Coast Of America Research Articles

Microplastics in Santos São Vicente estuarine – Hotspot in sediments caused by low energy hydrodynamic events in strongly populated areas

Microplastics (MPs) have emerged as a significant class of contaminants due to their widespread presence in various environmental compartments. The ingestion of these particles poses a risk to both human health and the local biota. The investigation of the Santos estuary reveals the abundance of microplastics in the mangrove sediment. The highest concentration was 62,850–93,050 MPs·kg−1dw, never seen before in Latin America coast. The region investigated is characterized for silting sites and low energy events, notably Rio dos Bugres, influenced by anthropic aspects, while the São Vicente e Santos channels prevail the high energy hydrodynamic regime. In consequence, the MPs are entrapped in the interior of the estuary, affecting drastically the biota of mangrove. Spectroscopic investigation identified: polymers, pigments, herbicide and additives. The hypothesis is that densely populated siltation areas combined with low-energy events serve along the estuary for MPs accumulation and hotspots formation.

Wave Energy Potential and the Role of Extreme Events on South America's Coasts. A Regional Frequency Analysis

This study examines wave energy potential and generation capacity from extreme waves along South America's Pacific and Atlantic coasts. Utilizing the Regional Frequency Analysis (RFA) method and the WAVERYS wave reanalysis model, 27 homogeneous regions with distinct wave patterns were identified. There's a notable southward increase in median and average wave heights and energy. Unlike previous studies, this research emphasizes the significant role of extreme wave events, which contribute up to 33 % of the total energy—a critical factor often overlooked in regional energy assessments. In the Pacific, three main zones were delineated, with energy peaks reaching 120 kW/m south of 50°S, while the Atlantic identified two zones with energy values ranging from 10 kW/m to 30 kW/m. Zones between 10°S to 40°S in the Pacific and 30°S to 60°S in the Atlantic stand out as particularly promising for energy harvesting. A comprehensive statistical methodology enabled predictions of wave heights and energy for 50 and 100-year return periods, predominantly utilized generalized Pareto and Gumbel distributions. The study affirms the efficacy of the RFA in improving the understanding of wave dynamics and highlights the necessity of integrating extreme events in energy assessments. This research provides a foundation for advancing wave energy initiatives and coastal risk mitigation in South America.

Current Status of Remote Sensing for Studying the Impacts of Hurricanes on Mangrove Forests in the Coastal United States

Current Status of Remote Sensing for Studying the Impacts of Hurricanes on Mangrove Forests in the Coastal United States

First Report of the Sanderling (Calidris alba) in Cuatro Ciénegas Valley, Coahuila, Mexico

The Sanderling (Calidris alba) is the most widely distributed shorebird that winters on both coasts of America, with records of vagrant individuals in the interior of the continent. On 14 September 2022, we observed and photographed two juvenile Sanderlings at a small pool adjacent to the Río Mezquites in the Cuatro Ciénegas protected area, Coahuila, Mexico. This sighting represents the first record of this species in this RAMSAR site, and increases the known inland distribution in northeastern Mexico, as well as the first documented for the state of Coahuila.

Snapshots of Coastal Ecology Using Multiproxy Analysis Reveals Insights Into the Preservation of Swamp and Marsh Environments Since the Late Pleistocene

AbstractThe southeastern United States Coastal Plain ecosystem contains baldcypress (Taxodium distichum) swamps and grass‐dominated marshes. These ecosystems also occurred on the exposed continental shelf during lower sea levels but are rarely preserved due to the mechanically erosive nature of transgression and regression. Two presently marine sites on the northeastern Gulf of Mexico's continental shelf contain well‐preserved woody terrestrial sediments that were the subject of previous studies. This study continues the investigation using geochemical (δ13C, δ15N, δ34S) and palynological characteristics of these formerly terrestrial sediments to determine if swamps and/or marshes existed at the time of deposition. The first site is located ∼20 km southeast of Horn Island, Mississippi (MS) and the core has terrestrial sediments radiocarbon dated to 11,066–10,228 (2σ) calibrated years BP (early Holocene). The second site is the “Alabama Underwater Forest” located ∼13 km south of Gulf Shores, Alabama (AL) and the cores have terrestrial sediments optically stimulated luminescence dated to 63 ka (±10 ka, 2σ) to 72 ka (±16 ka, 2σ) (late Pleistocene). Geochemical results for the MS sediments indicate a swamp‐to‐freshwater marsh transitional series, whereas the AL sediments indicate a swamp‐to‐saltwater marsh transitional series, both supported by palynological results. Further exploration of the geochemical results using linear discriminant analysis, trained with published geochemical data, supports the swamp and marsh interpretations. We conclude that the near‐pristine preservation of these woody deposits is not solely due to physical mechanisms, such as rapid burial, but is also coupled with anoxia‐ and euxinia‐driven biogeochemical reactions promoting wood and woody debris preservation in swamp and marsh environments.

