Relative Abundance Patterns Research Articles

Exceptional preservation in mayfly nymphs (Insecta: Ephemeroptera) from the Early Cretaceous of the Las Hoyas fossil site

The present study focuses on a group of macroinvertebrates that have played an important role in past and present lentic ecosystems: the Ephemeroptera. The study analyses the diversity, relative abundance, taphonomic alterations and fossilisation patterns of the Las Hoyas nymphs. The objective is to investigate the factors that may contribute to the presence of soft tissues in fossils with poor corporeal preservation. In accordance with this, only three morphotypes of the Leptophlebiidae family and one of the Euthyplociidae family have been characterised. However, the ultrastructural details of digestive and respiratory tissues have been documented, including the digestive canal, the shape of the gills, tracheoles, chloride cells, and importantly, in situ bacteria in cytokinetic stages located at the hindgut. The nymphs were fossilised in a variety of ways, including carbonaceous films, mineralised casts, and impressions. The nymphs that have been fossilised as composite moulds (Type III) and carbon films (Type II) tend to be larger in size. However, their bodies are rather well-preserved and show less soft tissue remains than those of the nymphs that have been preserved as impressions (Type I) and mineralised phosphorus casts (Type IV). These latter nymphs are smaller in size, and their bodies are poorly preserved. However, they show a greater variety of soft tissue details. This bias suggests an interesting link to environmental factors differentiating watered and flooding from microbial mat binding conditions.

Characterizing juvenile blacktip shark (Carcharhinus limbatus) nursery areas in the Galapagos: new methods and understandings.

New approaches to abundance surveying utilizing unoccupied aerial vehicles (UAVs) are proving to be effective tools in marine and terrestrial environments. We explored UAV efficacy for surveys in the Galapagos Marine Reserve (GMR), where relative abundance patterns of juvenile sharks and subsequent classifications of putative nursery areas based on environmental drivers are lacking. The UAV method allowed greater temporal and spatial coverage. We expanded classification of shark nursery habitat through monthly drone surveys and environmental data collection at 14 sites around San Cristobal Island (GMR) from November 2018 to July 2019. In the period of surveying, 56 flights identified 453 juvenile Carcharhinus limbatus (blacktip shark). Classification of nurseries followed three criteria, necessitating higher density, short-term residency, and annual site fidelity in target locations. We developed preliminary generalized linear models to elucidate potential environmental parameters influencing the perceived abundance and habitat preference of juveniles. Four sites were identified as either potential nurseries or nursery areas for the target species based on previous excursions. An averaged model was subsequently created from the models found to best explain deviance patterns (R2 = 0.10-0.44) in perceived shark abundance and habitat preference. Relative variable importance (RVI) values further clarified the parameters most associated with higher juvenile presence. This approach provides a systematic method of abundance surveying while simultaneously beginning the process of defining when and where we expect to find higher abundance through environmental modelling of most influential parameters to perceived abundance in this environment.

DUNE: Dust depletion UNified method across cosmic time and Environments

We present a novel method to characterize dust depletion, namely, the depletion of metals into dust grains. We used observed correlations among relative abundances combining a total of 17 metals in diverse galactic environments, including the Milky Way (MW), Large Magellanic Cloud (LMC), Small Magellanic Cloud (SMC), and damped Lyman-α absorbers (DLAs) towards quasars and gamma-ray bursts (GRBs). We only considered the relative abundances of metals that qualify as tracers of dust and we used all available dust tracers. We find linear correlations among all studied dust tracers in a multidimensional space, where each dimension corresponds to an individual dust tracer. The fit to the linear correlations among the dust tracers describes the tendencies of different elements when depleting into dust grains. We determined the overall strength of dust depletion, ∆, along individual lines of sight, based on the correlations among different dust tracers. We avoided any preference for specific dust tracers or any other assumptions by including all available dust tracers in this multidimensional space. We also determined the dust depletion of Kr, C, O, Cl, P, Zn, Ge, Mg, Cu, Si, Fe, Ni, and Ti. Finally, we offer simple guidelines for the application of the method to the study of the observed patterns of abundances and relative abundances. This has allowed for a straightforward determination of the overall strength of depletion and the dust depletion of individual elements. We also obtained an estimate for the gas-phase metallicity and identified any additional deviations due to the nucleosynthesis of specific stellar populations. Thus, we have established a unified methodology for characterizing dust depletion across cosmic time and diverse galactic environments, offering a valuable new approach to the study of dust depletion in studies of the chemical evolution of galaxies.

