Scientific and Technical Advisory Committee Publications

The workshop convened technical and management personnel to consider pathways to achieve the aforementioned goals. Acquiring CSI at no cost is an option under the NextView License agreement between the National Geospatial-Intelligence Agency (NGA) and Maxar (previously DigitalGlobe, Inc). The NextView License was developed by the NGA to accommodate United States Government (USG) agencies, contractors, partners, and other entities that require CSI to support USG interests. The basic premise of the agreement is that any federal agency that requires satellite imagery from contracted commercial sources can request and obtain said imagery at no cost to the local agency. As 2017 updates to the Water Resource Development Act, which amends Section 117 of the Clean Water Act, called for the U.S. Environmental Protection Agency (EPA) to carry out an annual SAV survey in Chesapeake Bay. This makes it theoretically feasible for the EPA to now request and obtain the high-resolution CSI necessary for the annual SAV assessment.

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Shoreline alterations in the Chesapeake Bay have led to a loss of native tidal and shallow water habitats throughout the waterways of the Bay. Efforts to reduce the proliferation of shoreline hardening through the use of Living Shorelines and similar restoration practices have slowed the loss of native habitats, but do not address areas that have already been hardened. Green Riprap is a low cost, simple restoration technique to improve the water quality, habitat, and aesthetics of shorelines previously hardened with rock revetments by planting marsh vegetation in the voids between riprap rocks. However, Green Riprap techniques are new to the Chesapeake Bay and before widespread use is encouraged, a synthesis of the science and identification of research gaps are needed. This workshop was developed to provide the foundation to evaluate the state of the science on Green Riprap and its potential for providing enhanced water quality, increased near shore biodiversity, and improved aesthetic functions of previously hardened tidal shorelines.

The workshop brought together scientists, practitioners, and NGOs to share aspects of shoreline systems that Green Riprap could contribute to and elucidate the best practices for their construction. The workshop was a single-day online meeting with an optional field trip to example Green Riprap projects. The workshop convened experts from multiple disciplines to evaluate the state of the science for Green Riprap, including estuarine scientists that study tidal wetlands and tidal shorelines, shoreline engineers, physical modelers, and social scientists. Several Green Riprap projects built by the U.S. Fish and Wildlife Service and other groups were shared through talks, a virtual field trip, and an in-person field trip. The talks were followed by discussion on the next steps forward. Results were a prioritized list of research questions related to: site criteria; plant species most effective for Green Riprap use; water quality criteria that could be used to assess project success; ecological benefits, including increased biodiversity; and social benefits, including increased recreational/aesthetic values made possible by Green Riprap habitats.

Key recommendations from the workshop include:

1. Additional research to help understand both the best design of these shorelines and their benefits;
2. Increased visibility of the technique through the creation of public pilot projects; and
3. Additional outreach to all the involved parties, including property owners, contractors, and regulators to ensure clear definitions and that the projects are sited and designed correctly.

Potential partners for addressing these recommendations include the Chesapeake Bay Program’s Wetland and Fish Habitat Workgroups and the U.S. Fish and Wildlife Service.

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A two-day STAC workshop entitled Microplastics in the Chesapeake Bay and its Watershed: State of the Knowledge, Data Gaps, and Relationship to Management Goals, was convened April 24th – 25th, 2019 at the George Mason University Potomac Science Center in Woodbridge, VA. Over 50 participants from government, academia, consulting, and non-governmental organizations met to present current research and policy initiatives, followed by facilitated discussion on data gaps and needs. The workshop was designed within the framework of an ecological risk assessment (ERA), treating microplastics in the environment similarly to other pollutants. Participants noted that while our understanding has progressed in recent years, we still have little idea of the magnitude and distribution of microplastics within the watershed, much less the potential impact microplastic pollution may be having on living resources.
Workshop participants concluded that microplastics pose a potential serious risk to successful restoration of the Chesapeake Bay watershed. As a result, the following recommendations are being presented to the Chesapeake Bay Program (CBP) as urgent and immediate needs:
1. The CBP should create a cross-GIT Plastic Pollution Action Team to address the growing threat of plastic pollution to the bay and watershed.
2. The Scientific, Technical Assessment and Reporting Team should incorporate development of ERAs of microplastics into the CBP strategic science and research framework, and the Plastic Pollution Action Team should oversee the development of the Ecological Risk Assessments (ERAs) focused on assessment of microplastic pollution on multiple living resource endpoints.
3. STAC should undertake a technical review of terminology used in microplastic research, specifically size classification and concentration units, and recommend uniform terminology for the CBP partners to utilize in monitoring and studies focused on plastic pollution in the bay and watershed.
4. The CBP should develop a source reduction strategy to assess and address plastic pollution emanating from point sources, non-point sources, and human behavior.
5. The CBP should direct the Plastic Pollution Action Team and STAR Team to collaborate on utilizing the existing bay and watershed monitoring networks to monitor for microplastic pollution.

