Is local adaptation a factor in planning eelgrass restoration? Initial assessment of responses to temperature by eelgrass growing across a stressor gradient

Large-scale eelgrass restoration in an environment as complex as the Salish Sea requires estimating the effects of a wide range of environmental conditions (e.g. temperature, salinity, turbidity) on the effectiveness of restoration actions in different locations. We have developed a spatial model of eelgrass growth in response to environmental drivers, based on physiological data collected in Sequim Bay, WA, to aid in identifying restoration sites. However, field tests suggest that the model underestimates the capability of eelgrass to grow in conditions more stressful than Sequim Bay. A critical uncertainty is the extent of localized genotypic and/or phenotypic adaptations by eelgrass to high temperature and light limitation, which would affect our ability to predict restoration success over large scales with a single model. We have conducted an initial set of experiments to explore the physiological response of eelgrass collected from multiple locations across a temperature stress gradient. We collected eelgrass samples from two high-stress locations (South Sound and Hood Canal), and one low-stress location (Sequim Bay) and measured photosynthesis and respiration rates of cleaned, healthy leaf sections via instantaneous oxygen flux in light and dark bottles across a range of temperatures. The samples had notable differences in morphology and epiphytes. We found that respiration and photosynthesis did not differ between sites across the temperature treatments. Counter to expectations, eelgrass from more stressful locations had higher respiration rates, though the difference was not statistically significant. We observed significantly higher gross and net productivity at 25° C for eelgrass from Hood Canal. The results suggest that eelgrass populations throughout Puget Sound may not be as differentially adapted to temperature as we expected, despite discrepancies between modeling and field observations. We hope to extend this study with additional data collection, including moderate- to long-term common garden growth experiments for multiple stressors

Eelgrass (Zostera marina) restoration in Puget Sound: restoration tools, successes and challenges

Eelgrass (Zostera marina) is one of 25 Vital Signs to track the health of Puget Sound and restoration of this critical nearshore habitat is part of the overall regional recovery strategy. Eelgrass restoration will provide a multitude of benefits, ranging from habitat for species to ameliorating the effects of climate change. Since 2013, the Washington State Department of Natural Resources has led regional evaluation of potential eelgrass restoration sites and transplanting in Washington State. Through collaborations we have developed and tested strategies to enhance transplant success and restore natural processes. We developed an eelgrass transplant suitability model to identify potential restoration sites using key variables essential for seagrass production and long-term resilience in a changing environment. Eelgrass was planted at five sites for initial model verification with an additional 81 test sites planted between 2013 and 2017 to identify areas suitable for large scale restoration. Eelgrass test transplant results varied and 15 sites with the highest success were selected for large-scale transplantation. A comparison of standard transplant methods was performed and preliminary results suggest that proper method selection plays an important role in transplant success. Long-term monitoring is scheduled with an emphasis on the success of specific donor stocks, the recovery of donor sites, and the effect seagrass restoration has on water chemistry. The restoration process has endured challenges that ranged from permitting issues to anthropogenic and environmental stressors. However, issue specific solutions and adaptive management allowed the restoration process to progress and contribute valuable information towards strategies to recover this valuable habitat in the region

Eelgrass donor sites: potentially overlooked impacts of restoration in Puget Sound

Eelgrass (Zostera marina) is an important habitat in the Salish Sea and restoration efforts are being undertaken around the region to increase eelgrass abundance and resilience. Eelgrass restoration is typically performed by transplanting whole shoots or dispersing viable seeds collected from reproductive shoots to a site. Most of the restoration efforts in the Pacific Northwest utilize whole shoots harvested from donor meadows and transplanted into restoration areas, but little work has been done to look at the impacts of the harvest on the donor stock. In response to the lack of existing data for Puget Sound, Washington Department of Natural Resources and Pacific Northwest National Laboratory’s Marine Sciences Laboratory conducted a controlled harvest experiment in two regions of the Salish Sea at sites associated with ongoing restoration activities. These meadows were harvested under different pressure (i.e., different percentage of plants taken from 0 to 50%) using traditional harvesting techniques. The meadows were then monitored for two years for changes in density. The results indicated that the eelgrass meadows were surprisingly resilient to all levels of harvest under ideal conditions and in small harvest areas. Interpretation and implications of these results will be discussed, as well as potential considerations for choosing potential donor sites for future restoration efforts

