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Coastal marshes are one of the world's most productive ecosystems. Consequently, they have been heavily used by humans for centuries, resulting in ecosystem loss. Direct human modifications such as road crossings and ditches and climatic Stressors such as sea-level rise and extreme storm events have the potential to further degrade the quantity and quality of marsh along coastlines. We used an 18-year marsh-bird database to generate population trends for 5 avian species (Rallus crepitans, Tringa semipalmata semipalmata, Ammodramus nelsonii subvirgatus, Ammodramus caudacutus, and Ammodramus maritimus) that breed almost exclusively in tidal marshes, and are potentially vulnerable to marsh degradation and loss as a result of anthropogenic change. We generated community and species trends across 3 spatial scales and explored possible drivers of the changes we observed, including marsh ditching, tidal restriction through road crossings, local rates of sea-level rise, and potential for extreme flooding events. The specialist community showed negative trends in tidally restricted marshes (-2.4% annually from 1998 to 2012) but was stable in unrestricted marshes across the same period. At the species level, we found negative population trends in 3 of the 5 specialist species, ranging from -4.2% to 9.0% annually. We suggest that tidal restriction may accelerate degradation of tidal marsh resilience to sea-level rise by limiting sediment supply necessary for marsh accretion, resulting in specialist habitat loss in tidally restricted marshes. Based on our findings, we predict a collapse of the global population of Saltmarsh Sparrows (A. caudacutus) within the next 50 years and suggest that immediate conservation action is needed to prevent extinction of this species. We also suggest mitigation actions to restore sediment supply to coastal marshes to help sustain this ecosystem into the future. Los humedales costeros son uno de los ecosistemas más productivos en el mundo. Consecuentemente, han sido utilizados intensivamente por los humanos durante siglos, resultando en la pérdida del ecosistema. Modificaciones humanas directas como caminos y zanjas, así como agentes climáticos estresantes como el incremento del nivel del mar y eventos de tormentas extremas tienen el potencial de degradar aun más la cantidad y calidad de humedales a lo largo de las costas. Utilizamos una base de datos de 18 años de aves de humedal para generar tendencias poblaciones de especies de aves (Rallus crepitans, Tringa semipalmata semipalmata, Ammodramus nelsonii subvirgatus, A. caudacutus, y A. maritimus) que se reproducen casi exclusivamente en marismas y que son potencialmente vulnerables a la degradación y pérdida de humedales como resultado de cambios antropogénicos. Generamos tendencias de la comunidad y de especies en 3 escalas espaciales y exploramos los posibles factores de los cambios observados, incluyendo la construcción de canales, la restricción de mareas por medio de caminos, tasas locales de incremento del nivel del el potencial de eventos de inundación extremos. La comunidad de especialistas mostró tendencias negativas en humedales restringidos por las mareas (-2.4% anualmente de 1998 a 2012), pero fue estable en humedales no restringidos. A nivel de especies, encontramos tendencias poblacionales negativas en 3 de las 5 especies especialistas que variaron entre -4.2% a 9% anualmente. Sugerimos que la restricción de mareas puede acelerar la degradación de la resiliencia de marismas al incremento del nivel del mar al limitar el aporte de los sedimentos necesarios para la acreción de marismas, lo cual resulta en la pérdida de habitat en marismas restringidas por las mareas. Con base en nuestros resultados, pronosticamos un colapso de la población global de A. caudacutus en los próximos 50 años y sugerimos que se requieren acciones de conservación inmediatas para prevenir la extinción de esta especie. También sugerimos acciones de mitigación para restaurar el aporte de sedimentos en los humedales costeros para ayudar a sostener este ecosistema en el futuro.