Predicting Ocean Current Temperature Off the East Coast of America with XGBoost and Random Forest Algorithms Using Rstudio

This research investigates the comparative predictive efficacy of two leading machine learning methodologies, specifically the XGBoost and Random Forest models, in estimating ocean temperature dynamics in the TS Gulf Stream and Labrador Current regions along the east coast of North America. Using annual temperature datasets and relevant oceanographic parameters, the data is carefully processed, cleaned and sorted into training and test subsets via the RStudio Platform. The performance evaluation model is carried out using predetermined machine learning assessment criteria, including Mean Absolute Error (MAE), Root Mean Squared Error (RMSE), Mean Squared Error (MSE), and R-squared. The results show the superiority of the XGBoost model compared to Random Forest in terms of prediction accuracy and minimizing prediction errors. The XGBoost model shows lower MSE values and higher R-squared values than the Random Forest model, indicating its better capacity in explaining data variations. XGBoost consistently provides more accurate predictions and shows higher sensitivity in identifying important factors influencing ocean temperature fluctuations than Random Forest. This research significantly improves understanding and prognostic capabilities regarding ocean temperature dynamics in the TS Gulf Stream and Labrador Current regions. Empirical evidence underlines the efficacy of the XGBoost model in predicting ocean temperatures in the studied region. Continuous model evaluation and parameter refinement for both methodologies is critical to establishing standards for optimal prediction performance. The findings of this research have implications for the fields of oceanography and climate science, and offer potential pathways to comprehensively understand and mitigate the impacts of climate change on marine ecosystems.

The 2022 Tonga Tsunami on the Pacific and Atlantic Coasts of the Americas

AbstractThe Hunga‐Tonga volcano eruption on 15 January 2022 generated tsunami waves that impacted both the Pacific and Atlantic coasts of the Americas. A unique feature of this event was the dual tsunami generation mechanism, which led to motions with long (several days) ringing and slow energy decay. The first ocean waves to reach the coast were “atmospheric tsunamis” generated by atmospheric Lamb waves that propagated with the speed of sound (∼314 m/s) and circled the globe in both directions several times before being fully attenuated. The second type of ocean waves were classical “oceanic tsunami” waves forced directly by the volcanic eruption and which propagated across the Pacific at roughly 2/3 the speed of the atmospheric waves. This study focuses on time series of the Hunga‐Tonga event recorded by tide gauges, microbarographs and Deep‐ocean Assessment and Reporting of Tsunamis on and off the Pacific coasts of North and Central America and in the Gulf of Mexico. Atmospheric tsunami waves only were recorded in the Gulf of Mexico, where the sea level response to the second, westward (shoreward) propagating atmospheric wave was stronger than to the first, eastward (seaward) propagating wave. Along the Pacific coast, the atmospheric tsunami waves were approximately 3–4 times smaller than the oceanic tsunami waves, which at several Mexican stations exceeded 2 m in height. The broad frequency range of 0.2–0.25 to 30 cph spanned by the oceanic tsunami in the Pacific indicates that the “effective” source area for the oceanic waves was more extensive than initially proposed.

