14 Oct 2020

Estimating the Density of Secretive, At-risk Snake Species on DoD Installations Using an Innovative Approach: IDEASS

Abstract: The Department of Defense (DoD) expends considerable resources managing and conserving threatened, endangered, or at-risk snake species. Management for these species is often hampered by a lack of basic knowledge regarding their population size and trajectory. The low detectability of most snakes makes it difficult to determine their presence, or to employ traditional methods to estimate abundance. This work demonstrated a novel, simulation-based method, Innovative Density Estimation Approach for Secretive Snakes (IDEASS), for estimating snake density based on systematic road surveys, behavioral observations of snake movement, and spatial movement (radio telemetry) data. This method was used to generate meaningful density estimates for two rare and cryptic snakes of conservation concern, the Southern Hognose and Eastern Diamondback Rattlesnake, at Fort Stewart, Georgia. IDEASS was also applied to an existing dataset to retroactively estimate density of a more common species of management concern, the Western Ratsnake, at Fort Hood, Texas. In all three cases, traditional density estimation via visual surveys and capture-mark-recapture (CMR) failed completely due to lack of captures and re-captures, despite extensive field effort. We conclude that IDEASS represents a powerful tool, and in some cases the only viable method, for estimating density of secretive snakes.

1 Oct 2020

Aligning Research and Management Priorities for Nitellopsis obtusa (Starry Stonewort)

Abstract: In 2018, the US Army Corps of Engineers and Washington and Waukesha Counties in Wisconsin hosted a workshop on the invasive macroalga starry stonewort (Nitellopsis obtusa). Leading water resource managers (agencies and commercial applicators), researchers, regulators, and other interested parties discussed issues surrounding starry stonewort invasions in the Great Lakes Region (GLR). Technical sessions presented information on current research, invasion monitoring, early detection, rapid-response efforts, and operational management activities. Research summaries included invasion in Lake Ontario, prediction of invasion risk in Minnesota and Wisconsin using water chemistry data, and bulbil efficacy and distribution modeling in New England. In addition, the workshop offered summaries of attempted chemical and mechanical control tactics. Following presentations on previous studies, workshop participants identified research and management priorities. Critical research gaps identified from this workshop include (a) better understanding of the biology, invasion ecology, and management of starry stonewort; a greater understanding of distribution and movement, especially in the Great Lakes basin; enhanced population monitoring, applied research, and management strategies; and increased technical cooperation across government, academia, industry, and nonprofit organizations. Conclusions from this meeting will help prioritize future efforts focused on the adaptive management of starry stonewort in the United States and Canada.

29 Sep 2020

Using Unmanned Aircraft System (UAS) and Satellite Imagery to Map Aquatic and Terrestrial Vegetation

Purpose: The purpose of this study is to demonstrate the application potential of using unmanned aerial systems (UAS) combined with a time series of moderately high-resolution satellite imagery for mapping ecological restoration progress and resulting land cover changes. This technical note addresses a project under the US Army Corps of Engineers Ecosystem Management and Restoration Research Project (EMRRP) focusing on image acquisition and assessment, digital image processing techniques, analytical methodology, geospatial product development, and documentation of best practice for future data acquisition and analysis in support of ecological management efforts.

17 Jun 2020

PUBLICATION NOTICE: Water Quality Visualization Tools: A Python Application (1/A)

Abstract: On May 4, 2016, US District Court Judge Simon ordered the US Army Corps of Engineers and two other Action Agencies to produce a comprehensive Environmental Impacts Statement (EIS) by March 26, 2021. To do this, the Columbia River Systems Operation (CRSO) EIS will evaluate and compare a range of alternatives to offset or minimize any remaining unavoidable impacts. Due to the unique large system model approach, there is a need to quickly develop and analyze water quality model results. Therefore, there was a need for several visualization tools to assist the CRSO EIS team in promptly analyzing the results and creating publication-ready graphics. To create the most accessible desktop application for the CRSO EIS team, the Python programming language was used to quickly create three visualization tools. These three tools are only useful for relatively small data sets. If the team wishes to expand the functionality for larger data sets, it is recommended that model execution and analysis be moved to the supercomputers.

17 Jun 2020

PUBLICATION NOTICE: Development and Application of the CASM-SL to Support Nutrient Management in Potential Sangamon River Levee Setbacks

Abstract: Levee setbacks are defined by the intentional relocation of levees away from the river bank. This placement is often done to reduce flood risk, but it can also have environmental benefits. The Comprehensive Aquatic System Model (CASM) was used to look at the potential fate of nutrients and several environmental benefits for five potential management scenarios along the lower Sangamon River in Illinois. The model results showed that two scenarios were much more environmentally favorable relative to the outcomes considered here. One of the scenarios, where the existing gates were operated to allow the river access to the area behind the levee during extreme floods, was better at nitrogen and phosphorous accumulation. Removing the gates and creating a levee setback at this same site produced more aquatic plants, invertebrates, and fish but was not as effective at nutrient accumulation. This application of CASM demonstrates the potential of the model to provide objective rankings for the environmental benefits of levee setbacks.

