Long-term change in the avifauna of undisturbed Amazonian rainforest: ground-foraging birds disappear and the baseline shifts.

How are rainforest birds faring in the Anthropocene? We use bird captures spanning > 35 years from 55 sites within a vast area of intact Amazonian rainforest to reveal reduced abundance of terrestrial and near-ground insectivores in the absence of deforestation, edge effects or other direct anthropogenic landscape change. Because undisturbed forest includes far fewer terrestrial and near-ground insectivores than it did historically, today's fragments and second growth are more impoverished than shown by comparisons with modern 'control' sites. Any goals for bird community recovery in Amazonian second growth should recognise that a modern bird community will inevitably differ from a baseline from > 35 years ago. Abundance patterns driven by landscape change may be the most conspicuous manifestation of human activity, but biodiversity declines in undisturbed forest represent hidden losses, possibly driven by climate change, that may be pervasive in intact Amazonian forests and other systems considered to be undisturbed.

Changing climate associated with the range-wide decline of an estuarine finfish.

Southern flounder (Paralichthys lethostigma) are a coastal flatfish species that supports recreational and commercial fisheries but are currently experiencing range-wide declines. To quantify the range-wide declines and investigate the role of climate in these declines, fishery-independent sampling data of age-0 flounder were obtained from 34 estuaries representing four states in the Gulf of Mexico (TX, LA, AL, and FL) and three states in the Southeastern United States Atlantic Ocean (FL, SC, and NC) spanning from 1976 to 2019. Generalized additive models (GAM) were used to estimate age-0 recruitment trends. Spatial and temporal synchrony analyses were then conducted using annual GAM-predicted values to determine if trends were similar between estuaries in close proximity, and if declines occurred at the same time. Because the species is dependent on physical transport (i.e., winds and tides) for recruitment, hourly wind speed, wind direction, water temperature, and air temperature were obtained for estuaries with non-zero sampling totals and long-term data sets. Only six estuaries showed significant relationships between age-0 flounder indices and growing degree days. However, all estuaries with wind data showed significant relationships between age-0 flounder indices and hourly summed wind speed. Southern flounder also have environmental sex determination, meaning warming estuaries could also account for population changes and declines. We document that water temperatures in the same space and time where southern flounder sexually determine are warmer now than even a decade ago, which could masculinize populations and substantially change population demographics. These results illustrate the vulnerability of estuarine finfish populations to climate change and increased climate variability. Understanding how climate acts on southern flounder biology may help managers respond to and prevent fishery collapses.

Reproductive biology of hardhead catfish Ariopsis felis: evidence for overwintering oocytes.

Hardhead catfish Ariopsis felis are a common marine catfish in the coastal waters of the Gulf of Mexico (GOM). The low economic value of this species has depressed interest and research, and although the species is known for its extremely low fecundity and large oocytes, little else is known about this catfish species. A total of 1230 samples across all months of the year from 2016 to 2018 resulted in 681 females, and analysis of gonado-somatic index (IG ) revealed 1% to be a clear cut-off indicating maturity. Females are considered capable of spawning from April to June when IG averaged 4-8%. Both atresia and post-ovulatory follicles were present in July, suggesting that spawning ends in July in the northern GOM. The 1% IG cut-off was used to designate maturity, and from that an L50 of 253 mm was estimated. Batch fecundity from 41 females estimated a mean batch size of 36 oocytes. Perhaps the most interesting finding was the presence of secondary growth stage oocytes (e.g., cortical alveoli) from July through November, well outside the spawning capable period. Furthermore, 78% of females had some early vitellogenic oocytes present during the non-spawning season, and the distribution of these relatively large (2-5 mm) oocytes did not change over time. The results here are not only important as reproductive biology information for a common and abundant species, but also present interesting and unusual patterns of non-spawning season oocyte development that is not commonly seen in Western Hemisphere subtropical fish species.

Effects of temperature and salinity on body fluid dynamics and metabolism in the estuarine diamondback terrapin (Malaclemys terrapin).

