Lessons learned: tidal marsh restoration in a dynamic context of stress and climate change

In the Stillaguamish estuary, tidal wetlands have been receding for decades as a result of both natural and anthropogenic changes. Despite current restoration efforts, monitoring suggests that rising stress from climate change impacts on summer flows, legacy stresses from the levee system, and increased plant mortality from avian and insect herbivores may interact to accelerate the rate of marsh loss. Lessons learned from a 2012 restoration project should inform adaptive management and future restoration projects. Post-restoration monitoring has revealed a pattern of interacting stresses at both the site and system scales that affects marsh productivity and resilience to climate change. These stresses are spatially and temporally variable. Different marsh areas respond differently, revealing characteristics of marshes that are vulnerable, resilient, or able to resist disturbance. At current restoration rates, marsh loss may slow temporarily, but not reverse. To accelerate estuary recovery, restoration must focus on reducing system-scale stresses by restoring the processes of freshwater and sediment distribution. At the site-scale, projects should identify pre-restoration conditions that may contribute to elevated plant stress post-restoration, including topography, drainage, and soil profile characteristics

Coastal Resilience for Habitats and Humans: Integrating Green and Grey Infrastructure Solutions

Communities are protected from floods and storms by both engineered infrastructure like levees, and natural habitat infrastructure like wetlands. We understand the performance and cost effectiveness of engineered or grey infrastructure well. However, recent natural disasters have illustrated both their insufficiency in protecting communities and the high repair costs. We know that green infrastructure, or natural habitats, also protect communities from river floods and coastal storms but we know little about their performance and cost. This knowledge gap leads to greater investment in grey at the expense of green. In addition, green infrastructure provide other benefits to human communities, and are often the restoration target of recovery plans for ecosystems and endangered species. In Puget Sound we evaluated the changes in vulnerability for both ecosystems and built infrastructure that may result from climate change, including changes in high and low river flows, sea level, storm dynamics, sediment recruitment and salinity intrusion. We developed an interactive tool called Coastal Resilience that allows users to examine community risk in a way that integrates both green and grey infrastructure. The tool allows users to evaluate different sources of risk, such as “dike freeboard” which indicates how close a dike comes to being overtopped under various current and future storm scenarios. Another tool provides a model that quantifies the reduction in storm wave energy and height that is provided by tidal wetlands which protect adjacent dike systems from erosion and overtopping. In areas where tidal wetlands are receding, it can indicate how community risk and financial cost may change as a result of this loss of protective green infrastructure. With this information, communities can develop better response plans that reduce the costs of disaster prevention and recovery, and increase the economic efficiency of both risk reduction and ecosystem recovery actions

Variable marsh resilience to stress offers clues to climate change adaptive management

In Puget Sound’s Stillaguamish estuary, tidal marshes exhibit evidence of multiple stressors that affect their vulnerability and provide insight into adaptive management opportunities to enhance their resilience. Despite high accretion rates, some marsh areas have receded by 10m/yr since 1964. Sources of stress include overgrazing by snow geese, high soil salinities, insect attacks, and changes in flow and inundation patterns. These interact with winter vegetation structure, sediment composition, and wave exposure to result in spatially variable marsh resilience. Some marshes are receding quickly, some slowly, and others are minimally affected. In the context of climate change, with potentially substantial near-term salinity changes due to summer low flow projections, and likely changes in sediment dynamics, it is critical to identify how marshes will respond, and develop adaptive management actions to increase resilience. Geese consume the rhizomes of four dominant bulrushes, and loosen the soil during winter storm season. Each bulrush species has different winter structural characteristics that affect grazing vulnerability, and the ability to trap sediment and attenuate erosive wave energy. Coarser sediments affect grazing intensity, being more difficult for geese bills to probe. Sediment and soil salinity affect plant density and height. During summer 2015, a harbinger for coming decades, twice-normal soil salinities resulted in stunted marsh that failed to flower. Finally, small differences in winter wave exposure affect marsh susceptibility to erosion after heavy grazing. With spatially variable marsh resilience to stress, potential adaptive management responses should similarly vary. Responses could include, among others, restoration to improve freshwater connectivity, sediment addition in restored areas to shift them above erosion thresholds or to target grazing-resistant bulrush species, snow goose population management or behavior modification, manipulation of soil particle size with sediment addition, and strategic use of logjams and sediment addition to reduce wave energy

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

The Somatic Genomic Landscape of Glioblastoma

We describe the landscape of somatic genomic alterations based on multi-dimensional and comprehensive characterization of more than 500 glioblastoma tumors (GBMs). We identify several novel mutated genes as well as complex rearrangements of signature receptors including EGFR and PDGFRA. TERT promoter mutations are shown to correlate with elevated mRNA expression, supporting a role in telomerase reactivation. Correlative analyses confirm that the survival advantage of the proneural subtype is conferred by the G-CIMP phenotype, and MGMT DNA methylation may be a predictive biomarker for treatment response only in classical subtype GBM. Integrative analysis of genomic and proteomic profiles challenges the notion of therapeutic inhibition of a pathway as an alternative to inhibition of the target itself. These data will facilitate the discovery of therapeutic and diagnostic target candidates, the validation of research and clinical observations and the generation of unanticipated hypotheses that can advance our molecular understanding of this lethal cancer

Genomic epidemiology of SARS-CoV-2 in a UK university identifies dynamics of transmission

AbstractUnderstanding SARS-CoV-2 transmission in higher education settings is important to limit spread between students, and into at-risk populations. In this study, we sequenced 482 SARS-CoV-2 isolates from the University of Cambridge from 5 October to 6 December 2020. We perform a detailed phylogenetic comparison with 972 isolates from the surrounding community, complemented with epidemiological and contact tracing data, to determine transmission dynamics. We observe limited viral introductions into the university; the majority of student cases were linked to a single genetic cluster, likely following social gatherings at a venue outside the university. We identify considerable onward transmission associated with student accommodation and courses; this was effectively contained using local infection control measures and following a national lockdown. Transmission clusters were largely segregated within the university or the community. Our study highlights key determinants of SARS-CoV-2 transmission and effective interventions in a higher education setting that will inform public health policy during pandemics.</jats:p

Tidal marsh as green infrastructure: Evaluating marsh capacity to reverse historical coastal retreat and mitigate future coastal hazards in a Salish Sea estuary

Coastal retreat of up to 1 km since the 1960s in Port Susan Bay has led to loss of tidal marshes that historically buffered coastal overwash of important agricultural lands and dike infrastructure. The associated coastal change rates of 5.0 to 20.0 meters per year are thought to have resulted from multiple factors including emplacement of shoreline armoring that deflected fluvial sediment delivery away from the marshes. In addition, the combined influence of sea level rise and waves that resuspend and redistribute sediments may also have changed. In 2012 restoration of PSB reduced these barriers to sediment transport and research to quantify the recovery of sediment connectivity and the influence of waves today and under projected sea level rise commenced. Initial models indicate that loss of tidal marsh habitat has led to a notable loss of the ecosystem service that marsh contributes to buffering shorelines and coastal communities from wave and coastal storm surge impacts. A network of instrumentation and integrated sediment transport-wave modeling is being used to quantify the sediment budget and physical processes that influence sediment retention and marsh accretion. Using historical reconstructions of the marsh extent, we model the amount of sediment required to recover the lost marshes (green infrastructure) and associated benefit of wave attenuation. These models are run for a range of projected seal level rise and sediment delivery rates likely to be affected by changes in precipitation and runoff to evaluate the importance and value of tidal marsh as green infrastructure to protect coastal lands in Port Susan Bay and similar environments around the Salish Sea and coastal United States