Scholarly Articles

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Access status: Open Access ,
Fluid-Resistant Hyponatremia in Active Inflammatory Bowel Disease: A Case Report
(Graduate Medical Education Research Journal, 2023-06)
Access status: Open Access ,
A Case of MIRAGE Syndrome with <i>SAMD9</i> Mutation and Refractory Infantile Diarrhea: Endoscopic Biopsy Evaluation via Light and Electron Microscopy.
(Pediatric and developmental pathology : the official journal of the Society for Pediatric Pathology and the Paediatric Pathology Society, 2025-03) Bove, Kevin Emil; Lopez-Nunez, Oscar; Bedrnicek, Jiri; Huang, Andrew; Freestone, David; Birge, Nicole; Kumar, Sandeep
An infant with intrauterine growth restriction, suspected of having MIRAGE syndrome based on prenatal ultrasound, presented with genital ambiguity, adrenal insufficiency, intractable diarrhea from birth, and a pathogenic <i>SAMD9</i> mutation (<i>c.1376G>A, p.R459Q</i>). Endoscopic biopsies of the duodenum revealed complex light and electron microscopic abnormalities. Hypoplastic villi without signs of enteritis suggests a disorder of mucosal growth with reduced absorptive surface area contributes to intractable diarrhea. Ultrastructural study showed prominent dilated endoplasmic reticulum, abnormalities of Golgi morphology, specialized granule, and mucin processing. We hypothesize that the <i>SAMD9</i> mutation alters mucosal growth, and the processing of mucin, Paneth and neurosecretory granules, with premature degradation of specific granules in enterocyte lysosomes. These distinctive morphological findings support the idea that multisystem manifestations of MIRAGE syndrome are due to a primary disorder of microsomal trafficking.
Access status: Open Access ,
A Comparison of Serum Lipase Levels and Clinical Outcome Trends in Hospitalized Pediatric Patients With Acute Pancreatitis: A Single-Center Retrospective Study
(Cureus, 2026-02-12) Puri, Sandeep K; Masthan, Amreen; Freestone, David J; Huang-Pacheco, Andrew S; Quiros-Tejeira, Ruben E
Access status: Open Access ,
Harsh Parenting, Maternal Depression, and Executive Function in Early Childhood.
(Child: care, health and development, 2025-11) Davis, Julia O; Goodman, W Benjamin; Bai, Yu; Dodge, Kenneth A
<h4>Background</h4>Executive function (EF), a multimodal construct that captures one's control over cognition and behaviour, is associated with academic achievement and social-emotional competence. Prior research suggests that early childhood experiences and the family context shape EF development. Harsh parenting practices-defined through verbal and psychological aggression-and maternal depression are identified as factors that may inhibit early EF development. We examined the relation between these two parenting factors at child age 30 months and two fundamental EF skills, attention and inhibitory control (IC), measured at 42 months.<h4>Methods</h4>We used a combination of parent self-report (Center for Epidemiological Studies Depression, Childhood Behaviour Questionnaire) and independent observational data (Home Observational Measurement of the Environment) from a random, representative sample of 549 births in Durham County, North Carolina. Linear regression models estimated the effects of harsh parenting and maternal depression on later child EF outcomes, while accounting for child and family characteristics.<h4>Results</h4>Harsh parenting behaviours at 30 months predicted lower child IC skills (b = -0.46, p = 0.041) and lower attention skills (b = -0.64, p = 0.007) at 42 months. Greater maternal depression symptoms at 30 months predicted lower IC skills (b = -0.14, p = 0.017) and lower attention skills (b = -0.21, p = 0.001) at 42 months.<h4>Conclusions</h4>Results highlight the importance of parenting behaviours and parental mental health in shaping early EF. Although correlational in design, this work may inform future early childhood interventions aimed at altering parental behaviour and mental health to promote childhood EF.
Access status: Open Access ,
Community Navigation: Iterative Development and Implementation of a Prenatal Psychosocial System of Care.