The diamondback terrapin is the only temperate turtle species that exclusively inhabits estuarine environments. Morphological, behavioral and physiological features contribute to the terrapin's ability to regulate body fluid osmotic pressure in a euryhaline environment. Low integument permeability combined with aquatic-terrestrial shuttling behavior limits passive exchange of water and salts with the environment, and terrapins regulate active uptake of salts via alterations in drinking and feeding behavior. The lachrymal salt gland facilitates excretion of excess sodium (Na+) and chloride (Cl-) ions through active transport mechanisms. We investigated body fluid dynamics, oxygen consumption (V̇O2 ) and osmotic status of terrapins exposed to an acute increase in salinity (12 to 35 psu) at 10 and 25°C to gain insight into the relative importance of behavioral versus physiological osmoregulatory adjustments over a range of seasonally relevant temperatures. Linear mixed models were used to evaluate the effects of experimental temperature, salinity and mass. Overall, temperature effects were stronger than salinity effects. Terrapins acclimated to 25°C had significantly lower blood osmolality and Na+, and higher water turnover rates, daily water flux (DWF) and V̇O2  compared with terrapins acclimated to 10°C. Salinity effects were restricted to DWF, which significantly decreased in response to acute exposure to 35 psu. Our results support the notion that behavioral adjustments predominate in the osmoregulatory strategy of terrapins.

Predicting coastal fishing community characteristics in Tanzania using local monitoring data.

Small-scale marine fisheries in Tanzania provide the main source of subsistence for coastal communities, yet due to poor management, they have been overexploited for decades. These coastal fisheries have historically been described as homogeneous in gear-use and fish community makeup. Yet, regional and local variability in the characteristics of these fishing communities was recently identified with community-based fisheries-dependent data. We proposed a flexible modeling approach that incorporated local monitoring data with spatial data to predict the spatial characteristics of the marine fisheries in Tanzania. The spatial models identified relationships between fishery landings and coral reef, seagrass, and mangrove habitat patch attributes, along with fisher density and a hydrologic index. Furthermore, the predicted spatial characteristics matched previously reported fishery characteristics in both districts. The maps developed by our modeling process provide a means for stakeholders and managers to understand the spatial distribution of their fisheries and in turn, focus on explicitly managing what, how, and where fishers operate. Overall, the flexible modeling approach developed here may act as a first step in incorporating local monitoring data into co-management frameworks, which may promote more sustainable fisheries management strategies in data-poor regions.

Peer review trends in six fisheries science journals.

BACKGROUND: As the production of scientific manuscripts and journal options both increase, the peer review process remains at the center of quality control. Recent advances in understanding reviewer biases and behaviors along with electronic manuscript handling records have allowed unprecedented investigations into the peer review process. METHODS: We examined a sample of six journals within the field of fisheries science (and all published by the American Fisheries Society) specifically looking for changes in reviewer invitation rates, review time, patterns of reviewer agreements, and rejection rates relative to different forms of blinding. RESULTS: Data from 6,606 manuscripts from 2011-2021 showed significant increases in reviewer invitations. Specifically, four journals showed statistically significant increases in reviewer invitations while two showed no change. Review times changed relatively little (± 2 weeks), and we found no concerning patterns in reviewer agreement. However, we documented a consistently higher rejection rate-around 20% higher-of double-blinded manuscripts when compared to single-blinded manuscripts. CONCLUSIONS: Our findings likely represent broader trends across fisheries science publications, and possibly extend to other life science disciplines. Because peer review remains a primary tool for scientific quality control, authors and editors are encouraged to understand the process and evaluate its performance at whatever level can help in the creation of trusted science. Minimally, our findings can help the six journals we investigated to better understand and improve their peer review processes.

Heat, hurricanes, and health: Effects of natural disturbances on angling effort.

Recreational angling is a very popular outdoor activity that is weather-dependent, although investigations of this relationship are rare. This study used weekly fishing effort (2015-2021) estimates throughout coastal Louisiana to understand how effort changed in response to weather conditions. Although we found evidence for some effect of all the weather variables, temperature reported the greatest number of monthly effects, along with an overall declining effect throughout the year. We also examined how tropical storms and hurricanes reduce fishing effort, but that effort recovers rapidly after the storm. Finally, we examined fishing effort during the first year of the pandemic (2020) compared to previous years and found some monthly increases exceeding 100% of normal effort. Understanding angler motivations remains an important part of fishery management, and in a future with changes to weather, hurricanes, and global health crises, we can now know more about how environmental factors change angling effort.

Year-round weather alters nest-provisioning rates in a migratory owl.

