Marine environmental research最新文献

{"title":"Microplastic contamination and biological alterations in Atlantic wild fish populations, and human health risks associated to fillet consumption","authors":"Sara C. Lourenço ,&nbsp;Alexandre A.M.R.A. Aleluia ,&nbsp;L. Gabriel A. Barboza ,&nbsp;Xosé L. Otero ,&nbsp;Sara C. Cunha ,&nbsp;José O. Fernandes ,&nbsp;Lúcia Guilhermino","doi":"10.1016/j.marenvres.2025.107139","DOIUrl":"10.1016/j.marenvres.2025.107139","url":null,"abstract":"<div><div>This study tested the hypothesis that long-term exposure to microplastics (MPs) is causing biological alterations in North Atlantic wild populations of <em>Trisopterus luscus</em> (pouting) and <em>Merluccius merluccius</em> (hake). It also estimated the human risk of MP intake (HRI) through fillet consumption, and combined the HRI and polymer health hazard in the Risk of Intake and Polymer Hazard Index (RIPHI). Fish (103) were analysed for MPs (gastrointestinal tract, gills, liver, brain, muscle), biomarkers (physical condition, neurotoxicity, energy production, oxidative stress and damage) and general stress (Integrated Biomarker Response – IBR). After particle analysis (Fourier Transform Infrared spectroscopy, Raman spectroscopy) and data correction for contamination, MPs accounted for 77 % of 311 particles. From 103 fish, 79 % contained MPs. The overall mean concentration ±SD was 0.09 ± 0.09 MP g⁻¹ (2.32 ± 2.35 MPs ind⁻¹) with no significant interspecific differences (p &gt; 0.05). Among body sites, brain had the highest MP concentration (pouting: 0.6 MP g⁻¹; hake: 0.5 MP g⁻¹). Most abundant polymers were polyethylene (40 %), polypropylene (21 %) and polymethyl methacrylate (12 %). Fragments (&lt;150 μm) predominated. MP profiles pointed to prey-predator transfer. Fish with MPs had higher stress levels (IBR, pouting: 0.317; hake: 0.200) than specimens without MPs (pouting: 0.0; hake: 0.062). Oxidative stress was the effect most clearly linked to MPs. Hake fillet poses lower HRI (e.g., 0.2 to 1.5 MPs day⁻¹) than pouting fillet (e.g., 0.4 to 3.0 MPs day⁻¹). RIPHI values showed the opposite trend (e.g., hake: 138 to 1038; pouting: 113 to 845), indicating medium to high risk to human consumers. Findings related long-term MPs exposure in the natural habitat with biological alterations in wild fish populations, highlight the importance of food diversification for a healthy alimentation, and stress the urgent need of reducing MPs pollution to promote ecosystem sustainability and global health.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"208 ","pages":"Article 107139"},"PeriodicalIF":3.0,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling the impact of bisphenol A on date mussels: Insights into oxidative stress, hormonal imbalance, gonadal atresia, and immune resilience","authors":"Heba-Tallah Abd Elrahim Abd Elkader ,&nbsp;Ahmed S. Al-Shami","doi":"10.1016/j.marenvres.2025.107143","DOIUrl":"10.1016/j.marenvres.2025.107143","url":null,"abstract":"<div><div>Sedentary organisms, such as mussels, may be susceptible to environmental estrogenic compounds, including bisphenol A (BPA). This study aimed to evaluate the interplay between BPA exposure and the immune response, hormonal imbalance, tissue damage (specifically in the digestive glands, labial palps, and male gonads), gonadal atresia, and antioxidant mechanisms in the marine mussel, <em>Lithophaga lithophaga</em>. Over a period of 28 days, mussels were exposed to BPA concentrations of 0, 0.25, 1, 2, and 5 μg/L. The exposure resulted in notable morphological alterations in the hemocytes of <em>L. lithophaga</em>, characterized by irregularities in the outer cell membranes of granulocytes and hyalinocytes, with some cells exhibiting filopodia formation. Granulocytes displayed an increased number of granules and vacuoles, while the nuclei of hyalinocytes appeared shrunken. The condition index, along with levels of testosterone and 17β-estradiol, significantly decreased with increasing BPA concentration, except for the 1 and 2 μg/L treatments. BPA exposure led to a marked increase in malondialdehyde (MDA) levels and a reduction in reduced glutathione (GSH) across all tissues at every concentration tested. The activity of antioxidant enzymes varied among the gonads, digestive glands, and labial palps. Notably, there was a significant increase in superoxide dismutase (SOD) activity in the gonads of mussels exposed to 2 μg/L of BPA, as well as in the digestive glands and labial palps of those exposed to 1 μg/L, suggesting a potential alteration in redox homeostasis. Additionally, structural changes in the digestive tubules of BPA-exposed mussels were observed. The observed pathological symptoms were characteristic of an inflammatory response, including hemocyte diapedesis and infiltration, the formation of syncytia, and the sloughing of epithelial tissue, indicated