(Prevention science : the official journal of the Society for Prevention Research, 2026-06) Milojevich, Helen M; Best, Debra L; Goodman, W Benjamin; Rehder, Peter D; Dodge, Kenneth A
We describe the iterative process of developing a universal psychosocial system of primary care across early life, called Community Navigation, and evaluate whether it can be implemented during the prenatal period with high engagement, identification of family needs, connections to community services, and family satisfaction. Community Navigation is a manualized program to improve child and family outcomes by engaging families during pregnancy, co-identifying their family-specific needs, and connecting them with community resources to address their needs. Continuous quality improvement efforts enhanced and refined the program leading to three iterative versions (Navigation 1.0, 2.0, and 2.1). Here, we report implementation metrics across all three versions. In each version, families were recruited during pregnancy and offered 1-3 visits with a trained Navigator. Findings from Versions 1.0 and 2.0 were used to improve the Navigation protocol, resulting in Navigation 2.1. Of the 194 Navigation 2.1 families who were eligible and offered the program, 81% completed the initial Navigation visit and 82% of those families completed at least one follow-up visit prior to birth (net total completion = 65% of the eligible population). Adherence to the protocol was 93%. Nearly all families (98%) reported at least one unmet need, with 75% reporting a major need requiring a community resource connection. Connection rates were high: 66% of families who received referrals were successfully connected to at least one community agency. Families reported high satisfaction with the program. Community Navigation holds promise as a novel system of universal primary psychosocial care for birthing families.
Access status: Open Access ,
GLP-1 Receptor Agonist Medications: Patient Education
(Medsurg Nursing) Liggett, Laura; Bell-McClure, Elizabeth
Access status: Open Access ,
Community Health Workers in the Veterans Administration: Exploring Opportunities and Barriers to Integration for Rural and Caregiver Populations.
(Medical care, 2026-07) Harker, Katlin; Howard, Teresa; Smith, Battista; Pinheiro, Sandro; Boucher, Nathan A
<h4>Background</h4>Rural Veterans and caregivers face challenges related to health care access, care coordination, and institutional trust-areas where Community Health Workers (CHWs) are well positioned to make an impact. Despite their potential, CHW integration into complex federal systems such as the US Department of Veterans Affairs (VA) remains limited. CHWs represent a promising strategy to enhance access and care continuity for rural Veterans and caregivers.<h4>Objectives</h4>To examine perceptions of community and institutional partners regarding integration of CHWs into the VA to support rural Veterans and their family caregivers.<h4>Methods</h4>We conducted virtual, semistructured interviews with 24 key informants from community organizations and VA-affiliated institutions (October 2024 to February 2025). Interviews explored key informant views on CHW roles, responsibilities, training needs, and implementation considerations. A community advisory board of CHWs guided all aspects of the project.<h4>Results</h4>Four themes emerged: (1) CHW scope of work, (2) barriers and facilitators to CHW implementation, (3) CHW support needs, and (4) training and requisite knowledge.<h4>Conclusions</h4>Effective CHW integration into the VA will require role clarity, robust support systems, and context-specific training tailored to this population. To ensure sustainability, VA leadership will need to standardize role definitions across clinical and community domains. A strong business case-demonstrating improved care coordination, reduced emergency department use, and enhanced screening for social determinants of health-will be critical to secure funding and supportive policy. CHW integration could also offset staff burden within the VA.
Access status: Open Access ,
Reconfigurable quantum computer juggles 98 qubits.
(Nature, 2026-07) Noel, Crystal
A quantum computer based on trapped ions can connect any two quantum bits, reaching performance levels that conventional computers cannot match.
