Getting ahead of the crises: Developing an avian malaria disease management plan for Hawaiian forest birds
Eben H. Paxton, Eldridge Naboa, Nicholas R. Agorastos
et al.
Abstract Avian malaria is an existential threat to a majority of native Hawaiian forest birds. Climate change is facilitating the spread of malaria to historically disease‐free areas, and despite the risk of native Hawaiian forest bird extinctions from malaria outbreaks, no comprehensive disease management plans exist for forest bird conservation areas. Hakalau Forest National Wildlife Refuge, Hawai‘i, supports a thriving bird community in a historically disease‐free area that is now vulnerable to malaria incursion. Drawing on the expertise of land managers and research scientists, we developed an approach that could be used to proactively address the risk of expanding malaria into the Refuge. The plan lays out a multi‐level approach that includes options for monitoring and management actions depending on defined threat levels: Vigilant, High Alert, Disease Outbreak, and Crisis levels. Initial Vigilant and High Alert levels monitor bird populations, climate conditions, and mosquito occurrence for signs of possible disease outbreaks, with higher levels shifting toward more direct management responses. While specific actions will change as new tools become available, the proactive approach can help Refuge managers better respond to changing malaria levels in the future and provide a model for managing disease here in Hawai‘i and elsewhere.
Ecology, General. Including nature conservation, geographical distribution
Mining expansion may reduce livestock but facilitate vicuñas recovery in tropical Puna of South America
Ana Patricia Sandoval-Calderon, Ana Patricia Sandoval-Calderon, Marijke van Kuijk
et al.
High-elevation tropical grasslands in South America are vital for sustaining the livelihoods of indigenous communities, particularly in the Central Andes where herding of both wild and domesticated camelids has been a primary socio-economic activity for centuries. However, these grasslands are facing challenges due to changes in land use, economic activities, and climate, posing threats to the sustainability of camelid herding. Here, we determine the intricate relationship between land use management and camelid populations of the highlands of Apolobamba National Park in Bolivia. We identified two critical milestones in land use management across the indigenous communities: the creation of the Tierra Comunitaria de Origen (TCO) in 1999 and the expansion of the National Park in 2000. These initiatives collectively resulted in the diversification of livelihood sources by increasing the number of mining concessions and facilitating the management of wild camelids for their wool and fibers, catering to international markets. We found that this diversification of livelihood sources was negatively related to the densities of domesticated camelids across the studied communities. In contrast, the densities of wild camelids populations increased with an increasing number of mining concessions, likely due to local conservation efforts and reduced competition with livestock. Our results indicate a potential shift in land use management strategies and suggest that mining activities encroach upon pastoralism practices within indigenous communities. Understanding the long-term effects of land use changes is essential for providing comprehensive and sustainable land use strategies that will support both grasslands and animal conservation while providing livelihood security in this ecologically sensitive region.
General. Including nature conservation, geographical distribution
A Nature Thing: What Does Contemporary Ecological Art Produce?
Barbara Stoltz
This article demonstrates that ecological art is a very specific art form that follows its own methods of creation and, consequently, of dealing with material and its definitions. This view of ecological art is directed by art theory factors and fundamental questions of art history. Therefore, the main question in discussions on material and the functions of art is that of what contemporary ecological art produces in terms of the concepts ‘natural’ and ‘nature-fair.’ By analysing the artists Thomas Dambo, Aviva Rahmani and Tomás Saraceno, this article finds that, compared to various artistic forms that deal with ecology and the environment, ecological art acts more in the physical reality of the environment and ecosystems. Subsequently, what ecological art is actually producing is ‘a nature thing’, meaning a concrete effect on or intervention in the environment with gestures of appropriation, regeneration and coexistence, being above all ‘art for nature.’ The article shows that, in ecological art, the linear relationship between material and artwork, in that the artist transforms the material to its final form, namely the artwork, is absent. In ecological art, the aim is an ongoing process in which material can have different facets: the material can be a mere auxiliary instrument, the art object itself can become material for something else and the material in general can be understood as an overarching aim and motive: nature.
Identifying conservation priority areas for North American bumble bee species in Canada under current and future climate scenarios
Amanda R. Liczner, Richard Schuster, Leif L. Richardson
et al.
