Tracking long-term changes in California current ocean chemistry and water masses using seabirds and stable isotopes

Using a unique dataset of over 1700 feather samples from 5 species of locally breeding seabirds between 1880 - 2005, we are using compound specific (amino acid) nitrogen isotopes  to understand the long-term variation of the california current and the california undercurrent in supplying nutrients to nearshore marine food webs. 

Collaborators: Steve Beissinger and Ben Becker (UC Berkeley)

     

Marine Predator Diets, Population Dynamics and Conservation in the California Current

We work with pinnipeds and seabirds to understand population connectivity and responses to oceanographic change. Study organisms include harbor seals, northern elephant seals, pigeon guillemots, common murres, marbled murrelets, and Ashy storm petrels. Much of our work uses stable isotopes to infer short and long-term changes in diet and oceanography and state-space models to model unobserved population processes.

Publications:  

     Using Convolutional Neural Networks and Aerial Imagery to Monitor Seals at Point Reyes National Seashore

     Ocean-influenced estuarine habitat buffers high interannual variation in seabird reproductive success

     Species recovery and recolonization of past habitats: lessons for science and conservation from sea otters in estuaries

Collaborators: UC Berkeley (Silas Gifford), National Park Service (Sarah Codde, Sarah Allen, Tori Seher), United States Geological Survey (Josh Adams, Jonathan Felis)

    

Nearshore Ecosystem Monitoring and Restoration

We collaborate with the Multi-Agency Rocky Intertidal Monitoring Network (MARINe) to understand variation in the thin band of rocky intertidal habitat along the California Coastline. Monitoring helps assess impacts of climate change, invasive species, marine heat-waves, and the overall resilience of these ecosystems to anthropogenic impacts.  We also are tracking ecosystem recovery (regrowth of eelgrass-a foundational species) in a central california estuary after decades of aquaculture impacts.

Publications:

     Latitudinal variation in long-term stability of North American rocky intertidal communities

     Status, Trend, and Monitoring Effectiveness of Marbled Murrelet (Brachyramphus marmoratus) at Sea Abundance and Reproductive Output off Central California, 1999–2021

Collaborators: UC Santa Cruz and National Park Service

       

Coastal Invasive Species Ecology and Restoration

With Lorraine Parsons and Dylan Voeller of the National Park Service, we assist investigations into the impacts and restoration potential of dune and coastal grassland habitats to impacts from invasive species and grazing.

Publications:

     Method for controlling invasive Ammophila arenaria in coastal dunes alters restoration trajectory

     Improved Microbial Water Quality Associated with Best Management Practices on Coastal Dairies and Livestock Grazing Operations

     Invasion by Ammophila arenaria alters soil chemistry, leaving lasting legacy effects on restored coastal dunes in California

Collaborators: Lorraine Parsons, Dylan Voeller, Ben Becker (National Park Service)

       

Long-term population dynamics of Northern Spotted Owls and Prairie Falcons

We are using multistate occupancy models to understand the long-term population dynamics of Endangered Northern Spotted Owls (NSO) in Marin County. Throughout their range in the Pacific Northwest, NSO has suffered dramatic population declines. However, we study the southern-most population which is the only location that has not yet suffered declines due competition from the  Barred Owl, a newly arrived east coast transplant. Our research is helping to understand the impacts of a small number of Barred owls on the NSO.

Similarly, we are analyzing occupancy and reproduction of Prairie Falcons at Pinnacles National Park to understand potential disturbance impacts from hikers, weather events, and an increasing peregrine falcon population. 

Collaborators: Point Blue Conservation Science (Renee Cormier), National Park Service (Gavin Emmons, David Press, Taylor Ellis), and UC Berkeley (CeeCee Chen and Noor Wahle)