Impacts of a Cascadia Subduction Zone Earthquake on Water Levels and Wetlands of the Lower Columbia River and Estuary

Subsidence after a subduction zone earthquake can cause major changes in estuarine bathymetry. Here, we quantify the impacts of earthquake-induced subsidence on hydrodynamics and habitat distributions in a major system, the lower Columbia River Estuary, using a hydrodynamic and habitat model. Model results indicate that coseismic subsidence increases tidal range, with the smallest changes at the coast and a maximum increase of ∼10% in a region of topographic convergence. All modeled scenarios reduce intertidal habitat by 24%–25% and shifts ∼93% of estuarine wetlands to lower-elevation habitat bands. Incorporating dynamic effects of tidal change from subsidence yields higher estimates of remaining habitat by multiples of 0–3.7, dependent on the habitat type. The persistent tidal change and chronic habitat disturbance after an earthquake poses strong challenges for estuarine management and wetland restoration planning, particularly when coupled with future sea-level rise effects

The Oncor Geodatabase for the Columbia Estuary Ecosystem Restoration Program: Handbook of Data Reduction Procedures, Workbooks, and Exchange Templates

This Handbook of Data Reduction Procedures, Workbooks, and Exchange Templates is designed to support the Oncor geodatabase for the Columbia Estuary Ecosystem Restoration Program (CEERP). The following data categories are covered: water-surface elevation and temperature, sediment accretion rate, photo points, herbaceous wetland vegetation cover, tree plots and site summaries, fish catch and density, fish size, fish diet, fish prey, and Chinook salmon genetic stock identification. The handbook is intended for use by scientists collecting monitoring and research data for the CEERP. The ultimate goal of Oncor is to provide quality, easily accessible, geospatial data for synthesis and evaluation of the collective performance of CEERP ecosystem restoration actions at a program scale

20% More Eelgrass in Puget Sound by 2020: Restoration Site Selection

As part of a larger program by the state of Washington to restore the Puget Sound ecosystem, we are engaged in a selection process to locate specific areas where eelgrass could be restored or enhanced to meet the goal of 20% more eelgrass by 2020, amounting to a ~4,000 ha increase in areal eelgrass coverage. Embedded in this goal is the establishment and development of meadows that are resilient to the effects of climate change and anthropogenic and natural disturbances. We hypothesize that: (1) many sites are recruitment limited; (2) eelgrass has been lost in some areas because of temporary disturbance; and (3) there may be broader stresses limiting eelgrass in subregions of Puget Sound. Our approach utilizes an understanding of eelgrass growth requirements coupled with hydrodynamic and water quality models, an eelgrass growth model, field observations, and test plantings. We are using these results along with spatial data and stressor information collected as part of regional assessments of nearshore ecosystem condition to identify restoration sites. We are also working with local governments to determine actions that could be taken to improve conditions for eelgrass within their jurisdictions to maximize the success and long-term viability of planted meadows. The models revealed differences in the predicted growth rate of eelgrass among regions. In general, northern Puget Sound and Strait of Juan de Fuca provided the best conditions, whereas Hood Canal and southern Puget Sound were relatively less suitable for eelgrass. Field visits were conducted at 23 sites where the eelgrass model predicted good growing conditions but where eelgrass does not presently exist based on available information. From among these sites we selected five sites for test planting. Test plantings, modeling and jurisdictional information will form the basis to develop strategies for larger recovery efforts

Protocols for Monitoring Habitat Restoration Projects in the Lower Columbia River and Estuary