by an increased ratio of mean luminal radius to mean epithelial thickness in a dose-dependent manner. In the BPA-exposed group, testicular follicles exhibited atrophy, deformation, and a reduction in both size and number per area, appearing nearly empty and lacking spermatids and spermatozoa, alongside hypertrophy and hyperplasia of auxiliary cells. Scanning electron microscopy further revealed structural abnormalities in the heads and flagella of spermatids from the BPA-exposed group. Thus, this study demonstrates the risk of long-term exposure to BPA in immune response, tissue, and biochemical responses of date mussel <em>L. lithophaga</em>. The gonad was the most affected tissues followed by the digestive gland and labial palps.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"208 ","pages":"Article 107143"},"PeriodicalIF":3.0,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Co-occurring foundation species increase habitat heterogeneity across estuarine intertidal environments on the South Island of New Zealand","authors":"Ken Joseph E. Clemente ,&nbsp;Mads S. Thomsen","doi":"10.1016/j.marenvres.2025.107150","DOIUrl":"10.1016/j.marenvres.2025.107150","url":null,"abstract":"<div><div>Estuaries are traditionally considered sedimentary ‘bare’ ecosystems, dominated by infauna that bury into sediments to avoid being eaten by fish or birds. However, estuaries can be converted to biogenic complex ‘hard’ habitats, like seagrass beds, seaweed patches or surface-deposits of live or dead shells. Furthermore, habitat heterogeneity is enhanced if these foundation species co-occur. Still, few studies have quantified abundances and co-occurrences of different types of foundation species along spatiotemporal stress gradients. We therefore quantified abundances of seagrasses (<em>Zostera muelleri</em>), seaweeds (<em>Ulva</em> spp., <em>Gracilaria chilensis</em>), surface deposited dead shells and densities of dominant and partly buried cockles (<em>Austrovenus stutchburyi</em>) in estuaries on the South Island of New Zealand. A total of 927 large-scale drone images, 1264 small-scale camera images, and 160 sediment-quadrats were collected from 32 common estuarine environments (fully crossed 5-factorial surveys with 2 latitudes x 2 sites x 2 intertidal elevations x 2 seasons x 2 intra-seasonal sampling months). Across the 32 environments, seagrass was most abundant (19–22 % cover, depending on sampling method), followed by shells (9–13 %) and seaweed (4 %). Scattered seaweed and shells were, despite their low cover, ubiquitous in the 32 environments, and seagrasses always co-occurred with shells and/or seaweed. The spatial gradients had a stronger influence on abundances of foundation species than temporal factors, that mainly affected seaweed and live cockles, with high (70 %), medium (50 %) and low (30 %) statistical agreement between analysis of drone vs. camera images for seaweed, shells and seagrass, respectively. Finally, correlation analysis revealed negative associations between seagrasses and both shells and seaweed, but with large variation between seasons. Our study highlights that foundation species rarely occur as single-species stands, and that the ecological impacts of scattered seaweeds and dead surface-deposited shells within seagrass beds should be studied in more detail. Our findings also underscore the critical role of spatiotemporal stressors in shaping estuarine ecosystems and highlight the importance of using supplementary sampling methods to inform management strategies for estuaries in the face of environmental change.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"208 ","pages":"Article 107150"},"PeriodicalIF":3.0,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A non-lethal technique for sampling liver from live juvenile Siberian sturgeon (Acipenser baerii)","authors":"Bahram Falahatkar ,&nbsp;Samaneh Poursaeid","doi":"10.1016/j.marenvres.2025.107133","DOIUrl":"10.1016/j.marenvres.2025.107133","url":null,"abstract":"<div><div>The liver, as a pivotal organ in the body responsible for a wide range of functions, including metabolism, detoxification, nutrient storage, and overall well-being is commonly sampled for various studies in fish research. Traditional methods for liver sampling require euthanizing the specimens. This study demonstrated a non-lethal or minimally invasive technique for collecting liver tissue from live juvenile Siberian sturgeon (<em>Acipenser baerii</em>) using a needle biopsy. We successfully collected small liver samples (100–250 mg) from each individual without any recorded mortalities. The incision was fully closed after 10 days post sampling. No significant differences in growth performance were observed between the needle-biopsied and control fish after 10 and 30 days. This technique offers a practical and valuable method for liver sampling, suitable for various research studies without sacrificing and harming fish. This is particularly beneficial for endangered and threatened species.