Access status: Open Access ,
Hospital and operator procedural volumes and one-year outcomes for TAVR in the United States: A STS/ACC TVT Registry Analysis
Vemulapalli, Sreekanth
Background: Prior analyses have demonstrated an inverse association between transcatheter aortic valve replacement (TAVR) procedural volume and short-term outcomes. However, less is known regarding the relationship between procedural volume and 1-year outcomes in the contemporary TAVR era. Objectives: To evaluate the association between annual hospital and operator TAVR procedural volumes and 1-year clinical outcomes in a contemporary national cohort. Methods: Clinical records from the Society of Thoracic Surgeons (STS)/American College of Cardiology (ACC) Transcatheter Valve Therapies (TVT) Registry for patients undergoing commercial TAVR between January 2020 and December 2022 were linked to Centers for Medicare & Medicaid Services administrative claims. Annualized hospital and operator TAVR volumes were modeled continuously and categorized into tertiles. Primary outcomes included 1-year all-cause mortality, stroke, the composite of mortality or stroke, and all-cause readmissions. Hierarchical risk-adjusted models accounting for patient clustering within sites were used to evaluate associations between procedural volume and outcomes. Results: Among 215,335 patients undergoing TAVR at 788 hospitals by 3,444 operators between 2020 and 2022, median annual hospital and operator volumes were 74 (IQR: 43-115) and 16 (IQR: 10-32), respectively. Volume was then categorized into tertiles (low, medium and high). Compared with high-volume hospitals (≥102/year), low-volume hospitals (≤52/year) had higher adjusted rates of 1-year all-cause mortality (Odds Ratio (OR): 1.10 [95% CI: 1.05-1.16]), stroke (OR: 1.10 [95% CI: 1.01-1.19]), mortality or stroke (OR: 1.10 [95% CI: 1.05-1.15]), and all-cause readmissions (OR: 1.05 [95% CI: 1.00-1.09]). Compared with high-volume operators (≥25/year), low-volume operators (≤11/year) had higher adjusted rates of stroke (OR: 1.16 [95% CI: 1.05-1.28]) and mortality or stroke (OR: 1.09 [95% CI: 1.03-1.15]) but not other endpoints. Conclusions: In a large, contemporary national TAVR registry, lower annual hospital (≤ 52/year) and operator (≤ 11/year) procedural volumes were independently associated with worse 1-year clinical outcomes. These findings suggest that procedural experience continues to influence outcomes despite maturation of contemporary TAVR practice.
Access status: Open Access ,
Unexpected Breakdown: Influenza A-Associated Rhabdomyolysis in the 2024-2025 Season.
(Mayo Clinic proceedings, 2026-05) Chan, Justin M; Roomiany, Pahresah L; Naeem, Halima A; Hruby, Carter W
Access status: Open Access ,
Tropicalization of mid-western Atlantic coastal bays by pinfish Lagodon rhomboides: a combined ecological and oceanographic perspective
(Marine Ecology Progress Series, 2024-01-01) Lefcheck, JS; Orth, RJ; Fodrie, FJ; Gong, D; Faulkner, M; Laumann, KM; Patrick, CJ
As climate change continues to shift the distributions of species worldwide, understanding where, why, and how organisms move beyond their historical ranges is of critical importance. Here, we report on the expansion of pinfish Lagodon rhomboides poleward along the mid-western Atlantic in response to rising temperatures. Pinfish are a key interactor in nearshore subtidal habitats like seagrasses in the southwestern Atlantic and Gulf of Mexico, but they have been historically sparse north of the ecotone at Cape Hatteras, North Carolina, USA. Using multidecadal trawl surveys, we show that while pinfish have been present both below (North Carolina) and above (Virginia and Maryland) this ecotone for many years, they have increasingly intruded into restored eelgrass (Zostera marina) meadows in the coastal bays of Virginia over the past decade. In 2022, for instance, pinfish abundances in Virginia equaled those observed historically in North Carolina. To understand the factors promoting these changes in abundance, we used a passive drifter model to show that these increases are not necessarily tied to changes in offshore currents. Instead, linear models revealed that the local abundance of pinfish in Virginia correlates most with inshore summertime water temperatures. Thus, favorable environmental conditions of the recipient bays appear to encourage greater recruitment and therefore greater abundance of pinfish. Given their outsized ecological role in subtropical ecosystems, and that the climate will continue to warm, our findings suggest that pinfish may soon come to dominate the structure and functioning of temperate seagrass meadows in Virginia and beyond.
Access status: Open Access ,
Are nursery approaches maturing in their application to US fisheries management?