Phylogeography of a Widely Distributed Atlantic Species: The Case of the Ghost Crab Ocypode quadrata (Fabricius, 1787) (Decapoda: Brachyura: Ocypodidae)

Ocypode Weber, 1795 (Brachyura: Ocypodidae) is popularly known as ghost crab, and encompasses 21 valid species, including Ocypode quadrata (Fabricius, 1787). This species has wide distribution along the Atlantic coast of America, from the USA (Massachusetts) to Brazil (Rio Grande do Sul), Central America, and Antilles. Such distribution, along with some biological characteristics of its life cycle and the presence of geographic barriers, could lead to genetic structuring. Herein, we evaluate the hypothesis of the presence of geographic barriers using COI and 16S partial gene fragments. The Maximum Likelihood tree suggests the monophyly of O. quadrata, while the values of intraspecific genetic distance along with the star-shaped haplotype network suggested a lack of genetic structure in Brazilian, Panama, and French Guiana populations, probably caused by larval dispersion. USA and Mexico populations may be a new lineage, but we cannot say it with few sequences and with no morphological characters.

Regional climate change adaptation planning: a case study on single-story wooden-frame residential buildings vulnerable to hurricane winds in selected US coastal locations

The projected increase in sea surface temperature due to climate change is expected to substantially intensify future hurricanes. Wooden light-frame residential buildings are particularly vulnerable to hurricane damage, and their risk is expected to increase due to heightened exposure and intensifying hurricanes. Therefore, adaptation strategies need to be planned to reduce damage to such buildings while considering the impact of climate change on hurricanes. This study investigates the effectiveness of various climate change adaptation strategies for coastal wood-frame single-story residential buildings and demonstrates how these strategies can be planned. The study considers the four Representative Concentration Pathways (RCPs) proposed by the IPCC to investigate the impact of climate change on wind hazard and losses. Additionally, three locations in the coastal United States of varying sizes, exposure, and hurricane hazard levels are considered: Harris County, Texas; Mobile County, Alabama; and Miami-Dade County, Florida. The results show that the increase in wind speeds and losses will be non-linear with time. All considered adaptation strategies decreased losses, with some able to completely counter the increasing losses even under high emission scenarios. Investigating the effectiveness of adaptive measures can guide stakeholders in allocating funds and efforts for hurricane risk management and enhancing community resilience.

Transcriptome analysis of reproductive tract tissues of male river prawn Macrobrachium americanum.

The river prawn, Macrobrachium americanum (M. americanum), is one of the largest prawns of the genus in Latin America and is an amphidromous species distributed along the Pacific coast of America. This prawn has commercial value due to its size and taste, making it a good option for aquaculture production. Its culture has been attempted in ponds and concrete tanks, but no successful technique can still support commercial production. Understanding the mechanisms that regulate reproduction at the molecular level is very important. This knowledge can provide tools for manipulating transcripts, which could increase the number or size of animals in the culture. Our understanding of the mechanism that regulates the reproduction of M. americanum at the molecular level is limited. Perform and analyze the transcriptome assembly of the testes, vas deferens, and terminal ampulla of M. americanum. to provide new molecular information about its reproduction. The cDNA library was constructed and sequenced for each tissue to identify novel transcripts. A combined transcriptome with the three tissues was assembled using Trinity software. Unigenes were annotated using BLASTx and BLAST2GO. The transcriptome assembly generated 1,059,447 unigenes, of which 7222 genes had significant hits (e-value < 1 × 10-5) when compared against the Swiss-Prot database. Around 75 genes were related to sex determination, testis development, spermatogenesis, spermiogenesis, fertilization, maturation of testicular cells, neuropeptides, hormones, hormone receptors, and/or embryogenesis. These results provide new molecular information about M. americanum reproduction, representing a reference point for further genetic studies of this species.

Nationwide Aquatic Envenomations Reported to US Poison Control Centers from 2011 to 2020.

Aquatic envenomations are common injuries along the coastal United States that pose a public health risk and can cause significant morbidity. We examined aquatic envenomation exposures that were called in to poison control centers (PCC) in the United States from 2011 to 2020. The Association of Poison Control Center's (AAPCC) National Poison Data System was queried for all aquatic envenomations reported during the 10 y period from January 1, 2011, to December 31, 2020. Data collected included date, exposure and geographic location, patient age and sex, signs and symptoms, management setting, treatments, and clinical outcome. Duplicated records, confirmed nonexposure, and reports not originating within the United States were excluded. There were 8517 human aquatic envenomations reported during the study period, 62% (5243) of whom were male; 56% (4264) of patients were 30 y or younger. There were an average of 852 calls per year, with 46% of calls occurring during June to August. California, Texas, and Florida had the highest number of envenomations during the study period. Fish (61%; 5159) and Cnidaria (30%; 2519) envenomations were the most common exposures. Overall, 37% (3151) of exposures were treated in healthcare facilities, with no deaths reported. The highest proportion of aquatic envenomations occurred among younger males (≤30 y) during the summer months. While rarely leading to major adverse events, aquatic envenomations were commonly reported injuries to PCC and occurred in all 50 states. Poison control centers continue to be real-time sources of information and data regarding aquatic envenomation trends.