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"208 ","pages":"Article 107133"},"PeriodicalIF":3.0,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptive divergence in response to shared environmental pressures: examining gastropod shell exploitation by intertidal hermit crabs","authors":"Guillermina Alcaraz,&nbsp;Fernanda Herce,&nbsp;Brian Urbano,&nbsp;Marcia M. Ramírez-Sánchez,&nbsp;Eduardo E. Garcia-Cardenas","doi":"10.1016/j.marenvres.2025.107141","DOIUrl":"10.1016/j.marenvres.2025.107141","url":null,"abstract":"<div><div>Gastropods commonly cope with the biotic and abiotic pressures of the intertidal through morphological adaptations of their shells. Snails from wave-exposed areas commonly have more streamlined shells that reduce drag forces with larger openings that favor their attachment to the substrate. In contrast, snails from sites with high predation commonly have a more globose shape that hinders breakage by predators. Hermit crabs use the shells of dead snails to protect their soft abdomen and confront similar biotic and abiotic pressures. Our main goal was to determine whether hermit crabs exploit intraspecific variation in snail shell shape in ways that may be adaptive; we tested two snail species with different shell profiles (<em>Mancinella</em> = globose-like and <em>Stramonita</em> = streamlined) across two intertidal zones. Using geometric morphometrics, we compared the shape and size of shells of snails with those used by hermit crabs in the upper and mid intertidal zones. We found that shell shape differed depending on the type of organism and the intertidal zone they inhabit. <em>Mancinella</em> shell shape was similar between snails and hermit crabs in the mid intertidal, and <em>Stramonita</em> shells were similar between crabs and snails in the upper intertidal. However, the shell shape differed between snails and hermit crabs in <em>Mancinella</em> shells in the upper intertidal and <em>Stramonita</em> shells in the mid intertidal. Furthermore, in the upper intertidal, hermit crabs occupied the most extreme shapes of each snail species, the most globose <em>Mancinella</em> and most streamlined <em>Stramonita</em> shells. Thus, although both taxa are subject to similar pressures on shell shape, different constraints result in some shape similarities and contrasts among species depending on the intertidal zones they inhabit.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"208 ","pages":"Article 107141"},"PeriodicalIF":3.0,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterising tropical oyster reefs: invertebrate-environment associations and a newly documented reef building species","authors":"Marina A. Richardson ,&nbsp;Christina Buelow ,&nbsp;Rod M. Connolly ,&nbsp;Chris L. Gillies ,&nbsp;Nikolina Nenadic ,&nbsp;Robert Porter ,&nbsp;Michael Traurig ,&nbsp;Carmel McDougall","doi":"10.1016/j.marenvres.2025.107136","DOIUrl":"10.1016/j.marenvres.2025.107136","url":null,"abstract":"<div><div>Oyster reefs were once widespread across the global tropics but have often been excluded from global assessments of historical distributions, declines and conservation needs. Consequently, little is known about tropical oyster reefs, including ecological function, which species are reef-building, structural characterisations of remnant reefs, associated biodiversity, and whether conservation actions are needed to ensure their recovery. We compared the characteristics of newly documented tropical oyster reefs across three Australian locations to gain a foundational understanding of their ecology. At each location, structural reef traits were assessed, and associated invertebrate communities were quantified taxonomically and functionally. Location had a strong effect on invertebrate communities, with reefs in Gladstone hosting a greater abundance, and larger, invertebrates, followed by Mapoon, and then Proserpine. Most invertebrates were positively associated with the lower intertidal zone and shelly sediment – we hypothesise that heat stress, interstitial reef spaces, and the proportion of habitat edges could be explanations for these observed patterns, however, further research is needed to confirm this. Reef-building oysters identified using molecular markers at all locations were predominantly <em>Saccostrea</em> lineage B, a species broadly distributed across tropical Australia and the Indo-Pacific. These characterisations provide novel insights into the ecology of tropical oyster reefs and baseline information to inform appropriate conservation strategies.