. No flowers nor fruits were found for <em>H. uninervis</em> from any of the four investigated populations. One <em>H. ovalis</em> population had more than 46 % of plants bearing flowers, while other populations exhibited very limited numbers of flowering individuals, demonstrating highly variable sexual reproductive effort among different seagrass species and populations in the region. Our findings fill a critical gap in knowledge in the regional seagrass biology and offer important implications in seagrass research and restoration activities across the Arabian Gulf.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"201 ","pages":"Article 103922"},"PeriodicalIF":1.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144556753","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}
Aquatic BotanyPub Date : 2025-11-01Epub Date: 2025-06-20DOI: 10.1016/j.aquabot.2025.103918
Manutsawan Manokieng, Arunothai Jampeetong
{"title":"Growth, morphology, and nitrogen uptake adaptivity of Phragmites karka in response to nitrogen forms and oxygen availability","authors":"Manutsawan Manokieng, Arunothai Jampeetong","doi":"10.1016/j.aquabot.2025.103918","DOIUrl":"10.1016/j.aquabot.2025.103918","url":null,"abstract":"<div><div>The responses of <em>Phragmites karka</em> to different N-forms and O<sub>2</sub> supply were investigated. Fourteen-day old plants were selected and assigned randomly to six experimental treatments (n = 10), with three N-forms (NH<sub>4</sub><sup>+</sup>, NO<sub>3</sub><sup>-</sup>, NH<sub>4</sub>NO<sub>3</sub>) at equilibrium concentration (500 µM N) and two O<sub>2</sub> conditions (normoxia and hypoxia). All plants were cultivated in greenhouse conditions for 77 days. Under normoxia, NH<sub>4</sub><sup>+</sup>-fed plants had significantly higher dry mass production and NH<sub>4</sub><sup>+</sup> removal capacity than NO<sub>3</sub><sup>-</sup>-fed plants. In addition, the NH<sub>4</sub><sup>+</sup>- and NH<sub>4</sub>NO<sub>3</sub>-fed plants had significantly higher root dry mass and nitrogen use efficiency (NUE) compared to the NO<sub>3</sub><sup>-</sup>-fed plants. This suggests NH<sub>4</sub><sup>+</sup> preference under normoxia. Under hypoxia, the plants had reduced growth, biomass production, N removal capacity, and NUE. The plants also modulated root traits by reducing root dry mass, root length and root diameter. The plants had no significant difference in dry mass across N-forms under hypoxia. However, the NH<sub>4</sub><sup>+</sup>-fed plants increased their shoot:root ratios, while the NO<sub>3</sub><sup>-</sup>-fed plants retained their shoot:root ratios under hypoxia. Moreover, the NO<sub>3</sub><sup>-</sup>-fed plants had slighter changes in root size and biomass, NH<sub>4</sub><sup>+</sup> removal capacity, and NUE, suggesting better stability under hypoxia compared to the NH<sub>4</sub><sup>+</sup>-fed plants. The different response patterns between N-form are probably due to the energy preservation of roots associated with N uptake and assimilation. It appears that, <em>P. karka</em> utilizes both NH<sub>4</sub><sup>+</sup> and NO<sub>3</sub><sup>-</sup>, but that it prefer NH<sub>4</sub><sup>+</sup> when sufficient O<sub>2</sub> is available. In addition, this species can tolerate prolonged hypoxia and adaptation patterns appear to be N-form dependent.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"201 ","pages":"Article 103918"},"PeriodicalIF":1.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144471579","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}
Aquatic BotanyPub Date : 2025-11-01Epub Date: 2025-05-30DOI: 10.1016/j.aquabot.2025.103904
Jennifer L. Ruesink , Fiona C. Boardman , Bryan A. Briones Ortiz , Christopher R. Jendrey , Kerry Ann Naish
{"title":"Demographic and morphological responses of intertidal eelgrass (Zostera marina) transplanted across sediment conditions","authors":"Jennifer L. Ruesink , Fiona C. Boardman , Bryan A. Briones Ortiz , Christopher R. Jendrey , Kerry Ann Naish","doi":"10.1016/j.aquabot.2025.103904","DOIUrl":"10.1016/j.aquabot.2025.103904","url":null,"abstract":"<div><div>Eelgrass (<em>Zostera marina</em>) shows substantial spatiotemporal variation in morphological and demographic traits that can arise from phenotypic plasticity. These traits commonly shift across light and depth gradients, as well as seasonally, but less consistency has been demonstrated across sediment conditions. We conducted two field transplant experiments in which seedlings or overwintering shoots of <em>Z. marina</em> were moved among sand and muddy-sand sites within a bay (Willapa Bay, Washington, USA). Shoots were regularly re-marked and measured for size, asexual, and sexual reproduction for 1–1.5 year, and upon collection, for rhizome extension and root investment. Seedlings, which were sourced from one site, had poor survival in muddy-sand, but smaller size and more branching with less flowering in sand. Shape also exhibited phenotypic plasticity, with relatively wide leaves and longer rhizome internodes at the sandier site. Overwintering shoots, which were transplanted among four sites in a fully reciprocal design, had lower survival and size after 6 months at sand compared to muddy-sand sites, but with greater root investment at collection. Shoots from one muddy-sand site, regardless of outplant site, maintained relatively short internodes over 1.5 years. Overall, shoots tended to remodel in summer as a function of sediment type, while internode extension was phenotypically plastic in both experiments, as well as fixed by source. Because sediment correlated with water movement, eelgrass traits expressed in sand could reduce drag (smaller above-ground size) and provide anchorage (root investment). Shorter internodes at muddy-sand outplant sites and from one muddy-sand source site could influence space-filling and foraging strategies. Across experiments, poor survival of seedlings relative to vegetative shoots in muddy-sand may reflect low-oxygen conditions that are challenging for early life stages of eelgrass to overcome. The substantial trait variation in transplants across sediment type could be a response to below-ground chemistry and above-ground hydrodynamics, but these drivers were not distinguishable with the study design.</div></div>","PeriodicalId":8273,"journal":{"name":"Aquatic Botany","volume":"201 ","pages":"Article 103904"},"PeriodicalIF":1.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144204534","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}