Task 23: Habitat dynamics, subsidies and food webs for surf zone fish on a "wild coast" sandy beach

Award Period
to
Award Amount
$20,125
Agency Name
The Nature Conservancy
Award Number
SB200210-Task23
PI First Name
Jenifer
PI Last Name
Dugan
CO-PI
Kyle Emery
MSI People
Area/s of Research
Climate Change Science
Ecology and Evolution
Abstract
  1. The PIs will establish a characterization of dynamic beach features, wrack, and vegetation to establish ecosystem conditions before a strong ENSO event: New approaches to quantify the elevations and extent of beach features and the dynamics and distribution of wrack subsidies to the beaches as well as coastal strand and dune vegetation using drones are being piloted by this research group. However, the majority of their study beaches are heavily impacted by human activities and lack the combination of intense physical dynamics and processes and high subsidies found on the Dangermond Preserve beaches. In order to establish this characterization of the baseline beach conditions, the research team will:
    1. use a multispectral drone in conjunction with their transect surveys to collect new data and calibrate and ground truth these methods and observations at Percos Beach, providing needed data from a pristine, wild mainland beach. They will also incorporate these data into models being developed to automatically detect and quantify wrack and dune vegetation cover. In addition, they will use the resulting data to train a different model for the identification of coastal strand and dune plant species.
    2. use a mobile, RTK-enabled GPS unit to collect control point position and elevation data on dynamic beach features and elevations. Using the elevation data from the drone and this GPS unit they will construct site-wide digital elevation models (DEMs) for each survey. The elevation data will be available to refine predictions and modelling for projecting the effects of sea level rise and storm impacts on a biodiverse Dangermond Preserve beach.
    3. ground truth the drone surveys they will conduct transect-based surveys of dune vegetation cover, wrack cover, and physical features of the beach and dunes (dune crest, dune toe, vegetation toe, high tide strandline, berms, water table outcrop, etc.) They will also collect GPS data on the position and elevation of these features.
  2. Surfperch diet and food web connections: The research team’s study of barred surfperch diet is in progress, with all samples of stomach contents analyzed for Percos Beach. The stomach content analysis provides a view of fish diet that is fairly short term, one day or less. A complementary analysis of diet that has not been conducted for barred surfperch from Percos Beach is the stable isotope analysis of muscle tissue samples. These tissue samples were collected in concert with the stomach content samples. This new analysis will allow the research team to evaluate a more integrated view of surfperch diet and their position as predators in the beach food web. All surfperch tissue samples for this component of their study have been prepared for isotopic analysis.  All of these prepared samples still need to be analyzed with a mass spectrometer.  Analysis of these samples at the UCSB Analytical Laboratory will cost $20 each, there are ~ 200 samples.