FACETS
● Canadian Science Publishing
Preprints posted in the last 30 days, ranked by how well they match FACETS's content profile, based on 14 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.
Beaulieu, C.; Vaz, S.; Henault, T.; Labrune, C.; Barras, C.; Schweizer, M.; Rzeznik-Orignac, J.; Maillet, G.; Pruski, A.; Henry, N.; Arnaud-Haond, S.
Show abstract
Bottom trawling is the most widespread human disturbance on the seafloor, known to affect seabed structure and benthic biota. Yet, its impact on benthic communities remains documented mainly for taxa identifiable through morphology, leaving microscopic benthic communities largely overlooked. The Gulf of Lion continental shelf has been trawled for decades by French and Spanish fleets, to the point that encountering untrawled reference areas became elusive. Here, we examined prokaryote, protist and Animalia benthic communities at eight stations, using eDNA metabarcoding of core sediment samples, with five primer-pairs. Benthic communities were cross-referenced with contrasted trawling impacts, integrated across three periods: over one month, three years or ten years preceding the sampling. The community composition was primarily structured by ecological habitats, yet, trawling pressure showed association with prokaryotes and Animalia diversity. Diversity was higher at sites trawled more intensively in the preceding month, whereas long-term trawling was associated with a significant erosion of Animalia alpha diversity. Unexpectedly, communities did not display consistent vertical structure and the relative contributions of trawling and hydrodynamic reworking remain unresolved due to the absence of untrawled sites. Overall, our results show that trawling effects extend to prokaryotic compartments rarely considered in impact assessments, providing a proof of concept for eDNA-based assessment, and underline a pervasive long-term effect on Animalia communities. This study also highlights the importance of the timescale used to quantify fishing pressure and underscores the complexity of impact assessment when monitoring begins too late to establish a clear baseline, particularly when no reference site remains.
Ashraf, H.; Tsasis, P.; Mathers, K. E.; DiSanto, L.; Wong, A.; Sharma, D.; Heffernan, J. M.; Wagner, B.; Saumur, T. M.
Show abstract
BackgroundMultimorbidity is common among U.S. skilled nursing facilities (SNFs) residents and complicates pharmacologic management, yet real-world evidence on treatment patterns in this population remains limited. This study evaluated medication order rates and identified resident- and facility-level factors among SNF residents with multimorbidity. MethodsRetrospective, observational study using electronic health record (EHR) data from PointClickCares Life Sciences database. Participants were 728,222 residents active in a U.S. SNF on April 30, 2025 with at least one documented diagnosis of hypertension, hyperlipidaemia, type 2 diabetes (T2D), depression, or Alzheimers disease and related dementias (ADRD). The outcome was presence of guideline-recommended medication order for each condition, modelled with modified Poisson regression to estimate adjusted prevalence risk ratios (RRs) and 95% confidence intervals. ResultsMedication order rates were 79% for ADRD, 79.1% for T2D, 87.7% for hypertension, 83.3% for hyperlipidaemia, and 90.8% for depression. Rates varied across comorbidity combinations: ADRD was associated with lower medication order prevalence, while cardiometabolic multimorbidity profiles associated with higher prevalence. Black/African American identity had the lowest likelihoods of a medication order for 3 of 5 conditions (RRs of 0.93 to 0.92), while having hypertension or hyperlipidaemia medication order was associated with higher likelihood of having orders for 3 of remaining 4 conditions (RRs of 1.02 to 1.19). ConclusionsMost SNF residents with multimorbidity had a medication order for common chronic conditions, although important variability and disparities remain. Differences by comorbidity profile and social context underscore the need for targeted strategies supporting equitable, integrated prescribing and person-centred care in SNFs.
Ioannidis, J.; Baas, J.