(Bioscience, 2024-02-01) Trackenberg, SN; Baillie, CJ; Fodrie, FJ; Bartusek, SM; Wellman, EH; Gittman, RK
There have been significant conceptual advances for identifying nursery habitats within coastal systems used by juvenile fishes and crustaceans. The approaches for delineating nursery areas include measures of juvenile abundance, growth, or survival; habitat characteristics; seascape connectivity; population fitness; and contribution to adult biomass (per unit area or total). We used all US coastal states as replicate trials to evaluate the integration of nursery concepts into fisheries management and found an obvious disconnect between expanding academic interest in nursery roles and management application. Among the few states that afford a subset of coastal environments with nursery status, easily obtained metrics (e.g., juvenile density or presence/absence of biogenic structure) are used, and it remains unclear what role nursery designations have played in promoting sustainable fisheries. Gathering the data necessary to use higher-order nursery approaches and metrics (e.g., connectivity and biomass contribution) to designate nurseries will require significant research investment and greater collaboration between ecologists and fisheries scientists.
Access status: Open Access ,
Habitat area more consistently affects seagrass faunal communities than fragmentation per se
(Ecological Monographs, 2024-11-01) Yarnall, AH; Yeager, LA; Lopazanski, C; Poray, AK; Morley, JW; Hurlbert, AH; Fodrie, FJ
Seminal ecological theories, island biogeography and the single large or several small (SLOSS) reserve debate, examine whether large contiguous habitats conserve biodiversity better than multiple smaller patches. Today, delineating the ecological effects of habitat area versus configuration in a fragmentation context remains difficult, and often confounds efforts to understand proximate and ultimate drivers of community change in response to habitat alteration. We examined how the major components of fragmentation, habitat division versus area loss, independently influence faunal communities using landscapes constructed from artificial seagrass at scales relevant for juvenile estuarine nekton. We deployed 25 unique, 234-m<sup>2</sup> landscapes designed along orthogonal axes: habitat percent cover (i.e., area) and fragmentation per se (i.e., patchiness) to examine their effects on faunal density, community composition, and probability of bait-assay consumption. Faunal sampling occurred in both artificial seagrass and interspaced sandflat matrix. We also examined whether larval-settler density drove faunal density patterns across landscapes. Further, we assessed the relative importance of landscape-scale parameters versus fine-scale complexity–canopy height and epiphyte biomass–in determining faunal densities. We most consistently observed increasing epibenthic fish and macroinvertebrate density with increasing seagrass percent cover. Fragmentation per se only negatively affected epibenthic faunal density within the matrix at low seagrass coverage. Bait consumption increased with seagrass cover, suggesting larger habitats are relative foraging hotspots. Alternatively, benthopelagic fish density was unaffected by habitat parameters, reflecting lower seagrass reliance, or increased matrix tolerance. Community compositions did not vary across landscapes, suggesting that abundant species used landscapes indiscriminately. Finally, the relative importance of habitat parameters shifted across faunal guilds and life stages. Landscape percent cover most affected epibenthic faunal density, but not benthopelagic fish density, and neither pattern was related to settler density. Further, only fine-scale complexity influenced settler densities. Collectively, our results indicate habitat area is a primary, positive driver of faunal densities and generalist consumption, and therefore should be prioritized in seagrass conservation. However, sampling across spatial scales and habitat types revealed nuances in habitat use patterns among faunal guilds and life stages that were not solely area-dependent, illustrating that a variety of landscape configurations support essential nursery functions.
Access status: Open Access ,
A Latitudinal Cline in the Taxonomic Structure of Eelgrass Epifaunal Communities is Associated With Plant Genetic Diversity
(Global Ecology and Biogeography, 2024-12-01) Gross, CP; Duffy, JE; Hovel, KA; Reynolds, PL; Boström, C; Boyer, KE; Cusson, M; Eklöf, J; Engelen, AH; Eriksson, BK; Fodrie, FJ; Griffin, JN; Hereu, CM; Hori, M; Hughes, AR; Ivanov, MV; Jorgensen, P; Kardish, MR; Kruschel, C; Lee, KS; Lefcheck, J; McGlathery, K; Moksnes, PO; Nakaoka, M; O'Connor, MI; O'Connor, NE; Olsen, JL; Orth, RJ; Peterson, BJ; Reiss, H; Rossi, F; Ruesink, J; Sotka, EE; Thormar, J; Tomas, F; Unsworth, R; Voigt, EP; Whalen, MA; Ziegler, SL; Stachowicz, JJ
Aim: Biogenic structural complexity increases mobile animal richness and abundance at local, regional and global scales, yet animal taxa vary in their response to complexity. When these taxa also vary functionally, habitat structures favouring certain taxa may have consequences for ecosystem function. We characterised global patterns of epifaunal invertebrates in eelgrass (Zostera marina) beds that varied in structural and genetic composition. Location: North America, Europe and Asia. Time Period: 2014. Major Taxa Studied: Peracarid crustaceans and gastropod molluscs. Methods: We sampled epifaunal invertebrate communities in 49 eelgrass beds across 37° latitude in two ocean basins concurrently with measurements of eelgrass genetic diversity, structural complexity and other abiotic and biotic environmental variables. We examined how species richness, abundance and community composition varied with latitude and environmental predictors using a random forest approach. We also examined how functional trait composition varied along with community structure. Results: Total species richness decreased with latitude, but this was accompanied by a taxonomic shift in dominance from peracarid crustaceans to gastropods, which exhibited different sets of functional traits. Greater eelgrass genetic diversity was strongly correlated with both richness and abundance of peracarids, but less so for gastropods. Main Conclusions: Our results add to a growing body of literature that suggests genetic variation in plant traits influences their associated faunal assemblages via habitat structure. Because peracarids and gastropods exhibited distinct functional traits, our results suggest a tentative indirect link between broad-scale variation in plant genetic diversity and ecosystem function.