As global temperatures and precipitation become more extreme, habitat specialists are at particular risk of being pushed past their environmental tolerance limits. Flammulated Owls (Psiloscops flammeolus) are small migratory owls that breed in temperate conifer forests of western North America. Their highly specialized nesting and foraging requirements make them indicators of ecosystem health. Using 17 years of nest observations, we investigated how annual weather patterns affected Flammulated Owl nesting and foraging behaviors during the breeding season. We used generalized linear models with a changepoint parameter to evaluate nest provisioning and nestling growth rates in years of extreme temperature and precipitation. We also evaluated how adult mass, division of labor, and productivity varied based on precipitation and temperature. Compared to wet and warm years, adults made more frequent prey deliveries to nestlings in dry and cold years, particularly early in the night and early in the season, and they experienced earlier changepoints in these years. We found a significant effect of temperature on the number of fledglings in broods, but weather did not affect other variables including productivity, nestling growth rates, adult masses, and division of labor. Our findings suggest that extreme annual weather patterns influence insect prey availability during the Flammulated Owl breeding season, forcing adults to work harder to provision for nests during dry and cold years. While productivity and nestling growth did not vary between years, these may incur a long-term tradeoff in adult survival.

A 30-year dataset of CO2 in flowing freshwaters in the United States.

Increasing atmospheric carbon dioxide (CO2) concentrations have been linked to effects in a wide range of ecosystems and organisms, with negative effects of elevated CO2 documented for marine organisms. Less is known about the dynamics of CO2 in freshwaters, but the potential exists for freshwater organisms to be challenged by elevated CO2. In flowing freshwaters CO2 exhibits more variability than in lakes or the ocean, yet spatiotemporally extensive direct measures of CO2 in freshwater are rare. However, CO2 can be estimated from pH, temperature, and alkalinity-commonly collected water quality metrics. We used data from the National Water Quality Monitoring Council along with the program PHREEQC to estimate CO2 in flowing freshwaters across 35,000 sites spanning the lower 48 US states from 1990 through 2020. Site data for water chemistry measurements were spatially joined with the National Hydrology Dataset. Our resulting dataset, CDFLOW, presents an opportunity for researchers to add CO2 to their datasets for further investigation.

Shifting taxonomic and functional community composition of rivers under land use change.

Land use intensification has led to conspicuous changes in plant and animal communities across the world. Shifts in trait-based functional composition have recently been hypothesized to manifest at lower levels of environmental change when compared to species-based taxonomic composition; however, little is known about the commonalities in these responses across taxonomic groups and geographic regions. We investigated this hypothesis by testing for taxonomic and geographic similarities in the composition of riverine fish and insect communities across gradients of land use in major hydrological regions of the conterminous United States. We analyzed an extensive data set representing 556 species and 33 functional trait modalities from 8023 fish communities and 1434 taxa and 50 trait modalities from 5197 aquatic insect communities. Our results demonstrate abrupt threshold changes in both taxonomic and functional community composition due to land use conversion. Functional composition consistently demonstrated lower land use threshold responses compared to taxonomic composition for both fish (urban p = 0.069; agriculture p = 0.029) and insect (urban p = 0.095; agriculture p = 0.043) communities according to gradient forest models. We found significantly lower thresholds for urban versus agricultural land use for fishes (taxonomic and functional p < 0.001) and insects (taxonomic p = 0.001; functional p = 0.033). We further revealed that threshold responses in functional composition were more geographically consistent than for taxonomic composition to both urban and agricultural land use change. Traits contributing the most to overall functional composition change differed along urban and agricultural land gradients and conformed to predicted ecological mechanisms underpinning community change. This study points to reliable early-warning thresholds that accurately forecast compositional shifts in riverine communities to land use conversion, and highlight the importance of considering trait-based indicators of community change to inform large-scale land use management strategies and policies.

CreelCat, a Catalog of United States Inland Creel and Angler Survey Data.

The United States Inland Creel and Angler Survey Catalog (CreelCat) contains a national compilation of angler and creel survey data collected by natural resource management agencies across the United States (including Washington, D.C. and Puerto Rico). These surveys are used to help inform the management of recreational fisheries, by collecting information about anglers including what they are catching and harvesting, the amount of effort they expend, their angling preferences, and demographic information. As of May 1, 2023, CreelCat houses over 14,729 surveys from 33 states, Puerto Rico, and Washington, D.C., comprising 235 data fields across 8 tables. These tables contain 235,015 records of fish catch and harvest metrics, 27,250 angler preference metrics, 14,729 records of survey characteristics, 13,576 records of effort metrics, and 409 records of angler demographics. Though individual creel surveys are often deployed to meet local science and management objectives, creel data aggregated across jurisdictions has the potential to address larger scale research and management needs.

Global responses to the COVID-19 pandemic by recreational anglers: considerations for developing more resilient and sustainable fisheries.

