Abstract
The CTD (Conductivity, Temperature, and Depth), often called the “workhorse” of oceanography, is essential for understanding the marine environment. However, commercial CTDs are expensive and can pose a financial barrier to increased environmental observations by researchers and citizen scientists alike. OpenCTD, an open-source, low-cost alternative, presents a novel solution for expanding environmental monitoring while supporting and integrating marine energy research. Developed with affordability and accessibility in mind, OpenCTD can be constructed for approximately $430, a fraction of the cost of traditional CTDs.
Funded by and in partnership with the North Carolina Renewable Ocean Energy Program (NCROEP), we deployed a network of 16 OpenCTDs throughout the Albemarle-Pamlico estuarine system (APES) (Figure 1) to assess small-scale wave energy potential in the region. By adjusting the instrument’s pressure sensor to rapidly sample at 20Hz, we aimed to capture site-specific wave fields at multiple locations. This 4-month deployment serves as a pilot study to evaluate the feasibility of OpenCTD for low-cost wave energy resource characterization while providing valuable environmental data for other coastal research efforts.
OpenCTD’s accessibility and adaptability make it ideal for community-driven coastal observation. By integrating local stakeholders in data collection, we seek to expand environmental monitoring capacity in the Outer Banks while supporting North Carolina’s growing marine energy portfolio. Beyond its use in wave energy characterization, OpenCTD data can support other research initiatives, such as monitoring submerged historic properties, optimization of aquaculture practices in local oyster farms, and student-led building and project planning. The instruments used in this project were built with high school and undergraduate college students, providing a valuable learning experience.
A key goal of this project is to use the data collected during this initial deployment to inform future modifications to the OpenCTD, ultimately transforming it into a wave-powered instrument. By harnessing small-scale wave energy to power the device, we aim to extend deployment durations and provide access to real-time temperature, salinity, and wave conditions. This modification would enable long-term, non-intrusive monitoring of both natural and cultural resources while reducing reliance on battery power and minimizing maintenance needs.
This presentation will share preliminary findings from the 2024-2025 OpenCTD deployment, including site-specific wave field characterization and insights into instrument performance. We will also discuss best practices for integrating OpenCTD into other marine energy and environmental research efforts, and next steps toward developing a fully autonomous, wave or current-powered version of the instrument. By providing a scalable, cost-effective solution for small-scale wave energy assessment, OpenCTD has the potential to significantly reduce barriers to entry in marine research and increase data collection in coastal environments worldwide.