Individual variation of boldness in free-ranging bottlenose dolphins (Tursiops truncatus) interacting with scuba divers in French Polynesia

Marine wildlife tourism is known to affect target species across multiple spatial and temporal scales, from short-term behavioral responses to changes in relative abundance and habitat use patterns. However, despite a growing number of population-, community-, and group-level studies, a limited number of them have focused their research on individual responses to wildlife tourism, particularly on free-ranging cetaceans. Between 2018 and 2020, we investigated the behavioral responses of 20 non-provisioned bottlenose dolphins (Tursiops truncatus) to recreational scuba divers in Rangiroa Atoll, French Polynesia, to understand whether these individuals that had been repeatedly exposed to scuba diving tourism on at least one year exhibited temperament traits along the ‘shyness-boldness’ axis. We also considered potential variation in boldness in relation to sex, age, and tourist-site fidelity. The study documented individual differences in the dolphins’ boldness. There was no variation in boldness according to sex and tourist-site fidelity, but age significantly influenced the dolphins’ boldness with immature dolphins being bolder than mature individuals. The more extreme case of boldness involved four dolphins that tolerated repeated physical interactions with scuba divers. In Rangiroa, scuba diving tourism promotes repeated intrusive interactions with dolphins that might make bold individuals particularly vulnerable to collateral threats associated with human activities. It is therefore crucial to consider individual variation in the dolphins’ behavioral responses to tourism to implement optimal tourism management measures. We suggest in the discussion recommendations to help minimize the risks for both the dolphins and humans associated with repeated close interactions.

Differential inclusion of NEB exons 143 and 144 provides insight into NEB-related myopathy variant interpretation and disease manifestation

Biallelic pathogenic variants in the gene encoding nebulin (NEB) are a known cause of congenital myopathy. We present two brothers with congenital myopathy and compound heterozygous variants (NC_000002.12:g.151692086G>T; NM_001271208.2: c.2079C>A; p.(Cys693Ter) and NC_000002.12:g.151533439T>C; NM_001271208.2:c.21522+3A>G ) in NEB. Transcriptomic sequencing on affected individual muscle revealed that the extended splice variant c.21522+3A>G causes exon 144 skipping. Nebulin isoforms containing exon 144 are known to be mutually exclusive with isoforms containing exon 143, and these isoforms are differentially expressed during development and in adult skeletal muscles. Affected individuals MRI patterns of muscle involvement were compared to the known pattern of relative abundance of these two isoforms in muscle. We propose that the pattern of muscle involvement in these affected individuals better fits the distribution of exon 144-containing isoforms in muscle than with previously published MRI findings in NEB-related disease due to other variants. Our report introduces disease pathogenesis and manifestation as a result of alteration of isoform distributions in muscle.

Depositional Environment and Ecological Response of Bioconstructions: A Case Study of Southern China (Guizhou Province) in Moscovian-Gzhelian.

