Monitoring ocean health with a new, low-cost, real-time sensor suite

Human activities are causing unprecedented impacts on coral reefs and other marine ecosystems around the globe. Measuring ocean temperature, as well as other metrics, is an important way of monitoring ocean health. A number of oceanographic sensors exist, but they are expensive and rarely web-enabled. Scientists and the public need affordable tools to measure ocean parameters in real time.

What is the context of this research?

It is widely accepted that measuring ocean conditions in real-time can give scientists and the public advanced notice of events that are harmful to ocean health.

Temperature, salinity, dissolved oxygen, pH, ORP, water depth, insolation, turbidity, nutrient loads and other factors all affect the health of marine organisms.

Commercially-available multi-parameter ocean sensors measure variables to multiple decimal places (1, 2, 3). Yet, the high cost of these products means that most of the ocean is not monitored at all.

Our OceanSense instrument will have sufficient accuracy/precision to collect baseline data and detect meaningful changes in ocean health. Yet, its low cost will ensure that it can be deployed at the scale necessary to monitor the health of our oceans worldwide.

What is the significance of this project?

Coral reefs and other marine ecosystems support at least 500 million people for food and their livelihoods, and provide innumerable other benefits. Nevertheless, most ocean ecosystems are not monitored, leaving scientists and the public blind to the state of their health.

The high cost of seawater sensors inhibits broad scale monitoring and collection of important ocean health datasets, as well as the dissemination of the data in real-time.

By providing a tool to collect important physical and chemical ocean condition data at low cost, OceanSense will add vital additional data streams to, for example, existing satellite-connected ocean monitoring buoys and small ocean micro-observatories that provide underwater audio and video in real time.

What are the goals of the project?

The goal is to deploy and test a full ocean health sensor suite in five ocean habitats. The OceanSense probes will be tested for accuracy, precision, data drift and longevity.

The OceanSense instrument will measure six variables in real-time: temperature, depth (pressure) salinity, dissolved oxygen, ORP, and pH. Five existing web-accessible observatory platforms have been selected for data collection. Each variable will be measured on five-minute intervals for thirty days (8640 readings per variable) and stored locally on the instrument and in the cloud.

After thirty days, each instrument will be tested against standard calibration solutions to assess data drift, and redeployed. This regime will be continued for twelve months.