Simulating eutrophication effects in Puget Sound using qualitative network models

Ecosystems are complex, dynamic networks of interacting physical, chemical, biological and social components. A stressor such as eutrophication thus can cause responses throughout the system via direct and indirect pathways and feedbacks. Ecosystem models are typically designed to account for as many critical components, functions and pathways as possible in order to reasonably simulate how a system may respond to a stressor; however, many aspects of ecosystem structure and function are poorly studied and too data-poor to represent in a quantitative, mechanistic model. Qualitative network models (QNMs) assume comparably simple (i.e., positive or negative) relationships between interacting components, and allow users to quickly assess potential impacts of stressors or management actions on both data-rich and data-poor aspects of a system. Here, we adapt a previously published QNM of Puget Sound to assess how eutrophication at different scales of space, time and system complexity might affect key species at all trophic levels as well as ecosystem services and human wellbeing. The outcomes of QNM simulations can be compared to other types of models for support and validation, and should be regarded as hypotheses that guide future quantitative studies and decision making in Puget Sound

Section 4: Climate Change: A Global Problem With Local Impacts

Section 4 shifts from the local impacts of urbanization to the locally realized impacts of global climate change, including ocean acidification and sea level rise, followed by evidence of climate change in the ecosystem, ranging from phytoplankton and kelp, to wetlands, salmon, and marine birds

Section 1: Introduction

Section 1 is an introduction to the report and the Salish Sea as a whole. The introduction provides an overview of the Salish Sea, the concept of ecosystem health, and a roadmap to the rest of the report

Section 2: Context

Section 2 sets a foundation for understanding the Salish Sea ecosystem by describing its fundamental biophysical processes and structure, including estuarine circulation, ecological productivity, and an overview of several important biogenic habitats

Section 6: Opportunities for Improving Assessment and Understanding of the Salish Sea

Section 6 offers a list of science-based needs and opportunities brought to light by the report and various existing efforts within the Salish Sea science community, representing opportunities for greater collaboration across geographic and jurisdictional boundaries

State of the Salish Sea: Executive Summary

This report synthesizes information on past, current, and emerging stressors within the Salish Sea estuarine ecosystem. The Salish Sea is a complex waterbody shared by Coast Salish Tribes and First Nations, Canada, and the United States. It is defined by multiple freshwater inputs and marine water from the Pacific Ocean that mix in two primary basins, Puget Sound and the Strait of Georgia. Human impacts are multifaceted and extensive within the Salish Sea, with a regional population of almost 9 million people. Population growth has driven urbanization and development, which in turn has triggered structural changes to the landscape and seascape. Meanwhile, the growing effects of climate change are fundamentally altering physical and biological processes. The report describes the most pervasive and damaging impacts affecting the transboundary ecosystem, recognizing that some are generated locally while others are the locally realized impacts from global-scale changes in climate, oceans, land use, and biodiversity. The Salish Sea is under relentless pressure from an accelerating convergence of global and local environmental stressors and the cumulative impacts of 150 years of development and alteration of our watersheds and seascape. Some of these impacts are well understood but many remain unknown or are difficult to predict. While strong science is critical to understanding the ecosystem, the report provides a spectrum of ideas and opportunities for how governments, organizations, and individuals can work together to meet the needs of science and science-driven management that will sustain the Salish Sea estuarine ecosystem

Section 3: Urbanization and Human Impacts to the Seascape

Section 3 turns to an in-depth discussion of stressors and impacts to the ecosystem from population growth and urbanization, such as increases in impervious surfaces, hardening of shorelines, and the problems caused by a myriad of marine contaminants

Fishes in Seagrass Habitats: Species Composition, Trophic Interactions, and Production