Abstract Many bumble bee species are declining globally from multiple threats including climate change. Identifying conservation priority areas with a changing climate will be important for conserving bumble bee species. Using systematic conservation planning, we identified priority areas for 44 bumble bee species in Canada under current and projected climates (year 2050). Conservation priority areas were identified as those that contained targeted amounts of each species predicted occurrence through climate envelope models, while minimizing the area cost of conserving the identified conservation priority areas. Conservation priority areas in the two periods were compared to established protected areas and land cover types to determine the area of current and future priority sites that are protected and the types of landscapes within priority areas. Notably, conservation priority areas were rarely within established protected areas. Priority areas were most often in croplands and grasslands, mainly within the mountain west, central and Southern Ontario, Northern Quebec, and Atlantic Canada under all climate scenarios. Conservation priority areas are predicted to increase in elevation and latitude with climate change. Our findings identify the most important regions in Canada for conserving bumble bee species under current and future climates including consistently selected future sites.
Ecology, General. Including nature conservation, geographical distribution
Changes in species compositions of fish in the bays of the Northwestern Gulf of Mexico
Milton Torres Ceron, Milton Torres Ceron, Masami Fujiwara
et al.
IntroductionLocal biodiversity is increasing in many temperate and subtropical waters due to climate change. It is often caused by shifting fish distributions, thus the biodiversity gradient, from lower to higher latitudes. However, these shifts in distributions do not occur uniformly across all species. Consequently, communities are not only shifting their spatial distributions, but species compositions are also changing. We investigated spatiotemporal differences in the compositions of fish species in the bays of the northeastern Gulf of Mexico and identified species that contribute to the temporal changes.MethodsWe used fish count data collected using gillnets in eight major bays, encompassing over 600 km of coastline, during spring and fall seasons from 1982 to 2019. The nonmetric multidimensional scaling (NMDS) on the Bray-Curtis dissimilarity index among species composition vectors was used to detect the differences in species composition, and the similarity percentages (SIMPER) were used to determine the contribution of species to the differences. ResultsThe result shows there was a gradual change in species composition in all bays over the years, and the composition was different among bays and seasons. The species contributing to the temporal changes included those that are expanding (e.g., Common snook, Centropomus undecimalis, and Smallscale fat snook, C. parallelus) as well as retracting (e.g., Southern flounder, Paralichthys lethostigma, and Spanish mackerel, Scomberomorus maculatus) their distributions toward the north. The species observed only in recent years in these bays tended to have a preference for warmer water (e.g., Gulf pipefish, Syngnathus scovelli, and Chain pipefish, S. louisiana). DiscussionThe results are consistent with the potential effects of climate change. However, the salinity of the bays in the study area generally exhibits an increasing trend from the northern to southern bays. The spatial salinity gradient has a substantial impact on species compositions, indicating that species distributions are influenced by multiple environmental conditions. This complexity makes our ability to accurately predict future species compositions under changing environmental conditions challenging.
Science, General. Including nature conservation, geographical distribution
Soil organic carbon storage in Liaohe River Estuary Wetlands under restoration and multiple management strategies, based on landscape patterns
Guanxun Wang, Jingyu Pan, Jing Yu
et al.
IntroductionManagement of coastal wetlands has resulted in extensive conservation of this natural resource; however, changes in carbon storage function are not yet known. There is a direct link between landscape and soil carbon storage. Predicting future changes in the landscape and carbon storage in coastal wetlands is important for developing wetland management policies.MethodHere, remote sensing and physical methods were used to measure and calculate the landscape and surface soil carbon stocks of the Liaohe River Estuary Wetland (LREW). The changes in the landscape and soil carbon stocks under three scenarios: natural development, strict protection, and culture pond transfer, were then predicted using the PLUS model.ResultThe results indicate that the surface soil organic carbon storage was 2107.97×103 t, while soil organic carbon density decreased from land to sea. Anthropogenic activity was found to be the main driver of the current landscape evolution. However, the impact of sea level rise is increasing. By 2030, considerably more storage will be gained under the culture pond transfer scenario than at present.DiscussionOur results reveal that some of the methods of ecological restoration may diminish the carbon storage capacity of coastal wetlands. Making full use of areas with high carbon storage potential may be an effective wetland carbon sink management strategy. Governments should consider more comprehensively for a better carbon pool when developing restoration strategies.
Science, General. Including nature conservation, geographical distribution
Nitrous oxide production and isotopomer composition by fungi isolated from salt marsh sediments
Birch Maxwell Lazo-Murphy, Samantha Larson, Sydney Staines
et al.
