Autonomous Robotic Rover Helps Scientists With Long-Term Monitoring of Deep-Sea Carbon Cycle and Climate Change
The sheer expanse of the deep sea and the technological challenges of working in an extreme environment make these depths difficult to access and study. Scientists know more about the surface of the moon than the deep seafloor. The Monterey Bay Aquarium Research Institute is leveraging advancements in robotic technologies to address this disparity.
The sheer expanse of the deep sea and the technological challenges of working in an extreme environment make these depths difficult to access and study. Scientists know more about the surface of the moon than the deep seafloor. The Monterey Bay Aquarium Research Institute (MBARI) is leveraging advancements in robotic technologies to address this disparity.
An autonomous robotic rover, Benthic Rover II, has provided new insight into life on the abyssal seafloor, 4,000 m beneath the surface of the ocean. A study published in Science Robotics details the development and proven long-term operation of this rover. This innovative mobile laboratory has further revealed the role of the deep sea in cycling carbon. The data collected by this rover are fundamental to understanding the effects of climate change on the ocean.
"The success of this abyssal rover now permits long-term monitoring of the coupling between the water column and seafloor. Understanding these connected processes is critical to predicting the health and productivity of our planet engulfed in a changing climate," said MBARI Senior Scientist Ken Smith.
Despite its distance from the sunlit shallows, the deep seafloor is connected to the waters above and is vital for carbon cycling and sequestration. Bits of organic matter—including dead plants and animals, mucus, and excreted waste—slowly sink through the water column to the seafloor. The community of animals and microbes on and in the mud digests some of this carbon while the rest might get locked in deep-sea sediments for up to thousands of years.
The deep sea plays an important role in Earth's carbon cycle and climate, yet little is known about processes happening thousands of meters below the surface. Engineering obstacles such as extreme pressure and the corrosive nature of seawater make it difficult to send equipment to the abyssal seafloor to study and monitor the ebb and flow of carbon.
In the past, Smith and other scientists relied on stationary instruments to study carbon consumption by deep seafloor communities. They could only deploy these instruments for a few days at a time. By building on 25 years of engineering innovation, MBARI has developed a long-term solution for monitoring the abyssal seafloor.
"Exciting events in the deep sea generally occur both briefly and at unpredictable intervals. That's why having continuous monitoring with Benthic Rover II is so crucial," explained Electrical Engineering Group Lead Alana Sherman. "If you're not watching all the time, you're likely to miss the main action."
Benthic Rover II is the result of the hard work of a collaborative team of MBARI engineers and scientists, led by Smith and Sherman.
Engineers at MBARI designed Benthic Rover II to handle the cold, corrosive, and high-pressure conditions of the deep sea. Constructed from corrosion-resistant titanium, plastic, and pressure-resistant syntactic foam, this rover can withstand deployments up to 6,000 m deep.
"In addition to the physical challenges of operating in these extreme conditions, we also had to design a computer control system and software reliable enough to run for a year without crashing—nobody is there to press a reset button," explained MBARI Electrical Engineer Paul McGill. "The electronics also have to consume very little power so that we can carry enough batteries to last for a year. Despite all it does, the rover consumes an average of only 2 watts—about the same as an iPhone."