Show abstract
We used Scopus data on 243949 top-cited scientists to map scientific cosmopolitanism defined as having at least two different countries that contribute alone at least 10 percent of an author published record as indexed in Scopus. 20.4 percent of the top-cited authors were cosmopolitan based on this definition. Based on current author affiliation, rates varied widely from 9% to 76% across countries with at least 250 top-cited authors. Countries with few top-cited authors had almost always high rates of cosmopolitanism. The proportion of top-cited authors who are cosmopolitan has steadily increased over time in younger generations among those who started publishing after 1965 reaching 43% recently. Large differences were also seen across scientific subfields from 1% in General Psychology and Cognitive Sciences to 46% in Econometrics. Across the 30 country pairs that were most over-represented, countries shared borders, languages, most common religion pairs, or any of these features in 15, 19, 26, and 29 cases, respectively. The map of cosmopolitan authors reveals a large and increasing proportion of the most influential scientists who share two or more scientific homes that each has made a substantial contribution to their career. Cosmopolitanism among scientists requires better study to help facilitate its potential positive contributions not only to individual scientists but to science and society more broadly.
Sepulveda Correa, A.; Turgeon, K.; Rodriguez, M.
Show abstract
The rapid global expansion of dams has significantly reshaped freshwater ecosystems, yet long-term trophic dynamics and food-web stability within reservoirs remain underexplored. This study examines the reorganization of fish communities induced by the trophic surge following dam construction and river impoundment. We used the predator-to-consumer mass ratio (PCMR) as a proxy for trophic pyramid structure to track changes in fish biomass distribution across three large boreal reservoirs in Quebec, Canada, over 20 years, using data from before and after impoundment. We found transient top-heaviness events (i.e., PCMR values > 1; predator accumulation), characterized by a hump-shaped trajectory of the PCMR values in two reservoirs (Opinaca and Robert Bourassa). The third reservoir (Caniapiscau) showed a gradual increase in top-heaviness but did not exhibit a clear transient pattern. The magnitude and duration of top-heaviness varied across reservoirs, potentially due to differences in the system's capacity to receive and accumulate nutrients, which are driven by water residence time and reservoir size. This research provides a conceptual framework for understanding the long-term trophic dynamics of reservoirs, which can help inform the development of more effective management strategies to preserve ecological health in these ecosystems.
Dharmasiri, M. E.; Lindo, Z.; Cameron, E. K.
Show abstract
Soil is one of the most biodiverse habitats on the planet, yet the extent of soil biodiversity knowledge in Canada is unknown. To better understand our knowledge, we systematically mapped soil invertebrate biodiversity knowledge from peer-reviewed literature to identify spatial and taxonomic gaps and to assess whether areas projected to experience different magnitudes of climate change are adequately sampled. A total of 1,176 Canadian sampling locations were identified from 427 articles. We found biases in sampling coverage spatially and in relation to current and projected climatic conditions. The geographic region above 60 degrees North is sparsely sampled. Colder regions (< -0.12 C) and regions receiving the least (< 646.47 mm), moderately high (2268.67 to 2809.40 mm), and high (2809.40 to 3350.14 mm) amounts of precipitation were under sampled. Regions projected to have the smallest (< 0.86 C) and greatest (> 1.59 C) magnitudes in temperature change and regions projected to have moderate (-2.06 to +2.69 mm) to large changes (+2.69 to +7.44 mm) in precipitation were underrepresented. The sampled locations also suffer from taxonomic biases which were skewed toward Nematoda (19%), Annelida (18%), Acari (15%), and Collembola (14%). Our results suggest that methods such as stratified sampling is essential to capture underrepresented regions, taxonomic groups, and an array of current and projected climatic conditions. Additionally, shifting to a multispecies sampling approach is essential for broader soil ecosystem knowledge. Importantly, data from well-sampled areas should be examined to determine how it can be leveraged to advance conservation management of soil invertebrates.
Arias-Gonzalez, J. E.; Morales-Aranda, A. A.; Morales-de-Anda, D.; Horta-Puga, G.
