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Greenspaces provide crucial nature contact for urban residents. When we have greater access and exposure to nature in the places where we live, work, learn, and play, we tend to experience better human health outcomes. Urban parks, trees, and vegetation encourage physical activity, reduce anxiety and depression, support social cohesion by providing gathering spaces, and are associated with reduced mortality and improved overall health.

While traditionally biodiversity conservation has focused on large open spaces, cities can also play a key role in supporting biodiversity. Many of the world’s major cities developed in biodiversity hotspots due to historical settlement patterns dependent on natural resources. Thus cities contain vital remnant habitat as well as globally important native and endangered species that rely on urban greenspaces.

As urbanization increases, cities around the world are developing and implementing plans to better integrate nature within urban settings. Many of these plans emphasize the importance of urban greening in providing multiple, substantial benefits such as biodiversity conservation, stormwater management, human health and well-being improvements, climate resilience, and more. However not all greenspaces are created equal in their biodiversity support and human health provision.

The goal of this document is to provide science-based guidance for designing urban spaces that foster both human health and urban biodiversity. Anyone making decisions about land use and urban design in cities across the world can benefit from the recommendations in this document (including community organizations, local non-profits, local leaders and policy makers, city planners, urban designers, landscape architects, engineers, gardeners/horticulturists/arborists, residents, and landowners). However, the majority of the document is specifically aimed at supporting designers and planners who work at the planning, site, and detailed design scales such as landscape architects, civil engineers, and urban designers. As noted in more detail in the limitations section below, this document synthesizes global research and design strategies while strongly informed by our experience as scientists and designers in California’s San Francisco Bay Area.

A future Sacramento-San Joaquin Delta and Suisun Marsh (“Delta” herein) that supports healthy ecosystems and native species, while also meeting flood risk reduction, water supply, water quality, carbon sequestration, economic, and cultural objectives, requires that appropriate restoration and management actions be taken in the right place at the right time. Geographic setting affects the potential opportunities available—not all actions are suitable everywhere. Physical factors determining what types of activities are appropriate now and in the future include a site’s elevation, degree of tidal and fluvial influence, salinity, soil type, and local effects of climate change, which all vary spatially across the Delta. While there has been considerable progress over the last several decades, continued acceleration of the pace and scale of enhancement actions appropriate to landscape position is needed. Understanding the physical template is necessary for developing strategies that move beyond opportunistic restoration, support resilience over time, and have the potential to connect and magnify benefits across the larger landscape.

The beneficial reuse of dredged sediment is one strategy in a broader portfolio that is being developed for San Francisco Bay to help marshes adapt to rising sea level. Dredged sediment is currently being used in restoration projects around the Bay, but additional sediment is needed to meet the demand. The guidelines for determining if sediment is appropriate for beneficial reuse were developed twenty years ago. As part of assessing the role of dredged sediment in Bay restoration and adaptation strategies, the Regional Monitoring Program for Water Quality (RMP) and stakeholders recognized the need to revisit the beneficial reuse guidelines for dredged sediment. In September 2019, the RMP convened a workshop that included four technical experts to review the beneficial reuse guidelines. The experts were asked to answer three questions: 1) Are the current screening guidelines appropriate for beneficial reuse? 2) Is the current screening process appropriate and adequate? If not, what are your recommendations for improving it? and 3) How should bioaccumulation potential be addressed for the beneficial reuse of sediment? Based on the discussion of these three questions, six recommendations emerged from the workshop.

The physical and ecological environment of the upper San Francisco Estuary has been profoundly altered since the early 1800s. Recent efforts have utilized maps of the upper estuary’s historical habitat types to infer associated changes in desired ecosystem processes and functions. The work presented in this memo builds on these previous efforts, but utilizes a new tool for evaluating change over time: a 3D hydrodynamic model of the pre-development estuary. This model was constructed by Resource Management Associates (RMA) using a new digital elevation model of the pre-development upper estuary generated by SFEI and UC Davis (UCD) and “natural” boundary flows calculated by the California Department of Water Resources (CDWR).