From the late Carboniferous to the early Permian, multiple pulses of glaciation and deglaciation have been caused by the LPIA. The Pennsylvanian period experienced phases of recovery, proliferation, and decline, ultimately forming a reef system distinctly different from that of the Mississippian period. During the late Bashkirian to Moscovian, the metazoan reef experienced a limited resurgence, with reef predominantly formed by chaetetid developing in the United States, northern China, and Japan. During the Kasimovian to Gzhelian, the phylloid algal reef dominated the global reef systems. In the late Pennsylvanian, bioconstruction cases and paleoenvironmental proxies in southern Guizhou Province were studied to investigate the composition, recovery, and evolutionary processes of the bioconstructions as well as their response to environmental variations during this period. Several bioconstructions have been reported in the Lumazhai section of Houchang Town, Guizhou Province, southern China, from the Moscovian to the Gzhelian. The upper Carboniferous strata are well-preserved and continuously exposed. The continuous strata, abundant fossils, and diverse bioconstructions provide excellent research materials for exploring the mutual constraints between organisms and their environment. This study identified ten microfacies, whose vertical evolution indicated significant changes in the depositional environment related to relative sea-level fluctuations. Skeletal grains are widely present in these facies. Among them, foraminifera, algae, bryozoans, crinoids, and Tubiphytes are the most common and exhibit distinct distribution characteristics in various environments. Quantitative statistics, CCA and theoretical ecospace have been utilized to examine and interpret environmental impact factors. Quantitative analysis of their relative abundance and distribution patterns provides insights into the complex interactions between organisms and environmental factors. The relative abundances of different organisms and factors controlling their bioconstructions are influenced by relative sea-level changes. CCA analysis reveal that hydrodynamic conditions are the primary influencing factor. Variation trends in average tiering and motility reveal the characteristics of biological communities during environmental changes in phylloid algae and microbial bioconstructions. These bioconstructions are not directly correlated with changes in environmental factors, and the biological communities in phylloid algae mounds and biostromes exhibit similar organism compositions and ecological niches across different environments.

Distribution of pelagic and demersal fish assemblages by video prospection in the archipelago of Fernando de Noronha

This study presents an approach that complements previously identified trends in the distribution of acoustic biomass of demersal and pelagic fishes in Fernando de Noronha. Using underwater video as the main method of analysis, patterns of relative fish abundance were evaluated as indicators of biomass, richness, and trophic levels of demersal and pelagic assemblages. Thus, depth stratum, Marine Protected Area (MPA) including the National Marine Park and the Sustainable Fishing Zone, and oceanographic/abiotic factors (e.g., winds, currents, and substrate complexity) were considered. The results confirm that complex substrates and shallow areas (0–20 m) are characterised by greater abundance and species richness. However, it is important to note the limitation of video in detecting fish in deeper areas. Wind exposure also positively influences the abundance and diversity of demersal fish, demonstrating the impact of the "island effect" on species distribution. The research also highlights the relevance of the MPA in Fernando de Noronha for both biodiversity conservation and the sustainability of fishing activities. However, the analysis of trophic levels revealed an increased prevalence of higher trophic levels outside the MPA, mainly due to the abundance of the species Melichthys niger. The presence of complex substrates and lower trophic competition may explain this observation. Therefore, the study provides important insights for the planning of MPAs and the need to include the spatial distribution of higher trophic level species for marine conservation.

Performance of unmarked abundance models with data from machine‐learning classification of passive acoustic recordings

AbstractThe ability to conduct cost‐effective wildlife monitoring at scale is rapidly increasing due to the availability of inexpensive autonomous recording units (ARUs) and automated species recognition, presenting a variety of advantages over human‐based surveys. However, estimating abundance with such data collection techniques remains challenging because most abundance models require data that are difficult for low‐cost monoaural ARUs to gather (e.g., counts of individuals, distance to individuals), especially when using the output of automated species recognition. Statistical models that do not require counting or measuring distances to target individuals in combination with low‐cost ARUs provide a promising way of obtaining abundance estimates for large‐scale wildlife monitoring projects but remain untested. We present a case study using avian field data collected in the forests of Pennsylvania during the spring of 2020 and 2021 using both traditional point counts and passive acoustic monitoring at the same locations. We tested the ability of the Royle–Nichols and time‐to‐detection models to estimate the abundance of two species from detection histories generated by applying a machine‐learning classifier to ARU‐gathered data. We compared abundance estimates from these models with estimates from the same models fit using point‐count data and to two additional models appropriate for point counts, the N‐mixture model and distance models. We found that the Royle–Nichols and time‐to‐detection models can be used with ARU data to produce abundance estimates similar to those generated by a point‐count‐based study but with greater precision. ARU‐based models produced confidence or credible intervals that were on average 31.9% (±11.9 SE) smaller than their point‐count counterpart. Our findings were consistent across two species with differing relative abundance and habitat use patterns. The higher precision of models fit using ARU data is likely due to higher cumulative detection probability, which itself may be the result of greater survey effort using ARUs and machine‐learning classifiers to sample significantly more time for focal species at any given point. Our results provide preliminary support for the use of ARUs in abundance‐based study applications, and thus may afford researchers a better understanding of habitat quality and population trends, while allowing them to make more informed conservation recommendations and actions.