Show abstract
Reef fish assemblages in the Veracruz Reef System National Park (VRSNP) are strongly structured along a pronounced north-south gradient, where environmental conditions, urban proximity, and protection levels interact to shape functional diversity and ecosystem functioning. This gradient creates contrasting ecological conditions between northern and southern reefs, providing a natural framework for evaluating how spatial variation influences resilience. Using a stationary visual census across ten reefs distributed latitudinally, we quantified functional entities based on six ecological traits and calculated functional richness, redundancy, over-redundancy, vulnerability, specialization, and originality. A two-way permutational ANOVA and redundancy analysis were used to detect spatial and temporal patterns and to link functional indices with environmental features. The southern sector displayed the most intense functional shifts. Nearshore southern reefs, strongly exposed to sedimentation, nutrient loading, and physical disturbance, exhibited reduced functional richness, fewer functional entities, and high functional vulnerability, indicating strong environmental filtering. Over time, these reefs shifted toward generalist-dominated assemblages with rising redundancy, suggesting functional convergence. In contrast, southern offshore reefs supported higher taxonomic and functional richness, buffered by greater habitat complexity and distance from shore, although they showed declining redundancy, likely reflecting sensitivity to regional climatic disturbances. In the northern sector, the gradient was moderated by effective protection, which reshaped functional configurations. Nearshore protected reefs such as Isla Sacrificios and Isla de Enmedio maintained high redundancy, low vulnerability, and high biomass of large-bodied fishes, resembling offshore systems rather than disturbed southern nearshore reefs. The northern offshore reef (Isla Verde) shared some of these attributes but exhibited temporal declines in richness, signaling emerging vulnerabilities along the gradient. Functional originality and specialization aligned with benthic states across the gradient, particularly where macroalgal or calcareous substrates prevailed. Overall, the north-south gradient is the primary axis of functional organization in VRSNP, revealing that resilience emerges from the interplay among reef geomorphology, urban influence, and governance effectiveness.
Ippei, N.; Naruse, K.
Show abstract
The decline in fishery yields in Japan's enclosed coastal seas has been accompanied by a reduction in phytoplankton biomass, suggesting a widespread decrease in ecosystem productivity. Oligotrophication in Mikawa Bay has caused substantial declines in phytoplankton biomass and Manila clam (Ruditapes philippinarum) production. To assess whether external nutrient enhancement could stimulate phytoplankton growth, a controlled demonstration experiment using treated effluent from two sewage treatment plants (WWTPs) was conducted (spanning fiscal years 2022 to 2024) based on analysis using a three-dimensional non-hydrostatic model. Although effluent DIP and nitrogen concentrations were increased, model results showed that WWTP-derived nutrients represent only a minor portion of the total nutrient budget. Field observations revealed limited increases in surface water phosphorus, strong seasonal variability, and only temporary rises in chlorophyll-a and clam harvests. Monthly TP data demonstrated that seasonal DIP pulses, especially spring phosphorus bursts, dominate nutrient dynamics and overshadow external loading effects. Laboratory experiments further showed that phosphate is efficiently fixed by Fe(III) under oxidizing conditions and rapidly released during reductive dissolution of [FeOOH-HPO4]2- complexes, confirming iron as the principal regulator of internal P cycling. Because current numerical models omit iron-driven internal cycling, they cannot accurately predict bioavailable P or ecosystem responses. Overall, the study indicates that localized nutrient enhancement is insufficient to counter long-term oligotrophication, and effective management must integrate nitrogen limitation, internal Fe and P cycling, oceanic exchange, and seasonal variability in Ise and Mikawa Bays.
Aul, L.; Clegue, C.; Burrows, D.; Martin, J. L.; Mathews, D.; Widdicombe, S.; Stahl, H.; Strugnell, J.; Havermans, C.; Villacorta-Rath, C.
Show abstract
Detecting dugongs at low densities remains a major challenge for conservation monitoring, particularly in remote or turbid coastal habitats where conventional surveys are difficult. Environmental DNA (eDNA) offers a complementary approach, but robust species-specific tools are needed before it can be confidently applied to dugong surveillance. We developed and analytically validated a quantitative PCR TaqMan assay for detecting dugong (Dugong dugon) eDNA and evaluated its performance across controlled aquarium conditions in Australia and Abu Dhabi, and wild populations in northern Australia and the Arabian/Persian Gulf. The assay detected dugong eDNA in aquarium and field samples, with Sanger sequencing confirming amplification of dugong mitochondrial DNA from positive field detections. Our assay provides a robust and geographically transferable tool for targeted dugong eDNA detection, performing reliably across contrasting coastal environments and widely separated populations. This approach can strengthen local-scale surveillance of low-density or difficult-to-detect dugong populations.
