A low‐cost modular control system for multistressor experiments

Abstract

Marine organisms and ecosystems face multiple, temporally variable stressors in a rapidly changing world. Realistic experiments that incorporate these aspects of physiological stress are important for advancing our ability to understand, predict, and manage their ecological impacts. However, the experimental systems needed to conduct such experiments can be costly. Here, we describe a low-cost, modular control system that can be used with seawater sensors and actuators to dynamically manipulate multiple seawater variables. It enables researchers to run a variety of realistic multiple-stressor, variable exposure experiments with a range of marine organisms. This tank controller system is based on the open-source Arduino prototyping platform and features a custom-made circuit board with a 16-bit analog-to-digital converter, a real-time clock, a MicroSD memory card reader, a high-voltage transistor array, and solderless screw terminal connectors for easy connection of sensors, actuators, and power supplies. The assembly and use of this controller system does not require extensive electronics engineering or programming experience, and each module can be assembled for under 80 USD in parts. To demonstrate the system's capabilities, we present seawater manipulations from experiments involving (1) simultaneous manipulations of dissolved oxygen and pH; (2) fluctuating dissolved oxygen levels; and (3) a controlled stepwise decrease in dissolved oxygen at different temperatures. The low cost and high customizability of this Arduino-based control system can contribute to expanding capacities for running global change experiments for researchers and students worldwide.

The Open acidification Tank Controller: An open-source device for the control of pH and temperature in ocean acidification experiments

“…Pinpoint pH Controller costing $200 [13] . More recently, open-source applications have been published to control aquarium pH, but these devices have invariably been feature-poor, relied on expensive external equipment, or both [14] , [15] , [16] .…”

A low-cost, accessible, and high-performing Arduino-based seawater pH control system for biological applications

“…The use of Arduino platforms in seawater pH modulation is an important step in advancing this goal [7] , [19] , [20] . Arduino platforms are comprised of programmable physical circuit boards and a companion software—Integrated Development Environment (IDE).…”

“…Together, the Arduino hardware and IDE provide an accessible way for scientists and individuals alike to design and control circuits of varying sizes and complexities. Low et al recently demonstrated this by controlling a complex, robust, and high-performing pH modulation system with an Arduino Uno [19] . While these systems have made important advances in increasing their accessibility, they still carry some of the burdens described above, including relatively high system complexity and the need for custom-made hardware.…”

High frequency monitoring of feeding activity in benthic suspension feeders

“…The use of microcontrollers and prototyping tools to undertake laboratory and field monitoring tasks offer a wide range of options to design experimental set-ups. Among other applications micro-controllers allow for automation and handling of data recording, prototyping of mechanical parts and sensors and interfacing with other instruments [14, 15, 5]. Microcontroller prototyping can be use to build systems to execute manual and supervised tasks automatically and/or remotely [16].…”