Threats and Stressors completed

Adaptive Management of Coastal Sand Dunes in Mission Bay to Benefit Native Plants and the CA Least Tern

San Diego Audubon has been leading efforts to restore coastal sand dunes in Mission Bay for decades, largely focused on supporting nesting California Least Terns (Sternula antillarum browni), and rare and endangered sand dune plants such as Nuttall's Lotus (Acmispon prostratus) and Coast Wooly Head (Nemacaulis denudata). The primary threat to these species is the presence of fast-growing, nonnative vegetation, which takes up space that Least Terns require for nesting, and outcompetes native dune plants. Volunteer-led hand management of these sites has resulted in a dramatic reduction in invasive cover, and bi-annual vegetation monitoring has revealed that hand management is a more effective strategy in reducing nonnative growth than the more traditional mechanized scraping and broadcast herbicide application strategies. These results are being used to inform year-to-year site management, and to create longterm strategies for managing coastal dunes in Mission Bay.
Project Focus

California least tern, cottonheads, Nuttall's acmispon

dunes and coastal bluffs

Megan Flaherty

San Diego Audubon Society

City of San Diego; Institute for Ecological Modeling and Management at San Diego State University; Mission Bay Park Rangers; San Diego Management and Monitoring Program

Megan Flaherty

Sarah McCutcheon

Kris Preston

Megan Flaherty

California least tern Sternula antillarum browni

Goal: Protect, enhance, and restore California least tern occupied and historically occupied habitat to create resilient, self-sustaining populations that provide for persistence over the long-term (>100 years).

local NFO 2017, 2018, 2019, 2020, 2021 SO
MGT-IMP-IMG STEANT-5

Management units: 1, 7

From 2017-2021, perform routine management activities such as invasives removal, sand replenishment, nest prep, and protecting occurrences from disturbance through fencing, signage, and enforcement.

Action Statement Action status Projects
IMP-1 Perform management activities protecting occurrences from disturbance through fencing, signage, and enforcement. Available for implementation Adaptive Management of Coastal Sand Dunes in Mission Bay to Benefit Native Plants and the CA Least Tern
IMP-2 Submit project metadata and management data to MSP web portal. Available for implementation Adaptive Management of Coastal Sand Dunes in Mission Bay to Benefit Native Plants and the CA Least Tern
Criteria Deadline year
Management Completed as Needed Based Upon Monitoring Recommendations 2021

Nuttall's acmispon Acmispon prostratus

Goal: Maintain or enhance existing Nuttall's acmispon occurrences to ensure multiple conserved occurrences with self sustaining populations to increase resilience to environmental and demographic stochasticity, maintain genetic diversity, and ensure persistence over the long term (>100 years) in coastal bluff and coastal dune habitats.

local NFO 2017, 2018, 2019, 2020, 2021 SO
MGT-IMP-IMG ACMPRO-2

Management units: 1, 7

Beginning in 2017, conduct routine management actions identified through the IMG monitoring at Nuttall's acmispon occurrences on Conserved Lands (see occurrence table). Depending on the type and level of threat, management should be conducted as needed, not necessarily every year, and using BMPs with precautions to do no harm.

Action Statement Action status Projects
IMP-1 Perform routine management activities such as protecting occurrences from disturbance through fencing and enforcement and controlling invasive non-native plant species =20% absolute cover. some occurrences are in progress
IMP-2 Submit project metadata and management data to the MSP Web Portal. some occurrences are in progress Adaptive Management of Coastal Sand Dunes in Mission Bay to Benefit Native Plants and the CA Least Tern
Criteria Deadline year
Routine Management Completed as Needed Based Upon Monitoring Recommendations 2021
Threat Name Threat Code
Human uses of the PreservesHUMUSE
Invasive plantsINVPLA
Urban developmentURBDEV
Code Obj. code Statement
ACMPRO-1 MON-IMP-IMG From 2017-2012, inspect extant Nuttall's acmispon occurrences annually on Conserved Lands (see occurrence table) using the regional rare plant IMG monitoring protocol to record abundance and collect habitat and threats covariate data to determine management needs.
File name Lead Author Year Type
Final Report Mission Bay Park Redfern, Chris 2015 report
Maps of treatment and monitoring sites for California least tern on Mission Bay San Diego Audubon 2012 other
Mission Bay IBA Conservation Planning Quarterly Report San Diego Audubon Society 2012 report
Mission Bay IBA Conservation Planning Workshop Summary San Diego Audubon Society 2012 workshop summary
Mission Bay Park Conservation Program: Habitat Assessment, Invasive Control, and Community-Based Habitat Restoration Redfern, Chris 2013 powerpoint presentation
Nuttall's Lotus: Final Report Redfern, Chris; Flaherty, Megan 2018 report
San Diego Audubon Society Research Study: Project proposal and methods San Diego Audubon Society 2012 report