Aldrich, H.; Barr, J.; James, B.; Lawrence, R.; Mayerle, M.; Sutton, A.
Show abstract
Funding and publishing scientific research has become increasingly competitive, highlighting a growing need for clear and accurate scientific communication. Scientific editors are professionals who help ensure that grant proposals and research manuscripts meet the standards of funding agencies and peer-reviewed journals while effectively communicating research significance to diverse audiences. However, detailed information characterizing the scientific editing profession is scarce. While some organizations have conducted salary surveys, to our knowledge, no comprehensive survey of the scientific editing field has been conducted. Here, we report findings from a 2024 comprehensive survey of 132 scientific editors. We collected data on demographics and education, career experience and current employment, skills and types of editing, and outcomes and satisfaction. Our data reveal that scientific editors have homogenous demographic characteristics but considerable variability in job titles, employment mechanisms, and career pathways. As the responsibilities of many scientific editors, including supporting proposal development, applying best practices in grantsmanship, and identifying strategies to enhance competitiveness for research funding, overlap with those of research development professionals, our findings provide considerations for further incorporating or defining the role of scientific editors within research development offices. Our results also suggest avenues for scientific editors to start or advance their careers. We anticipate that our results will serve as a foundation for discussions on the future directions of the scientific editing profession as well as areas for future research and professional development.
Ellis Soto, D.; Crespo-Perez, V.; Pike, C. L.; Cabrera, F.; Penafiel, C.; Pierre-Paul, H.; Dutton, C. L.; Blake, S.; Post, D. M.; Subalusky, A. L.
Show abstract
Animal movements can transport materials across ecosystem boundaries, while simultaneously modifying habitats through physical engineering. We integrated GPS telemetry, camera trapping, sediment measurements and physicochemical sampling of ponds on Santa Cruz Island, Galapagos, to evaluate how giant tortoises connect and shape terrestrial and freshwater ecosystems. Telemetry revealed 2,254 visits by 21 tortoises to 12 ponds, with visits lasting up to 21.38 h and showing strong seasonal and diel variation, while camera traps showed peak pond use in January and during early morning and late afternoon. Greater tortoise abundance was associated with higher ammonium, dissolved organic carbon and total phosphorus concentrations, while ponds with persistently greater tortoise abundance had higher total suspended solids. Departing tortoises carried a mean 505.9 g of sediment, yielding a conservative potential export of 8.20 kg per tortoise per year and tens of tonnes annually. These findings identify giant tortoises as mobile zoogeochemical engineers linking terrestrial and freshwater ecosystems through physical and biogeochemical pathways.
Fagbohun, I. R.; Allen, D. C.; Sweetman, J. N.; Hilderbrand, R. H.