Holocene biogeography of the southwestern European white‐toothed shrew (Crocidura iculisma, Eulipotyphla) through its fossil record

AbstractCrocidura iculisma(=C.suaveolens) is a shrew (Soricidae, Eulipotyphla) showing a fragmented distribution limited to the Iberian Peninsula, southern and western France and northwestern Italy. Although it has been in the Iberian Peninsula since the Middle Pleistocene, its biogeographical history remains poorly known.Here, we provide new data onCrocidura iculismafrom the Castillejo del Bonete site (southern Spain) dated as 3.8–3.6 cal kyr BP. At the same time, we analyse changes in its geographic distribution based on its palaeontological record.We have reviewed thoroughly the Holocene record ofCrocidura iculismain southwestern Europe, considering independently the three time intervals according to the stages defined for this geological time series (Greenlandian, Northgrippian and Meghalayan). Whenever found together in fossil sites, the relative abundance of the two sympatric shrews of the genusCrocidura(Crocidura russulaandCrocidura iculisma) was analysed. The data obtained concerning past distribution range and relative abundance were compared with the current status of the species in Iberia to interpret changes through time.The distribution range of the southwestern European white‐toothed shrew in the Iberian Peninsula has notably reduced over time until today. The occurrence at Castillejo del Bonete and other palaeontological records located beyond its current distribution range show that it was distributed in several areas of the eastern part and southern interior of Iberia, at least until the second half of the Meghalayan. Relative abundance patterns observed in the fossil assemblages suggest that competitive exclusion byCrocidura russulaand climatic changes played a crucial role in driving the extirpation ofCrocidura iculismafrom a substantial portion of the Iberian Peninsula.

Ecological drivers of parrotfish coral predation vary across spatial scales

Parrotfishes (Labridae: Scarini) are widely recognized for their important functional role in reducing coral-algae competition by grazing algae, yet some species are also coral predators (corallivores) and thereby have direct negative impacts on corals they prey upon. To better understand the ecological drivers of parrotfish corallivory intensity, we compared patterns of relative predation scar size and abundance across spatial scales from individual coral colonies (<1 to several meters in size), to reefs within islands (1 to 10s of km), to 4 regions across the Greater Caribbean (100s to 1000s of km) including Panamá, Florida, St. Croix, and Bonaire. Across reef sites, there was a positive correlation of both parrotfish density and biomass with the relative coral area preyed upon, but not predation scar abundance. While there was no apparent site-level effect of coral cover on corallivory intensity, we found that the abundance of colonies preyed upon was positively correlated with both coral diversity and the proportional cover of frequently targeted coral taxa within localized 30 m2 reef areas. At the scale of individual coral colonies, we found that while numerous coral taxa were preyed upon, corallivory was concentrated on a few species across regions, such as Orbicella spp., Porites spp., and Stephanocoenia intersepta. Our findings suggest that while increased parrotfish densities may result in an increased coral area preyed upon across reefs, corallivory intensity within reefs may decrease in response to declines in the cover of frequently targeted coral taxa and overall coral diversity.Spanish and Papiamentu versions of the abstract are provided in the Supplement at www.int-res.com/articles/suppl/m740p145_supp.pdf

Forecasting animal distribution through individual habitat selection: insights for population inference and transferable predictions

