Deep-Sea Research Part I-Oceanographic Research Papers最新文献

{"title":"Summer circulation and water masses transport in Bransfield Strait, Antarctica: An evaluation of their response to combined effects of Southern Annular Mode and El Niño–Southern Oscillation","authors":"Brendon Yuri Damini ,&nbsp;André L. Brum ,&nbsp;Rob A. Hall ,&nbsp;Tiago S. Dotto ,&nbsp;José Luiz L. Azevedo ,&nbsp;Karen J. Heywood ,&nbsp;Mauricio M. Mata ,&nbsp;Carlos A.E. Garcia ,&nbsp;Rodrigo Kerr","doi":"10.1016/j.dsr.2025.104516","DOIUrl":"10.1016/j.dsr.2025.104516","url":null,"abstract":"<div><div>Bransfield Strait, situated in the northern Antarctic Peninsula, is a critical area for studying the impacts of climate change. This complexity arises from the convergence of distinct water masses: Transitional Zonal Water with Weddell influence (TWW), and Transitional Zonal Water with Bellingshausen influence (TBW). This study aims to give a long–term description of Bransfield Strait circulation during austral summers through high-quality hydrographic data from 2003 to 2019, altimetry data and the global eddy–resolving ocean reanalysis product GLORYS12v1. Findings reveal a cyclonic ocean circulation pattern within Bransfield Strait, characterized by the northeastward Bransfield Current along the South Shetland Islands and extending to Elephant Island, and the southwestward Antarctic Coastal Current entering near 62.40°S and 55.00°W. GLORYS12v1 and altimetry datasets revealed that: part of the Bransfield Current leaves the eastern basin between King George and Clarence Islands and recirculation around the South Shetland Islands, and provides the first robust estimate over an extended period that TBW is transported between King George and Elephant Islands and feeds Bransfield Current. Our results highlight links between the strength of TBW transport and variability in climate modes, quantifying their magnitude and variability due to wind forcing modulation by combined effects of Southern Annular Mode and El Niño–Southern Oscillation indices (jointly called the SEI index). For instance, time-averaged years of SEI negative conditions reveal 0.10 Sv of TBW entering the Bransfield Strait between King George and Elephant Islands. On the other hand, under SEI positive conditions, the TBW transport increases to 0.31 Sv. These observed changes are crucial for advancing our understanding of regional circulation patterns and their underlying mechanisms, as they directly influence the physical and biogeochemical properties of the region.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"222 ","pages":"Article 104516"},"PeriodicalIF":2.3,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The hanging gardens of Blanes Canyon, Northwestern Mediterranean Sea","authors":"Meri Bilan ,&nbsp;Jordi Grinyó ,&nbsp;Cecilia Cabrera ,&nbsp;Andrea Gori ,&nbsp;Andreu Santín ,&nbsp;Veerle A.I. Huvenne ,&nbsp;Marie-Claire Fabri ,&nbsp;Marta Arjona-Camas ,&nbsp;Sarah Paradis ,&nbsp;Claudio Lo Iacono ,&nbsp;Stefano Ambroso ,&nbsp;Ruth Durán ,&nbsp;Stefano Piraino ,&nbsp;Sergio Rossi ,&nbsp;Pere Puig","doi":"10.1016/j.dsr.2025.104514","DOIUrl":"10.1016/j.dsr.2025.104514","url":null,"abstract":"<div><div>Submarine canyons are ubiquitous geomorphic features found intercepting the continental margins. As such, they provide environmental conditions suitable for many suspension feeding organisms, as they settle on steep rocky canyon walls, whilst taking advantage of increased currents that bring suspended organic matter and food. Additionally, demersal fishing grounds can be found surrounding submarine canyons where it can negatively affect species inhabiting these environments, including vulnerable ecosystems such as cold-water corals (CWCs). In order to understand the impacts of demersal fisheries in CWC communities, we first need to understand their distribution, species composition and vulnerability. Blanes Canyon is an example of a submarine canyon surrounded by demersal fishing grounds, where baseline knowledge on CWCs currently lacks. This study contributes to filling these knowledge gaps by using a dense grid of ROV transects along the canyon, high resolution bathymetry data and CTD surveys, which altogether provide a quantitative description of megabenthic assemblages. Blanes Canyon hosts at least 12 CWC species within 450–1300 m depth range, mainly inhabiting the steep canyon walls. Different assemblages of CWC species were found. <em>Desmophyllum dianthus</em> was the most abundant species, found throughout the entire canyon. Colonial scleractinian species (<em>Desmophyllum pertusum</em> and <em>Madrepora oculata</em>) were found in the canyon head but were lacking in the eastern canyon branch, where octocorals (<em>Muriceides lepida</em>) and black corals (<em>Leiopathes glaberrima</em>) were prevailing. Detailed CTD survey indicated that nepheloid layers (bottom and intermediate) were found at the same depth range as the megabenthic communities, since they provide suspension feeders with particulate organic matter (POM). Overall, this study confirms Blanes Canyon as a CWC habitat, providing densities and spatial distribution of different megabenthic species, along with information of their environmental niches.