Almost half of the world’s human population lives in coastal areas, and associated coastal development has significantly degraded or destroyed many coastal ecosystems. Burgeoning human populations and rising sea levels only further constrain the availability of habitat that coastal species depend on.

California’s 1,100 mile coast has more than 200 threatened, endangered or rare species living in coastal habitats. There are hundreds of coastal estuaries that provide critical rearing habitat for marine species, and are also important for recreation, water filtration, and carbon sequestration.

Only 10 percent of California’s historic coastal wetlands remain. Without intervention, we are at risk of losing 40 percent of our remaining coastal wetlands to sea level rise over the coming decades. Conservancy scientists are working to reverse these trends. 

Freshwater Systems

California is one of the most hydrologically altered landscapes in the world. As water becomes ever more scarce and… >>

Groundwater

In a normal year, groundwater accounts for 40 percent of California’s water supply. That number jumps to 60… >>

Surface Flows

Californians have fundamentally altered many of the state’s rivers and streams with dams, pipes, and diversions, and the… >>

Terrestrial Systems

In California, a day’s drive can take a visitor from record-setting desert heat to glaciated peaks to temperate… >>

Wildlands

Nearly half of California is protected in some land status that prevents most kinds of intensive human land… >>

Harvested Landscapes

A third of California is privately-owned forestland, woodland or grassland. From redwood forests on the north coast to… >>

Cultivated Landscapes

California is the leading agricultural state in the country and it’s agriculture generates more than $45 billion annually.… >>

Urban Areas and Infrastructure

With California’s population on track to reach 50 million people, the demand for energy, water, and land will… >>

Fisheries

Wild capture fisheries supply food and jobs for hundreds of millions of people across the globe. Yet an… >>

Coastal Conservation

Almost half of the world’s human population lives in coastal areas, and associated coastal development has significantly degraded… >>

Science in Action

Terrestrial | Planning | Technology | Economics

Wildfire and Communities

How can land protection and restoration help protect communities from wildfire?

Terrestrial | Marine | Economics | Science

TNC and FEMA

How do we increase climate resilience in ways that work for people and nature?

2022 | Marine | Technology | Science | Publications & Reports

Using unoccupied aerial vehicles to map and monitor changes in emergent kelp canopy after an ecological regime shift

Vienna R. Saccomanno, Tom Bell, Camille Pawlak, Charlotte K. Stanley, Katherine C. Cavanaugh, Rietta Hohman, Kirk R. Klausmeyer, Kyle Cavanaugh, Abby Nickels, Waz Hewerdine, Corey Garza, Gary Fleener, Mary Gleason

Kelp forests are complex underwater habitats that provide valuable services for both people and nature. Despite their importance, increasingly severe stressors have resulted in declines in kelp forests in many regions including the North Coast of California. Given the significant and sustained loss of kelp…


2022 | Marine | Planning | Economics | Science | Publications & Reports

The Business of Restoration: Examining the oyster reef restoration industry in the U.S. with recommendations for how conservation organizations can increase efficiencies and decrease costs to scale restoration efforts

Elliot Hall, Bryan DeAngelis

Oyster reefs are one of the most imperiled habitats on earth. However, current rates of restoration are too slow. We must radically increase the pace, scale, and impact of restoration to recover the abundance, resilience and benefits of these invaluable coastal ecosystems. Fortunately, incredible transformations…


2022 | Terrestrial | Planning | Science | Publications & Reports

Blueprint for Resilience: Tahoe-Central Sierra Initiative

Patricia N. Manley, Nicholas A. Povak, Kristen Wilson, Kristen Wilson, Mary Lou Fairweather, Vivian Griffey

The Blueprint is a set of strategy maps that identify opportunities for forest protection and adaptation across a 2.4-million-acre region of the central Sierra Nevada. It uses a novel application of the Ecosystem Management Decision Support (EMDS) tool to evaluate spatial data layers against target…


2022 | Freshwater | Science | Publications & Reports

Water balance for gaged watersheds in the Central Sierra Nevada, California and Nevada, United States

James W. Roche, Kristen N. Wilson, Qin Ma, Roger C. Bales

This study evaluated the water balance components of precipitation, evapotranspiration, discharge, and change in storage compared to measured streamflow and unregulated streamflow estimates in the central Sierra Nevada. The fifty-two watersheds varied in size and in elevation. This study found that the evapotranspiration estimates plus gridded…


2022 | Terrestrial | Technology | Science | Publications & Reports

Soil microbial community composition and tolerance to contaminants in an urban brownfield site

