Characterizing The San Francisco Estuary

What is an estuary? Where do they occur? How do they work? Who lives there? And why are estuaries important to our planet? This collection will answer all of these questions and more. Estuaries are places where fresh water from rivers moving downstream from the mountains mixes with salty water moving upstream from the ocean. Estuaries thus contain both fresh and salty water habitats (places) where many kinds of plants and animals can live and grow. San Francisco Estuary is the largest estuary on the West Coast of the United States and is home to millions of people, plants and animals. Our scientists have been studying all aspects of the San Francisco Estuary for nearly 50 years and we have 35 stories to tell about the people, plants, and animals in the estuary. We will tell you horror stories of how tiny poisonous plants and vampire fish kill other fish, and we have success stories of how conservation saves the lives of tiny mice in marshes and birds along the Pacific Flyway. The Collection of stories is divided into six sections, so you can easily find the stories that interest you the most. The first section describes the many kinds of habitats in the estuary, including rivers, shallow bays, wetlands, and marshes, and what makes them a good home for plants, animals, and people. In the second section, the water quality scientists will describe how they use boats, special instruments, and new technology to determine whether the water is healthy for people, plants, and animals. In the third and fourth sections we will tell stories about how plants and animals live in the estuary. Microbiologists will describe the tiny, microscopic plants and animals that live in the estuary, what makes them grow, how important they are as food for animals and why they are sometimes poisonous. Fish scientists will describe the many kinds of fish in the estuary and how we measure their growth, determine where they are, what they eat, and the ways they use both fresh and saltwater habitats to grow and raise their young. In the fifth section, scientists will discuss how invasions of plants and animals from outside of the estuary have changed habitats and the survival of native plants and animals. Lastly, in the sixth section, we will share how scientists in the estuary are using new technologies and management actions to control invasions of unwanted plants and animals, increase the growth of native plants and animals, improve water quality and restore habitats in the estuary.

Estuaries are highly dynamic systems subject to changes occurring over a spectrum of time scales ranging from very short periods (e. g. over a tidal cycle) to geologic time scales. The nature of an estuary reflects complex responses to many driving forces, each having a characteristic frequency (or frequencies) of change. For example, freshwater inflow to estuaries varies daily in response to short-term events such as storms, seasonally, and between years as a result of longer-term climatic variability. Other important components of weather, e. g. wind speed/ direction and daily insolation, also vary over time scales ranging from hours to years. Tidal amplitude changes continuously with dominant frequencies associated with the semi-diurnal cycle, the fortnightly neap-spring, and the semi-annual cycle. Temporal dynamics of these driving forces evoke responses in the form of changing (I) circulation patterns and mixing, (2) sediment composition and transport, (3) solute speciation and distribution, (4) composition and abundance of particulates, (5) biomass, species composition, and productivity of plant and animal communities, (6) rates of material exchange between the sediments, water column, and atmosphere, and (7) bioavailability of trace metals and other pollutants. The purpose of this book is to examine the temporal dynamics of these properties and processes in the San Francisco Bay estuary.

San Francisco Bay is a shallow estuary surrounded by a large population center. The forces that built it began with plate tectonics and involved the collision of the Pacific and North American plates and the subduction of the Juan de Fuka plate. Changes in the climate resulting from the last ice age yielded lower and then higher sea levels. Human activity influenced the Bay. Gold mining during the California gold rush sent masses of slit into the Bay. Humans have also built several major cities and filled significant parts of the Bay. This book describes the natural history and evolution of the SF Bay Area over the last 50 million years through the present and into the future. Key selling features: Summarizes a complex geological, geographical and ecological history Reviews how the San Francisco Bay has changed and will likely change in the future Examines the different roles and various drivers of Bay ecosystem function Includes the role of humans - both first peoples and modern populations - on the Bay Explores San Francisco Bay as an example of general bay ecolgical and environmental issues