Access status: Open Access ,
Demonstration of MicroPlastics Distribution Map in the Sediment and Water of Gorgan Bay, Caspian Sea
(Water Air and Soil Pollution, 2024-12-01) Yazarloo, M; Hedayati, A; Gholizadeh, M; Fazel, A; Fodrie, FJ; Mostafavi, H
Gorgan Bay is located along the southeast Caspian Sea and surrounded with significant agricultural and urban areas. Plastic pollution is a significant issue that affects aquatic ecosystems globally. The accumulation and degradation of plastics into microplastics in aquatic ecosystems highlight the importance of studying them to assess pollution risks. So, an investigation was conducted for the assessment of MicroPlastics pollution (MPs) in water and sediment of this ecosystem. The study involved collecting water and sediment samples from 40 stations within the Bay. Microplastics (MPs) extracted from these samples were identified using microscopic detection methods, specifically visual observation under polarized light to SEM–EDX, and µ-Raman. A total of 16,360 MP particles per kilogram of sediment, and 211 particles per liter of water were detected. The research demonstrated that the river inlets situated within agriculturally intensive regions of the watershed exhibited the highest levels of microplastics (MPs) in both water and sediment samples. Fiber MPs were the most frequent (> 50%) shape in sediment and water. The size of mostly MPs (> 90%) was smaller than 1,000 µm. The dominant polymer within MPs in Gorgan Bay sediment identified as polypropylene (PP), polyethylene (PE), and polystyrene (PS), while polypropylene (PP) and polyethylene (PE) were the frequent polymer in water, respectively. The most amount of MPs was found in the areas close to the rivers and agricultural fields (including stations S4, S12, S13, S14, S22).
Access status: Open Access ,
A Comparison of DNA Metabarcoding Cloacal Swabs and Stomach Contents for Shark Diet Reconstruction
(Environmental DNA, 2026-01-01) Ryburn, SJ; Wisely, E; Plumlee, JD; Branham, CC; Fodrie, FJ; Bruno, JF
Metabarcoding fecal matter is increasingly common in dietary studies across a variety of taxa. This approach assumes that enough prey DNA remains detectable in the fecal DNA (fDNA) as the prey DNA becomes degraded while passing through the digestive tract. However, as prey DNA is degraded during digestion, diet reconstruction based on metabarcoding of fDNA could become incomplete, i.e., species for which DNA was highly degraded would not be detected. The purpose of this study was to test the use of cloacal swabs and metabarcoding fDNA for shark diet reconstruction. To do this, both stomach contents and cloacal swabs were collected from the same individual sharks and metabarcoded using two previously published primer sets targeting teleost fishes and crustaceans. Samples were collected from four coastal species of sharks in a temperate estuary: bonnethead (Sphyrna tiburo; n = 10), blacknose (Carcharhinus acronotus; n = 4), blacktip (C. limbatus; n = 4), and Atlantic sharpnose (Rhizoprionodon terraenovae; n = 5). We determined how well the fDNA represented the corresponding prey DNA from the stomach contents (stDNA) and found no statistical difference in taxonomic richness or diversity when comparing the two sample types. Our results indicate that the less invasive, non-lethal method of DNA metabarcoding cloacal swabs provided higher taxonomic resolution than more common methods for studying trophic ecology (i.e., morphological stomach contents identification and trophic biomarkers such as stable isotope analysis) with no statistical difference in overall diet description between the two sample types.