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"221 ","pages":"Article 104514"},"PeriodicalIF":2.3,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143942418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Creepy-Crawlies of the Arctic deep sea: Metazoan meiobenthic communities across latitudinal and bathymetric gradients in the western Arctic Ocean","authors":"Jona R. Silberberg ,&nbsp;Dieter Piepenburg ,&nbsp;Christiane Hasemann","doi":"10.1016/j.dsr.2025.104513","DOIUrl":"10.1016/j.dsr.2025.104513","url":null,"abstract":"<div><div>Knowledge on meiofauna in the Arctic Ocean is lacking despite their importance for ecosystem functioning. The Synoptic Arctic Survey aimed to fill such knowledge gaps and thus included meiofaunal sampling. A bathymetric transect (from shelf to central basins) was sampled in the western Arctic Ocean during the HLY2202 expedition. Four sampled transect stations were investigated to answer three key questions: (1) How does the meiofaunal community change along the transect? (2) Which sedimentary parameters drive the meiofaunal community compositions? (3) Has the meiofaunal community at the North Pole changed since 1996, and if so, how? The uppermost 3 cm of sediment were analyzed for metazoan meiofaunal composition (including meiofaunal abundance and nematode biomass) in relation to food proxies (i.e. bacterial abundance and biomass, organic carbon, phospholipids, chlorophyll <em>a</em>, phaeophytin) and sediment porosity. Meiofaunal density and taxa count decreased with increasing water and sediment depth, as did nematode body sizes. This supported the concept of deep-sea miniaturization. Thicker nematodes dominated near-surface sediments, while slimmer individuals dominated deeper layers, a pattern related to sediment porosity. Sediment pigments (i.e. chlorophyll) and bacteria were confirmed as important food sources, and sediment porosity was corroborated as an important driver of meiofaunal communities. Virtually no differences were found in abundance of higher meiofauna taxa at the North Pole between 1996 and 2022, potentially due to relative stability provided by the still permanent ice-cover. Examining the meiofaunal composition at genus level will allow analysis of potential changes in diversity and ecosystem functions in relation to environmental changes.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"221 ","pages":"Article 104513"},"PeriodicalIF":2.3,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variation in the arrival time of internal solitary waves in the northern South China Sea","authors":"Gang Wang ,&nbsp;Dianfu Fu ,&nbsp;Yuanling Zhang ,&nbsp;Peichao Zhang ,&nbsp;Shumin Jiang ,&nbsp;Dejun Dai ,&nbsp;Chuanjiang Huang ,&nbsp;Fangli Qiao","doi":"10.1016/j.dsr.2025.104505","DOIUrl":"10.1016/j.dsr.2025.104505","url":null,"abstract":"<div><div>Mooring observations conducted at a station in the northern South China Sea (SCS) in 2019 and 2020 revealed two daily packets of internal solitary waves (ISWs) during spring tides, a finding consistent with previous reports. On the basis of arrival time, ISWs in the northern SCS are usually classified into two types: type-a waves that appear at 24-h intervals and type-b waves that appear at approximately 25-h intervals. However, the two daily ISW packets observed in this study exhibited no notable differences in arrival time intervals. Instead, their arrival times mutually transitioned; that is, the arrival time of the two ISW packets interchanged during two consecutive neap-spring cycles, demonstrating that ISW arrival time is modulated by the tide itself rather than by a tidal constituent of specific frequency. In addition to the transition phenomenon, daily deviations were found between the arrival time interval of the ISWs and the background tidal peak intervals. The daily deviations were modulated by the tidal inequality of the neap-spring cycle, whereby stronger tides generate larger ISWs with higher phase speeds. The difference in phase speed resulted in the different arrival time intervals recorded at the observing station. Furthermore, daily deviation magnitudes increased with the distance between the observing station and the ISW generation site. These findings highlight the challenges in classifying field-observed ISWs into type-a or type-b categories.