Spiders as Metrics of Salt Marsh Productivity
Authors:Aaron Barro, Andrew Brinkman, Kelsey Erisman, Hannah Mize, Kurt Zias
Mentor:Sean Anderson, Associate Professor of Environmental Science and Resource Management, CSU Channel Islands
Little arthropod research has been conducted within Southern California salt marshes. Our previous work has shown spiders (order Araneae) are apparent apex predators within this arthropod community and may therefore be critical components of these systems. Due to results from our previous sampling efforts, we hypothesize that spider abundance and biomass are higher in more disturbed salt marsh habitats. We surveyed coastal wetlands spanning reference (e.g. Mugu Naval Base), degraded (e.g. Ormond Beach) and restored (e.g. Ash Avenue) salt marsh. Previous sampling (in 2011) showed the frequency, species richness, and total biomass of spiders to be greater in degraded salt marshes compared to restored marshes (p>0.05). Our 2013 sampling effort is still on going, but preliminary analyses show strong support for this spider pattern and imply that this spider response is a robust and general aspect of ecosystem response across time and space. We therefore suggest that monitoring the arachnid community will afford robust measure of the overall functioning and “health” of this complex and dynamic ecosystem.