Die-offs of cordgrass are pervasive throughout western Atlantic salt marshes, yet understanding of the mechanisms precipitating these events is limited. We tested whether herbivory by the native crab, Sesarma reticulatum, is generating die-offs of cordgrass that are currently occurring on Cape Cod, Massachusetts (U.S.A.), by manipulating crab access to cordgrass transplanted into die-off areas and healthy vegetation. We surveyed 12 Cape Cod marshes to investigate whether the extent of cordgrass die-off on creek banks, where die-offs are concentrated, was related to local Sesarma grazing intensity and crab density. We then used archived aerial images to examine whether creek bank die-off areas have expanded over the past 2 decades and tested the hypothesis that release from predation, leading to elevated Sesarma densities, is triggering cordgrass die-offs by tethering crabs where die-offs are pervasive and where die-offs have not yet been reported. Intensity of crab grazing on transplanted cordgrass was an order of magnitude higher in die-off areas than in adjacent vegetation. Surveys revealed that Sesarma herbivory has denuded nearly half the creek banks in Cape Cod marshes, and differences in crab-grazing intensity among marshes explained >80% of variation in the extent of the die-offs. Moreover, the rate of die-off expansion and area of marsh affected have more than doubled since 2000. Crab-tethering experiments suggest that release from predation has triggered elevated crab densities that are driving these die-offs, indicating that disruption of predator-prey interactions may be generating the collapse of marsh ecosystems previously thought to be exclusively under bottom-up control.

The mangrove ecosystem stands out for the numerous environmental services it provides, in addition to being one of the most vulnerable ecosystems to climate change. Marismas Nacionales is located in northwestern Mexico and hosts one of the most extensive areas of continuous mangrove ecosystem along the Pacific North coast of Mexico. Although vital, this mangrove ecosystem faces multiple pressures and is shifting inland in response to climate change —making ongoing monitoring of its size and health essential. Aiming for monitoring the health of mangrove and disturbed mangrove areas, a time series of monthly NDVI composites derived from Sentinel-2 imagery (10 m spatial resolution) was analyzed for the period 2019–2024. At the pixel level, the Mann-Kendall test was applied to determine significant trends. An inspection of the Z-statistic was conducted to identify gradual and relevant changes; when possible, these changes were validated with field data and high-resolution imagery. The results revealed heterogeneity in the behavior of pixel time series, reflected in the values of the Z-statistic. This heterogeneity is due to the fact that mangroves are subject to different change factors depending on their spatial location. Among the key factors identified were hurricane-induced damage, land-use change, inland colonization, recovery driven by restoration efforts, post-hurricane vegetation rebound, and losses resulting from coastal erosion. Across the 80,959 hectares encompassed by the study area, 47.08% exhibited a significant negative trend, 20.19% a non-significant negative trend, 18.07% a non-significant positive trend, and 14.66% a significant positive trend. The analyzed data revealed the dynamic nature of the mangrove ecosystem in response to various change factors, and the proposed method could serve as a foundation for integration into the national products generated by Mexico’s Mangrove Monitoring System.

In this study, multisensor remote sensing datasets were used to characterize the land use and land covers (LULC) flooded by Hurricane Willa which made landfall on October 24, 2018. The landscape characterization was done using an unsupervised K-means algorithm of a cloud-free Sentinel-2 MultiSpectral Instrument (MSI) image, acquired during the dry season before Hurricane Willa. A flood map was derived using the histogram thresholding technique over a Synthetic Aperture Radar (SAR) Sentinel-1 C-band and combined with a flood map derived from a Sentinel-2 MSI image. Both, the Sentinel-1 and Sentinel-2 images were obtained after Willa landfall. While the LULC map reached an accuracy of 92%, validated using data collected during field surveys, the flood map achieved 90% overall accuracy, validated using locations extracted from social network data, that were manually georeferenced. The agriculture class was the dominant land use (about 2,624 km 2 ), followed by deciduous forest (1,591 km 2 ) and sub-perennial forest (1,317 km 2 ). About 1,608 km 2 represents the permanent wetlands (mangrove, salt marsh, lagoon and estuaries, and littoral classes), but only 489 km 2 of this area belongs to aquatic surfaces (lagoons and estuaries). The flooded area was 1,225 km 2 , with the agricultural class as the most impacted (735 km 2 ). Our analysis detected the saltmarsh class occupied 541 km 2 in the LULC map, and around 328 km 2 were flooded during Hurricane Willa. Since the water flow receded relatively quickly, obtaining representative imagery to assess the flood event was a challenge. Still, the high overall accuracies obtained in this study allow us to assume that the outputs are reliable and can be used in the implementation of effective strategies for the protection, restoration, and management of wetlands. In addition, they will improve the capacity of local governments and residents of Marismas Nacionales to make informed decisions for the protection of vulnerable areas to the different threats derived from climate change.