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"208 ","pages":"Article 107136"},"PeriodicalIF":3.0,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gut microbiota and metabolic functions in herbivorous fish from Xisha coral reefs, China","authors":"Xiyue Yang ,&nbsp;Yayuan Xiao ,&nbsp;Xiaojun Shi ,&nbsp;Tuanjie Li ,&nbsp;Xiaofei Xiong ,&nbsp;Teng Wang ,&nbsp;Lin Lin ,&nbsp;Yu Liu ,&nbsp;Jian Zou ,&nbsp;Chunhou Li ,&nbsp;Yong Liu ,&nbsp;Peng Wu","doi":"10.1016/j.marenvres.2025.107148","DOIUrl":"10.1016/j.marenvres.2025.107148","url":null,"abstract":"<div><div>Herbivorous fishes are the major consumers of macroalgae on coral reefs. Macroalgae are then degraded by fish gut microbiota. Despite the importance of this process, there remains a lack of information about the gut bacterial community of herbivorous fishes in coral reefs. This study examined the composition and potential metabolic functions of gut microbiota through full-length 16S rRNA amplicon sequencing for coral reef fish species from the Xisha islands of China, including five herbivorous species (<em>Naso unicornis</em>, <em>N. lituratus</em>, <em>N. brevirostris</em>, <em>Ctenochaetus striatus</em>, and <em>Siganus argenteus</em>) and one carnivorous species (<em>Myripristis kuntee</em>). The composition of the gut bacterial community and potential functional genes were observed and significant differences were identified between herbivorous and carnivorous fish species. The bacterial diversity (Shannon and Simpson indexes) in herbivorous fish was significantly higher than in carnivorous fish. <em>Clostridium</em> was significantly more abundant in carnivorous fish than herbivorous fish (<em>p</em> &lt; 0.05). Conversely, <em>Niameybacter</em>, <em>Alistipes</em>, <em>Desulfovibrio</em>, and <em>Akkermansia</em> were more abundant in herbivorous fish (<em>p</em> &lt; 0.05). These bacterial genera, which are shared among herbivorous fish, are believed to play crucial roles in macroalgae metabolism. A principal coordinate analysis further revealed that the gut bacterial composition of the five herbivorous fish species could be divided into two distinct clusters, which was influenced by selective feeding behaviors on different macroalgae types. Functional analysis of gut bacteria in herbivorous fishes showed a high abundance of carbohydrate metabolism pathways. Through comparison with the carbohydrate-active enzyme (CAZy) database, eight glycoside hydrolases (GHs) and one glycosyltransferase (GT) were identified in herbivorous fishes, providing further insights into the roles of gut microbiota in macroalgae metabolism. This study provides valuable insights into the roles of the gut microbiota in herbivorous fishes with regard to metabolizing various types of macroalgae.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"208 ","pages":"Article 107148"},"PeriodicalIF":3.0,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Setting the limit: cold rather than hot temperatures limit intertidal distribution of a coastal foundation species","authors":"Kerstin Wasson ,&nbsp;Kim Cressman ,&nbsp;Kathryn Beheshti ,&nbsp;Erin C. Herder ,&nbsp;Charlie Endris ,&nbsp;Christopher D.G. Harley ,&nbsp;Alicia Abadía-Cardoso ,&nbsp;Rodrigo Beas-Luna ,&nbsp;Joachim Carolsfeld ,&nbsp;Andrew L. Chang ,&nbsp;Jeffrey A. Crooks ,&nbsp;Matthew C. Ferner ,&nbsp;Edwin D. Grosholz ,&nbsp;Neil Harrington ,&nbsp;Jacob Harris ,&nbsp;Hilary Hayford ,&nbsp;Alicia R. Helms ,&nbsp;Julio Lorda ,&nbsp;Jennifer L. Ruesink ,&nbsp;Amaia Ruiz de Alegría-Arzaburu ,&nbsp;Chela J. Zabin","doi":"10.1016/j.marenvres.2025.107149","DOIUrl":"10.1016/j.marenvres.2025.107149","url":null,"abstract":"<div><div>Long-lasting restoration success of foundation species requires understanding their responses to climate change. For species with broad distributions, lower latitudes may serve as a proxy for future warming at higher latitudes. Such space-for-time substitutions are a powerful tool for developing climate change predictions for species distributed along steep elevational gradients. To understand climate resilience of a key coastal foundation species, we examined the upper elevational limit of the native Olympia oyster (<em>Ostrea lurida</em>) along its entire range at 26 sites spanning 21° latitude, from British Columbia to Baja California. Counter to our expectations, high air temperatures did not affect variation in the upper limit of Olympia oysters. Indeed, Olympia oysters extended high into the intertidal zone at the warmer southern sites, and shading did not influence the upper limit. Our models indicated instead that extreme low temperatures set the upper limit for Olympia oysters at higher latitudes. In contrast, neither the Pacific oyster (<em>Magallana gigas</em>), a co-occurring global invader, nor barnacles exhibited clear latitudinal patterns. These findings suggest that Olympia oysters and restoration projects aimed at supporting their recovery will be resilient to increased temperatures projected by climate change models. Our results also illustrate the importance of testing the assumption that species on steep elevational gradients are living close to their upper thermal limits and will be negatively impacted by warming; for this foundation species, the assumption was false. Latitudinal studies enhance understanding of species response to climate stressors and are key to the design of climate-resilient conservation strategies.