Products

We identify issues and uncertainties that pose obstacles to conservation and then—in collaboration with internal and external colleagues—develop science products that help overcome those obstacles.

2022 | Freshwater | Planning | Science | Publications & Reports

A Machine Learning Approach to Predict Groundwater Levels in California Reveals Ecosystems at Risk

Melissa M. Rohde, Tanushree Biswas, Ian W. Housman, Leah S. Campbell, Kirk R. Klausmeyer, Jeanette Howard

Groundwater dependent ecosystems (GDEs) are increasingly threatened worldwide, but the shallow groundwater resources that they are reliant upon are seldom monitored. In this study, the researchers used satellite-based remote sensing, climate data, and machine learning to predict groundwater levels over a 35 year period (1985…


2022 | Freshwater | Planning | Science | Maps & Webmaps

SAGE: Shallow Groundwater Estimation Tool

Melissa M. Rohde, Tanushree Biswas, Ian W. Housman, Leah S. Campbell, Kirk R. Klausmeyer, Jeanette Howard

Groundwater dependent ecosystems (GDEs) are critical habitats throughout California that rely on shallow groundwater. Unfortunately, only a small subset of wells provide monitoring data for shallow groundwater. This tool, developed for a publication in Frontiers in Earth Science, uses satellite data and machine learning tools to…


2022 | Freshwater | Planning | Science | Publications & Reports

Groundwater dependence of riparian woodlands and the disrupting effect of anthropogenically altered streamflow

Melissa M. Rohde, John C. Stella, Dar A. Roberts, Michael Bliss Singer

This study combines satellite, groundwater, and streamflow data over a 5 year period (2015-2020) to understand the impacts of groundwater depth and streamflow alteration on groundwater-dependent vegetation across California. The study shows that deeper groundwater levels resulted in poor vegetation health, but that current water management…


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

Quantity and fate of synthetic microfiber emissions from apparel washing in California and strategies for their reduction

Roland Geyer, Jenna Gavigan, Alexis M. Jackson, Vienna R. Saccomanno, Sangwon Suh, Mary G. Gleason

Synthetic microfibers are the most prevalent type of microplastic and apparel washing is a major source of microfiber pollution. Using California as a case study to estimate the magnitude of microfiber emissions and evaluate mitigation approaches, the authors estimate that in 2019 over 4,850,000 pounds (2.2…


2022 | Marine | Technology | Science | Publications & Reports

Reducing the Risk of Mortality to Whales

Jessica Morten, Ryan Freedman, Jeffrey D. Adams, Jono Wilson, Aliya Rubinstein, Sean Hastings

The great whales, including, blue, humpback, and fin whales are threatened by collisions with ocean going vessels. Global shipping traffic is projected to increase up to 12-fold in coming decades. Slowing vessels down reduces the risk of whale collisions and mortality. Here, the authors examined…


2022 | Marine | Technology | Science | Publications & Reports

Lost Fishing Gear is a Key Contributor to Ocean Plastic Pollution

Brandon Kuczenski, Camila Vargas Poulsen, Eric L. Gilman, Michael Musyl, Roland Geyer, Jono Wilson

More than 4.5 million fishing vessels ply ocean waters each year, setting countless nets, traps, hooks and lines. Much of this fishing gear is made of plastic components and a significant fraction of it is lost in the ocean each year, causing irreparable harm to…


2022 | Marine | Technology | Science | Publications & Reports

Use of Simple Indicators to Improve Fisheries Management

William J. Harford, Ricardo Amoroso, Richard J. Bell, Matias Caillaux, Jason Marc Cope, Dawn Dougherty, Natalie Anne Dowling, Frank Hurd, Serena Lomonico, Josh Nowlis, Dan Ovando, Ana M. Parma, Jeremy D. Prince, Jono R. Wilson

Overfishing threatens the health of ocean ecosystems. Effective fisheries management is key to minimizing ocean impacts and improving outcomes for millions of fishing dependent people throughout the world. Most fisheries, however, lack sufficient data for managers to perform quantitative stock assessments and inform management regulations.…


2022 | Freshwater | Science | Publications & Reports

Hydraulic Properties of the Riffle Crest and Applications for Stream Ecosystem Management

Gabriel Rossi, Darren Mierau, Jennifer Carah

A simple stream depth measurement at the deepest part of a riffle crest in a river or stream provides an easy-to-measure and inexpensive metric for ecological researech, environmental flow management, and habitat assessment. This paper describes measurement methods, as well as ways to use riffle measurements…


2022 | Freshwater | Technology | Science | Publications & Reports

Modeling Functional Flows in California’s Rivers

Theodore E. Grantham, Daren M. Carlisle, Jeanette Howard, Belize Lane, Robert Lusardi, Alyssa Obester, Samuel Sandoval-Solis, Bronwen Stanford, Eric D. Stein, Kristine T. Taniguchi-Quan, Sarah M. Yarnell, Julie K. H. Zimmerman