The emissions of nitrous oxide (N2O), a potent greenhouse gas and ozone-depleting agent, have been steadily increasing from coastal environments, such as salt marsh sediments, as a result of anthropogenic nutrient loading. Biotic processes, including nitrification and denitrification, are the largest sources of N2O from salt marsh sediments. While it is assumed that the bulk of N2O from salt marsh sediment is produced by nitrification and bacterial denitrification, recent reports suggest fungal denitrification may contribute significantly. In this study, four fungi capable of growth under sulfidic conditions were isolated from salt marsh sediments in North Inlet, South Carolina, USA. Fungal species included Purpureocillium lilacinum, Trichoderma harzianum, Trichoderma virens, and Rhodotorula glutinis, as determined by sequencing the18S and 28S rRNA genes. The isotopomer signatures of N2O produced by these fungi were measured using isotope ratio mass spectrometry, which can be used to estimate the contribution of different sources of N2O. Up to 22.8% of nitrite provided in growth media was converted to N2O by fungal strains isolated from salt marsh sediments. The site preference (SP) of N2O produced by salt marsh sediment fungi ranged from 7.5 ± 1.6‰ to 33.4 ± 1.2‰. These values are lower than the SP of N2O from the model fungal denitrifier Fusarium oxysporum (37.1 ± 2.5‰), which is the SP typically used as an endmember in isotope mass balance considerations. The N2O SP values we measured expand the range of N2O SP used for isotope mass balances calculations to determine the relative contribution of fungi to N2O production in salt marsh sediments.
Science, General. Including nature conservation, geographical distribution
Satellite-Based Lagrangian Model Reveals How Upwelling and Oceanic Circulation Shape Krill Hotspots in the California Current System
Monique Messié, Diego A. Sancho-Gallegos, Jerome Fiechter
et al.
In the California Current System, wind-driven nutrient supply and primary production, computed from satellite data, provide a synoptic view of how phytoplankton production is coupled to upwelling. In contrast, linking upwelling to zooplankton populations is difficult due to relatively scarce observations and the inherent patchiness of zooplankton. While phytoplankton respond quickly to environmental forcing, zooplankton grow slower and tend to aggregate into mesoscale “hotspot” regions spatially decoupled from upwelling centers. To better understand mechanisms controlling the formation of zooplankton hotspots, we use a satellite-based Lagrangian method where variables from a plankton model, forced by wind-driven nutrient supply, are advected by near-surface currents following upwelling events. Modeled zooplankton distribution reproduces published accounts of euphausiid (krill) hotspots, including the location of major hotspots and their interannual variability. This satellite-based modeling tool is used to analyze the variability and drivers of krill hotspots in the California Current System, and to investigate how water masses of different origin and history converge to form predictable biological hotspots. The Lagrangian framework suggests that two conditions are necessary for a hotspot to form: a convergence of coastal water masses, and above average nutrient supply where these water masses originated from. The results highlight the role of upwelling, oceanic circulation, and plankton temporal dynamics in shaping krill mesoscale distribution, seasonal northward propagation, and interannual variability.
Science, General. Including nature conservation, geographical distribution
La industria lítica del sitio Cañadón Las Coloradas 1, un sitio de molienda en el noroeste de la Patagonia argentina
Eduardo Crivelli Montero, Fernando Fernandez
El presente trabajo tiene el objetivo de caracterizar tecnológica, tipológica y funcionalmente la industria lítica del alero Cañadón Las Coloradas 1 (CLC1). Este sitio arqueológico está ubicado en la zona de Alicurá (provincia de Río Negro), cuenca media del río Limay. Cuenta con ocupaciones humanas desde el Holoceno tardío final (1525 ± 80 14C AP) hasta tiempos históricos (hallazgos de restos de fauna exótica). De toda la secuencia prehispánica de CLC1 se recuperaron abundantes rodados fluviales medianos y grandes de rocas volcánicas, plutónicas y metamórficas que, sumariamente tallados, fueron utilizados por percusión y fricción, así como también reactivados in situ. Los denominamos machacadores. La gama del instrumental de CLC1 presenta una riqueza elevada, una diversidad baja y una composición bien diferente de la de otros sitios arqueológicos cercanos en espacio y tiempo. Se interpreta que CLC1 tuvo ocupaciones breves no residenciales, especializadas en tareas de molienda, con actividad de taller para producción y reactivación de instrumentos líticos masivos que actuaron por fricción. Estas características le confieren un papel singular en el área durante el Holoceno tardío en un marco regional de intensificación en la explotación de los recursos. Aunque los productos que se molieron en CLC1 aún se desconocen, la existencia de este sitio comporta una utilización del espacio diferente, más organizada que en tiempos anteriores.