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"208 ","pages":"Article 107149"},"PeriodicalIF":3.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Idiosyncratic patterns of chlorophyll-a anomalies in response to marine heatwaves in the Adriatic Sea (Mediterranean Sea) over the last two decades","authors":"Gregorio Motta ,&nbsp;Valentina Olmo ,&nbsp;Luca Xamin ,&nbsp;Antonio Terlizzi ,&nbsp;Francesco Petruzzellis ,&nbsp;Giovanni Bacaro ,&nbsp;Daniele Iudicone ,&nbsp;Stanislao Bevilacqua","doi":"10.1016/j.marenvres.2025.107144","DOIUrl":"10.1016/j.marenvres.2025.107144","url":null,"abstract":"<div><div>In the open ocean, marine heatwaves (MHWs) have been associated to a decline of Chlorophyll<em>-a</em> (Chl<em>-a</em>) concentration in tropical and temperate areas while, at higher latitudes, they seem to enhance phytoplankton productivity. Currently, uncertainties remain on the outcomes of MHWs on primary production in coastal and heterogenous marine regions. We analyzed long-term modeled satellite-derived data on sea surface temperature and Chl<em>-a</em> concentration in the Adriatic Sea (Mediterranean Sea), a semi-enclosed basin where coastal and open-sea environmental conditions co-occur, to explore Chl<em>-a</em> responses to MHWs.</div><div>We found that both low and high Chl<em>-a</em> anomalies were strictly dependent on MHWs, although following direct or inverse relationships in different areas, as a consequence of regional-scale heterogeneities in nutrient availability, riverine inputs, circulation and geomorphology. Along the west coast and shallow areas of the North and Central Adriatic, high MHWs frequency, duration and intensity corresponded to high frequency of Chl<em>-a</em> peaks and/or increased intensity and duration of low Chl<em>-a</em> anomalies, suggesting pronounced fluctuations with intense phytoplankton blooms alternating to extremely low production events. Conversely, in offshore and deeper areas, especially in the South Adriatic, MHWs frequency, duration and intensity inversely correlated with Chl<em>-a</em> anomalies, indicating a possible reduction of phytoplankton biomass and a decline of organic matter flow towards the sea floor. Prolonged MHWs may therefore drive shifts in primary production with possible ecosystem-wide effects in both coastal and pelagic areas. These multifaceted MHW-Chl<em>-a</em> interactions observed in the Adriatic Sea emphasize the need for context-specific assessments in environmentally complex marine regions to develop management strategies addressing ecological and socioeconomic issues arising from the unrelenting increase of temperature anomalies.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"208 ","pages":"Article 107144"},"PeriodicalIF":3.0,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143807559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Driving mechanisms of monthly ocean front variations in a typical mariculture bay: insight from quantitative analysis of dual water isotopes","authors":"Ruixue Cao ,&nbsp;Qibin Lao ,&nbsp;Guangzhe Jin ,&nbsp;Chunqing Chen ,&nbsp;Xuan Lu ,&nbsp;Haoyu Yao ,&nbsp;Fajin Chen","doi":"10.1016/j.marenvres.2025.107146","DOIUrl":"10.1016/j.marenvres.2025.107146","url":null,"abstract":"<div><div>The ocean front in the estuary plays a key role in regulating the transport of terrestrial pollutants into the ocean. It also significantly impacts the eco-environment of coastal and estuary waters. This study conducted monthly investigations of hydrology and dual water isotopes in Zhanjiang Bay spanning from January to December 2019, quantifying the contributions of various water masses in the region and exploring the mechanisms behind changes in frontal intensity. The results showed that the salinity front began to strengthen in the early rainy season and peaked in August, while its intensity was generally weaker in the dry season. This seasonal variation is attributed to the increased contribution of riverine freshwater input during the rainy season, rising from less than 5 % in the dry season to approximately 15 % in the rainy season. Importantly, the strengthening of the ocean front may lead to the accumulation of land-based pollutants, such as nutrients, within the bay, thereby deteriorating water quality.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"208 ","pages":"Article 107146"},"PeriodicalIF":3.0,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}