Adding Texture and Relief to Seattle’s New Seawall, an Application of Ecological Engineering

The aftermath of the 2001 Nisqually earthquake revealed that Seattle’s seawall was decaying and in need of replacement. The resulting seawall replacement project presented an opportunity to replace vertical featureless walls with more complex and productive habitat. Several years before the new seawall was designed, the City of Seattle invited University of Washington biologists to participate in developing concepts for improved seawall habitat. This resulted in collaborations with several City of Seattle departments, during which we designed, deployed, and evaluated large habitat panels that tested several types of slopes and textures. Four years of monitoring algae, sessile invertebrates, and epibenthic organisms demonstrated that important biological “ecosystem engineers” benefited from adding texture and relief to seawalls. For example, compared to simple flat treatments and the existing seawall, recruitment of mussels was increased on panels with cobble texture, and rockweed was more abundant on high relief “finned” and “stepped” panels. Species richness of biota was also higher on surfaces with higher habitat complexity. This project represents a successful test of ecological engineering concepts, and the findings are being incorporated into the seawall that is currently being built. The City’s 10-year monitoring and adaptive management plan will allow for continued evaluation of these types of habitat enhancements on a larger scale. Invited comment: Mark Mazzola, Environmental Manager for the Seattle Department of Transportatio

Salmonid early response to restored freshwater floodplain

Shortly after the construction of the Hansen Creek floodplain restoration project in 2010-2011, we conducted a pilot study of the initial use of the site by juvenile salmonids and the early development of invertebrate communities. We found that juvenile Coho salmon collected from the restored floodplain during periodic inundation events had higher instantaneous rations (a measure of feeding intensity) than Coho collected during regular monthly sampling in the creek channels. The floodplain site also had consistently higher insect abundances. Applying the data and lessons learned from the pilot study, we undertook a more comprehensive 13-month study of Hansen creek and its restored floodplain in 2012 and 2013. We conducted snorkel surveys and electrofishing in pools and riffles in both diked and newly restored habitats within the project site and at a reference area. Diets of juvenile Coho and Steelhead and Cutthroat trout were collected, as well as invertebrates from neuston net samples and fallout traps. In this talk we discuss salmonid distribution seasonally and by reach, compare salmonid diets (prey quantity and quality) among different creek reaches and floodplain habitat, and evaluate the relationship between salmonid diets and invertebrate results

Feeding ecology of juvenile Pacific salmon (Oncorhynchus spp.) in a northeast Pacific fjord: diet, availability of zooplankton, selectivity for prey, and potential competition for prey resources

We investigated the feeding ecology of juvenile salmon during the critical early life-history stage of transition from shallow to deep marine waters by sampling two stations (190 m and 60 m deep) in a northeast Pacific fjord (Dabob Bay, WA) between May 1985 and October 1987. Four species of Pacific salmon—Oncorhynchus keta (chum) , O. tshawytscha (Chinook), O. gorbuscha (pink), and O. kisutch (coho)—were examined for stomach contents. Diets of these fishes varied temporally, spatially, and between species, but were dominated by insects, euphausiids, and decapod larvae. Zooplankton assemblages and dry weights differed between stations, and less so between years. Salmon often demonstrated strongly positive or negative selection for specific prey types: copepods were far more abundant in the zooplankton than in the diet, whereas Insecta, Araneae, Cephalapoda, Teleostei, and Ctenophora were more abundant in the diet than in the plankton. Overall diet overlap was highest for Chinook and coho salmon (mean=77.9%)—species that seldom were found together. Chum and Chinook salmon were found together the most frequently, but diet overlap was lower (38.8%) and zooplankton biomass was not correlated with their gut fullness (%body weight). Thus, despite occasional occurrences of significant diet overlap between salmon species, our results indicate that interspecific competition among juvenile salmon does not occur in Dabob Bay

Shoreline armoring disrupts marine-terrestrial connectivity in the Salish Sea, with consequences for invertebrates, fish, and birds

Within the marine-terrestrial ecotone, upper intertidal “wrack zones” accumulate organic debris from algae, seagrass, and terrestrial plant sources and provide food and shelter for many organisms. We conducted detailed surveys of wrack and log accumulations and supralittoral invertebrates in spring and fall over 3 years at 29 armored-unarmored beach pairs in Puget Sound, WA, USA. Additionally, behavioral observations of juvenile salmon (Oncorhynchus spp.) and birds were conducted at 6 pairs. Armored beaches had substantially less wrack overall, a lower proportion of terrestrial plant material in the wrack, and far fewer logs. Armored beaches had significantly fewer invertebrates and differed from unarmored beaches in their taxonomic composition. Unarmored invertebrate assemblages were dominated by talitrid amphipods and insects, and were correlated with the amount of beach wrack and logs, the proportion of terrestrial material in wrack, and the maximum elevation of the beach. Shoreline armoring influenced juvenile salmon distribution, with fewer overall observations and fish in deeper water at armored beaches, but their feeding rates were relatively high at all sites. Terrestrial birds were commonly observed foraging among beach wrack and logs at unarmored beaches, but were largely absent from armored beaches. This study demonstrates that shoreline armoring disrupts marine-terrestrial connectivity, affecting the amount and type of organic material delivered to the nearshore ecotone in the form of wrack and logs, the abundance and taxonomic composition of supralittoral invertebrates, and the distribution and behavior of secondary consumers (juvenile salmon and birds)

Quantifying the effectiveness of shoreline armoring removal on coastal biota of Puget Sound

