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. 

Science in Action

Terrestrial | Marine | Planning

TNC and the U.S. Navy

How can we protect natural resource and coastal military assets from sea level rise?

Marine | Technology | Science

Closing the Abalone Data Gap

Can putting technology in the hands of citizen scientists transform how abalone are managed?

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…


2022 | Freshwater | Terrestrial | Marine | Planning | Technology | Science | Maps & Webmaps

The Mitigation Wizard

Carrie Schloss, Liz O’Donoghue, Dan Rademacher, Patric Huber, Jodi McGraw, Kim Becerril, Janine Knapp

Every year, infrastructure agencies and developers spend hundreds of millions of dollars to mitigate for impacts to sensitive species and habitats. These mitigation sites are often piecemeal projects, which can result in islands of mitigation. Regional advance mitigation programs seek to change this paradigm so…


2022 | Marine | Planning | Science | Publications & Reports

Kelp Restoration Guidebook: Lessons Learned from Kelp Restoration Projects Around the World

Aaron M. Eger (University of New South Wales), Cayne Layton (University of Tasmania), Tristin A. McHugh (TNC), Mary Gleason, and Norah Eddy (TNC)

Kelp forests around the world are experiencing significant declines due to a variety of factors, driving the need for more active kelp restoration efforts. The science and practice of kelp forest restoration is still in its infancy and there remains a wealth of knowledge to…


2021 | Terrestrial | Marine | Planning | Technology | Science | Publications & Reports

Jack and Laura Dangermond Preserve Invasive Plant Species Action Plan

Moses Katkowski, H. Scott Butterfield, John Knapp, Kelly Easterday, Laura Riege, Mark Reynolds

This 5-year action plan describes the vision for invasive plant species mapping, monitoring and treatment at the Jack and Laura Dangermond Preserve in Sourthern California. The plan is adaptive and will updated as new species, management approaches (including new and emerging technologies), and monitoring results…


2021 | Marine | Science | Publications & Reports

Disease-driven mass mortality event leads to widespread extirpation and variable recovery potential of a marine predator across the eastern Pacific

S. L. Hamilton, V. R. Saccomanno, W. N. Heady, A. L. Gehman, S. I. Lonhart, R. Beas-Luna, F. T. Francis, L. Lee, L. Rogers-Bennett, A. K. Salomon and S. A. Gravem

The sunflower sea star (Pycnopodia helianthoides) is an important mesopredator in kelp forest ecosystems that was devastated by the outbreak of sea star wasting disease (SSWD). This study quantifies how SSWD impacted this iconic animal across its range and documents that the outbreak occurred more…


2021 | Freshwater | Terrestrial | Marine | Planning | Publications & Reports

Coastal Adaptation Vision for Naval Base Ventura County Point Mugu: Technical Report

Environmental Science Associates (ESA) for The Nature Conservancy and Naval Base Ventura County


2021 | Freshwater | Terrestrial | Marine | Planning | Science | Video

StoryMap: Restoring coastal wetlands for climate resilience: A case study at Naval Base Ventura County Point Mugu

Charlotte Stanley, Alyssa Mann, Walter Heady

The United States operates thousands of military installations in the U.S. and worldwide, worth about $1.2 trillion. These facilities are where personnel train and test weaponry, with the specific aim of ensuring the nation’s security. With climate change, coastal installations are now being impacted by rising sea levels, erosion and…


2021 | Freshwater | Terrestrial | Marine | Planning | Science | Publications & Reports

Restoring coastal wetlands for climate resilience: A case study at Naval Base Ventura County, Pt. Mugu

Walter Heady, Alyssa Mann, Stacey Solie, Bob Battalio, James Jackson, Kendall Lousen, and Bob Barnes

The U.S. Congress and the Department of Defense (DoD) have determined that climate change is a threat to national security and have required military installations to develop plans to improve the climate resilience of both military installations and key supporting civilian infrastructure. This report, co-authored…


2021 | Freshwater | Terrestrial | Marine | Planning | Science | Publications & Reports