Anthropology, Natural history (General)
Same Space, Different Standards: A Review of Cumulative Effects Assessment Practice for Marine Mammals
Emily L. Hague, Carol E. Sparling, Ceri Morris
et al.
Marine mammals are vulnerable to a variety of acute and chronic anthropogenic stressors, potentially experiencing these in isolation, successively and/or simultaneously. Formal assessment of the likely impact(s) of the cumulative effects of multiple stressors on a defined population is carried out through a Cumulative Effects Assessment (CEA), which is a mandatory component of the Environmental Impact Assessment (EIA) process in many countries. However, for marine mammals, the information required to feed into CEA, such as thresholds for disturbance, frequency of multiple (and simultaneous) exposures, interactions between stressors, and individual variation in response, is extremely limited, though our understanding is slowly improving. The gaps in knowledge make it challenging to effectively quantify and subsequently assess the risk of individual and population consequences of multiple disturbances in the form of a CEA. To assess the current state of practice for assessing cumulative effects on marine mammals within UK waters, 93 CEAs were reviewed across eleven maritime industries. An objective framework of thirteen evaluative criteria was used to score each assessment on a scale of 13-52 (weak - strong). Scores varied significantly by industry. On average, the aquaculture industry produced the lowest scoring CEAs, whilst the large offshore windfarm industry (≥ 20 turbines) scored highest, according to the scoring criteria used. There was a significant increase in scores over the sample period (2009-2019), though this was mostly attributed to five industries (cable, large and small offshore wind farms, tidal and wave energy). There was inconsistency in the language used to define and describe cumulative effects and a lack of routinely applied methodology. We use the findings presented here, along with a wider review of the literature, to provide recommendations and discussion points aimed at supporting the standardisation and improvement of CEA practice. Although this research focused on how marine mammals were considered within UK CEAs, recommendations made are broadly applicable to assessments conducted for other receptors, countries and/or environments. Adoption of these proposals would help to ensure a more consistent approach, and would aid decision-makers and practitioners in mitigating any potential impacts, to ensure conservation objectives of marine mammal populations are not compromised.
Science, General. Including nature conservation, geographical distribution
Distribution, Temporal Change, and Conservation Status of Tropical Seagrass Beds in Southeast Asia: 2000–2020
Kenji Sudo, T. E. Angela L. Quiros, Anchana Prathep
et al.
Although Southeast Asia is a hotspot of global seagrass diversity, there are considerable information gaps in the distribution of seagrass beds. Broad-scale seagrass distribution has not been updated in the global seagrass database by UNEP-WCMC since 2000, although studies on seagrasses have been undertaken intensively in each region. Here we analyze the recent distribution of tropical seagrass beds, their temporal changes, causes of decline and conservation status in Southeast Asia (plus southern mainland China, Taiwan and Ryukyu Island of Japan) using data collected after 2000. Based on the 195 literature published since 2000, we identified 1,259 point data and 1,461 polygon data showing the distribution of seagrass beds. A large discrepancy was found in the seagrass bed distribution between our updated data and the UNEP-WCMC database, mostly due to inaccurate and low resolution location information in the latter. Temporal changes in seagrass bed area analyzed for 68 sites in nine countries/regions demonstrated that more than 60% of seagrass beds declined at an average rate of 10.9% year–1, whereas 20% of beds increased at an average rate of 8.1% year–1, leading to an overall average decline of 4.7% year–1. Various types of human-induced threats were reported as causes for the decline, including coastal development, fisheries/aquaculture, and natural factors such as typhoons and tsunamis. The percentage of seagrass beds covered with existing marine protected areas (MPAs) varied greatly among countries/regions, from less than 1% in Brunei Darussalam and Singapore to 100% in southern Japan. However, the degree of conservation regulation was not sufficient even in regions with higher MPA coverage. The percentage of seagrass beds within EBSAs (Ecologically and Biologically Significant Area determined by the Convention of Biological Diversity) was higher than that within MPAs because EBSAs cover a greater area than MPAs. Therefore, designating EBSAs as legally effective MPAs can greatly improve the conservation status of seagrass beds in Southeast Asia.
