To many, the final frontier isn’t space: it’s our oceans. There’s so much that we don’t understand about the ocean, a knowledge gap attributable to the unique challenges posed by aquatic observation and measurement. Reaching remote parts of the ocean is expensive and difficult, as is exploring the ocean’s depths, where it is impossible to linger for long. Even technology is hampered by the ocean’s harsh conditions. “Instruments are limited by available power, beaten by waves, corroded by saltwater, and fouled by prolific marine organisms that accumulate rapidly on their surfaces,” wrote the Woods Hole Oceanographic Institute (WHOI).
[Read more: What is Biofouling and How Can We Stop It?]
Promising developments in ocean sensor technology, however, are helping us overcome these challenges. Micro and nanotechnology, biotechnology, and sensor integration are playing a role in advancing low-power, affordable, and precise sensors that can withstand even the harshest ocean conditions. Sofar Ocean’s Spotter and Smart Mooring devices, for instance, are built with rugged and durable materials that can handle being encased in ice or tossed around in a storm surge.
These improvements still beg the question: why do ocean sensors matter? Broadly speaking, ocean observation and ocean monitoring efforts rely on these sensors to collect reliable, consistent, and high-quality data about the final frontier. Let’s unpack why ocean sensors are critical and how new developments in ocean sensor technology will provide invaluable information about life beneath the waves.
What do ocean sensors measure?
Oceanographic sensors can be adapted to measure a range of different metrics, such as light, temperature, sound, mass, or chemical species. Ocean weather buoys like Sofar Ocean’s Spotter & Smart Mooring devices continuously collect and transmit spectral wave measurements, inferred wind readings, and temperature on and below the surface in real-time. Observers can use sensors to collect information about a diverse set of variables, including:
- All common wave statistics from 3D motion time series, including complete wave spectrum, directional moments, bulk statistics, hourly resolution, and “sea” and “swell” data partitioning.
- Wind speed and wind direction estimated from the equilibrium range of wave spectrum.
- Sea surface temperature with an accuracy of +/-0.1C and a precision of 0.02C.
- Water level (via a pressure sensor) for infragravity waves, non-tidal residuals, tides, and water level measurements.
- Water column stratification and sub-surface water properties.
[Read more: How Weather Buoys Can Fast-Track Ocean Research]
Other types of ocean sensors are used to sample, analyze, and identify biological molecules, including DNA, proteins, enzymes, and lipids. Researchers at the University of Washington are using sensors to plan renewable energy sites in areas that won’t disturb delicate marine ecosystems. As sensor technology continues to develop, its impact on the efficacy of ocean monitoring and ocean observation will continue to grow.
Ocean sensors help measure ocean pollution
Ocean sensors can detect synthetic and chemical compounds and measure pollution caused by plastics, petroleum, vehicle exhaust, pesticides, fertilizers, etc. More than 80% of ocean pollution comes from land-based sources and some pollutants — plastic waste (e.g. microplastics), mercury, petroleum pollutants, etc. — have a large negative impact on human and ocean health.
[Read more: How Ocean Health is Connected to Human Health]
Effectively measuring ocean pollution allows coastal communities to reduce their negative climate impact, clean up their shores, and protect local economies, tourism, fishing, and overall human health.
Ocean sensors help measure climate change
Scientists are tracking climate change across a range of ocean observations. Some organizations are measuring the temperature of the ocean with ocean sensors, while others are using sensors to understand changes in ocean currents and sea level rise. At WHOI, experts use chemical sensors to determine how the oceans can act as carbon sinks and help reduce global warming.
“To determine whether the oceans can absorb excess greenhouse gases, we need sensors that measure climatically and ecologically important gases such as carbon dioxide, methane, hydrogen, hydrogen sulfide, and radon,” wrote the WHOI.
“Other chemical sensors can indicate how much carbon dioxide is converted by photosynthetic plankton into organic carbon, and how much of this sinks to the deep ocean—to mitigate the buildup of greenhouse gases, or to feed hungry populations of deep-sea organisms.”
Ocean sensors help understand marine ecosystems
Ocean sensors also help researchers understand where species of all sizes are present in the water column, how they interact with one another, how they communicate, and more.
Ocean noise, for example, can be tracked by sensors, and the disruptive impact that it can have on the behavior of marine life can be measured. The Bio-Optical Multifrequency Acoustical and Physical Environmental Recorder, or BIOMAPER-II, is one example of a sensor device that is used to detect small marine organisms using sound.
Ocean sensors help researchers and scientists intimately understand remote, inaccessible parts of the ocean. With this information, scientists can protect endangered species, improve ocean health, and better understand the effects of climate change.
“Our decade-old dream is now becoming a reality: to be able to observe phenomena in the ocean continuously, on all scales and in real-time, and to be able to interact with sensors in the oceans—all from shore,” wrote the WHOI.
To learn more about ocean sensors, check out our blog.