10 Jun 2020

PUBLICATION NOTICE: Nearshore Placement Workshop 2019: Sediment Nourishment of the Nearshore Environment

Abstract: The Coastal Inlets Research Program and the Regional Sediment Management Program co-sponsored the 2019 Nearshore Placement Workshop. Thirty-four participants from the US Army Engineer Research and Development Center (ERDC) and numerous districts met in Vicksburg on January 29–30, 2019, as a part of the workshop. This workshop was convened to facilitate discussions on concerns districts face regarding nearshore placements from resource agencies and stakeholders, challenges to placing sediment in the nearshore, and future research needs. The workshop included ERDC presentations on the state of the science regarding nearshore placements; specific implementations of nearshore placements within various US Army Corps of Engineers districts; break-out-style discussions on nearshore placement challenges and potential paths forward; and group discussions on metrics for success, quantification of benefits, Statements of Need (SON), and research priorities. A few of the major recurring themes throughout the workshop were the importance of monitoring, concerns over the fate of fine-grained sediment, and difficulties conveying the benefits of nearshore placements to a wide range of audiences. The workshop culminated in a discussion of possible SON to be put forth to the ERDC research and development community. This special report describes the discussions and outcomes of the 2019 Nearshore Placement Workshop.

28 Apr 2020

PUBLICATION NOTICE: Baldcypress (Taxodium distichum) at the Wallisville Lake Project: A Review of Applicable Literature and Management Considerations

Abstract: Changing hydropatterns within the Wallisville Lake Project, near the mouth of the Trinity River in Chambers and Liberty Counties, Texas, have the potential to alter baldcypress forest resiliency. Increasing water levels support saltwater barrier operations while maintaining navigation and recreational access. However, potential impacts of increased water levels on the baldcypress forests are of particular concern because these ecosystems provide unique ecological value and wildlife habitat. The maintenance, succession, and resiliency of baldcypress under various flooding, salinity, and inundation regimes remain poorly defined and pose challenges to resource managers. This report reviews available literature pertaining to salinity and inundation impacts to baldcypress forests. Specific emphasis is placed on the ecological effects of water quality and quantity on the health and persistence of baldcypress. The information gathered in this report is intended to supplement material in the Wallisville Lake Project Water Control Manual to improve management of baldcypress forest conditions and avoid negative ecological impacts. Additionally, this report provides management considerations designed to maintain or enhance baldcypress forests within the Wallisville Lake Project.

27 Apr 2020

PUBLICATION NOTICE: Proceedings from the US Army Corps of Engineers (USACE) and the National Oceanic and Atmospheric Administration (NOAA)–National Ocean Service (NOS): Ecological Habitat Modeling Workshop

ABSRACT: This special report summarizes the activities of the Ecological Habitat Modeling Workshop held April 11–12, 2019, at the US Fish and Wildlife Service (USFWS) Blackwater National Wildlife Refuge Visitors Center in Cambridge, Maryland. The workshop guided 21 participants through the process of conceptualizing, quantifying, evaluating, and communicating ecological responses to inform guidance and management decisions for ecological restoration projects. Working in interactive groups, participants used the restoration work already in progress at nearby Swan Island as the basis for their model development. Over the course of the two-day workshop, participants learned the mechanics and challenges of applying modeling processes to shape the restoration of dynamic ecosystems. Through group work and brainstorming, they identified a number of benchmarks to assess restoration success and future resilience. To accommodate the changeable and often unpredictable natural events that can shape ecosystems, workshop facilitators emphasized building iterative, fluid ecological habitat models. Next steps include publishing this special report and scheduling a follow-up workshop that will include a site visit to Swan Island.

27 Apr 2020

PUBLICATION NOTICE: Benefits of Engineered Habitats to Seasonal Bird Communities on the Savannah Harbor Navigation Project, Dredged Material Containment Areas, 1994-2012

Abstract: This report presents the results of a long-term habitat and trend analyses of bird community data from a monitoring effort conducted on five Dredged Material Containment Areas (DMCAs) from 1994 to 2012. The USACE Savannah District developed and implemented a Long-Term Management Strategy (LTMS) for the DMCAs in 1996 to mitigate lost wetland habitat due to maintenance operations in the Savannah Harbor, and to provide habitat for the floral and faunal communities that otherwise would be available if not for the urban and economic development of the area. Bimonthly surveys were conducted from 1994 to 2012 to assess the effectiveness of the LTMS to provide seasonal habitat for the bird community. Archived quarterly satellite imagery was collected and analyzed from 2001 to 2011 to assess year-round seasonal habitat availability. All bird community data collected were fitted to a negative binomial (mean abundance) or Poisson distribution (mean species richness) and used to assess trends for 180 individual species and 12 species groups for spring, summer, fall, and winter seasons from 1994 to 2012. Results indicate that the Savannah DMCAs support stable to increasing populations of most species and species groups during each season, including many species ranked as regional priority species.

27 Apr 2020

PUBLICATION NOTICE: Evaluation of the Potential Impacts of the Proposed Mobile Harbor Navigation Channel Expansion on the Aquatic Resources of Mobile Bay, Alabama

Abstract: This report assesses potential impacts to aquatic resources resulting from proposed navigation channel expansion activities within Mobile Bay, Alabama. This work was conducted for the U.S. Army Corps of Engineers (USACE) Mobile District, to support development of a supplemental Environmental Impact Statement. Changes in water quality and hydrodynamics were evaluated for potential impacts to benthic macroinvertebrates, wetlands, submerged aquatic vegetation, oysters, and fish. The assessment includes extensive characterization of baseline conditions, evaluation of estimated post-project conditions related to aquatic resource habitat (e.g., changes in salinity, dissolved oxygen). An analysis of potential impacts related to a 0.5-m sea level rise scenario were also evaluated. Results suggest that no substantial impacts in aquatic resources within the study area are anticipated due to project implementation, as the area of greatest potential changes to environmental conditions are already adapted to natural shifts in salinity (and other factors), and to conditions resulting from the existing navigation channel. Although sea level rise has the potential to alter aquatic resource habitats with Mobile Bay, additional impacts related to project implementation remain negligible under the 0.5-m sea level rise scenario.