Maura Palacios Mejia, Connie Rojas, Emily Curd, Mark Renshaw, Kiumars Edalati, Beverly Shih, Nitin Vincent, Meixi Lin, Peggy Nguyen, Robert Wayne, Kelsey Jessup, Sophie Parker

This paper presents results from a study conducted at TNC’s multi-benefit stormwater management and habitat enhancement project site adjacent to the Los Angeles River. Due to a history of industrial use, soils at the project site are contaminated with heavy metals, petroleum hydrocarbons, and…


2022 | Terrestrial | Technology | Science | Publications & Reports

Predictive ecological land classification from multi-decadal satellite imagery

Daniel Sousa, Frank W. Davis, Kelly Easterday, Mark Reynolds, Laura Riege, H. Scott Butterfield, Moses Katkowski

This paper details a first of its kind approach to land classification, using random forests and multivariate regression trees and historical Landsat satellite imagery to map and then assess changes in oak canopies at the Jack and Laura Dangermond Preserve. Using this “topoclimatic-edaphic” approach to…


2022 | Freshwater | Terrestrial | Technology | Economics | Science | Publications & Reports

Developing an adaptive management approach to cowbird control on the Santa Clara River, California

Sophie S. Parker, Linnea S. Hall, Mary J. Whitfield, Laura Riege, Kathryn R. Selm, René Corado

This paper presents results from a field-based study that can be used to benefit songbirds in riverside habitats like those found along the Santa Clara River in Ventura County, California. Songbirds such as the Least Bell’s Vireo suffer population declines in part because Brown-headed…


2022 | Terrestrial | Science | Publications & Reports

Spatiotemporal impacts of the Anthropocene on small mammal communities, and the role of small biological preserves in maintaining biodiversity

Maria C. Viteri, Elizabeth A. Hadly

This paper investigates the ability of small protected spaces to conserve small mammal diversity in urban areas. The authors identified small mammal bones from both modern owl pellets and archaeological sites along an urbanization gradient in the San Francisco Bay Area, CA and compared their…


2022 | Freshwater | Terrestrial | Marine | Economics | Science | Publications & Reports

Unlocking FEMA’s Hazard Mitigation Funding for Coral Reef Restoration: A Feasibility Study in Maui, Hawaii

UC Santa Cruz (Austen E. Stovall, Michael W. Beck), The Nature Conservancy (Alyssa Mann, Tamaki Bieri), Radbridge/formerly Earth Economics (Johnny Mojica, Rowan Schmidt)

Climate change poses severe threats to coastal communities and the ecosystems on which they depend. Warming ocean temperatures increase the magnitude and frequency of storm and coral bleaching events, allowing less time for recovery amidst these threats. Coral reefs complex and stable structure protects against…


2022 | Freshwater | Science | Publications & Reports

Water Resources Allocation and Agriculture: Allocations and Environmental Flows

Eric D. Stein, Michael E. McClain, Ashmita Sengupta, Theodore E. Grantham, Julie K.H. Zimmerman, Sarah M. Yarnell

In this chapter of Water Resources Allocation and Agriculture, the authors provide insights on how to integrate environmental flows into water allocation for agriculture across the world. They argue that holistic environmental flows approaches that are fully protective of ecosystem needs and integrate surface and…


2022 | Freshwater | Terrestrial | Planning | Science | Publications & Reports

Stress Testing the BCA Toolkit with Nature-based Solutions: Observations and Recommendations for FEMA

The Nature Conservancy, Earth Economics

FEMA requires that hazard mitigation projects must be cost-effective to the federal government, as demonstrated in a Benefit-Cost Analysis (BCA), which compares the present value of a project’s future benefits and costs. A BCA is required for the vast majority of FEMA-funded hazard mitigation projects,…


2022 | Freshwater | Terrestrial | Science | Publications & Reports

Potential Lithium Extraction in the United States: Environmental, Economic, and Policy Implications

Sophie S. Parker, Bradley Franklin, Brian S. Cohen, Melissa M. Rohde, Michael Clifford, Andrew Williams

Climate change will cause severe financial, social, and environmental upheaval if a massive reduction in carbon emissions is not achieved by 2030. To address this challenge, rechargeable lithium-ion batteries will play a key role in transitioning the energy and transportation sectors away from fossil fuel…


2022 | Freshwater | Terrestrial | Marine | Planning | Technology | Science | Publications & Reports

