IDBR: TYPE A: Development of an Animal Tracking Tag for Biological Research: Refractive Index for Rapid Georeferenced Salinity Measurements over a Wide Dynamic Range

Sri International, Menlo Park CA

Investigators

Abstract

An award is made to SRI International to develop small tags which will be attached to marine animals and acquire data from the ocean environment. The first prototype tags will be sized for medium to large animals, such as penguins, turtles, and sharks. These data tags will record information central to understanding animal migration. In more general applications, the increased amount of data obtained by the tags will provide valuable information to scientists and policymakers to help understand the complex properties and changes in the ocean and other aquatic environments, thus aiding conservation efforts. Important areas for study include estuarine environments, where rapid profiling can record dynamic conditions, and low and high salinity areas such as choked lagoons, coastal isolated lakes, and subglacial lakes. The data will enhance our ability to understand seasonal variations, changes caused by human populations and activities, and global climate change. This project will support three undergraduate student internships (one chemical engineer and two biologists). The project will also include a lesson plan on ocean salinity measurements for a local high school with a high percentage of underrepresented groups to increase interest in science, technology, engineering, and math (STEM) education, and to encourage young students to consider multidisciplinary careers in engineering and the sciences with environmental conservation in mind. Sensors in the innovative tags will measure water temperature, depth, and salinity (the amount of dissolved salts), which are interrelated indicators of ecosystem health. The data produced will be geo-referenced; that is, the tag will provide a location of the collected information. These tags will differ from current commercial devices by measuring salinity as a function of the optical properties of the water (the refractive index) by detecting and recording changes in the interaction of light with the sensor (patent pending). The major advantages of the optical measurement include fast operation, wide dynamic range, and cost effectiveness for the attainable resolution. The parameters collected by the tag will provide valuable information about the marine environment that can be correlated to locations where specific animals travel to satisfy their basic food and reproduction needs, and will provide insight into habitat changes linked to declining marine populations.