Bat winter foraging habitat use in working forests: a multispecies spatial occupancy approach

AbstractInsectivorous bats in temperate zones have evolved strategies such as migration or hibernation to overcome challenges of reduced resource availability and increased energy demand during winter. In the southeastern United States Coastal Plain, bats are either year‐round residents and remain active during winter or are migrants from colder areas seeking milder temperatures. Southeastern Coastal Plain forests also may represent important areas for remnant populations of species impacted by white‐nose syndrome. Working pine (Pinus spp.) forests comprise a large proportion of southeastern Coastal Plain forests, yet winter bat habitat associations and how forest management affects bat use remain understudied. Hence, we used hierarchical multispecies spatial occupancy models to evaluate factors influencing winter bat occupancy and foraging habitat associations in working forests of the southeastern Coastal Plain. From January to March 2020–2022, we deployed Anabat Swift acoustic detectors and measured site‐ and landscape‐level covariates on six working landscapes. We detected five species of bats and three species groups at 93% (224/240) of sites. We observed higher species richness at sites with high proportions of contiguous forest and low levels of basal area. At the species level, occupancy patterns were influenced by site and landscape covariates, which had varying effects on species with distinct foraging strategies. Temperature was an important predictor of detectability. Our findings offer new insights into the ecology of bats in working forest landscapes during winter, where we highlight positive responses in occupancy with contiguous forests and lower levels of basal area, as in previous summer work. By providing valuable information on winter community composition and foraging habitat associations, we hope to guide management decisions for forest attributes important to these species, thus increasing conservation opportunities within working forests.

A Bioinformatics Study of the Influenza H5N1 Virus that Infects Wild Fowl and Poultry and, Potentially, Humans

Introduction: More than sixteen countries are infected with the highly pathogenic avian influenza A-H5N1 virus. As the virus circles the world, it has led to the slaughter of millions of poultry birds as well as the infection of farmed mink in Europe and among seals and grizzly bears on the Northern coast of America; some infected mammals exhibited neurological symptoms like disorientation and blindness, which marks the first large H5N1 outbreak potentially driven by mammal-tomammal transmission that could be poised to spillover into humans its mortality rate in humans exceeds 50%. The virus pandemic potential is continuously monitored to characterize further and analyze its zoonotic potential (PAHO/WHO, March 2023). Objective: To gain comprehension of the envelope glycoproteins that express H5N1 influenza (hemagglutinin and neuraminidase proteins), computational studies were carried out. Methods: Calculating each sequence's Protein Intrinsic Disorder Predisposition (PIDP) and Polarity Index Method Profile 2.0 v (PIM 2.0 v) required the employment of multiple computer algorithms. Results:: The analysis of the PIM 2.0 v and PIDP profiles revealed specific patterns within the envelope glycoproteins (neuraminidase and hemagglutinin) of diverse strains of the H5N1 influenza virus. These patterns made it possible to identify structural and morphological similarities. Conclusions: Using the PIM 2.0 v profile, our computational programs were able to identify the influenza H5N1 virus envelope glycoproteins (hemagglutinin and neuraminidase strains). This study contributes to a better comprehension of this emerging virus.