Habitat selection models frequently use data collected from a small geographic area over a short window of time to extrapolate patterns of relative abundance into unobserved areas or periods of time. However, such models often poorly predict the distribution of animal space‐use intensity beyond the place and time of data collection, presumably because space‐use behaviors vary between individuals and environmental contexts. Similarly, ecological inference based on habitat selection models could be muddied or biased due to unaccounted individual and context dependencies. Here, we present a modeling workflow designed to allow transparent variance‐decomposition of habitat‐selection patterns, and consequently improved inferential and predictive capacities. Using global positioning system (GPS) data collected from 238 individual pronghorn, Antilocapra americana, across three years in Utah, USA, we combine individual‐year‐season‐specific exponential habitat‐selection models with weighted mixed‐effects regressions to both draw inference about the drivers of habitat selection and predict space‐use in areas/times where/when pronghorn were not monitored. We found a tremendous amount of variation in both the magnitude and direction of habitat selection behavior across seasons, but also across individuals, geographic regions, and years. We were able to attribute portions of this variation to season, movement strategy, sex, and regional variability in resources, conditions, and risks. We were also able to partition residual variation into inter‐ and intra‐individual components. We then used the results to predict population‐level, spatially and temporally dynamic, habitat‐selection coefficients across Utah, resulting in a temporally dynamic map of pronghorn distribution at a 30 × 30 m resolution but an extent of 220 000 km2. We believe our transferable workflow can provide managers and researchers alike a way to turn limitations of traditional habitat selection models – variability in habitat selection – into a tool to understand and predict species‐habitat associations across space and time.

Among‐river pattern in relative abundance of two salmonid fishes reflects temperature‐dependent competition

Abstract Temperature is a key driver in determining species distribution and abundance across climatic and geographical gradients. This occurs through direct physiological effects of temperature on performance, but may also result from temperature effects on species interactions. In the current study we experimentally test for temperature‐dependent competition between juvenile anadromous Atlantic salmon and brown trout and evaluate the role of temperature in shaping the relative abundance of these species across 88 Norwegian rivers. When the two species were reared in allopatry their somatic growth rates were similar across a range of temperatures (4–16°C). When reared in sympatry, the growth of salmon was greatly reduced at the coldest temperature relative to when reared in allopatry, whereas this was not the case for trout. The effect of interspecific competition on growth was more similar for the two species at warmer temperatures. Thus, interspecific competition effects were strongly asymmetric only at the lowest temperature, with trout outcompeting salmon. The results from the experiment were reflected in qualitative patterns of relative abundance of salmon and trout in natural populations, which shifted from being trout dominated in rivers with low summer temperatures to being salmon dominated in warmer rivers. These results provide an empirical example of how temperature effects on the relative abundance of species can only be understood in light of information about temperature‐dependent species interactions.

Exploring habitat use and movement patterns of humpback whales in a reoccupation area off Brazil: A comparison with the Abrolhos Bank

AbstractAfter the worldwide moratorium on whaling, humpback whale populations began to recover, reoccupying former areas of use, as also observed on the Brazilian coast. Abrolhos Bank represents the area of greatest humpback whale concentration but the number of individuals to the north has increased, as has happened in the region of Serra Grande. To compare relative abundance, habitat use, and movement patterns between a well‐established breeding and a reoccupation area, visual monitoring from land‐based stations was performed: 160 days in the Abrolhos Archipelago located on the Abrolhos Bank and 133 days in Serra Grande in 2014, 2015, 2018, and 2019. While relative abundance varied annually in the Abrolhos Archipelago, it gradually increased in Serra Grande, surpassing the number registered in Abrolhos in 2019. Group composition frequency was similar between areas except for mother and calf accompanied by one or more escorts, which were more frequent in Abrolhos. Despite similar movement speed and linearity values, whales in Serra Grande had a higher reorientation rate. Monitoring different areas occupied by this population supports decisions about spatial management of the Brazilian coast in relation to the implementation of anthropogenic activities, especially in areas where whales have recently returned to occupy.