Science, General. Including nature conservation, geographical distribution
A Cave Occupied by Cave Bears for Thousands of Years in the Sobrarbe-Pirineos UNESCO Global Geopark (Huesca, Aragon, Spain)
Raquel Rabal-Garcés, Gloria Cuenca-Bescós, Jose Canudo
The Sobrarbe-Pirineos UNESCO Global Geopark shows an extremely well-developed underground karst relief as a result of the great abundance and thickness of its limestone formations. The most important Pleistocene vertebrate site within the Geopark is Coro Tracito Cave at Tella. The fossil association is made up exclusively of bones belonging to Ursus spelaeus from the upper Pleistocene, accumulated over several thousand years. Based on scientific analysis of the fossil bones, an interesting public outreach project has been organized, involving the refurbishment of the site within the cave and the creation of a permanent exhibition called the Tella Cave Bear Museum. These two infrastructures are visited by thousands of tourists each year and constitute the main geoscientific tourist attraction of the Sobrarbe-Pirineos Geopark.
General. Including nature conservation, geographical distribution
Application of Three Deep Learning Schemes Into Oceanic Eddy Detection
Guangjun Xu, Guangjun Xu, Guangjun Xu
et al.
Recent years have witnessed the increase in applications of artificial intelligence (AI) into the detection of oceanic features. Oceanic eddies, ubiquitous in the global ocean, are important in the transport of materials and energy. A series of eddy detection schemes based on oceanic dynamics have been developed while the AI-based eddy identification scheme starts to be reported in literature. In the present study, to find out applicable AI-based schemes in eddy detection, three AI-based algorithms are employed in eddy detection, including the pyramid scene parsing network (PSPNet) algorithm, the DeepLabV3+ algorithm and the bilateral segmentation network (BiSeNet) algorithm. To justify the AI-based eddy detection schemes, the results are compared with one dynamic-based eddy detection method. It is found that more eddies are identified using the three AI-based methods. The three methods’ results are compared in terms of the numbers, sizes and lifetimes of detected eddies. In terms of eddy numbers, the PSPNet algorithm identifies the largest number of ocean eddies among the three AI-based methods. In terms of eddy sizes, the BiSeNet can find more large-scale eddies than the two other methods, because the Spatial Path is introduced into the algorithm to avoid destroying the eddy edge information. Regarding eddy lifetimes, the DeepLabV3+ cannot track longer lifetimes of ocean eddies.
Science, General. Including nature conservation, geographical distribution
The Global Prader–Willi Syndrome Registry: Development, Launch, and Early Demographics
Jessica E Bohonowych, Jennifer L Miller, S. McCandless
et al.
Advances in technologies offer new opportunities to collect and integrate data from a broad range of sources to advance the understanding of rare diseases and support the development of new treatments. Prader–Willi syndrome (PWS) is a rare, complex neurodevelopmental disorder, which has a variable and incompletely understood natural history. PWS is characterized by early failure to thrive, followed by the onset of excessive appetite (hyperphagia). Additional characteristics include multiple endocrine abnormalities, hypotonia, hypogonadism, sleep disturbances, a challenging neurobehavioral phenotype, and cognitive disability. The Foundation for Prader–Willi Research’s Global PWS Registry is one of more than twenty-five registries developed to date through the National Organization of Rare Disorders (NORD) IAMRARE Registry Program. The Registry consists of surveys covering general medical history, system-specific clinical complications, diet, medication and supplement use, as well as behavior, mental health, and social information. Information is primarily parent/caregiver entered. The platform is flexible and allows addition of new surveys, including updatable and longitudinal surveys. Launched in 2015, the PWS Registry has enrolled 1696 participants from 37 countries, with 23,550 surveys completed. This resource can improve the understanding of PWS natural history and support medical product development for PWS.
Rethinking length-based fisheries regulations: the value of protecting old and large fish with harvest slots
D. Gwinn, M. Allen, F. Johnston
et al.
Populating an economic model with health state utility values: moving toward better practice.
