15 Aug 2022

Identification and Preventative Treatment of Overwintering Cyanobacteria in Sediments: A Literature Review

Abstract: Freshwaters can experience growths of toxin-producing cyanobacteria or harmful algal blooms (HABs). HAB-producing cyanobacteria can develop akinetes, which are thick-enveloped quiescent cells akin to seeds in vascular plants or quiescent colonies that overwinter in sediment. Overwintering cells produce viable “seed beds” for HAB resurgences and preventative treatments may diminish HAB intensity. The purpose of this literature review was to identify (1) environmental factors triggering germination and growth of overwintering cells, (2) sampling, identification, and enumeration methods, and (3) feasibility of preventative algaecide treatments. Conditions triggering akinete germination (light ≥0.5 µmol m-2s-1, temperature 22-27℃) differ from conditions triggering overwintering Microcystis growth (temperature 15-30℃, nutrients, mixing). Corers or dredges are used to collect surficial (0-2 cm) sediment layers containing overwintering cells. Identification and enumeration via microscopy are aided by dilution, sieving, or density separation of sediment. Grow-out studies simulate environmental conditions triggering cell growth and provide evidence of overwintering cell viability. Lines of evidence supporting algaecide efficacy for preventative treatments include (1) field studies demonstrating scalability and efficacy of algaecides against benthic algae, (2) data suggesting similar sensitivities of overwintering and planktonic Microcystis cells to a peroxide algaecide, and (3) a mesocosm study demonstrating a decrease in HAB severity following preventative treatments. This review informs data needs, monitoring techniques, and potential efficacy of algaecides for preventative treatments of overwintering cells.

12 Aug 2022

Swan Island: Monitoring and Adaptive Management Plan

Abstract: Swan Island is a 10.12 ha island located in the Maryland waters of the Chesapeake Bay. Because of its value as a natural wave break for the town of Ewell on nearby Smith Island, as well as the ongoing erosion and subsidence of the island, in 2019 US Army Corps of Engineers (USACE)–Baltimore District placed 45,873 m³ of dredged sediment and planted 200,000 marsh plants. This restoration provided an opportunity to quantify the engineering (that is, resilience) and ecological performance of the island, postplacement. The lack of quantitative data on the performance of natural features such as islands has led to perceived uncertainties that are often cited as barriers to implementation. To address these data gaps, a multidisciplinary collaboration of five government entities identified project objectives and monitoring parameters through a series of mediated workshops and then developed a conceptual model to articulate those parameters and the linkages between them. This monitoring and adaptive management plan (MAMP) documents those monitoring parameters and procedures and can serve as an example for other scales, regions, and research questions. Documenting research and monitoring efforts may help to foster widespread acceptance of nature-based solutions such as islands.

12 Aug 2022

Development of a Three-Dimensional Vegetative Loss Mechanism for the Geophysical Scale Transport Multi-Block Hydrodynamic Sediment and Water Quality Transport Modeling System (GSMB)

PURPOSE: The US Army Engineer Research and Development Center’s (ERDC) Environmental Laboratory (EL) and Coastal and Hydraulics Laboratory (CHL) have completed several large scale hydrodynamic, sediment and water quality transport studies. These studies have been successfully executed utilizing the Geophysical Scale Transport Modeling System (GSMB), which is composed of multiple process models (Figure 1). Due to being directly and indirectly linked within the GSMB framework, the US Army Corps of Engineers (USACE) accepted wave, hydrodynamic, sediment, and water quality transport models are both directly and indirectly linked within the GSMB framework.

11 Aug 2022

Environmental Evaluation and Management of Dredged Material for Beneficial Use: A Regional Beneficial Use Testing Manual for the Great Lakes

Abstract: The Environmental Evaluation and Management of Dredged Material for Beneficial Use: A Regional Beneficial Use Testing Manual for the Great Lakes (a.k.a. Great Lakes Beneficial Use Testing Manual) is a resource document providing technical guidance for evaluating the suitability of dredged sediment for beneficial use in aquatic and terrestrial environments in the Great Lakes region. The procedures in this manual are based on the Environmental Laboratory extensive research, working with US Army Corps of Engineers (USACE) Great Lakes districts, state resource agencies, and local stakeholders seeking to develop dredged material beneficial use alternatives consistent with regional needs and goals. This manual is the first guidance document developed by USACE for evaluating the environmental suitability of dredged material specifically for beneficial use placements. It provides a tiered framework for evaluating the environmental suitability of aquatic and upland beneficial uses consistent with the Inland Testing Manual and the Upland Testing Manual. This manual is intended to serve as a regional platform to increase collaborative problem-solving and endorse a common understanding of the scientific and institutional practices for evaluating dredged material for any beneficial use. Dredged sediment may be managed as a valuable resource, with great potential to create economic, environmental, and social benefits.

11 Aug 2022

Realizing Multiple Benefits in a Southeast Louisiana Urban Flood Control Project through Application of Engineering With Nature® Principles

PURPOSE: The application of Engineering With Nature® (EWN®) principles in urban environments and watersheds within and outside the US Army Corps of Engineers (USACE) is increasing. Extreme rainfall events have triggered the need and development of more sustainable urban infrastructure in urban areas such as New Orleans, Louisiana. This technical note documents a USACE–New Orleans District (MVN) project that successfully applied EWN principles in an urban landscape to reduce flood risk while providing other environmental, social, economic, and engineering benefits to both the community and the environment.