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"221 ","pages":"Article 104505"},"PeriodicalIF":2.3,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced diapycnal mixing of a subsurface anticyclonic eddy pair in the northeastern South China Sea","authors":"Yingci Feng ,&nbsp;Qunshu Tang ,&nbsp;Jie Sun ,&nbsp;Zhiyou Jing ,&nbsp;Jian Li ,&nbsp;Weikang Zhan ,&nbsp;Wenhuan Zhan","doi":"10.1016/j.dsr.2025.104502","DOIUrl":"10.1016/j.dsr.2025.104502","url":null,"abstract":"<div><div>Mesoscale eddies, which play a vital role in transporting substances and regulating marine ecosystems, are particularly active and energetic in the northern South China Sea (SCS). However, their fine-scale structures and diapycnal diffusivity inside and outside eddies remain poorly understood. In this study, a pair of subsurface anticyclonic eddies (A1 and A2) in the northern SCS was investigated using 7 seismic reflection transects acquired in April 2009. The anticyclonic eddies consist of two closely adjacent, bowl-shaped subsurface structures, each approximately 70 km in diameter and extending to a depth of 700 m. The transition zone between the eddies is approximately 10 km wide and 500 m deep. These two eddies merge together in the upper water above 500 m. The average diffusivity across the eddy is ∼7.7 × 10⁻⁵ m² s⁻¹ quantified from seismic data. Within the eddy centers (A1 and A2), the diffusivities are relatively low, approximately 2.4 and 3.9 × 10⁻⁵ m² s⁻¹, but increase to more than 4.9 × 10⁻⁵ m² s⁻¹ in the eddy transition zone. Diffusivities in the frontal zone between the eddy and the Kuroshio reach a maximum of 13.9 × 10⁻⁵ m² s⁻¹. We suggest that the shear instability occurring near the frontal region is the primary energy source for turbulent mixing in this region. These findings provide valuable insights into the turbulent mixing associated with irregular eddies and contribute to a more comprehensive understanding of the interactions between eddies and the ocean.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"220 ","pages":"Article 104502"},"PeriodicalIF":2.3,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Full destruction of an anticyclonic eddy in the Northern South China Sea by Tropical Storm Mulan","authors":"Xueming Zhu ,&nbsp;Shaojing Guo ,&nbsp;Jinglong Chang ,&nbsp;Xiaobo Zhang ,&nbsp;Zhan Hu ,&nbsp;Hui Wang","doi":"10.1016/j.dsr.2025.104500","DOIUrl":"10.1016/j.dsr.2025.104500","url":null,"abstract":"<div><div>The destruction of an anticyclonic eddy (AE) as a Tropical Storm, Mulan, passed through the northern South China Sea in August 2022 was observed by two Sea Wing underwater gliders. By integrating glider observations and HYCOM outputs, this study investigated 3D structural destruction and dissipation of eddy kinetic energy (EKE) within an AE. The warm and low-salinity core inside the AE was devastated by Mulan-induced strong disturbances. Intense wind stress disrupted the upper anticyclonic flow around the AE by accelerating (reversing) the flow in the western (eastern) part of the AE. These severely destroyed the unique 3D structure of the AE and led to 57 % and 96 % reductions in EKE and eddy potential energy (EPE), respectively. Furthermore, EKE budget analyses demonstrated that the EPE to EKE conversion, wind stress work, and divergence of pressure work served as dominant sources of EKE before, during, and after Mulan's passage, respectively. However, the EKE dissipation was primarily driven by Mulan-induced turbulent mixing directly during its passage and strong vertical mixing associated with near-inertial waves after its passage. To our knowledge, this is the first study to elucidate the multiple dynamic processes contributing to or dissipating dramatic EKE changes in the South China Sea over the entire tropical cyclone-eddy interaction period. These findings advance our understanding of 3D structural destruction and complex oceanic energy transfer mechanisms within the AE under tropical cyclone-eddy interactions.