The value of habitats in terms of biological production is of interest to ecologists and resource managers. Seagrasses are a commonly occurring habitat type in shallow marine waters and have been shown to support high abundances of fish and invertebrates. In lower Chesapeake Bay, seagrasses grow in a shallow fringe in the subtidal zone. Although, ample evidence exists for the value of these habitats as foraging and rearing areas for a variety of organisms, the connectivity among species and the benefits derived from these habitats in terms of production have not been well described, especially for small, seasonally occurring finfishes. The main objective of this research was to document fish occurrence and abundance, describe trophic interactions within the seagrass community, and quantify export of biomass from the habitat using a model species to demonstrate the value of these habitats in terms of finfish production.;To address the research objective, I employed a variety of models---statistical, ecosystem, and individual-based. In Chapter 1, I conducted as census of finfishes in seagrass habitats and compared contemporary occurrences and abundances to data from the 1970s. This chapter showed that the fish fauna in these habitats is dominated by a small number of abundant and commonly occurring species, including Spot (Leiostomus xanthurus), Silver Perch ( Bairdiella chrysoura), Bay Anchovy (Anchoa mitchilli), Atlantic Silverside (Menidia menidia), Dusky Pipefish ( Syngnathus floridae), and Northern Pipefish (Syngnathus fuscus ). While abundances had changed since the 1970s for some species, most were highly variable with no discernible trend. There was a small decrease in species richness from the historical dataset to the contemporary dataset and multivariate analysis showed a shift in community composition. The data from this chapter formed the basis for the ecosystem model developed in Chapter 2. In this model, biomass, production, and diet data were inputs, and using a mass-balance approach, a food web model was iteratively developed. There were 35 model compartments in the model and scenarios based upon historical data and future projections were developed for comparison. Mesozooplankton were the most highly connected group, while piscivorous birds, several piscivorous fishes, and mesograzers were all considered keystone groups, controlling food web dynamics. In Chapter 3, an individual-based model was developed for Silver Perch, to assess growth and production within a seagrass habitat. Because Silver Perch settle in this habitat, grow during the summer season, and migrate to deeper waters in the fall, they were an appropriate model species for determining the contribution of seagrass habitats to production. With high seasonal abundance and rapid growth (~0.19 g/d), this species contributes a considerable amount of biomass to Chesapeake Bay, biomass that originates in seagrass habitats and moved via trophic transfer.;This study presents a quantitative view of community ecology in lower Chesapeake Bay seagrass habitats. With changing temperatures and habitat loss, these habitats are at risk, and this study demonstrates that their value to the Chesapeake Bay food web extends beyond the small fringe of their occurrence

Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, Lower Columbia River, 2007 Annual Report.

This document is the first annual report for the study titled 'Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta in the Lower Columbia River'. Hereafter, we refer to this research as the Tidal Freshwater Monitoring (TFM) Study. The study is part of the research, monitoring, and evaluation effort developed by the Action Agencies (Bonneville Power Administration, U.S. Army Corps of Engineers, U.S. Bureau of Reclamation) in response to obligations arising from the Endangered Species Act as a result of operation of the Federal Columbia River Power System (FCRPS). The project is performed under the auspices of the Northwest Power and Conservation Council's Columbia Basin Fish and Wildlife Program. The goal of the 2007-2009 Tidal Freshwater Monitoring Study is to answer the following questions: In what types of habitats within the tidal freshwater area of the lower Columbia River and estuary (LCRE; Figure 1) are yearling and subyearling salmonids found, when are they present, and under what environmental conditions?1 And, what is the ecological importance2 of shallow (0-5 m) tidal freshwater habitats to the recovery of Upper Columbia River spring Chinook salmon and steelhead and Snake River fall Chinook salmon? Research in 2007 focused mainly on the first question, with fish stock identification data providing some indication of Chinook salmon presence at the variety of habitat types sampled. The objectives and sub-objectives for the 2007 study were as follows: (1) Habitat and Fish Community Characteristics-Provide basic data on habitat and fish community characteristics for yearling and subyearling salmonids at selected sites in the tidal freshwater reach in the vicinity of the Sandy River delta. (1a) Characterize vegetation assemblage percent cover, conventional water quality, substrate composition, and beach slope at each of six sampling sites in various tidal freshwater habitat types. (1b) Determine fish community characteristics, including species composition, abundance, and temporal and spatial distributions. (1c) Estimate the stock of origin for the yearling and subyearling Chinook salmon captured at the sampling sites using genetic analysis. (1d) Statistically assess the relationship between salmonid abundance and habitat parameters, including ancillary variables such as temperature and river stage. (2) Acoustic Telemetry Monitoring-Assess feasibility of applying Juvenile Salmon Acoustic Telemetry System (JSATS) technology to determine migration characteristics from upriver of Bonneville Dam through the study area (vicinity of the Sandy River delta/Washougal River confluence). (2a) Determine species composition, release locations, and distributions of JSATS-tagged fish. (2b) Estimate run timing, residence times, and migration pathways for these fish. Additionally, both objectives serve the purpose of baseline research for a potential tidal rechannelization project on the Sandy River. The U.S. Forest Service, in partnership with the Bonneville Power Administration and the U.S. Army Corps of Engineers, is currently pursuing reconnection of the east (relict) Sandy River channel with the current channel to improve fish and wildlife habitat in the Sandy River delta. Our study design and the location of sampling sites in this reach provide baseline data to evaluate the potential restoration

Section 7: The Future of the Salish Sea? A Call to Action

Section 7 provides perspective from the Salish Sea Institute, acknowledging that science alone will not resolve continuing problems or emerging issues. Stronger policies along with education, leadership, and collaboration are needed