The global COVID-19 pandemic resulted in many jurisdictions implementing orders restricting the movements of people to inhibit virus transmission, with recreational angling often either not permitted or access to fisheries and/or related infrastructure being prevented. Following the lifting of restrictions, initial angler surveys and licence sales suggested increased participation and effort, and altered angler demographics, but with evidence remaining limited. Here, we overcome this evidence gap by identifying temporal changes in angling interest, licence sales, and angling effort in world regions by comparing data in the 'pre-pandemic' (up to and including 2019); 'acute pandemic' (2020) and 'COVID-acclimated' (2021) periods. We then identified how changes can inform the development of more resilient and sustainable recreational fisheries. Interest in angling (measured here as angling-related internet search term volumes) increased substantially in all regions during 2020. Patterns in licence sales revealed marked increases in some countries during 2020 but not in others. Where licence sales increased, this was rarely sustained in 2021; where there were declines, these related to fewer tourist anglers due to movement restrictions. Data from most countries indicated a younger demographic of people who participated in angling in 2020, including in urban areas, but this was not sustained in 2021. These short-lived changes in recreational angling indicate efforts to retain younger anglers could increase overall participation levels, where efforts can target education in appropriate angling practices and create more urban angling opportunities. These efforts would then provide recreational fisheries with greater resilience to cope with future global crises, including facilitating the ability of people to access angling opportunities during periods of high societal stress. Supplementary Information: The online version contains supplementary material available at 10.1007/s11160-023-09784-5.

COVID-19 influences on US recreational angler behavior.

Recreational angling in the United States (US) is largely a personal hobby that scales up to a multibillion-dollar economic activity. Given dramatic changes to personal decisions and behaviors resulting from the COVID-19 pandemic, we surveyed recreational anglers across the US to understand how the pandemic may have affected their fishing motivations and subsequent activities. Nearly a quarter million anglers from 10 US states were invited to participate in the survey, and almost 18,000 responded. Anglers reported numerous effects of the pandemic, including fishing access restrictions. Despite these barriers, we found that the amount of fishing in the spring of 2020 was significantly greater-by about 0.2 trips per angler-than in non-pandemic springs. Increased fishing is likely associated with our result that most respondents considered recreational angling to be a COVID-19 safe activity. Nearly a third of anglers reported changing their motivation for fishing during the pandemic, with stress relief being more popular during the pandemic than before. Driven partly by the perceived safety of social fishtancing, recreational angling remained a popular activity for many US anglers during spring 2020.

Principles of Effective Data Visualization.

We live in a contemporary society surrounded by visuals, which, along with software options and electronic distribution, has created an increased importance on effective scientific visuals. Unfortunately, across scientific disciplines, many figures incorrectly present information or, when not incorrect, still use suboptimal data visualization practices. Presented here are ten principles that serve as guidance for authors who seek to improve their visual message. Some principles are less technical, such as determining the message before starting the visual, while other principles are more technical, such as how different color combinations imply different information. Because figure making is often not formally taught and figure standards are not readily enforced in science, it is incumbent upon scientists to be aware of best practices in order to most effectively tell the story of their data.

Mercury concentrations in store-bought shrimp.

Most mercury exposure to humans comes from consumption of fish and shellfish; however, mercury concentrations are not known for all available seafood, particularly shrimp. Our objective was to estimate the concentration of mercury in a variety of store-bought shrimp and then to compare total mercury concentrations to other information such as brand, harvest type, and total fat. We sampled a total of n = 159 shrimp from 10 different brands. Across 10 brands of shrimp, there was a significant effect of brand, with mean mercury concentrations among brands varying by up to an order of magnitude. We found no significant differences comparing shrimp between two capture types (wild-caught and farm-raised), which was perfectly collinear to whether shrimp were domestic or foreign. We did detect significant differences in mercury levels among different amounts of total fat in shrimp, with the lowest fat shrimp (1 g) having significantly more mercury than the highest fat shrimp (2 g). Although our results confirm that shrimp contains relatively low levels of mercury and is generally considered a good choice for consumers, this study is the first to report significant differences in mercury among both brands of shrimp and total fat content in shrimp.

Trends in global shark attacks.

Shark attacks are a global phenomenon that attracts widespread attention and publicity, often with negative outcomes for shark populations. Despite the widespread perceptions of shark attacks, trends in human water activities and shark populations are both dynamic, resulting in variable rates of shark attacks over space and time. Understanding variable trends in shark attacks may contribute to a better understanding of risk, and a more tempered response in the wake of an attack. We found that global shark attack rates are low, yet variable across global regions and over decades. Countries with low populations were found to have the highest rates of attack, while countries with high populations (U.S.A., Australia, South Africa) tended to have overall low attack rates, but also much more interannual variability. From the 1960s to the present, those countries with the highest populations also tended to be the places where attack rates have increased. Ultimately, shark attack risk is also driven by local conditions (e.g., time of day, species present); however, a global scale understanding of attack rates helps place risk into perspective and may contribute to a more scientifically-grounded discussion of sharks, and their management and conservation.