Coastal Adaptation with the U.S. Navy at Point Mugu

Alyssa Mann, Walter Heady, Charlotte Stanley

TNC and the United States Navy partnered together to prepare for the impacts of climate change on Naval Base Ventura County (NBVC), Point Mugu in California. NBVC is a critical and strategic asset of the U.S. Navy. It is also home to Mugu Lagoon, the…


2021 | Marine | Planning | Science | Publications & Reports

A Structured Approach for Kelp Restoration and Management Decisions

Mary G. Gleason, Jennifer E. Caselle, Walter N. Heady, Vienna R. Saccomanno, Julie Zimmerman, Tristin Anoush McHugh, Norah Eddy

Global kelp forests are biodiverse and productive nearshore ecosystems that provide a wide range of ecosystem services, but they are at risk from both local stressors and global drivers of kelp loss. A structured decision making (SDM) framework can help guide kelp management and restoration…


2021 | Marine | Science | Publications & Reports

Ecological Impact of Abandoned, Lost, and Discarded Fishing Gear

Eric Gilman, Michael Musyl, Petri Suuronen, Milani Chaloupka, Saeid Gorgin, Jono Wilson, Brandon Kuczenski

More than 4.5 million fishing vessels deploy fishing gear in the ocean every year. A significant amount of these nets, traps, lines, and floats are abandoned, lost, or discarded, threatening the health of ocean ecosystems through ghost fishing, transfer of microplastics, toxins and  invasive species,…


2021 | Marine | Planning | Publications & Reports

Beyond the boundaries: How regulation-centered marine protected area information improves ocean protection assessments

Jennifer Sletten, Mimi D’Iorio, Mary G. Gleason, Alex Driedger, Timoth´e Vincent, Claire Colegrove, Dawn Wright, Virgil Zetterlind

Understanding the complex seascape of regulations that apply across U.S. ocean waters is critical for effective marine resource management. This study found that cumulative restrictions from overlapping fisheries regulations often provide stronger levels of protection than traditional marine protected areas (MPAs). About 85% of U.S. waters are…


2020 | Marine | Science | Publications & Reports

Effective fisheries management instrumental in improving fish stock status

Ray Hilborn, Ricardo Oscar Amoroso, Christopher M. Anderson, Julia K. Baum, Trevor A. Branch, Christopher Costello, Carryn L. de Moor, Abdelmalek Faraj, Daniel Hively, Olaf P. Jensen, Hiroyuki Kurota, L. Richard Little, Pamela Mace, Tim McClanahan, Michael C. Melnychuk, Cóilín Minto, Giacomo Chato Osio, Ana M. Parma, Maite Pons, Susana Segurado, Cody S. Szuwalski, Jono Wilson, Yimin Ye

Does fisheries management work at improving the status of fish stocks? The answer is a resounding, yes. This article compiles estimates of the status of global fish stocks, comprising roughly half of the world’s fish catch. Findings suggest that on average, fish stocks are increasing…


2020 | Freshwater | Terrestrial | Marine | Planning | Technology | Science | Publications & Reports

Jack and Laura Dangermond Preserve Integrated Resources Management Plan

Butterfield, H.S., M. Reynolds , M.G. Gleason, M. Merrifield, B.S. Cohen, W.N. Heady, D. Cameron, T. Rick, E. Inlander, M. Katkowski, L. Riege, J. Knapp, S. Gennet, G. Gorga, K. Lin, K. Easterday, B. Leahy, M. Bell

This Plan frames the biological and cultural significance and provides the short- and long-term goals, objectives, and priority actions for the Jack and Laura Dangermond Preserve.


2020 | Marine | Science | Publications & Reports

Unusual occurrences of fishes in the Southern California Current System during the warm water period of 2014–2018

H.J. Walker Jr., Philip A. Hastings, John R. Hyde, Robert N. Lea, Owyn E. Snodgrass, Lyall F. Bellquist

In response to anomalously warm sea-surface temperatures, poleward shifts in the geographic range of hundreds of marine organisms worldwide have been documented. This paper reports on the unusual occurrences of 36 fish species recorded from the Southern California Current System (SCCS) during the period of…