Restore or retreat? Saltwater intrusion and water management in coastal wetlands

Coastal wetlands perform a unique set of physical,chemical,and biological functions,which provide billions of dollars of ecosystem services annually.These wetlands also face myriad environmental and anthropogenic pressures,which threaten their ecological condition and undermine their capacity to provide these services.Coastal wetlands have adapted to a dynamic range of natural disturbances over recent millennia,but face growing pressures from human population growth and coastal development.These anthropogenic pressures are driving saltwater intrusion(SWI)in many coastal systems.The position of coastal wetlands at the terrestrial-marine interface also makes them vulnerable to increasing rates of sealevel rise and changing climate.Critically,anthropogenic and natural stressors to coastal wetlands can act synergistically to create negative,and sometimes catastrophic,consequences for both human and natural systems.This review focused on the drivers and impacts of SWI in coastal wetlands and has two goals:(1)to synthesize understanding of coastal wetland change driven by SWI and(2)to review approaches for improved water management to mitigate SWI in impacted systems.While we frame this review as a choice between restoration and retreat,we acknowledge that choices about coastal wetland management are context-specific and may be confounded by competing management goals.In this setting,the choice between restoration and retreat can be prioritized by identifying where the greatest return in ecosystem services can be achieved relative to restoration dollars invested.We conclude that restoration and proactive water management is feasible in many impacted systems.

Dynamic conjugate F-SHARP microscopy

Optical microscopy is an indispensable tool in biomedical sciences,but its reach in deep tissues is limited due to aberrations and scattering.This problem can be overcome by wavefront-shaping techniques,albeit at limited fields of view(FOVs).Inspired by astronomical imaging,conjugate wavefront shaping can lead to an increased field of view in microscopy,but this correction is limited to a set depth and cannot be dynamically adapted.Here,we present a conjugate wavefront-shaping scheme based on focus scanning holographic aberration probing(F-SHARP).We combine it with a compact implementation that can be readily adapted to a variety of commercial and home-built two-photon microscopes.We demonstrate the power of the method by imaging with high resolution over extended FOV(>80μm)deeper than 400μm inside a mouse brain through a thinned skull.