The California Current is one of only four temperate upwelling systems in the world. Seasonal upwelling of nutrient-rich waters fuels a highly productive ecosystem, supporting biodiversity and fisheries that, along with coastal tourism, are a foundation of California’s economy.  

Yet California’s coasts and oceans are also under increasing threat. Relatively few fisheries are managed based on robust scientific assessments, and more needs to be done to avoid overfishing and reduce bycatch. Plastics and other pollutants are pervasive. Climate change compounds these challenges. Ocean chemistry is changing. Sea levels and temperatures are rising – threatening important resources, biodiversity, and human populations.

Fortunately, the coastal and ocean ecosystems of California are bolstered by a network of marine protected areas and some of the most science-based marine policies in the world. Conservancy scientists look to build on those foundations by applying science and technology to enhance resilience of marine resources in the face of emerging threats.

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 | Marine | Economics | Science

TNC and FEMA

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

Terrestrial | Marine | Planning

TNC and the U.S. Navy

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

2024 | Marine | Economics | Science | Publications & Reports

Advancing fisheries sustainability and access through community fisheries trusts

Kate Kauer, Lyall Bellquist, Jenn Humberstone, Vienna Saccomanno, Dwayne Oberhoff, Sherry Flumerfelt, Mary Gleason

This 2024 paper by TNC staff and partners represents the first U.S.-wide synthesis of fisheries trusts – which are community-based entities that acquire and manage fishery privileges with the goal of sustaining community access to locally important fisheries. These entities have emerged following the implementation…


2023 | Marine | Economics | Science | Publications & Reports

Static management presents a simple solution to a dynamic fishery and conservation challenge

Christopher M. Free, Lyall F. Bellquist, Karin A. Forney, Jenn Humberstone, Kate Kauer, Qui Lee, Owen R. Liu, Jameal F. Samhouri, Jono R. Wilson, Darcy Bradley

Dynamic ocean management frameworks can be a useful approach to fisheries management under climate change. In the oceans, marine heatwaves are increasingly common symptoms of climate change that can impact ecosystems, economies, and communities. The recent 2014-2016 marine heatwave in the NE Pacific resulted in…


2023 | Marine | Science | Publications & Reports

Characterizing state-managed and unmanaged fisheries in coastal marine states and territories of the United States

Michael C. Melnychuk, Charmane E. Ashbrook, Richard J. Bell, Lyall Bellquist, Kate Kauer, Jono R. Wilson, Ray Hilborn, Jay Odell

America’s fisheries provide nearly two million jobs and contribute $117 billion to the national GDP. Although state and territory fisheries account for 40% of the commercial value of U.S. marine fisheries overall, there has not been a nationwide synthesis of the performance of state/territory fisheries…


2023 | Marine | Technology | Science | Publications & Reports

The CALFISH database: A century of California's non-confidential fisheries landings and participation data

Christopher M. Free, Camila Vargas Poulsen, Lyall F. Bellquist, Sophia N. Wassermann, Kiva L. Oken

Commercial and recreational fisheries in California influence a long and dynamic history of coastal economies, cultural heritage, and marine ecosystem health. Fisheries-dependent data sources are critical for monitoring these trends over time, but even public data sources are often difficult to access. This slows down…


2023 | Marine | Science | Publications & Reports

Use of management strategy evaluation to understand the value of citizen science in managing an iconic California recreational fishery

Lyall Bellquist, William J. Harford, Frank Hurd, Alexis Jackson, Jeremy D. Prince, Jan Freiwald, Anna Neumann, Jack Likins, Jono Wilson

Conventional fisheries management relies largely on professional sources of scientific data collection, typically from academic or government institutions. Development of community-led data sources (i.e., citizen/community science) has been slow, partially due to data quality concerns. Accelerating stressors to marine ecosystems and the dynamic nature of…


2023 | Marine | Science | Publications & Reports

Post-release survival and prolonged sublethal effects of capture and barotrauma on deep-dwelling rockfishes (genus Sebastes): implications for fish management and conservation