The reed Phragmites australis Cav. is aggressively invading salt marshes along the Atlantic Coast of North America. We examined the interactive role of habitat alteration (i.e., shoreline development) in driving this invasion and its consequences for plant richness in New England salt marshes. We surveyed 22 salt marshes in Narragansett Bay Rhode Island, and quantified shoreline development, Phragmites cover, soil salinity, and nitrogen availability. Shoreline development, operationally defined as removal of the woody vegetation bordering marshes, explained >90% of intermarsh variation in Phragmites cover. Shoreline development was also significantly correlated with reduced soil salinities and increased nitrogen availability, suggesting that removing woody vegetation bordering marshes increases nitrogen availability and decreases soil salinities, thus facilitating Phragmites invasion. Soil salinity (64%) and nitrogen availability (56%) alone explained a large proportion of variation in Phragmites cover, but together they explained 80% of the variation in Phragmites invasion success. Both univariate and aggregate (multidimensional scaling) analyses of plant community composition revealed that Phragmites dominance in developed salt marshes resulted in an almost three-fold decrease in plant species richness. Our findings illustrate the importance of maintaining integrity of habitat borders in conserving natural communities and provide an example of the critical role that local conservation can play in preserving these systems. In addition, our findings provide ecologists and natural resource managers with a mechanistic understanding of how human habitat alteration in one vegetation community can interact with species introductions in adjacent communities (i.e., flow-on or adjacency effects) to hasten ecosystem degradation.

Oryzomys texensis Allen, 1894, the Texas Marsh Rice Rat, is a yellowish gray-brown oryzomyine rodent with whitish feet and venter, black eyes, small hairy ears, short vibrissae, and a tail about one-half of total length. It was elevated to species status based on the results of an extensive molecular genetics analysis of the O. palustris complex. The poorly defined eastern boundary of O. texensis includes Mississippi, Arkansas, southern Missouri, and southern Illinois, with populations extending westward to southeastern Kansas, eastern Oklahoma, eastern and coastal Texas, into northeastern Tamaulipas, Mexico. Present in tidal marshes and other habitats near water, O. texensis is omnivorous, with some populations being highly carnivorous. Oryzomys texensis Allen, 1894, es un roedor de la tribu Oryzomyini, de color marrón grisáceo amarillento con pies y vientre blanquecinos, ojos negros, pequeñas orejas velludas, vibrisas cortas y una cola que constituye aproximadamente la mitad de su longitud total. Fue elevado del nivel de subespecie de O. palustris a especie en base a resultados de un extenso análisis de genética molecular del complejo O. palustris. El margen oriental de la distribución geográfica de O. texensis está mal definido e incluye partes de Mississippi y Arkansas, así como el sur de Missouri y sur de Illinois, con poblaciones adicionales extendiéndose en dirección oeste hacia el sureste de Kansas, este de Oklahoma, planicie costera y este de Texas y hasta el extremo suroccidental de Texas y noroeste de Tamaulipas, México. Está presente en marismas, humedales, y otros hábitats cercanos al agua. Si bien es omnívoro, algunas poblaciones constan de individuos mayormente carnívoros.