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The Scientific and Technical Advisory Committee (STAC) of the Chesapeake Bay Program (CBP) sponsored and convened a workshop on Legacy Sediment in Annapolis, MD on April 24-25, 2017. This workshop was developed in response to a request from the Chesapeake Bay Commission (CBC) with the primary goal of reviewing our collective understanding of “legacy” sediment and its relative influence on habitat and water quality, both locally and across the Chesapeake Bay, as well as the relative merits of different management approaches. This is a complex topic with important implications for Chesapeake Bay and speakers were invited to ensure a broad and comprehensive assessment of the relevant issues. As articulated by CBC Executive Director Ann Swanson, “A STAC workshop, with presentations from various points of view and a free and rigorous scientific debate, would greatly assist policymakers in understanding how “legacy” sediments fit within a suite of management activities to reduce nutrient and sediment loads to the Chesapeake Bay.”

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This report provides a summary of the proceedings of a STAC-sponsored workshop that explored market-based approaches for multifunctional buffers to identify means of accelerating riparian buffer plantings in the Bay watershed. This report also outlines specific recommendations identified by participants at the two-day workshop convened November 13-14, 2018 in Harrisburg, Pennsylvania.

This workshop focused on scalable solutions to promote implementation of multifunctional riparian buffers with the objective to accelerate the rate of buffer plantings in Pennsylvania and the greater Chesapeake Bay Watershed. This workshop brought together academics, government officials, industry professionals, and farmers to discuss potential solutions to overcome barriers to success for each buffer market-based opportunity.

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This report provides a summary of the proceedings of a Science and Technical Advisory Committee (STAC) sponsored workshop on targeting advanced best management practices to benefit shallow water resources and explore potential refinements to the current CBP model segmentation strategy. This report also outlines specific recommendations identified by participants at the 2-day workshop, held in Frederick, Maryland on May 23-24, 2018.
This workshop provided an opportunity to evaluate whether the “triblet” concept (natural channels draining to tributaries along the transition zone connecting uplands to coastal waters and functioning as bioreactors) provides a useful basis for informing watershed management and advancing coastal research. Participants were varied in expertise, including watershed hydrology, estuarine circulation, biogeochemistry, and behavioral-economics. A significant portion of the workshop was dedicated to sharing insights to understand the role of triblets as bioreactors affecting the exchange between upland and coastal waters. Participants collaborated to identify key information gaps and research opportunities to advance Bay restoration.
Lessons learned and major findings from the workshop focused on the science gaps, as well as improvements to the Bay Program’s modeling strategy.

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The Chesapeake Bay Total Maximum Daily Load (TMDL) sets goals for total nitrogen (TN), total phosphorus (TP), and total sediment reduction by political jurisdiction and by river basin in order to restore aquatic habitat. However, using total nitrogen and phosphorus rather than specific species of these nutrients, can mask processes that ultimately determine restoration success in terms of supporting fish communities and human safety, among other outcomes. For example, in some areas of the Chesapeake Bay Watershed, the proportion of phosphorus entering in a bio-available dissolved form (ortho P) is increasing, despite or even as a side effect of management efforts. A growing body of scientific evidence indicates that the speciation of nutrients influences algal biomass and the extent of hypoxia, which are reflected in water quality standards. Yet nutrient species effects are not factored into targeting TMDL effort nor the crediting system that tracks progress of jurisdictions towards their goals.