Blood Biochemical Reference Intervals for Wild Ornate Box Turtles ( Terrapene ornata) during the Active Season.

Blood biochemical and hematology analyses are helpful indicators of the physiologic health of animals, particularly when making conservation and management decisions for threatened species. In this study, we 1) established blood biochemical reference intervals for two populations of threatened, free-ranging ornate box turtles ( Terrapene ornata) in northern Illinois during their active season and 2) examined the effects of individual carapace temperature ( Tc) on blood biochemical variables by using a Bayesian hierarchical framework. Individual blood variables differed throughout the active season (May-September 2015), but there were few distinct patterns in concentrations over time. When controlling for individual variability, blood biochemical variables potassium, sodium, chloride, ionized calcium, hematocrit (percentage of packed cell volume), and osmolality showed no effect of Tc (i.e., slope estimates for these variables were not credibly different from zero) and had little individual variation. Glucose and urea nitrogen were found to have slopes credibly different from zero, with glucose having an estimated positive slope and urea nitrogen having an estimated negative slope, suggesting different relationships in response to Tc when controlling for individual variability. These physiologic blood data will serve as important baseline reference values for the clinical evaluation of wild ornate box turtles presented for veterinary care or for comparison to other studies of wild populations. Further, this study highlights the importance of considering individual-level effects (e.g., Tc) on physiologic health variables.

Twitter Predicts Citation Rates of Ecological Research.

The relationship between traditional metrics of research impact (e.g., number of citations) and alternative metrics (altmetrics) such as Twitter activity are of great interest, but remain imprecisely quantified. We used generalized linear mixed modeling to estimate the relative effects of Twitter activity, journal impact factor, and time since publication on Web of Science citation rates of 1,599 primary research articles from 20 ecology journals published from 2012-2014. We found a strong positive relationship between Twitter activity (i.e., the number of unique tweets about an article) and number of citations. Twitter activity was a more important predictor of citation rates than 5-year journal impact factor. Moreover, Twitter activity was not driven by journal impact factor; the 'highest-impact' journals were not necessarily the most discussed online. The effect of Twitter activity was only about a fifth as strong as time since publication; accounting for this confounding factor was critical for estimating the true effects of Twitter use. Articles in impactful journals can become heavily cited, but articles in journals with lower impact factors can generate considerable Twitter activity and also become heavily cited. Authors may benefit from establishing a strong social media presence, but should not expect research to become highly cited solely through social media promotion. Our research demonstrates that altmetrics and traditional metrics can be closely related, but not identical. We suggest that both altmetrics and traditional citation rates can be useful metrics of research impact.

Seasonal physiological dynamics of maturing female southern flounder (Paralichthys lethostigma).

Physiological information is rarely used in descriptions of maturity for managed, wild fish species; however, the use of physiological data holds great promise to provide important detail on the complexities of oocyte development and maturity. Investigating southern flounder (Paralichthys lethostigma)-an overfished commercial and recreational fishery resource-we examined pre-spawn physiological changes in females to provide further detail of the maturation process. Given that adults of this species complete maturation and spawn in unknown offshore locations, information on pre-spawn physiological changes is particularly informative for both size- and age-based patterns of maturity. We evaluated seasonal and ontogenetic changes in hormone concentrations in blood plasma that are commonly associated with sexual maturation, in addition to quantifying and classifying lipid stored in liver tissue. We found a strong positive relationship between body weight and lipid content during all months, as well as evidence for mobilization of lipids among larger females in September and October, presumably for gonadal development. Throughout the sampling period, the lipid content of smaller individuals was dominated by structural lipids (as opposed to storage lipids). In contrast, larger individuals possessed greater amounts of storage lipids. This suggests that larger, putatively maturing individuals were accumulating storage lipids for later production of vitellogenin. Females sampled for blood sex steroids and ovarian histology showed different testosterone and estradiol concentrations between putatively maturing and immature fish, and temporal variation with peaks in October and November. Overall, emerging patterns of liver lipid content and composition and blood steroid concentrations describe a multi-month maturation process that is often managed one dimensionally over short time periods. Insights from this work will improve our understanding of the life history of southern flounder, with the potential for better understanding of the dynamics of offshore spawning migration and informing subsequent species management.