Once completed and calibrated, the pre-development model was paired with a similar model of the contemporary system in order to analyze hydrodynamic changes in the upper estuary. These analyses are presented in a technical memorandum published by RMA (2015). This memorandum takes these analyses and considers the ecological implications of modeled changes (see the “Results” section). Hydrodynamic analyses include analyzing changes in tidal prism, isohaline positions, low-salinity zone habitat, channel velocity, and source water distribution.

 In addition to describing the ecological implications of modeled hydrodynamic changes, this memorandum summarizes major ongoing questions about estuarine hydrodynamics that might be explored using these models, including changes in water residence time, temperature, transport pathways, and the connectivity of aquatic and semi-aquatic habitats. Understanding changes in these and other factors would greatly improve our understanding of the desirable ecosystem functions provided by the historical system and, as a result, improve our ability to recover these functions now and into the future.

Dissolved copper is one of the more pervasive and toxic constituents of stormwater runoff and is commonly found in stream, estuary, and coastal marine habitats of juvenile salmon. While stormwater runoff does not usually carry copper concentrations high enough to result in acute lethality, they are of concern because sublethal concentrations of copper exposure have been shown to both impair olfactory function and alter behavior in various species in freshwater. To compare these results to other environments that salmon are likely to encounter, experiments were conducted to evaluate the effects of salinity on the impairment of olfactory function and avoidance of copper. Copper concentrations well within the range of those found in urban watersheds, have been shown to diminish or eliminate the olfactory response to the amino acid, l-serine in freshwater using electro-olfactogram (EOG) techniques. The olfactory responses of both freshwater-phase and seawater-phase coho and seawater-phase Chinook salmon, were tested in freshwater or seawater, depending on phase, and freshwater-phase coho at an intermediate salinity of 10‰. Both 10‰ salinity and full strength seawater protected against the effects of 50μg copper/L. In addition to impairing olfactory response, copper has also been shown to alter salmon behavior by causing an avoidance response. To determine whether copper will cause avoidance behavior at different salinities, experiments were conducted using a multi-chambered experimental tank. The circular tank was divided into six segments by water currents so that copper could be contained within one segment yet fish could move freely between them. The presence of individual fish in each of the segments was counted before and after introduction of dissolved copper (<20μg/L) to one of the segments in both freshwater and seawater. To address whether use of preferred habitat is altered by the presence of copper, experiments were also conducted with a submerged structural element. The presence of sub-lethal levels of dissolved copper altered the behavior of juvenile Chinook salmon by inducing an avoidance response in both freshwater and seawater. While increased salinity is protective against loss of olfactory function from dissolved copper, avoidance could potentially affect behaviors beneficial to growth, survival and reproductive success.

Several lines of evidence from the Regional Monitoring Program and other studies have suggested that sediment grain size characteristics influence amphipod (Eohaustorius estuarius) survival in 10 day toxicity tests.  Two workshops were convened to address the influence of non-contaminant factors on amphipod toxicity tests, and the current project was prioritized based on the recommendations of experts participating in these workshops.  The study was designed to investigate the effects of kaolin clay on amphipod survival since this is the dominant clay type in Francisco Estuary sediments.  In these experiments reference sand was spiked with increasing concentrations of kaolin to determine whether there was a dose-based relationship between amphipod mortality and increasing concentrations of this type of clay. Wild-caught E. estuarius were collected from Beaver Creek Beach (Oregon) and supplied by Northwest Aquatic Sciences. The initial experiment did not demonstrate a dose-response relationship: E. estuarius survival in all concentrations from 10% to 100% kaolin was lower than in the sand control, and survival in the clay spiked sand was also highly variable.  This experiment exposed a mixture of amphipod size classes representative of those typically provided by the amphipod supplier.  Reasoning that variable response to clay was related to variable tolerances by the different amphipod size classes, a follow-up experiment was conducted to investigate this relationship.  Amphipods were separated into small, medium and large size classes and these were exposed to 100% kaolin.  These results showed survival in 100% clay was 86%, 82% and 66% by small, medium and large amphipods, respectively.  To further investigate size-related responses to clay, small, medium and large amphipods were exposed to concentrations of sand spiked with clay from 0 to 100%.  The results of this experiment showed that smaller amphipods tolerated high clay concentrations better than larger animals, but there was not a strict monotonic dose-response relationship.  Conclusions based on this experiment were constrained by an inability to sort amphipods into three distinct size classes, because there were not enough of the largest animals present at the Oregon collection site.  In addition, grain size analysis of the sand spiked clay suggested that the clay tended to flocculate in the treatments above 70% kaolin.  This experiment was repeated when three distinct size classes were present in December 2014.  The results of this experiment also showed that smaller amphipods tolerated high kaolin better than larger amphipods.  As in the previous experiment, there was not a monotonic response to clay, especially at the higher kaolin concentrations, and the grain size analysis also showed flocculation occurred in the highest clay treatments.  Despite these inconsistencies, the results of this experiment suggest that tolerance of E. estuarius to clay varies with amphipod size.  Average survival was 81%, 79%, and 65% for small, medium and large amphipods, respectively in concentrations > 50% clay.  Possible mechanisms for size specific clay effects on this amphipod species include lower survival related to reduced energy reserves in larger animals, inhibition of gill function, and inhibition of feeding and locomotion through clogging of amphipod setae.  The results suggest that use of smaller amphipods in routine monitoring of high clay sediments will reduce the influence of this factor on test results.  Additional experiments with high clay reference site sediments from San Francisco Bay are recommended to confirm the size related response with field sediments.