Unveiling activity patterns of the deer Odocoileus virginianus (Artiodactyla: Cervidae) and its predators in Mexico's Arid Region

Introduction: Size, predator presence, and habitat nutritional quality influence herbivorous species' activity patterns and resource utilization. Objectives: This study aims to determine the relative abundance and activity patterns of white-tailed deer (Odocoileus virginianus) and their main predators. Methods: The study was conducted in the WMU "Bienes Comunales Santa Cruz Nuevo" in Totoltepec de Guerrero, Puebla, Mexico. Twenty-two quadrants were randomly selected, and camera traps were installed. Over a two-year period (2018-2020), wildlife visits were recorded to estimate the relative abundance index (RAI), activity patterns, and overlap coefficient (Dhat1) of white-tailed deer and their predators based on their activity schedule. Results: The estimated RAI for deer was 7.2%, while it was 3.4% for coyotes (Canis latrans), 2.3% for bobcats (Lynx rufus), and 0.14% for pumas (Puma concolor). White-tailed deer were observed in 31% of the camera traps, while coyotes were captured in 68% of them. The overlap of the activity schedule, Dhat1, between deer and coyotes was 0.18. In contrast, the activity overlap between foxes and deer was higher (Dhat1: 0.2979; EE 0.037) based on the analysis of variance. The activity pattern of coyotes indicated they were crepuscular, with increased activity during the afternoon and night. However, an increase in activity synchronized with deer's patterns was also observed. The bobcat coincided with deer in 10% of the cameras, but due to the limited number of observations, it was not possible to estimate the activity overlap between these species. Conclusions: The activity overlap between white-tailed deer and foxes is more significant than that of deer and coyotes in this region. The activity overlap between deer and coyotes is lower compared to other parts of the world.

EDNA metabarcoding reveals biodiversity and depth stratification patterns of dinoflagellate assemblages within the epipelagic zone of the western Coral Sea

BackgroundDinoflagellates play critical roles in the functioning of marine ecosystems but also may pose a hazard to human and ecosystem health by causing harmful algal blooms (HABs). The Coral Sea is a biodiversity hotspot, but its dinoflagellate assemblages in pelagic waters have not been studied by modern sequencing methods. We used metabarcoding of the 18 S rRNA V4 amplicon to assess the diversity and structure of dinoflagellate assemblages throughout the water column to a depth of 150 m at three stations in the Western Coral Sea. Additionally, at one station we compared metabarcoding with morphological methods to optimise identification and detection of dinoflagellates.ResultsStratification of dinoflagellate assemblages was evident in depth-specific relative abundances of taxonomic groups; the greatest difference was between the 5–30 m assemblages and the 130–150 m assemblages. The relative abundance of Dinophyceae (photosynthetic and heterotrophic) decreased with increasing depth, whereas that of Syndiniales (parasitic) increased with increasing depth. The composition of major taxonomic groups was similar among stations. Taxonomic richness and diversity of amplicon sequence variants (ASVs) were similar among depths and stations; however, the abundance of dominant taxa was highest within 0–30 m, and the abundance of rare taxa was highest within 130–150 m, indicating adaptations to specific depth strata. The number of unclassified ASVs at the family and species levels was very high, particularly for Syndinian representatives.ConclusionsDinoflagellate assemblages in open water of the Coral Sea are highly diverse and taxonomically stratified by depth; patterns of relative abundance along the depth gradient reflect environmental factors and ecological processes. Metabarcoding detects more species richness than does traditional microscopical methods of sample analysis, yet the methods are complementary, with morphological analysis revealing additional richness. The large number of unclassified dinoflagellate-ASVs indicates a need for improved taxonomic reference databases and suggests presence of dinoflagellate-crypto and–morphospecies.

Low diversity and abundance of predatory fishes in a peripheral coral reef ecosystem.