Show abstract
Introduction: Despite decades of investment, stream restoration often fails to recover diverse benthic macroinvertebrate communities, as restored reaches tend to remain dominated by pollution-tolerant taxa. This shortfall in recovery is commonly attributed to either poor habitat quality or dispersal limitation of aquatic macroinvertebrate taxa, yet these hypotheses are rarely tested directly. Objectives: We conducted a manipulative field experiment in the eastern Piedmont region (Maryland, USA) within the Chesapeake Bay Watershed to evaluate whether restored streams can support pollution-sensitive taxa when dispersal barriers are removed. Methods: We translocated whole macroinvertebrate communities from three nearby reference streams into three restored streams using standardized habitat substrates and quantified macroinvertebrate survival after 28 days. We also assessed how effective leaf vs rock substrates were for accumulating diverse and abundant macroinvertebrate communities for translocation. Results: Across all sites, 77% of translocated individuals and 16 of 22 taxa sensitive and moderately sensitive to pollution persisted under restored stream conditions, demonstrating that restored reaches can support short-term survival of pollution-sensitive taxa that typically fail to recover. Substrate comparisons revealed that leaf packs accumulated higher macroinvertebrate abundances, whereas both substrates accumulated macroinvertebrate communities with similar taxa richness, EPT richness, and Shannon Diversity. Conclusions: This work suggests that dispersal limitation, rather than unsuitable habitat, may be an underappreciated constraint limiting macroinvertebrate recovery in restored streams. These findings challenge the assumption that habitat restoration alone is sufficient for biological recovery and highlight the potential for whole-community translocations to accelerate recovery and ecological uplift as part of stream restoration practices. Implication for Practice: Our study highlights the need to consider habitat connectivity and dispersal pathways during stream restoration designs. Restoring streams to meet habitat requirements of pollution-sensitive macroinvertebrate taxa may not be sufficient for their populations to recover if these taxa are unable to reach the restored stream. In scenarios where restoring connectivity to source populations is infeasible, whole community translocations may offer a novel restoration tool to overcome dispersal barriers and accelerate biological recovery in restored streams.
Smith, W. V.; Bebbington, A.; Bowker, H.; Christbaum, T.; Pulver, S.
Show abstract
The health and wellbeing of living organisms and the environment are irrevocably interconnected. Animals constantly shape the environments in which they live, and environmental factors, in turn, shape the minds and behaviours of animals. The emerging discipline of environmental neuroscience studies this reciprocal interaction and offers a unique opportunity to integrate sustainability into undergraduate training. Here, we present and evaluate Forging Sustainable Research, an interdisciplinary undergraduate course that integrates teaching of neuroscience, biology, psychology, environmental science, and sustainable development. Students explore how research in these fields can be interlinked 24 and re-oriented towards addressing emerging environmental challenges. In parallel, students learn how to measure and mitigate the environmental impact of research activities. Student feedback suggests that the course is effective at raising awareness and understanding of sustainability in research, while also enhancing student perception of their own ability to promote positive change. As climate and ecosystem change impact all sectors, sustainability awareness in academic and professional spaces is increasingly sought after. Students in the course therefore receive training in transferable skills relevant for diverse career paths. In the long term, this course may serve as model for direct integration of sustainability training into undergraduate curricula in the natural sciences.
Smith, F.; Behr, D. M.; Bizzozzero, M. R.; Allen, S. J.; Connor, R. C.; King, S. L.; Ozgul, A.; Krutzen, M.
Show abstract
Extreme climate events are rapidly reshaping ecosystems and contributing to biodiversity loss, yet their long-term impacts remain poorly understood, particularly in marine systems. In 2011, an unprecedented marine heatwave (MHW) on the west coast of Australia drove declines in habitat-forming plants and across taxa spanning multiple trophic levels. Shark Bay, home to an iconic Indo-Pacific bottlenose dolphin (Tursiops aduncus) population, endured temperatures 3-5{degrees}C above long-term means, triggering catastrophic seagrass loss. Using 20 years (2003-2023) of dolphin photo-identification data, we fitted a Bayesian Hidden Markov Model to estimate annual, age-class specific survival probabilities, abundance and recruitment rate, and their association with MHW-mediated seagrass loss in the western (WSB) and eastern (ESB) gulfs of Shark Bay. Adult survival declined markedly, from 0.99 (0.98-1.00) pre-MHW to 0.85 (0.79-0.90) post-MHW in WSB, and from 0.96 (0.92-0.98) to 0.89 (0.85-0.95) in ESB, remaining below pre-MHW levels for several years, while juvenile and calf survival declined in both gulfs to a lesser extent. Recruitment declined in both gulfs and, although recovery was evident in WSB from 2019 onward, continued to decline in ESB until the end of the study. These sustained demographic declines drove substantial reductions in population growth and abundance in both WSB (39%) and ESB (36%). Demographic changes were associated with seagrass loss, here a proxy for habitat and prey availability, with clearest support for adult survival in WSB and a two-year-lagged recruitment response in ESB. This pathway is likely to operate across diverse ecosystems as climate change drives increasing loss of habitat-forming species. The severity and duration of these demographic impacts illustrate that habitat change can cascade through trophic systems to overwhelm demographic resilience in upper-trophic species. This has negative implications for even long-lived, K-selected species, whose slow demographic recovery may not keep pace with the accelerating frequency and intensity of climate disturbance.