Protocols for monitoring salmon habitat restoration projects are essential for the U.S. Army Corps of Engineers' environmental efforts in the Columbia River estuary. This manual provides state-of-the science data collection and analysis methods for landscape features, water quality, and fish species composition, among others

Evaluating Cumulative Ecosystem Response to Restoration Projects in the Columbia River Estuary, Annual Report 2006

This report is the third annual report of a six-year project to evaluate the cumulative effects of habitat restoration action in the Columbia River Estuary (CRE). The project is being conducted for the U.S. Army Corps of Engineers (Corps) by the Marine Sciences Laboratory of the Pacific Northwest National Laboratory, the Pt. Adams Biological Field Station of the National Marine Fisheries Service, and the Columbia River Estuary Study Taskforce. Measurement of the cumulative effects of ecological restoration projects in the Columbia River estuary is a formidable task because of the size and complexity of the estuarine landscape and the meta-populations of salmonids in the Columbia River basin. Despite the challenges presented by this system, developing and implementing appropriate indicators and methods to measure cumulative effects is the best way to enable estuary managers to track the overall effectiveness of investments in estuarine restoration projects. This project is developing methods to quantify the cumulative effects of multiple restoration activities in the CRE. The overall objectives of the 2006 study were to continue to develop techniques to assess cumulative effects, refine the standard monitoring protocols, and initiate development of an adaptive management system for Corps of Engineers’ habitat restoration monitoring efforts in the CRE. (The adaptive management effort will be reported at a later date.) Field studies during 2006 were conducted in tidal freshwater at Kandoll Farm on the lower Grays River and tidal brackish water at Vera Slough on Youngs Bay. Within each of area, we sampled one natural reference site and one restoration site. We addressed the overall objectives with field work in 2006 that, coupled with previous field data, had specific objectives and resulted in some important findings that are summarized here by chapter in this report. Each chapter of the report contains data on particular monitored variables for pre- and post-restoration conditions at both the Kandoll and Vera study areas

Evaluating Cumulative Ecosystem Response to Restoration Projects in the Columbia River Estuary, Annual Report 2007

The goal of this multi-year study (2004-2010) is to develop a methodology to evaluate the cumulative effects of multiple habitat restoration projects intended to benefit ecosystems supporting juvenile salmonids in the lower Columbia River and estuary. Literature review in 2004 revealed no existing methods for such an evaluation and suggested that cumulative effects could be additive or synergistic. Field research in 2005, 2006, and 2007 involved intensive, comparative studies paired by habitat type (tidal swamp vs. marsh), trajectory (restoration vs. reference site), and restoration action (tide gate vs. culvert vs. dike breach). The field work established two kinds of monitoring indicators for eventual cumulative effects analysis: core and higher-order indicators. Management implications of limitations and applications of site-specific effectiveness monitoring and cumulative effects analysis were identified

Evaluating Cumulative Ecosystem Response to Restoration Projects in the Lower Columbia River and Estuary, 2009

This is the sixth annual report of a seven-year project (2004 through 2010) to evaluate the cumulative effects of habitat restoration actions in the lower Columbia River and estuary (LCRE). The project, called the Cumulative Effects Study, is being conducted for the U.S. Army Corps of Engineers Portland District (USACE) by the Marine Sciences Laboratory of the Pacific Northwest National Laboratory (PNNL), the Pt. Adams Biological Field Station of the National Marine Fisheries Service (NMFS), the Columbia River Estuary Study Taskforce (CREST), and the University of Washington. The goal of the Cumulative Effects Study is to develop a methodology to evaluate the cumulative effects of multiple habitat restoration projects intended to benefit ecosystems supporting juvenile salmonids in the 235-km-long LCRE. Literature review in 2004 revealed no existing methods for such an evaluation and suggested that cumulative effects could be additive or synergistic. From 2005 through 2009, annual field research involved intensive, comparative studies paired by habitat type (tidal swamp versus marsh), trajectory (restoration versus reference site), and restoration action (tidegate replacement vs. culvert replacement vs. dike breach)