R. Ara, J. Brazier
BACKGROUND The methods used to estimate health-state utility values (HSUV) for multiple health conditions can produce very different values. Economic results generated using baselines of perfect health are not comparable with those generated using baselines adjusted to reflect the HSUVs associated with the health condition. Despite this, there is no guidance on the preferred techniques and little research describing the effect on cost per quality adjusted life-year (QALY) results when using the different methods. METHODS Using a cardiovascular disease (CVD) model and cost per QALY thresholds, we assess the consequence of using different baseline health-state utility profiles (perfect health, no history of CVD, general population) in conjunction with models (minimum, additive, multiplicative) frequently used to approximate scores for health states with multiple health conditions. HSUVs are calculated using the EQ-5D UK preference-based algorithm. RESULTS Assuming a baseline of perfect health ignores the natural decline in quality of life associated with age, overestimating the benefits of treatment. The results generated using baselines from the general population are comparable to those obtained using baselines from individuals with no history of CVD. The minimum model biases results in favor of younger-aged cohorts. The additive and multiplicative models give similar results. CONCLUSION Although further research in additional health conditions is required to support our findings, our results highlight the need for analysts to conform to an agreed reference case. We demonstrate that in CVD, if data are not available from individuals without the health condition, HSUVs from the general population provide a reasonable approximation.
Epidemiology of inflammatory bowel diseases: new insights from a French population-based registry (EPIMAD).
C. Gower‐Rousseau, F. Vasseur, M. Fumery
et al.
Introduced species policy, management, and future research needs
D. Simberloff, I. Parker, P. Windle
Clinical Outcomes of Deferred Lesions With Angiographically Insignificant Stenosis But Low Fractional Flow Reserve
Joo Myung Lee, Bon‐Kwon Koo, Eun‐Seok Shin
et al.
BackgroundData are limited regarding outcomes of deferred lesions in patients with angiographically insignificant stenosis but low fractional flow reserve (FFR). We investigated the natural history of angiographically insignificant stenosis with low FFR among patients who underwent routine 3‐vessel FFR measurement. Methods and ResultsFrom December 2011 to March 2014, 1136 patients with 3298 vessels underwent routine 3‐vessel FFR measurement (3V FFR‐FRIENDS study, ClinicalTrials.gov identifier NCT01621438), and this study analyzed the 2‐year clinical outcomes of 1024 patients with 2124 lesions with angiographically insignificant stenosis (percentage of diameter stenosis <50%), in which revascularization was deferred. All lesions were classified according to FFR values, using a cutoff of 0.80 (high FFR >0.80 versus low FFR ≤0.80). The primary end point was outcome of major adverse cardiovascular events (a composite of cardiac death, myocardial infarction, and ischemia‐driven revascularization) at 2 years. Mean angiographic percentage of diameter stenosis and FFR of total lesions were 32.5±10.3% and 0.91±0.08%, respectively. Among the total lesions with angiographically insignificant stenosis, 8.7% showed low FFR (185 lesions). The incidence of lesions with low FFR was 2.5%, 3.8%, 9.0%, and 15.1% in categories of percentage of diameter stenosis <20%, 20% to 30%, 30% to 40%, and 40% to 50%, respectively. At 2‐year follow‐up, the low‐FFR group showed a significantly higher risk of major adverse cardiovascular events compared with the high FFR group (3.3% versus 1.2%, hazard ratio: 3.371; 95% CI, 1.346–8.442; P=0.009). In multivariable analysis, low FFR was the most powerful independent predictor of future MACE in deferred lesions with angiographically insignificant stenosis (adjusted hazard ratio: 2.617; 95% CI, 1.026–6.679; P=0.044). ConclusionsIn deferred angiographically insignificant stenosis, lesions with low FFR showed significantly higher event rates than those with high FFR. FFR was an independent predictor of future major adverse cardiovascular events in lesions with angiographically insignificant stenosis. Clinical Trial RegistrationURL: http://www.clinicaltrials.gov. Unique identifier: NCT01621438.
Diseases of the circulatory (Cardiovascular) system
New insights on single-stranded versus double-stranded DNA library preparation for ancient DNA
Nathan Wales, Christian Carøe, Marcela Sandoval-Velasco
et al.
An innovative single-stranded DNA (ssDNA) library preparation method has sparked great interest among ancient DNA (aDNA) researchers, especially after reports of endogenous DNA content increases >20-fold in some samples. To investigate the behavior of this method, we generated ssDNA and conventional double-stranded DNA (dsDNA) libraries from 23 ancient and historic plant and animal specimens. We found ssDNA library preparation substantially increased endogenous content when dsDNA libraries contained <3% endogenous DNA, but this enrichment is less pronounced when dsDNA preparations successfully recover short endogenous DNA fragments (mean size < 70 bp). Our findings can help researchers determine when to utilize the time- and resource-intensive ssDNA library preparation method.