Subseasonal Variation Characteristics of Low-Cloud Fraction in Southeastern and Northwestern North Pacific

The subseasonal variability of the low-cloud fraction (LCF) over the southeastern North Pacific (SENP) and northwestern North Pacific (NWNP) was studied using satellite observations and the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis. It is found that subseasonal variability of the LCF was closely related to variations in the estimated inversion strength (EIS), sea surface wind speed (SSW), sensible heat flux (SHF), sea surface temperature (SST), surface temperature advection (Tadv), relative humidity (RH), surface level pressure (SLP) and surface air temperature (SAT). An increase in the LCF over the SENP is associated with the development of an anomalous anticyclonic circulation, which is located on the west coast of America. The cold advection, together with the subsidence warming associated with the anticyclonic circulation, strengthens the temperature inversion, favoring the development of the LCF. In the NWNP, the maximum LCF anomaly was also correlated with the stable boundary layer. The southerly wind blows airflow over the Kuroshio Extension from the subtropics, which brings warm and moist air. When air flows to the colder sea surface, it is cooled and condensed by the intensified heat exchange. A lead-lag composite analysis indicates that the mechanisms are different between the SENP and the NWNP, possibly due to the different types of low-level clouds over these two regions. In the SENP, the trade cumulus dominates under a strong capping inversion over the subtropics, whereas fog and stratus often occur under a shallow capping inversion in the NWNP. The effects of atmospheric circulation are also discussed.

Assessing potential of the Geostationary Littoral Imaging and Monitoring Radiometer (GLIMR) for water quality monitoring across the coastal United States

The Geostationary Littoral Imaging and Monitoring Radiometer (GLIMR) will provide unique high temporal frequency observations of the United States coastal waters to quantify processes that vary on short temporal and spatial scales. The frequency and coverage of observations from geostationary orbit will improve quantification and reduce uncertainty in tracking water quality events such as harmful algal blooms and oil spills. This study looks at the potential for GLIMR to complement existing satellite platforms from its unique geostationary viewpoint for water quality and oil spill monitoring with a focus on temporal and spatial resolution aspects. Water quality measures derived from satellite imagery, such as harmful algal blooms, thick oil, and oil emulsions are observable with glint <0.005 sr−1, while oil films require glint >10−5 sr−1. Daily imaging hours range from 6 to 12 h for water quality measures, and 0 to 6 h for oil film applications throughout the year as defined by sun glint strength. Spatial pixel resolution is 300 m at nadir and median pixel resolution was 391 m across the entire field of regard, with higher spatial resolution across all spectral bands in the Gulf of Mexico than existing satellites, such as MODIS and VIIRS, used for oil spill surveillance reports. The potential for beneficial glint use in oil film detection and quality flagging for other water quality parameters was greatest at lower latitudes and changed location throughout the day from the West and East Coasts of the United States. GLIMR scan times can change from the planned ocean color default of 0.763 s depending on the signal-to-noise ratio application requirement and can match existing and future satellite mission regions of interest to leverage multi-mission observations.

The spatiotemporal assessments for tidal flat erosion associated with urban expansion in the conterminous coastal United States from 1985 to 2015

Tidal flats are of great importance to coastal residents and environments, which are recently facing unprecedented challenges due to massive urban expansions. While some case studies have been conducted in small areas, it is yet to come a picture to examine the issue at the nationwide level. To fill this void, it is necessary to reconsider whether the analytical and statistical methods used in the previous studies are still appropriate to the larger scales, which accordingly needs to be refined and updated. Aiming at this issue, this study implemented a justification for the conterminous United States, in which nearly 70 % of the counties by the seashore with intensified tidal flats in 1985 were selected to conduct a comprehensive assessment. Based on the 156 selected counties, this paper firstly analyzed the spatiotemporal change patterns of tidal flats and urban extents from 1985 to 2015, and then combined these results and implemented a series of correlation assessments between tidal flat loss and urban expansion. As a result, we found that urban expansions in the conterminous coastal United States have not only substantially squeezed the space of tidal flats, but also significantly affected the surrounding tidal flat environments during the three decades.

Širenje atlantskog plavog raka Callinectes sapidus u Tirenskom moru: dokazi o postojanju ustanovljene populaciji u laguni Stagnone di Marsala (Sicilija, južna Italija)

The blue crab Callinectes sapidus is a portunid brachyuran native of the Atlantic coasts of America. In the last decades, the species has greatly expanded its range in invaded areas, currently including the Atlantic coasts of Morocco, the Mediterranean Sea, the Black Sea as well as the eastern Atlantic coasts of Europe from Portugal to France, Belgium, and Germany. In the present study, several specimens of C. sapidus were collected in May, June and July 2021 in the Stagnone di Marsala, a semi-enclosed basin located in the north-western coast of Sicily (southern Italy, Mediterranean Sea) characterized by low hydrodynamics and water exchange with the adjacent open sea and high salinity conditions. Juveniles at different instar stages and ovigerous females were repeatedly captured, suggesting the presence of an established population of the blue crab, despite the peculiar environmental conditions characterizing the basin. These findings are discussed in the context of the current expansion of the species along the African coasts of the Mediterranean Sea.