Access status: Open Access ,
Seasonal Residency and Movement Patterns of Bonnetheads (Sphyrna tiburo) in Two Subtropical Estuaries and Coastal Waters of the South Atlantic Bight
(Estuaries and Coasts, 2026-03-01) Benavides, MT; Fodrie, FJ; Kenworthy, MD; Byers, JE
Tracking animal movements underpins our understanding of habitat linkages, stock definitions, and life-history vital rates. The bonnethead (Sphyrna tiburo) is abundant seasonally in southeastern United States (US) Atlantic coast estuaries; however, there is relatively little information regarding bonnethead ecology at the northern end of its distribution. We employed acoustic telemetry to document patterns of seasonal residency and movement for bonnetheads in North Carolina (NC) and Georgia (GA) estuaries, as well as other portions of the South Atlantic Bight (SAB). We acoustically tagged 21 bonnetheads in Beaufort Inlet Estuary, NC and 16 in Wassaw Sound, GA, and tracked those fish within estuarine arrays of 78 and 8 hydrophones in NC and GA, respectively. Bonnetheads were resident in NC and GA estuaries from March through November. Overall, detections were highly localized within individual estuaries, with most bonnetheads remaining in the area where they had been tagged, suggesting small core areas of movement (≤ 2 km) during seasonal residency. Conversely, 15 bonnetheads tagged in NC and 10 tagged in GA were detected in 14 other coastal hydrophone arrays in South Carolina, GA, and Florida (FL). The location and timing of these detections suggest that bonnetheads from distinct estuaries along the SAB overlap during late fall and winter months along the southeast US Atlantic coast, especially offshore of Brunswick, GA and Cape Canaveral, FL. Return rates for NC and GA bonnetheads were at least 25% and 19%, respectively, indicating a notable degree of estuarine-scale site fidelity.
Access status: Open Access ,
Shell trace elemental fingerprints of the deep-sea methane seep mussel Gigantidas childressi vary by depth, site, and shell growth region
(Deep Sea Research Part I Oceanographic Research Papers, 2026-04-01) Grace, IJ; Génio, L; Eggleston, DB; Puckett, BJ; Fodrie, FJ; Smith, ANH; Young, CM
Larval dispersal is a key driver of population persistence and resilience of numerous metapopulations and communities in marine ecosystems. Determining where and how larvae disperse in the deep sea is one of the most vexing challenges in deep-sea ecology. Laser ablation inductively coupled plasma mass spectrometry was used to evaluate the potential role of trace elemental fingerprints (TEFs) of deep-sea methane seep mussel Gigantidas childressi (n = 92 valves) in discriminating among collection depths, geographic regions (Gulf of Mexico and West Atlantic Margin; GOM and WAM), methane seep sites, and shell growth regions (larval VS settler shell). A priori permutational analyses of variance (PERMANOVA) discriminated among mussel valve TEFs across a depth gradient (650 m–2206 m), among eight methane seep sites, and among shell growth regions. A priori canonical analyses of principal coordinates (CAP) generally matched and additionally discriminated TEFs among geographic regions. Results for post-hoc analyses on individual shell growth regions varied by statistical approach (PERMANOVA VS CAP) and by shell growth region (larval prodissoconch I and prodissoconch II VS settler dissoconch shell). Broadly, post-hoc PERMANOVA discriminated only among sites, while post-hoc CAP discriminated among all study factors. Discrimination among depths was mainly driven by the elemental ratio Ba:Ca. Discrimination among geographic regions was mainly by Ba:Ca and Sr:Ca. Discrimination among sites and shell growth regions was driven by all three elemental ratios analyzed (Ba:Ca, Sr:Ca, and Mg:Ca). Overall, shell TEFs show potential to discern spatial distribution of larval population pools.