Semi-enclosed seas are often associated with elevated local threats and distinct biogeographic patterns among marine fishes, but our understanding of how fish assemblage dynamics vary in relation to relatively small semi-enclosed seas (e.g., the Gulf of Aqaba) remains limited. Baited remote underwater video surveys (n = 111) were conducted across ~300 km of coral reef habitats in the Gulf of Aqaba and the northern Red Sea. A total of 55 predatory fish species were detected, with less than half of all species (n = 23) observed in both basins. Relative abundance patterns between the Gulf of Aqaba and the northern Red Sea were variable among taxa, but nearly twice as many predatory fish were observed per unit of effort in the northern Red Sea. In general, assemblages in both basins were dominated by three taxa (Epinephelinae, Carangidae, and Lethrinidae). Large-bodied and threatened species were recorded at very low abundances. Multivariate analysis revealed distinct assemblage structuring of coral reef predators between the Gulf of Aqaba and the northern Red Sea. Most of the species driving these differences were recorded in both basins, but occurred at varying levels of abundance. Environmental factors were largely unsuccessful in explaining variation in assemblage structuring. These findings indicate that biological assemblages in the Gulf of Aqaba are more distinct than previously reported and that reef fish assemblage structuring can occur even within a relatively small semi-enclosed sea. Despite inter-basin assemblage structuring, the overall low abundance of vulnerable fish species is suggestive of overexploitation in both the Gulf of Aqaba and the northern Red Sea of Saudi Arabia. As the region surveyed is currently undergoing large-scale coastal development, the results presented herein aim to guide spatial management and recovery plans for these coral reef systems in relation to this development.

Seasonality, distribution, and harvest trends of Crevalle Jack in Texas

AbstractObjectiveCrevalle Jack Caranx hippos are important coastal predators and support an increasingly popular catch‐and‐release sport fishery. However, population declines have recently been perceived by stakeholders in parts of the species' range. Here, we aimed to provide distribution and harvest trends for Crevalle Jack in the northwestern Gulf of Mexico.MethodsLong‐term fishery‐independent and fishery‐dependent data were collected by the Texas Parks and Wildlife Department from 1983 to 2021. Bag seine, bay trawl, and gill‐net samples were collected in conjunction with angler creel surveys. Crevalle Jack that were observed in fishery‐independent sampling were used to assess patterns in both juvenile and adult relative abundance, distribution, and seasonality. In addition, boosted regression tree models were used to highlight important predictors of Crevalle Jack presence. Crevalle Jack harvest observed during angler surveys was used to describe the fishery, including differences in inshore and offshore catch patterns. Relative abundance of both juveniles and adults was variable across years but displayed no trend throughout the time series.ResultCrevalle Jack of all sizes were found within inshore waters, with subadults and large adults particularly reliant on estuarine systems. Recruitment peaked in early summer, with juveniles occupying all major estuaries along the coast. Shifts in recruitment were evident in bag seines, as the mean date of catch trended almost 2 weeks earlier over the study period. The Crevalle Jack fishery was spread across inshore and offshore waters, with significantly larger fish harvested offshore during summer. The majority of anglers who harvested Crevalle Jack stated that they were specifically targeting other species, thus supporting the notion that the targeted fishery is mainly catch and release.ConclusionAs Crevalle Jack declines have been noted elsewhere in the species' range, these results could help to inform future management decisions in Texas.

Occupancy, relative abundance and activity patterns of three sympatric deer in ponds of Calakmul Biosphere Reserve, Campeche