Nicholas C. Wegner, Elan J. Portner, Drew T. Nguyen, Lyall Bellquist, Andrew P. Nosal, Alena L. Pribyl, Kevin L. Stierhoff, Paul Fischer, Ken Franke, Russell D. Vetter, Philip A. Hastings, Brice X. Semmens, and John R. Hyde

Historical overfishing led to depletion of several groundfish species on the US west coast. Two of these species, Cowcod and Bocaccio, heavily influenced the expansion of groundfish regulations to rebuild multiple stocks. However, the effects of fishing-induced barotrauma, and the effectiveness of descending devices as…


2023 | Marine | Economics | Science | Publications & Reports

Impact of the 2014–2016 marine heatwave on US and Canada West Coast fisheries: Surprises and lessons from key case studies

Christopher M. Free, Sean C. Anderson, Elizabeth A. Hellmers, Barbara A. Muhling, Michael O. Navarro, Kate Richerson, Lauren A. Rogers, William H. Satterthwaite, Andrew R. Thompson, Jenn M. Burt, Steven D. Gaines, Kristin N. Marshall, J. Wilson White, Lyall F. Bellquist

As symptoms of climate change, extreme environmental events (e.g., marine heatwaves) now represent the greatest global threat to the oceans, causing profound ecosystem and socioeconomic impacts. The recent marine heatwave on the North America west coast was the largest ever recorded, but the extent of…


2023 | Marine | Planning | Science | Publications & Reports

U.S. exempted fishing permits: Role, value, and lessons learned for adaptive fisheries management

Lindsay Bonito, Lyall Bellquist, Alexis M. Jackson, Kate Kauer, Mary G. Gleason, Jono Wilson, Stuart Sandin

Experimentation supports adaptive and climate-ready fisheries management in numerous contexts. Exempted Fishing Permits (EFPs) enable fisheries participants, scientists, and managers to collaboratively test new fishing regulations and/or gear types that might advance fishery sustainability, although no evaluation of federal EFP performance had ever been conducted.…


2023 | Marine | Economics | Science | Publications & Reports

Characterization of a developing recreational deep-drop fishery for swordfish off southern California

Scott A. Aalbers, Michael Wang, Lyall Bellquist, Kate Kauer, Alexis Jackson, Chugey A. Sepulveda

An emerging recreational fishery for swordfish has recently developed in California, outpacing existing fisheries monitoring programs, which prevents accurate estimation of swordfish catch and effort as well as any potential bycatch. The study documents a sharp increase in swordfish catch relative to previous decades, and…


2023 | Freshwater | Terrestrial | Marine | Planning | Economics | Publications & Reports

Valuing the Flood Reduction Benefits of Marsh Restoration

Taylor-Burns, R., Heard, S., Beck, M. W.

There is growing evidence for the beneficial role that wetlands can play in reducing flood risk, but in many urban estuaries, coastal development has resulted in dramatic habitat loss and fragmentation. In the past several decades, marsh restoration has emerged as a core management objective…


2023 | Freshwater | Terrestrial | Marine | Science | Publications & Reports

Conservation Science Catalyst Fund - 2022 Annual Report

Scott Morrison, Brynn Pewtherer

The Nature Conservancy deploys science to help overcome major challenges facing people and nature. In today’s fast-paced world, turning threats to nature into opportunities for conservation requires agility. The Conservation Science Catalyst Fund enables our science team to mobilize quickly — and produce the information…


2023 | Terrestrial | Marine | Technology | Science | Publications & Reports

Minimizing conservation impacts of net zero energy systems in the western United States

Grace C. Wu, Ryan A. Jones, Emily Leslie, James H. Williams, Andrew Pascale, Erica Brand, Sophie Parker, Brian Cohen, Joseph Fargione, Julia Souder, Maya Batres, Mary G. Gleason, Michael H. Schindel, Charlotte K. Stanley

This paper presents the results of the Power of Place-West project. The authors combined energy modeling with ecosystem and wildlife habitat data to determine the costs and impacts associated with deploying clean energy infrastructure across 11 states in the American West. The results of…


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 | 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 | 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…