Development of a Solar-Powered Remote Field Camera

To monitor the Spring 2023 river herring run on Cape Cod, Massachusetts, a prototype field camera system was designed and assembled using commercially available products. River herring is an important migratory species in the diverse ecosystems of the North American Atlantic coast. They are anadromous fish, returning to freshwater to spawn every spring. They are a key component of the energy transfer between marine and freshwater systems; they support many recreational and commercial fish species and the associated fisheries. Historically, river herring populations reached hundreds of millions (NOAA, 2022). River herring populations have declined due to habitat loss, overfishing, obstructions to passage for spawning populations, and anthropogenic impacts including coastal industrial development. Having supported some of the oldest fisheries in the United States, river herring is also a culturally significant species; the Mashpee Wampanoag tribe relies on the river herring as a food source, and local communities come together to celebrate the annual herring runs. Local and state fisheries managers and conservation groups are working to support the river herring populations using modern management methods: improving passage structures (fish ladders), establishing monitoring programs, and incorporating camera systems. Camera systems are widely used and are becoming increasingly available to researchers and citizen scientists alike. To monitor the river herring run at Santuit Pond on Cape Cod, Massachusetts, members of the Wampanoag tribe and MIT Sea Grant have installed an underwater camera at the pond's fish ladder. The camera is motion-activated and records the river herring that travel through the fish ladder. The predecessor camera system was clunky and resource/time intensive to install and use. The previous system used a laptop computer for camera control and local data storage. Power was supplied by multiple solar panels, a marine battery, and an inverter. This inefficient system identified different challenges and motivated the development of an accessible and cost-efficient field camera system using commercially available components. The "HelioCase" is a portable, solar-powered Raspberry Pi-based system. The Raspberry Pi acts as the camera controller unit and remote access point. This is intended to be a low-cost, replicable computer system that can be easily customized to fit user needs. The HelioCase aims to provide the opportunity to install monitoring stations at multiple locations, utilizing a cellular network connection for remote access and control. Retrieving the video/image data from the field camera most often involves a trip to the field site to access the data on local storage. A network-connected, remotely accessible camera would eliminate the need for such field trips, effectively reducing the resource cost of data acquisition to the cost of the onboard SIM card's data plan. This system would also alleviate the human burden, cost, time, and potential for error associated with manual observation efforts. The HelioCase was connected to a SeaView underwater camera and installed at a fish ladder. Footage from the camera was saved locally and transmitted to a remote user. The HelioCase improves upon current river herring population monitoring methods, with the possibility of broader applications, and provides valuable data for effective fisheries management. This remote camera technology development improves the capability of fisheries managers to conduct annual stock assessments and population estimates more accurately and efficiently. The strength of the HelioCase lies in its compact size and ease of use; the simple system is power-efficient and reduces on-site time. Although used for river herring population monitoring here, the HelioCase system may be used as a multi-purpose solar-powered field computer.