Prioritizing actions: spatial action maps for conservation

Heather Tallis, Joe Fargione, Edward Game, Rob McDonald, Leandro Baumgarten, Nirmal Bhagabati, Rane Cortez, Bronson Griscom, Jonathan Higgins, Christina M. Kennedy, Joe Kiesecker, Timm Kroeger, Trina Leberer, Jennifer McGowan, Lisa Mandle, Yuta J. Masuda, Scott Morrison, Sally Palmer, Rebecca Shirer, Priya Shyamsundar, Nicholas H.Wolff, and Hugh P. Possingham

Spatial analysis is a powerful tool in conservation planning. Yet it is often under-deployed as a means of elucidating which conservation actions may deliver the highest return on investment. This paper presents a framework for “spatial action mapping” and discusses how it can improve conservation…


2022 | Marine | Planning | Science | Publications & Reports

Restoring shellfish reefs: Global guidelines for practitioners and scientists

James A. Fitzsimons, Simon Branigan, Chris L. Gillies, Robert D. Brumbaugh, Jun Cheng, Bryan M. DeAngelis, Laura Geselbracht, Boze Hancock, Andrew Jeffs, Tein McDonald, Ian M.McLeod, Bernadette Pogoda, Seth J. Theuerkauf, Marine Thomas, Stephanie Westby, Philine S.E. zu Ermgassen

Widespread global declines in shellfish reefs have led to growing interest in their restoration and protection. With restoration projects now occurring on four continents and in at least seven countries, this project developed global restoration guidelines for these ecosystems, developed based on experience over the…


2022 | Marine | Planning | Science | Publications & Reports

The benefits of bivalve reef restoration: A global synthesis of underrepresented species

Philine S. E. zu Ermgassen, Ruth H. Thurstan, Jorge Corrales, Heidi Alleway, Alvar Carranza, Norbert Dankers, Bryan DeAngelis, Boze Hancock, Flora Kent, Ian McLeod, Bernadette Pogoda, Qing Liu, William G. Sanderson

Bivalve habitat restoration is growing in geographic extent and scale globally. Stakeholders and funders are increasingly drawn to shellfish restoration for the many ecosystem services these habitats provide. Ecosystem services, however, remain largely unquantified or even undescribed for the majority of species targeted for restoration.…


2022 | Marine | Planning | Science | Publications & Reports

Estimating and Applying Fish and Invertebrate Density and Production Enhancement from Seagrass, Salt Marsh Edge, and Oyster Reef Nursery Habitats in the Gulf of Mexico

Philine S. E. zu Ermgassen, Bryan DeAngelis, , Jonathan R. Gair, Sophus zu Ermgassen, Ronald Baker, Andre Daniels, Timothy C. MacDonald, Kara Meckley, Sean Powers, Marta Ribera, Lawrence P. Rozas & Jonathan H. Grabowski

Seagrasses, oyster reefs, and salt marshes are critical coastal habitats that support high densities of juvenile fish and invertebrates. Yet which species are enhanced through these nursery habitats, and to what degree, remains largely unquantified. Quantitative estimates of production enhancement within specific embayments can be…


2022 | Marine | Planning | Science | Publications & Reports

Social Factors Key to Landscape-Scale Coastal Restoration: Lessons Learned from Three U.S. Case Studies

Bryan M. DeAngelis, Ariana E. Sutton-Grier, Allison Colden, Katie K. Arkema, Christopher J. Baillie, Richard O. Bennett, Jeff Benoit, Seth Blitch, Anthony Chatwin, Alyssa Dausman, Rachel K. Gittman, Holly S. Greening, Jessica R. Henkel, Rachel Houge, Ron Howard, A. Randall Hughes, Jeremy Lowe, StevenB. Scyphers, Edward T. Sherwood, Stephanie Westby, Jonathan H. Grabowski

This study examined three case studies involving large-scale and long-term restoration efforts including the seagrass restoration effort in Tampa Bay, Florida, the oyster restoration effort in the Chesapeake Bay in Maryland and Virginia, and the tidal marsh restoration effort in San Francisco Bay, California.The studyfocused…


2022 | Marine | Planning | Science | Publications & Reports

Restoration Guidelines for Shellfish Reefs

J. Fitzsimons, S. Branigan, R.D. Brumbaugh , T. McDonald, and zu Ermgassen, P.S.E. (eds), Bryan M. DeAngelis, chapter author

The purpose of this guide is to provide guidance in decision-making for establishing shellfish reef restoration projects and examples of different approaches undertaken byexperienced practitioners in a variety of geographic, environmental and social settings. This publication is intended to provide foundational information to serve as…