Protecting water in rivers is made more challenging by the lack of quantitative estimates of the amount of water required to protect river ecosystems. The authors developed a model and made quantitative predictions of the amount of flow needed for five key functional flow components,…


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

Transforming Palmyra Atoll to native-tree dominance will increase net carbon storage and reduce dissolved organic carbon reef runoff

Kate Longley-Wood, Mary Engels , Kevin D. Lafferty, John P. McLaughlin, Alex Wegmann

Native forests on tropical islands have been displaced by non-native species, leading to calls for their transformation. Simultaneously, there is increasing recognition that tropical forests can help sequester carbon that would otherwise enter the atmosphere. At Palmyra Atoll, efforts are underway to transform the rainforest…


2022 | Freshwater | Science | Publications & Reports

Functional Flows in Groundwater-Influenced Streams: Application of the California Environmental Flows Framework to Determine Ecological Flow Needs

Sarah M. Yarnell, Ann Willis, Alyssa Obester, Ryan A. Peek, Robert A. Lusardi, Julie Zimmerman, Theodore E. Grantham, Eric D. Stein

Very few rivers have protections to protect flow for species and ecosystems, in part because of the complexity and resources required to develop ecological flow criteria - the amount of water needed in rivers to protect ecosystems. The authors applied the California Environmental Flows Framework,…


2022 | Terrestrial | Science | Publications & Reports

Oren Pollak Memorial Research Fund - 2022 RFP

Brynn Pewtherer

The Oren Pollak Memorial Research Fund was established in 2000 in memory of Dr. Oren Pollak, a leading grassland ecologist and restoration pioneer, as well as an ardent champion and mentor for grassland ecology students. As The Nature Conservancy’s lead ecologist in California in the…


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

Conservation Science Catalyst Fund - 2021 Annual Report

Brynn Pewtherer, Scott Morrison

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…


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

Sacramento River: balancing ecological and social restoration goals to restore riparian habitat along a lowland floodplain river, California, USA

Case study by: K.D. Holl, G.H. Golet

Advancing conservation requires understanding the constraints imposed on natural systems by human societies. This understanding typically comes from engagement with local stakeholders, as opposed to from scholastic training. A recent textbook on restoration ecology by Karen Holl seeks to alleviate this problem by providing real-world…


2021 | Freshwater | Terrestrial | Science | Publications & Reports

Integrating citizen science data with expert surveys increases accuracy and spatial extent of species distribution models.

O.J. Robinson, V. Ruiz-Gutierrez, M.D. Reynolds, G.H. Golet, M. Strimas-Mackey and D. Fink

Information on species’ habitat associations and distributions, across wide spatial and temporal scales, is fundamental for guiding conservation. Yet these data are often in short supply. In recent years citizen science data, such as that derived from eBird, has increasingly become available to fill…


2021 | Terrestrial | Planning | Science | Publications & Reports

Enhancing Habitat Value for Shorebirds in Rice Agriculture

Case study by: Khara Strum (Audubon California), Kristin Sesser (Point Blue Conservation Science), Greg Golet (TNC)

This case study communicates lessons learned by TNC and partners from years of research and monitoring of habitat enhancement projects in Sacramento Valley rice agriculture. It is a contribution to the Shorebird Management Manual that was developed by Manomet with guidance from shorebird…


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 | Terrestrial | Science | Publications & Reports

Assessing the reliability of raptor pellets in recording local small mammal diversity

Maria C Viteri, Mary Allison Stegner, Elizabeth A. Hadly

Biodiversity monitoring is a core part of conservation practice, however all sampling methods include biases. In particular, small mammal live-trapping, the field standard, produces highly skewed results and is both invasive and labor-intensive. The identification of small mammal bones from pellets produced by raptors, or…


2021 | Freshwater | Science | Publications & Reports

The California Environmental Flows Framework: Meeting the Challenges of Developing a Large-Scale Environmental Flows Program

Eric D. Stein, Julie Zimmerman, Sarah M. Yarnell, Bronwen Stanford, Belize Lane, Kristine T. Taniguchi-Quan, Alyssa Obester, Theodore E. Grantham, Robert A. Lusardi, Samuel Sandoval-Solis

The first step to protecting rivers is figuring out how much water they need to protect species and ecological functions - known as ecological flow criteria. Scientists have struggled to develop flow criteria to protect species and ecosystems across large regions, which means the vast…


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

Planting Stormwater Solutions: A methodology for siting nature-based solutions for pollution capture, habitat enhancement, and multiple health benefits

Kelsey Jessup, Sophie S. Parker, John M. Randall, Brian S. Cohen, Rowan Roderick-Jones, Shona Ganguly, Jill Sourial

This paper presents results from Planting Stormwater Solutions, part of TNC’s Urban Conservation work in Los Angeles. The authors develop a methodology to prioritize siting of vegetated nature-based solutions for stormwater capture so that these projects maximize benefits to biological diversity, social and public…