The Environmental Data Summit, convened under the auspices of the Delta Stewardship Council’s Delta Science Program in June 2014, witnessed remarkable participation from experts across California, the nation, and even the world. Summit attendees from the public, private, federal, and non-profit sectors shared their views regarding the urgent needs and proposed solutions for California’s data-sharing and data-integration challenges, especially pertaining to the subject of environmental resource management in the era of “big data.” After all, this is a time when our data sources are growing in number, size, and complexity. Yet our ability to manage and analyze such data in service of effective decision-making lags far behind our demonstrated needs.

In its review of the sustainability of water and environmental management in the California Bay-Delta, the National Research Council (NRC) found that “only a synthetic, integrated, analytical approach to understanding the effects of suites of environmental factors (stressors) on the ecosystem and its components is likely to provide important insights that can lead to enhancement of the Delta and its species” (National Research Council 2012). The present “silos of data” have resulted in separate and compartmentalized science, impeding our ability to make informed decisions. While resolving data integration challenges will not, by itself, produce better science or better natural resource outcomes, progress in this area will provide a strong foundation for decision-making. Various mandates ranging from the California Water Action Plan to the President’s executive order demanding federal open data policies demonstrate the consensus on the merits of modern data sharing at the scale and function needed to meet today’s challenges.

This white paper emerges from the Summit as an instrument to help identify such opportunities to enhance California’s cross-jurisdictional data management. As a resource to policymakers, agency leadership, data managers, and others, this paper articulates some key challenges as well as proven solutions that, with careful and thoughtful coordination, can be implemented to overcome those obstacles. Primarily featured are tools that complement the State’s current investments in technology, recognizing that success depends upon broad and motivated participation from all levels of the public agency domain. Executive Summary

This document describes examples, practices, and recommendations that focus on California’s Delta as an opportune example likely to yield meaningful initial results in the face of pressing challenges. Once proven in the Delta, however, this paper’s recommended innovations would conceivably be applied statewide in subsequent phases.

Contaminant concentrations from the Sacramento-San Joaquin River watershed were determined in water samples mainly during flood flows in an ongoing effort to describe contaminant loads entering San Francisco Bay, CA, USA. Calculated PCB and total mercury loads during the 6-year observation period ranged between 3.9 and 19 kg/yr and 61 and 410 kg/yr, respectively. Long-term average PCB loads were estimated at 7.7 kg/yr and total mercury loads were estimated at 200 kg/yr. Also monitored were PAHs, PBDEs (two years of data), and dioxins/furans (one year of data) with average loads of 392, 11, and 0.15/0.014 (OCDD/OCDF) kg/yr, respectively. Organochlorine pesticide loads were estimated at 9.9 kg/yr (DDT), 1.6 kg/yr (chlordane), and 2.2 kg/yr (dieldrin). Selenium loads were estimated at 16 300 kg/yr. With the exception of selenium, all average contaminant loads described in the present study were close to or below regulatory load allocations established for North San Francisco Bay.