1. Applying GIS to Santa Cruz Island:
An Analysis of Intertidal Biodiversity
clients.alexandria.ucsb.edu
By:
Carola Flores, Nic Galati, Jeff Overlock, and Heather Thakar-Hucks

2. Motivation GIS offers new forms of data analysis and visualization
Density estimation, kriging, overlay, etc.
Multiple scientific disciplines can benefit from GIS applications
Archeology, Biology, Ecology, Geology, Oceanography, Geography, etc.
Wealth of existing data not yet applied to GIS
SWAT (UCSC), PISCO (UCSB) team, Coastal Biodiversity Survey
Spatial relationships are key to understanding marine habitats
Ecologic, environmental, and oceanographic variables that influence
intertidal organism diversity and abundance

3. Main Objective Specific objectives
Perform a spatial analysis of intertidal ecology patterns on Santa Cruz Island
Understand if changes in the environment impact intertidal habitats
Specific objectives
Map intertidal species density within ecological sites
Look for spatial patterns of intertidal species density
Compare and contrast relationship between density and
environmental, ecological, and oceanographic variables among 6 sites
Look for potential causes and effects of the intertidal density variability

4. Methods Density Estimation
The objective of Density Estimation Data set is interpreted as a collection of discrete objects
Estimation of point density
Formation of a field from set of discrete objects

5. cbsurveys.ucsc.edu

6. Methods Map area is based on 30m baseline with 11 transects every 3m
Six site areas on Santa Cruz Island will be used to determine density of species per site
Discrete objects represented as x,y, and z coordinates along transects
Points contain number of species present at that location in the intertidal zone
Map will indicate spatial distribution of species density

7. Coastal Biodiversity Surveys on Santa Cruz Island
Data Source
Coastal Biodiversity Surveys on Santa Cruz Island
PISCO (UCSB), SWAT (UCSC): a large-scale marine research program that focuses on understanding the nearshore ecosystems of the U.S West Coast.

8. Data set Point Contact data Quadrat data Swath data Non-mobile species
Classification table data
Quadrat data
Mobile species
Classification table data
Swath data
Sea star presence or absence

9. Data set Santa Cruz Island sea surface temperature data
Average site temperature
Digital Elevation Model of each ecological site
and of Santa Cruz Island

10. Problems
Data size.
Large data sets from 10 years of intertidal surveying may
become difficult to work with considering
the time given to work on the project.
2. Sampling area
Since data sets are from just six ecological sites of Santa Cruz Island,
the number of samples might not represent the density
pattern of Santa Cruz’s intertidal species.
3. Uncertainty
Data to be used has fine-scale multiple measurements.
Due to the complex spatial distribution of species diversity
in the intertidal, to portray an accurate digital representation could be a challenge.

11. Anticipated results
Different areas of density within each ecological site.
Possibly due to the location of the species habitat in the
intertidal zone (high, medium or low zone).
Geo-spatial gradient in density among all ecological sites.
On a bigger scale, this spatial distribution could be
due to environmental factors such as sea surface
temperature gradients.

12. clients.alexandria.ucsb.edu