Calakmul Biosphere Reserve is one of the largest tropical forests in the Americas, home to three species of deer, the white-tailed deer, Odocoileus virginianus, the Yucatan brown brocket deer, Odocoileus pandora, and the Central American red brocket deer, Mazama temama. Important ecological aspects on the conservation of these species have been poorly studied. The aim of this study was to determine the occupancy, relative abundance and activity patterns of these species through 9 years of camera-trapping in ponds of a Neotropical Forest in southern Mexico, contributing to the understanding of the ecological patterns and conservation of Neotropical deer. To determine abundance, occupancy and activity patterns, 18 ponds were monitored from 2014 to 2022. The general relative abundance index was used to calculate abundance and the temporal kernel density was used to evaluate the overlap in daily activity of the species. The dynamic occupancy model was used to obtain the occupancy, colonization, extinction and detection of deer, while species co-occurrence occupancy models were used to assess the interaction of water and species. White-tailed deer were the most abundant (Table 1) during the nine years of the study, with low pond occupancy, but with a high probability of colonization. The brown brocket deer was the one with the highest probability of occupancy, showing a low abundance (Table 1), followed by the red brocket deer, with a very low occupancy and abundance (Table 1). Interaction with water was positive in two of the three analyzed species and activity was diurnal for Odocoileus species and cathemeral for Mazama (Fig. 3). The use of ponds by deer is varied in quantity and activity, but they are important places for their development. The protection of the ponds should be fundamental for the conservation of the species in the area, being one of the few semi-perennial water sources and places of food and shelter for wildlife.

Influence of Wetland and Landscape Characteristics on Freshwater Turtle Relative Abundance and Movement Patterns in West Virginia, USA

Wetland management practices often alter habitat characteristics to improve the function of the wetland (e.g., removing emergent vegetation for aesthetics or dredging for fish stocking), potentially at the cost of reducing habitat quality for wetland-dependent species such as freshwater turtles. We identified wetland and surrounding landscape characteristics related to painted turtle (Chrysemys picta) and snapping turtle (Chelydra serpentina) relative abundance and snapping turtle movement among wetlands. We surveyed turtles at 29 wetland sites (0.04–1.71 ha) in a mixed-use watershed in north-central West Virginia, USA, where hardwood forests and wetlands have been heavily fragmented by agriculture and roads. We also applied radio transmitters to 33 adult snapping turtles (17 females and 16 males) across 17 wetlands. Snapping turtle relative abundance was best estimated with mean substrate depth, mean wetland depth, and minimum distance from roads. Painted turtle relative abundance was best estimated with the null model. We documented movement among wetlands for 22 snapping turtles (67%), including 10 females and 12 males. The probability of inter-wetland movement decreased with increased minimum distance from wetlands. Our results suggest that the focal turtle species readily used shallow, mucky wetlands with deep substrate and that increasing the density of wetlands could increase snapping turtle population connectivity. Managers could consider restoring a diversity of wetland types that result in reduced travel distance between wetlands and that collectively have characteristics conducive to multiple species.

Microbial colonization and chemically influenced selective enrichment of bacterial pathogens on polycarbonate plastic.

Plastic pollution in aquatic environments poses significant concerns due to its potential to serve as a refuge for aquatic pathogens. However, the role of plastic surfaces and microbial biofilm interfaces in facilitating pathogen development remains poorly understood. In this study, a microcosm setup was employed to investigate the interactions between plastics and the microbial community and examine the differences in bacterial community composition and potential pathogen occurrences between the plastisphere-biofilm and surrounding seawater. Community composition analysis combined with SEM observations over time indicated that biofilm extracellular polymeric substance formation over 14 days had a link with the relative abundance and succession patterns of pathogen taxa. Colony clusters were observed on biofilms from day 7 and coincided with higher bacterial pathogen dominance. On day 14, pathogen abundance overall decreased with a potentially degrading biofilm. Pseudomonas and Pseudoalteromonas were the dominant potential pathogen groups observed in the microcosm. When further subjected to chemical treatment as an imposed environmental stress over time, biofilm-associated Psuedoalteromonas sharply increased in abundance after three days of exposure, but quickly diminished by 14days in favor of genera such as Acinetobacter, Pseudomonas, and Staphylococcus. These results suggest that environmental plastisphere-biofilms can promote the early selection, enrichment, and spread of pathogenic bacteria in the aquatic environment and could be later worsened under chemical and long-term pressure. This study provided new insights into the succession of pathogens in plastisphere biofilms, contributing to the understanding of pathogen risks involved in emerging plastisphere biofilms in light of global plastic pollution.