Access status: Open Access ,
DNA barcoding increases the taxonomic resolution of shark diet analysis compared to morphological stomach contents identification
(Conservation Genetics Resources, 2026-06-01) Ryburn, SJ; Srebnik, ER; Parker, CG; Plumlee, JD; Branham, CC; Gao, G; Fodrie, FJ; Bruno, JF
Morphological identification of stomach contents is the most common methodology used for shark diet reconstruction. However, this approach often limits prey identification to low taxonomic levels (i.e., order or class) and is prone to inaccuracies due to subtle morphological differences among prey. Additionally, varying digestion rates can lead to the underrepresentation of soft-bodied prey, which degrade and become unrecognizable more quickly than hard-shelled organisms. We used both visual morphological analysis and DNA barcoding on each prey item collected from the stomachs of four coastal shark species (i.e., Atlantic sharpnose [Rhizoprionodon terraenovae], blacknose [Carcharhinus acronotus], blacktip [Carcharhinus limbatus], and bonnethead [Sphyrna tiburo]) in North Carolina. Stomachs were collected from 49 sharks, yielding 118 prey items for analysis. We then compared the results of both visual and genetic methods to assess whether DNA barcoding increased taxonomic resolution of prey. Each prey item was also assigned an equivalency category to quantify the level of agreement between the two methodologies. DNA barcoding more than doubled the number of prey identified to the species level compared to morphological identification, and dietary composition significantly differed between methods for all shark species. Additionally, equivalency categories were significantly correlated with shark species and prey taxa. Bonnetheads had the highest proportion of prey classified as a match between methods due to their dietary specialization on Atlantic blue crabs (Callinectes sapidus). The hard carapace of this species digests more slowly, making Atlantic blue crabs easier to identify during morphological analysis. Blacknose sharks had the highest proportion of prey with their comparative equivalency categorized as ‘unidentified general morphological’, where morphological and DNA results aligned, but prey remained unidentifiable through morphology alone. Incorporating DNA barcoding into dietary studies provides an inexpensive, accurate, and effective approach to improving prey identification in sharks and other taxa. Improved resolution of shark diets strengthens our understanding of their ecological roles and supports ecosystem-based management approaches for shark and marine ecosystem conservation.
Access status: Open Access ,
Impacts of Culture Technique and Estuarine Position on Oyster Mariculture-mediated Nitrogen Removal in Temperate Estuaries
(Estuaries and Coasts, 2026-09-01) Funnell, NP; Thompson, SP; Brown, CM; Fodrie, FJ; Piehler, MF
Excess nitrogen is a driver of eutrophication and a threat to coastal water quality, ecosystems, and economies. Oyster reef habitat has been shown to enhance nitrogen removal processes, including denitrification (DNF), in adjacent sediments via nutrient-rich biodepositions. However, little is known regarding DNF within oyster mariculture leases, including how DNF varies among methods (i.e., gear types) or locations (i.e. between and within estuaries). Here, the effects of three common mariculture methods (i.e., floating bags, bottom cages, loose-on-bottom) on nitrogen cycling in three temperate North Carolinian waterbodies (Newport River, Stump Sound, Core Sound) and the effect of position along salinity (22–33 ppt) and sediment organic matter (SOM) (9.0–0.8%) gradients on nitrogen cycling in one estuary were measured. Oyster mariculture can match natural reefs’ DNF rates (floating bags 44.8 ± 11.7, bottom cages 38.6 ± 26.2, loose-on-bottom 104.8 ± 81.9, reef 103.2 ± 55.9 µmol N<inf>2</inf>-N m<sup>−2</sup>h<sup>− 1</sup>), but this service varies by method, waterbody, and over time. Loose-on-bottom DNF was ~ 10x higher than other methods in Newport River, bottom cages were highest (by 1.5x) in Stump Sound, and no culture method surpassed another in Core Sound. The following year, DNF on the Newport River loose-on-bottom lease decreased 10x, yielding no culture differences. Along an estuarine salinity and SOM gradient, oyster culture enhanced DNF relative to bare flats only up-estuary, by 6.5x. Overall, up to order-of-magnitude DNF variability among culture methods, locations, and over time suggests that quantifying an oyster lease’s nitrogen removal requires rigorous site-specific analysis rather than generalized estimation.

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