Shoreline armoring is prevalent around the world with unprecedented human population growth and urbanization along coastal habitats. Armoring structures, such as riprap and bulkheads, that are built to prevent beach erosion and protect coastal infrastructure from storms and flooding can cause deterioration of habitats for migratory fish species, disrupt aquatic–terrestrial connectivity, and reduce overall coastal ecosystem health. Relative to armored shorelines, natural shorelines retain valuable habitats for macroinvertebrates and other coastal biota. One question is whether the impacts of armoring are reversible, allowing restoration via armoring removal and related actions of sediment nourishment and replanting of native riparian vegetation. Armoring removal is targeted as a viable option for restoring some habitat functions, but few assessments of coastal biota response exist. Here, we use opportunistic sampling of pre- and post-restoration data for five biotic measures (wrack % cover, saltmarsh % cover, number of logs, and macroinvertebrate abundance and richness) from a set of six restored sites in Puget Sound, WA, USA. This broad suite of ecosystem metrics responded strongly and positively to armor removal, and these results were evident after less than one year. Restoration responses remained positive and statistically significant across different shoreline elevations and temporal trajectories. This analysis shows that removing shoreline armoring is effective for restoration projects aimed at improving the health and productivity of coastal ecosystems, and these results may be widely applicable

Shoreline armoring removal: assessment of restoration effectiveness in the Salish Sea

Shoreline armoring removal is becoming a common restoration technique in the nearshore of the Salish Sea, yet we lack a comprehensive understanding of the ecological benefits obtained, and how such an understanding could be used to inform management recommendations and educate diverse audiences. To address this knowledge gap, we studied effects of shoreline armor removal at 10 sites, expanding the spatial framework of what was previously known by collaborating across academic (University of Washington), agency (Washington Department of Fish and Wildlife), and citizen science groups. Each site had three beach types of: (1) restored beaches with armoring removed 1-11 years ago, with a mean of four years, (2) armored beaches altered by bulkheads or riprap, and (3) un-armored reference beaches with more natural conditions. We sampled eight metrics of physical and biological conditions, focusing on supratidal and upper intertidal elevations most affected by armoring and targeted by restoration actions: beach wrack, wrack invertebrates, sediments, terrestrial insects, riparian vegetation and logs, beach profiles, forage fish habitat, and stable isotopes of beach-hopper amphipods to reveal ratios of marine and terrestrial food sources. These metrics spanned the functions of beach stability, ecological diversity, and food web support for juvenile salmon and birds. Results indicated that some beach metrics restore quickly, such as wrack accumulation, while others take longer, such as log accumulation. Sediment sizes at restored beaches approximated those of reference beaches, and were appropriate for forage fish spawning. In general, terrestrial-associated metrics were greater at reference beaches, although there was evidence that insect diversity and logs with plant growth increased when beaches were restored greater than four years. This implies that restored beach functions increase through time, providing improved support for forage fish, salmon, and birds

Going global: the introduction of the Asian isopod Ianiropsis serricaudis Gurjanova (Crustacea: Peracarida) to North America and Europe

The Asian isopod Ianiropsis serricaudis is now well established in fouling communities, often associated with introduced ascidians, throughout the Northern Hemisphere but has gone largely unnoticed because of its diminutive size (typically less than 3 mm in length) and the difficulties of identifying small peracarid crustaceans. Known locations include the northeastern Pacific (Puget Sound, San Francisco Bay, and Monterey Bay), the northwestern Atlantic (from the Gulf of Maine to Barnegat Bay, NJ), and the northeastern Atlantic (England and the Netherlands). We predict that this species is widespread along North America and European coasts, and may already be introduced to cold temperate waters of the Southern Hemisphere as well.This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Regional Euro-Asian Biological Invasions Centre. The published article can be found at: http://www.aquaticinvasions.net/index.html.Keywords: shipping, fouling, marine, ballast water, Isopoda, Ianiropsis serricaudis, introduced specie

Chapter 4 Design Options, Implementation Issues and Evaluating Success of Ecologically Engineered Shorelines

Human population growth and accelerating coastal development have been the drivers for unprecedented construction of artificial structures along shorelines globally. Construction has been recently amplified by societal responses to reduce flood and erosion risks from rising sea levels and more extreme storms resulting from climate change. Such structures, leading to highly modified shorelines, deliver societal benefits, but they also create significant socioeconomic and environmental challenges. The planning, design and deployment of these coastal structures should aim to provide multiple goals through the application of ecoengineering to shoreline development. Such developments should be designed and built with the overarching objective of reducing negative impacts on nature, using hard, soft and hybrid ecological engineering approaches. The design of ecologically sensitive shorelines should be context-dependent and combine engineering, environmental and socioeconomic considerations. The costs and benefits of ecoengineered shoreline design options should be considered across all three of these disciplinary domains when setting objectives, informing plans for their subsequent maintenance and management and ultimately monitoring and evaluating their success. To date, successful ecoengineered shoreline projects have engaged with multiple stakeholders (e.g. architects, engineers, ecologists, coastal/port managers and the general public) during their conception and construction, but few have evaluated engineering, ecological and socioeconomic outcomes in a comprehensive manner. Increasing global awareness of climate change impacts (increased frequency or magnitude of extreme weather events and sea level rise), coupled with future predictions for coastal development (due to population growth leading to urban development and renewal, land reclamation and establishment of renewable energy infrastructure in the sea) will increase the demand for adaptive techniques to protect coastlines. In this review, we present an overview of current ecoengineered shoreline design options, the drivers and constraints that influence implementation and factors to consider when evaluating the success of such ecologically engineered shorelines

Community structure and standing stock of epibenthic zooplankton at five sites in Grays Harbor, WA

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