Huang, Y.; Hu, Z.; Hao, M.; Li, X.; Tang, Y.; Jiang, S.; Wang, X.; Han, L.; Wang, J.; Li, Y.; Zhang, H.
Show abstract
Background Emerging evidence has linked frailty to individual chronic diseases, but whether it predicts a broad disease spectrum and accelerates multimorbidity accumulation over time remains unknown. This study aimed to systematically evaluate the associations of physical frailty with the burden of incident disease across a wide range of chronic conditions, and with the long-term rates of multimorbidity accumulation. Methods In this prospective cohort study of 466,864 UK Biobank participants , frailty status was assessed using the Fried frailty phenotype and categorized as robust, pre-frailty, or frailty. Chronic diseases were defined based on International Classification of Diseases (ICD)-10 codes, and disease patterns were identified using network analysis. Cox proportional hazards models were used to examine the associations of frailty status with incident chronic diseases, and linear mixed models were used to assess the annual rate of chronic disease accumulation. Results During a median follow-up of 13.8 years (IQR: 13.1-14.5), 536 incident chronic diseases across multiple systems were recorded. Physical frailty was associated with a significantly increased risk of 458 incident diseases (Bonferroni-corrected P < 0.05/536). In the overall cohort, compared with robust participants, those with pre-frailty ({beta} = 0.266, 95% confidence interval [CI]: 0.264-0.267) and frailty ({beta} = 0.941, 95% CI: 0.936-0.946) exhibited significantly faster rates of multimorbidity accumulation. This accelerated multimorbidity accumulation was consistently observed across strata of baseline disease burden, including participant with 0 ({beta} = 0.644, 95% CI: 0.635-0.653), 1 ({beta} =0.748, 95% CI: 0.727-0.768), [≥] 2 ({beta} =0.940, 95% CI: 0.933-0.947) chronic conditions at baseline. Similar associations were also found across distinct disease patterns, including neurodegenerative, metabolic, and psychiatric patterns. Conclusions Physical frailty predicts a broad range of incident diseases and is associated with accelerated multimorbidity accumulation. Incorporating frailty assessment into prevention strategies may help mitigate the growing burden of multimorbidity.
Waters, T.; Gold, Z.; Parker, E.; Simon, O.; Jenny, L.; Ambrose, R. F.; Barber, P. H.; Eagle, R. A.
Show abstract
Management of marine protected areas (MPAs) require long-term monitoring and evaluation that is often limited by the cost and effort of conventional visual based surveys. We evaluated a community science-based eDNA approach to MPA monitoring over two years in the Point Dume State Marine Reserve, the Point Dume State Marine Conservation Area, and two paired unprotected reference sites. Across the sampling period, we detected 119 species of fish and marine mammals, including 19 of the 22 regional management-priority species for Southern CA MPAs. Protected and unprotected comparison sites were broadly similar in overall assemblage with 93 species shared across all sites. Multivariate analyses revealed site-level differences, although season and year explained more variation than protection status. Species presence also shifted during a La-Nina transition, highlighting the importance of long-term monitoring under different climatological contexts. Community scientists greatly expanded the temporal and spatial scope of eDNA sampling and generated high-quality data. Subsampling analysis showed that quarterly sampling, with three sample replicates and sequencing depths between 700k-990k, recovered 95% of observed biodiversity of the full time series. These results demonstrate that a community science-based eDNA program could provide a standardized, scalable, low-cost, and management-relevant approach for long-term monitoring across California's MPA network.
Tuma, T.; Robertson, M. E.; Dolan, E. L.