The consideration of nutrient species within the Chesapeake Bay TMDL and the broader management strategies of the Chesapeake Bay Program (CBP) would likely increase the efficiency of management by targeting effort to the nutrient species most responsible for hypoxia. For example, practices that reduce nitrate delivered to the Bay are likely more effective in reducing hypoxia than practices that reduce organic nitrogen, the latter likely being more effective in reducing harmful algal blooms. Additionally, achieving water quality goals within freshwater rivers, lakes, and reservoirs may require different reductions of nutrient species and timing of delivery. Management plans might better address multiple endpoints at a reduced cost, if these relationships were understood and made part of the management evaluation structure.

Calculations similar to those proposed have already been estimated and reflect geographic differences of nutrient loads in terms of hypoxia effects. Loads of N and P generated from different locations were converted into the common currency of “eutrophying units” to support the exchange of N and P reductions requested by some jurisdictions. A similar system to incorporate how nutrient species affect ecological outcomes could use the same concept of eutrophying units but has substantial information needs. Synthesis of existing science and new research or expert judgement to fill data gaps are required to build an understanding of the relative magnitude of speciation effects on hypoxia. Such effects must be considered under heterogeneity of nutrient inputs, land use, watershed physical characteristics, stream processes, and water body biogeochemistry. In addition, the ability of management practices to reduce specific nutrient species is understood for some, but not all, practices.

Movement toward a system that incorporates nutrient species is critical to successfully achieving the TMDL goals. In many areas of the Chesapeake Bay watershed, total nutrients are declining while bioavailable forms that contribute the most to hypoxia are increasing. These trends suggest that some waterways may not respond as expected to achieving the total nutrient cap. Synthesizing what is known about bioavailable forms of nutrients has the potential to improve the CBP’s ability to quantify effects of management efforts under a variety of conditions to ensure efforts are ultimately effective at restoring water bodies.

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As the Chesapeake Bay Program (CBP) passes the mid-point assessment, major point source discharges will have achieved (or nearly achieved) their final Total Maximum Daily Load (TMDL) nitrogen (N) and phosphorus (P) waste load allocations. Jurisdictions, however, still need to achieve substantial nutrient and sediment reductions from agricultural and urban nonpoint sources (NPS). Based on current understanding and modeling, the CBP estimates that agriculture and urban NPS need to achieve an additional 35 million and 12 million pounds of reductions, 1.3 and 0.6 million pounds of P reductions, and 941 and 594 million pounds of sediment, respectively to meet TMDL goals. State and local governments are poised to spend hundreds of millions of additional dollars to meet these goals, primarily by installing agricultural and urban nonpoint source best management practices (BMPs). Thus, BMP implementation stands at the center of CBP efforts to meet TMDL requirements. Yet, water quality monitoring suggests that the link between BMP implementation and load reductions is tenuous. In a recent STAC review, Keisman et al (2018) state “current research suggests that the estimated effects of conservation practices have not been linked to water quality improvements in most streams.” The Chesapeake Bay Watershed Model estimates substantial reductions in NPS loads, but monitoring data suggests little to no change in these loads between 1992-2012 (Keisman et al, 2018). A critical question is why? Potential explanatory factors include inadequate BMP coverage, poor implementation/maintenance, lag times between implementation and pollutant load reductions, pollutant transport and transformation processes that are incompletely understood, and inability to target BMPs to critical pollutant source areas. The purpose of this workshop was to make recommendations as to how the CBP can develop and integrate mechanisms to target BMPs to areas of the watershed producing disproportionate nutrient and sediment loads.

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A wide range of contaminants of agricultural, human, and industrial origin have degraded water quality, and pose a threat to the health of fish and wildlife populations, in the Chesapeake Bay and its watershed. A May 2019 STAC workshop brought together researchers and water quality managers working in urban and agricultural settings to synthesize the current knowledge on contaminants of concern and discuss opportunities for their reduction.

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Freshwater mussels were chosen as a focus for this workshop to consider ecosystem services, document biodiversity, outline intersections with Chesapeake Bay issues and to explore their potential to engage partners. The workshop brought diverse expertise together from across the watershed including mussel biologists, nutrient dynamics experts and water quality managers to provide recommendations which are summarized in this report.

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