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"220 ","pages":"Article 104500"},"PeriodicalIF":2.3,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143825741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isotopic signatures and nutritional composition of selected macrobenthos from the site F cold seep in the South China Sea","authors":"Haining Wang ,&nbsp;Xiaocheng Wang ,&nbsp;Minxiao Wang ,&nbsp;Chaolun Li","doi":"10.1016/j.dsr.2025.104501","DOIUrl":"10.1016/j.dsr.2025.104501","url":null,"abstract":"<div><div>Understanding the food sources and nutrient structures is crucial for grasping the community structure and function. At Site F, which is characterized by active seepages, a diverse macrobenthos community thrives. Carbon and nitrogen isotopic values vary among species and between species and their environment. We have constructed a hypothetical food web for Site F, which includes four trophic levels and encompasses 22 species. Two distinct communities were identified based on the presence or absence of seepage, and their complexity was compared using Bayesian metrics and specialization index. Our findings suggest that the availability and diversity of food resources, coupled with abiotic pressures and biotic interactions, play a crucial role in shaping community complexity. The non-seep community exhibited lower species richness and diversity, resulting in reduced community complexity compared to the seep community at Site F. These results contribute to a deeper understanding of nutritional ecology and community structure at Site F cold seep.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"220 ","pages":"Article 104501"},"PeriodicalIF":2.3,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coral and float-derived observations of flow around SG_áan K_ínghlas-Bowie Seamount in the Northeast Pacific: revisiting the Taylor cone","authors":"Tetjana Ross,&nbsp;Cherisse Du Preez,&nbsp;Debby Ianson","doi":"10.1016/j.dsr.2025.104499","DOIUrl":"10.1016/j.dsr.2025.104499","url":null,"abstract":"<div><div>Seamounts are oases of life within the deep sea. Recruitment mechanisms to these isolated systems, where benthic larvae spend weeks or months in the pelagic, remain a mystery. Persistent closed circulation patterns ('Taylor cones') are proposed to increase local retention around these underwater mountains, but the idea remains controversial. Some coral species may help us understand this puzzle. Cold-water corals, such as <em>Primnoa pacifica</em> and <em>Parastenella</em> spp., grow slowly, orienting their fan perpendicular to, and curved towards, the mean-flow direction. We took advantage of these long-term natural current meters, using a combination of benthic imagery, sea-surface height, Argo trajectory, hydrographic, and reanalysis model data to examine flow around S<span><math><mrow><munder><mi>G</mi><mo>_</mo></munder></mrow></math></span>áan <span><math><mrow><munder><mi>K</mi><mo>_</mo></munder></mrow></math></span>ínghlas-Bowie Seamount (S<span><math><mrow><munder><mi>K</mi><mo>_</mo></munder></mrow></math></span>-B) in the Northeast Pacific. We found that corals living on the seafloor on all sides of the seamount experienced a north to south flow (opposite to regional circulation), showing no evidence of a persistent closed circulation. We suggest that a combination of remotely generated internal tides breaking on the plateau and steering/rectification of local tides below 500m could cause these strong coherent bottom currents. Finally, we also observed transient clockwise circulation around the seamount when Haida Eddies became trapped. Eddies provide a regular mechanism for larval and food transport from the coast to S<span><math><mrow><munder><mi>K</mi><mo>_</mo></munder></mrow></math></span>-B. Once trapped, the closed clockwise circulation lasts months and likely aids in local retention and self-recruitment. Our findings reveal the dynamic nature of flow over seamount-like features and the importance of understanding this complexity in the broader context of marine conservation.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"220 ","pages":"Article 104499"},"PeriodicalIF":2.3,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143833394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On Anguillosyllis cf. hessleri Maciolek, 2020 – A species complex from the Clarion-Clipperton zone, abyssal central Pacific","authors":"Regan Drennan ,&nbsp;Lenka Neal ,&nbsp;Helena Wiklund ,&nbsp;Eva C.D. Stewart ,&nbsp;Muriel Rabone ,&nbsp;Corie Boolukos ,&nbsp;Innes Clatworthy ,&nbsp;Zuzana Jungmanova ,&nbsp;Thomas G. Dahlgren ,&nbsp;Adrian G. Glover","doi":"10.1016/j.dsr.2025.104453","DOIUrl":"10.1016/j.dsr.2025.104453","url":null,"abstract":"<div><div>The benthic annelid fauna of polymetallic nodule fields in the eastern Clarion-Clipperton Zone (CCZ) has recently been