11 Aug 2022

Oyster Reef Connectivity: Ecological Benefits and Associated Vulnerabilities

OVERVIEW: Global oyster abundance has declined ~85 % over the past 200 years, primarily because of overharvesting (Beck, Brumbaugh, and Airoldi 2011; Kirby 2004). Healthy oyster reef systems benefit the environment in many ways, including water-quality improvement, shoreline protection, increased biological and habitat diversity, and carbon sequestration. To maintain these environmental benefits, reef-restoration efforts that produce healthy, sustainable oyster reefs are essential. To this end, the US Army Corps of Engineers (USACE) has been involved in reef-restoration projects in many locations, including extensive efforts in the Chesapeake Bay (Virginia, Maryland), coastal regions of New York and New Jersey, and the Gulf of Mexico.

8 Aug 2022

A Community Engagement Framework Using Mental Modeling: The Seven Mile Island Innovation Lab Community Engagement Pilot—Phase I

Abstract: The US Army Corps of Engineers (USACE) engages and collaborates with multiple stakeholders—from agency partners, to public, private, and not-for-profit organizations, to community residents—to develop its dredged-sediment long-term management strategy (LTMS) that expands beneficial-use (BU) practices. In spring 2019, USACE collaborated with Decision Partners, the USACE–Philadelphia District Operations Division, The Wetlands Institute, and the Engineering With Nature program leadership to adapt, test, and refine the proven behavioral-science-based processes, methods, and tools based on Decision Partners’ Mental Modeling Insight, or MMI, approach for engaging stakeholders, including community members, as part of the Seven Mile Island Innovation Laboratory (SMIIL) initiative in coastal New Jersey. The team identified key community stakeholders and conducted research to better understand their values, interests, priorities, and preferences regarding wetlands and USACE activities in the Seven Mile Island area and those activities’ effects on wetlands, including protecting the environment, wildlife habitat, aesthetic beauty, maintaining navigability, and supporting coastal resilience. Understanding stakeholder needs, values, interests, priorities, and preferences is key to designing effective engagement strategies for diverse communities for SMIIL and provides a foundation for the community engagement framework currently being developed for application across USACE.

8 Aug 2022

The Use of US Army Corps of Engineers Reservoirs as Stopover Sites for the Aransas–Wood Buffalo Population of Whooping Crane

Abstract: This technical report summarizes the use of US Army Corps of Engineers (USACE) reservoirs as spring and fall migration stopover sites for the endangered Aransas–Wood Buffalo population of whooping cranes (WHCR), which proved much greater than previously known. We assessed stopover use within the migration flyway with satellite transmitter data on 68 WHCR during 2009–2018 from a study by the US Geological Survey (USGS) and collaborators, resulting in over 165,000 location records, supplemented by incidental observations from the US Fish and Wildlife Service (USFWS) and the USGS Biodiversity Information Serving Our Nation (BISON) databases. Significant stopover use was observed during both spring and fall migration, and one reservoir served as a wintering location in multiple years. Future efforts should include (a) continued monitoring for WHCR at USACE reservoirs within the flyway; (b) reservoir-specific management plans at all projects with significant WHCR stopover; (c) a USACE-specific and range-wide Endangered Species Act Section 7(a)(1) conservation plan that specifies proactive conservation actions; (d) habitat management plans that include potential pool-level modifications during spring and fall to optimize stopover habitat conditions; and (e) continued evaluation of habitat conditions at USACE reservoirs.

4 Aug 2022

Engineering With Nature® Principles in Action: Islands

Abstract: The Engineering With Nature® (EWN) Program supports nature-based solutions that reduce coastal-storm and flood risks while providing environmental and socioeconomic benefits. Combining the beneficial use of dredged sediments with the restoration or creation of islands increases habitat and recreation, keeps sediment in the system, and reduces coastal-storm and flood impacts. Given the potential advantages of islands, EWN seeks to support science-based investigations of island performance, impacts, and benefits through collaborative multidisciplinary efforts. Using a series of case studies led by US Army Corps of Engineers (USACE) districts and others, this technical report highlights the role of islands in providing coastal resilience benefits in terms of reducing waves and erosion as well as other environmental and socioeconomic benefits to the communities and the ecosystems they reside in.

4 Aug 2022

Supporting Bank and Near-bank Stabilization and Habitat Using Dredged Sediment: Documenting Best Practices

Abstract: In-water beneficial use of dredged sediment provides the US Army Corps of Engineers (USACE) the opportunity to increase beneficial use while controlling costs. Beneficial use projects in riverine environments include bank and near-bank placement, where sediments can protect against bank erosion and support habitat diversity. While bank and near-bank placement of navigation dredged sediment to support river-bank stabilization and habitat is currently practiced, documented examples are sparse. Documenting successful projects can support advancing the practice across USACE. In addition, documentation identifies data gaps required to develop engineering and ecosystem restoration guidance using navigation-dredged sediment. This report documents five USACE and international case studies that successfully applied these practices: Ephemeral Island Creation on the Upper Mississippi River; Gravel Island Creation on the Danube River; Gravel Bar Creation on the Tombigbee River; Wetland Habitat Restoration on the Sacramento-San Joaquin River Delta; and Island and Wetland Creation on the Lower Columbia River Estuary. Increased bank and near-bank placement can have multiple benefits, including reduced dredge volumes that would otherwise increase as banks erode, improved sustainable dredged sediment management strategies, expanded ecosystem restoration opportunities, and improved flood risk management. Data collected from site monitoring can be applied to support development of USACE engineering and ecosystem restoration guidance.