Show abstract
Interest in mentoring remains widespread within the scientific community, as mentorship is considered crucial to developing the scientific workforce. A longstanding focus on the positive aspects of mentorship obscures the reality that some mentoring relationships may be ineffective, counterproductive, or harmful. Progress has been limited by the absence of a scale capable of measuring both the positive and negative mentoring experiences of doctoral students. We addressed this need by developing a new scale: the Mentoring Experiences in Research and Graduate Education (MERGE). Results of three sequential multi-method studies (total N = 1,308) provide evidence for: (a) the content and response process validity of the MERGE; (b) a six-factor structure capturing the range of mentoring experiences; (c) negative mentoring experiences as empirically distinct from the absence of positive mentoring; (d) convergent, discriminant and criterion-related validity of the MERGE, with each factor demonstrating unique patterns of association with outcomes; and (e) the incremental validity of the MERGE in predicting outcomes beyond an existing measure of mentoring competence. We conclude by discussing implications for the use of the scale in doctoral education, including both theory advancement and applied practice.
de Breuyn, M.; Van Nynatten, A.; Baum, J.
Show abstract
The transformative impacts of global bleaching events are now a ubiquitous feature of coral reefs, often resulting in taxonomically simplified coral assemblages that can persist long-term due to ongoing ocean warming, heatwaves, and localized anthropogenic stressors. Understanding to what extent these processes shape symbiont biodiversity continues to be a major knowledge gap. Here, we examined Acropora host and symbiont communities on Kiritimati (Republic of Kiribati), seven and a half years after the 20152016 El Nino-associated marine heatwave, which caused a near total loss of the genus in the atoll's shallow reefs. We quantified Acropora cover and growth-form composition at 37 sites spanning a gradient of local human disturbance and characterised Symbiodiniaceae communities using ITS2 DNA metabarcoding from 109 coral tissue samples at 13 of the sites. Corymbose and tabular Acropora growth forms remained evenly represented across the atoll and cover declined with increasing human disturbance. Symbiodiniaceae communities were dominated by Cladocopium with 93 % of colonies associated with a single ITS2 profile. Communities were homogenous, with low diversity and insignificant differences amongst growth forms, but slight differences across disturbance levels. DNA barcoding of the PaxC intron identified the majority of host colonies as most similar to Acropora granulosa (62 %) and Acropora hyacinthus (24 %). Although dominance by a single symbiont lineage is common among Acropora species across the Pacific, the low Symbiodiniaceae diversity observed at Kiritimati contrasts with the substantial within- and among-lineage diversity documented elsewhere. The depauperate Symbiodiniaceae communities observed in this study may thus represent a lasting legacy of the 2015-2016 disturbance, with the recovering Acropora assemblage representing an early stage of community reassembly drawing from a potentially depleted environmental symbiont pool.
Ehlo, C. A.; Zeug, S.; Cavallo, B.; Ross, K.
Show abstract
Diverse life history strategies allow species to spread risk across a mosaic of habitat conditions. In Chinook Salmon (Oncorhynchus tshawytscha), particularly in the Central Valley of California, this is expressed through varied adult run timings and juvenile outmigration strategies. Anthropogenic impacts, particularly dams, disrupt these fundamental life stage transitions, often forcing managed populations to adapt to homogenized, less stochastic hydrologic regimes. This is exemplified in the Sacramento River, where the conservation of endangered Sacramento River winter run Chinook salmon requires balancing complex water operations with the ecological needs of a population confined to a short stretch of suitable habitat downstream of Shasta Reservoir. Using a 23 year dataset (2002 to 2024), we evaluated the combined effects of flow, temperature, and spawner abundance on juvenile production and life history expression in this habitat. We found that flow and spawner abundance best predicted juvenile abundance at Red Bluff Diversion Dam while temperature had considerably less support. The proportion of juveniles migrating as smolts exhibited significant density dependence that was negatively correlated to both female spawner abundance and peak flows. These results suggest focusing on temperature management alone may be insufficient. Effective management strategies should consider flow variability and habitat restoration to facilitate varying migration strategies and expand upstream rearing capacity. By addressing these physical and hydrologic constraints, managers can better support the full suite of life history strategies necessary for the resilience of winter run Chinook salmon.