the subject of taxonomic investigations aiming to document the biodiversity of this region. While investigating the annelids, a particularly high diversity was discovered within the genus <em>Anguillosyllis</em> Day, 1963 using a combination of morphological and molecular approaches. Initially, 38 specimens of <em>Anguillosyllis</em> were assigned to the known CCZ species <em>Anguillosyllis hessleri</em> Maciolek, 2020 based on morphological examination, including examination of the type specimen. However, our genetic data revealed that these specimens represent four distinct lineages (putative species) based on COI and 16S markers. Further morphological investigation using SEM revealed a complex structure of the prostomium, which could potentially differentiate these lineages. However, as no molecular or SEM data are available from the type specimen of <em>A. hessleri</em>, we cannot ascertain which, if any, of these lineages represent the known species described by Maciolek (2020). Thus, currently, we can only assign CCZ specimens to <em>Anguillosyllis</em> cf. <em>hessleri</em> and further distinguish the lineages by assigning each a unique code in the form of “NHM_####”. The SEM observations are the first reported for <em>Anguillosyllis</em>, revealing new taxonomic characters that may be used to disentangle the <em>A. hessleri</em> species complex and be of use in taxonomy of <em>Anguillosyllis</em> in general.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"220 ","pages":"Article 104453"},"PeriodicalIF":2.3,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early signs of recovery suggested by changes in the structure and function of deep-sea megabenthic communities on a seamount 19 years after fishing","authors":"Savannah L. Goode ,&nbsp;Ashley A. Rowden ,&nbsp;Malcolm R. Clark ,&nbsp;David A. Bowden ,&nbsp;Fabrice Stephenson","doi":"10.1016/j.dsr.2025.104488","DOIUrl":"10.1016/j.dsr.2025.104488","url":null,"abstract":"<div><div>Bottom trawling is the most widespread and severe human disturbance affecting deep-seafloor environments. Seafloor communities inhabiting seamounts (undersea hills or mountains) are especially vulnerable to trawling impacts as they are often dominated by long-lived, sessile epifauna (e.g., cold-water corals) that are easily damaged and/or removed by fishing gear. Trawling on seamounts is spatially concentrated, compounding effects on the benthos. However, the extent to which communities on seamounts that are closed to fishing can recover from earlier trawling impacts is uncertain. Previous studies have hypothesised that any post-trawling recovery of benthic communities on seamounts will probably be initially patchy, recolonised by surviving remnant populations, and may take several decades or more to occur. A fine-scale approach is thus needed to understand and determine the spatio-temporal dynamics of recovery. To address this need, we studied a New Zealand seamount located on Chatham Rise, Morgue, that was heavily trawled in the 1990s before being closed to fishing in 2001. We analysed seafloor imagery collected with a towed camera during repeat surveys in 2001, 2005, 2009, 2015, and 2020 to examine potential changes in benthic community structure and function after trawling ceased. A temporal shift in community structure driven by changes in the abundances of several taxa (mainly bryozoans, stylasterid hydrocorals, and comatulid crinoids) was observed over the study timescale, indicating the communities may have been in the early stages of post-trawling recovery. However, structural variation between different seamount sides and the summit (i.e., spatial variation) was still more pronounced than temporal variation and reflected the trawl fishing footprint. Community function showed little sign of ongoing recovery overall, though some change (driven by colonisation by stylasterid hydrocorals and bryozoans) indicative of early recovery was observed for communities on the seamount summit. Juvenile colonies of the reef-forming stony coral <em>Solenosmilia variabilis</em> were also observed between 8 and 19 years after the closure, demonstrating that the fisheries closure may have facilitated the early recovery process of this species and its associates. Overall, this work has important implications for the spatial management of seamounts vulnerable to bottom-contact fishing operations.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"220 ","pages":"Article 104488"},"PeriodicalIF":2.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143807569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}