Center for Marine Biodiversity and Conservation
Spatial and Temporal Variation within Fine-Scale, Particulate Organic Matter δ13C and δ15N Isoscapes of the Southern California Bight
- Author(s): McWhorter, Jennifer
- et al.
Stable carbon (δ13C) and stable nitrogen (δ15N) isotope values in particulate organic matter (POM) provide natural markers that can be used to trace animal foraging and movement patterns in marine systems. These isotope values are dependent upon the values at the base of the food web which can vary temporally depending upon the chemical, physical, and biological processes that dominate different geographic areas. We analyzed the δ13C and δ15N values from POM, which is a mixture of living organisms as well as detrital material such as phytoplankton, zooplankton, bacteria, fecal pellets, continental detritus amongst others. These POM samples were collected across five seasons from 2012-2013 at 30 sampling stations in collaboration with the California Cooperative Ocean Fisheries Investigations (Cal-COFI) program to create high resolution isotope maps or isoscapes of the Southern California Bight in the eastern Pacific Ocean. Our creation of a marine isoscape sets the framework for long-term isotope analysis within the Cal-COFI program, creates a methodology for the development of global marine isoscapes for their use in marine conservation, and provides insights into the potential for seasonal, yearly, and spatial variations in the stable isotope values that are used to create marine isoscapes.