Eyal, G.; Weinstein, D. K.; Hammerman, N. M.; Shaked, Y.; Torfstein, A.
Show abstract
Mesophotic coral ecosystems are commonly interpreted as thin biological veneers over relict shallow-water reef structures, but their capacity to generate late Holocene carbonate deposits remains poorly quantified. Here we combine diver excavations, rubble-bed thickness surveys, radiocarbon age-depth modelling, sediment grain-size analyses, coral-rubble assemblages, trace-element geochemistry, and modern Alveopora allingi growth measurements from two 40-65 m deep coral-rubble fields in the northern Gulf of Eilat/Aqaba, Red Sea. Rubble deposits are at least 1.0-1.5 m thick and accumulated at mean rates of 2.21 {+/-} 0.52 mm yr-1 at the Dekel site and 1.33 {+/-} 0.13 mm yr-1 at the IUI site, implying persistent carbonate accumulation over centuries to >1 kyr. Age-depth models indicate quasi-continuous deposition despite pronounced faunal changes, including a shift from A. allingi-dominated rubble to upper layers enriched in Euphyllia paradivisa at Dekel. The dominant modern rubble-forming coral, A. allingi, extends at 3.04 {+/-} 0.87 mm yr-1 and has skeletal density of 1.17 {+/-} 0.27 g cm-3. First-order cover-based accretion estimates at present coral cover fall well below the radiocarbon-derived rates, indicating that long-term mesophotic rubble accumulation integrates historical cover, secondary calcification and sediment retention rather than present live coral cover alone. These data demonstrate that mesophotic rubble fields can act as active carbonate factories and palaeoecological archives, challenging the assumption that modern mesophotic habitats are geomorphologically passive.
Randell, Z.; Williams, M.; Thomson, R.; Johnson, K.; McQueen, C.
Show abstract
(1) Kelp forests support ecologically, commercially, and culturally important species, yet their benthic communities remain difficult to monitor consistently across space and time. Scientific SCUBA surveys provide valuable observations but can be constrained by safety, bottom time, depth, and the spatial extent that divers can efficiently cover, motivating complementary approaches for collecting standardized benthic imagery. (2) We developed and field-tested a standardized, open-source framework for benthic visual-imaging surveys using a small, modular remotely operated vehicle (ROV). Across four cost-scalable hardware configurations, we integrated navigation sensors, custom BlueOS Extensions, and our surftrak contribution to ArduSub, which enables fixed-altitude flight above the seafloor, and developed two open-source desktop applications that streamline field operations (rov_flight_ops) and imagery processing (rov_imagery_processing). We also evaluated power supplies, benthic lighting, camera settings, field protocols, and telemetry-processing workflows over 303 transects conducted on 64 survey days from 2022 to 2026. (3) The ROV operated across soft-sediment and rocky habitats, currents of 0-3 kt, and underwater visibility of 0-10 m. surftrak held the ROV within 0.2 m of its target altitude for 96% of 21 h of survey transects, producing an approximately 1 m^2 standardized image footprint. Sufficient illumination and optimized camera settings yielded high-resolution imagery in visibility below 2 m, while topside power increased endurance and operational flexibility. Combining Doppler velocity log and underwater acoustic positioning data through the vehicle's extended Kalman filter improved navigation and post hoc transect reconstruction. During 2026 surveys, rov_flight_ops and rov_imagery_processing automated flight logging, log retrieval, fault diagnosis, and the sorting, development, and telemetry annotation of survey imagery. Dense kelp canopies nevertheless constrained vehicle operation, and downward-facing imagery provided limited observations of cryptic or obscured organisms. (4) We provide configuration-specific bills of materials, hardware and wiring documentation, software and firmware inventories, camera settings, open-source field and imagery-processing software, step-by-step field protocols, and pre- and post-dive checklists to support replication and adaptation of the framework. Together, these resources provide a field-tested starting point for expanding standardized benthic imaging while complementing diver surveys across kelp forests and other shallow coastal ecosystems.