Globally limited to 45,000 km2, salt marshes and their endemic species are threatened by numerous anthropogenic influences, including sea-level rise and predator pressure on survival and nesting success. Along the Atlantic coast of North America, Seaside (Ammospiza maritima) and Saltmarsh (A. caudacuta) sparrows are endemic to salt marshes, with Saltmarsh Sparrows declining by 9% annually. Because vital rates and factors affecting population persistence vary for both species, local estimates are necessary to best predict population persistence in response to management actions. We used a metapopulation model to estimate the population viability of the breeding Seaside and Saltmarsh sparrow populations in coastal New Jersey over a 42-yr period. We incorporated empirical data on the vital rates and abundances of these populations and simulated the effect of low (0.35 m) and high (0.75 m) levels of sea-level rise. We found that the Seaside Sparrow population persisted under both sea-level rise scenarios; however, the Saltmarsh Sparrow population reached a quasi-extinction threshold within 20 yr. Using the same framework, we modeled potential management scenarios that could increase the persistence probability of Saltmarsh Sparrows and found that fecundity and juvenile survival rates will require at least a 15% concurrent increase for the local population to persist beyond 2050. Future field research should evaluate the feasibility and effectiveness of management actions, such as predator control, for increasing Saltmarsh Sparrow vital rates in order to maintain the species in coastal New Jersey.

We evaluated the forest structure, pore water salinity, geochemical characteristics, grain-size distribution and sediment accumulation rates (SAR) in 15 mangrove sites along the San Pedro Mezquital River, one of the major sources of fresh water supply to the Marismas Nacionales System. Sediments were sandy-silty with high organic matter content (5.8 ± 1.5% to 23.6 ± 1.7%). The marine (Na, Cl and Br) and terrigenous (Al, Ti, Rb and Zr) elements indicated that sediments were mostly of continental provenance, with small marine contribution. SAR ranged from 0.08 ± 0.01 to 2.29 ± 0.28 cm yr −1 . Laguncularia racemosa was the dominant species in the northern sites (between Toluca Lagoon and Mexcaltitan Lagoon), with a mean basal area of 11.1–49.3 m 2  ha −1 , whereas Rhizophora mangle prevailed in the southern sites, closer to the river mouth (between Boca Camichin and Los Limones River, mean basal area of 2.0–11.0 m 2  ha −1 ). The southern area was characterized by lower forest attributes, and higher pore water salinity and sediment accumulation rates than the northern area. We concluded that mangrove preservation along SPMR requires insuring appropriate fresh water and sediment supply, and the control of organic matter pollution sources.

Australian Saltmarsh Ecology presents the first comprehensive review of the ecology and management of Australian saltmarshes. The past 10 years in particular have seen a sustained research effort into this previously poorly understood and neglected resource. Leading experts in the field outline what is known of the biogeography and geomorphology of Australian saltmarshes, their fish and invertebrate ecology, the use of Australian saltmarshes by birds and insectivorous bats, and the particular challenges of management, including the control of mosquito pests, and the issue of sea-level rise. They provide a powerful argument that coastal saltmarsh is a unique and critical habitat vulnerable to the combined impacts of coastal development and sea-level rise. The book will be an important reference for saltmarsh researchers, marine and aquatic biologists, natural resource managers, environmentalists and ecologists, as well as undergraduate students and the interested layperson.

West Nile virus (WNV) and Usutu virus (USUV) are neurotropic mosquito-borne orthoflaviviruses maintained in an enzootic cycle, in which birds are amplifying/reservoir hosts, while humans and equids are dead-end hosts. As northern Italy, especially the Veneto Region, is considered an endemic area for WNV and USUV circulation, a surveillance plan based on a One Health approach has been implemented since 2008. This work reports the results of entomological, veterinary and human surveillances for WNV and USUV in the Veneto Region in 2022 and 2023, through virological and/or serological examinations. In 2022, 531 human WNV infections were recorded, and 93,213 mosquitoes and 2193 birds were virologically tested, showing infection rates (IRs) of 4.85% and 8.30%, respectively. The surveillance effort in 2023 provided these results: 56 human WNV infections were confirmed, and 133,648 mosquitoes and 1812 birds were virologically tested, showing IRs of 1.78% and 4.69%, respectively. This work highlights the exceptional circulation of WNV in the Veneto Region, due to the new re-introduction of WNV lineage 1 and co-circulation with WNV lineage 2. This paper confirms the efficacy of integrated surveillance for early warning of viral circulation and gives new insights about avian hosts involved in the enzootic cycle of orthoflavivirus in the endemic region of Italy.