Small effect sizes are achievable in offshore wind monitoring surveys

Abstract Understanding the prospective environmental impacts of offshore wind energy development requires monitoring that allows for adequate testing of conditions for comparison of unimpacted vs. impacted states. A critical component when designing impact studies is determining the required sampling needed to statistically measure a difference between before and after states in the system, which is often challenging because there are little observational data available for the system of interest at the proper spatiotemporal scales. Here, we present the survey design with power and effect size analyses that were used to design a before-after gradient survey to assess American lobster impacts from an offshore wind submarine cable installation in coastal United States waters. By leveraging long-term monitoring data collected from a random-stratified sampling design survey, a gradient survey testing for effects on lobster at distance intervals from the cable using similar sampling methods was developed. Generalized linear mixed models were employed to determine the needed sampling frequency to assess varied catch-per-unit-effort impacts. We present the survey design and our findings from the power analyses to serve as an example of methodology for designing before and after impact surveys for offshore wind energy, and how preexisting data may be used to do so.

Unraveling Siren (Caudata: Sirenidae) systematics and description of a small, seepage specialist.

For approximately four decades, scientists have known of the existence of several undescribed species of Siren in the southeastern United States Coastal Plain. One of these species, S. reticulata, was recently described, but a small, seepage-dwelling species has remained undescribed until now. To resolve outstanding questions concerning the phylogeny of Siren, we collected sequence and morphometric data from specimens across the range of Siren. We found S. lacertina and S. reticulata to represent strongly supported monophyletic groups, with S. reticulata having a sister relationship to all other Siren. Additionally, we found five distinct mtDNA lineages within what has been recognized as S. intermedia. Siren lacertina and type-locality S. intermedia (lineage A) are sister mtDNA lineages, whereas S. intermedia lineages B and C show a high level of mitogenomic divergence from type-locality S. intermedia. Analyses of two scnDNA loci revealed that S. lacertina is monophyletic but nested with low positional support in a clade including the three S. intermedia mtDNA lineages. Further study is needed to determine whether S. intermedia lineages A, B, and C represent distinct species or incompletely sorted lineages. We restrict the range of S. intermedia to the region from the Escambia and Perdido river drainages of Florida and Alabama eastward through Virginia (the combined ranges of lineages A, B, and C). We also elevate S. i. nettingi (lineage E) to species status and include the larger S. i. texana form in that taxon, generating a species that occurs from the Mobile Bay drainages westward through the Mississippi Basin and southwest into northeastern Mexico. Lastly, we describe a new miniature species, S. sphagnicola, that ranges from the Florida Parishes of Louisiana eastward to the westernmost tributary creeks of Choctawhatchee Bay in the western Florida panhandle.

Shifting in the global flood timing

Climate change will have an impact on not only flood magnitude but also on flood timing. This paper studies the shifting in flood timing at 6167 gauging stations from 1970 to 2010, globally. The shift in flood timing and its relationship with three influential factors (maximum 7-day precipitation, soil moisture excess, and snowmelt) are investigated. There is a clear global pattern in the mean flooding date: winter (Dec–Feb) across the western Coastal America, western Europe and the Mediterranean region, summer (Jun–Aug) in the north America, the Alps, Indian Peninsula, central Asia, Japan, and austral summer (Dec–Feb) in south Africa and north Australia area. The shift in flood timing has a trend from − 22 days per decade (earlier) to 28 days per decade (delayed). Earlier floods were found extensively in the north America, Europe and northeast Australia while delayed floods were prevailing in the Amazon, Cerrado, south Africa, India and Japan. Earlier flood timing in the north America and Europe was caused by earlier snowmelt while delayed extreme soil moisture excess and precipitation have jointly led to delayed floods around the monsoon zone, including south Africa, India and Japan. This study provides an insight on the shifting mechanism of flood timing, and supports decisions on the global flood mitigation and the impact from future climate change.