Although not well known, seagrass meadows are an important ecosystem that play a vital role in combating climate change. Formed of flowering plants that grow underwater, seagrass meadows grow in sheltered coastal areas across six continents.
However, they are not simply attractive additions to the seaside – they in fact capture an estimated 10% of the atmospheric CO2 absorbed by the oceans and capture it 35 times faster than tropical rainforests.
Despite their usefulness, seagrasses face a number of threats, with coastal development, degraded water quality, and climate change being some of the main pressures. Protecting these fragile ecosystems is therefore a priority.
Ensuring they have the correct conditions for healthy growth means developing a monitoring system able to gather the right data.
In the past, monitoring has meant researchers taking on-site measurements, but this is very time-consuming, as well as being prone to errors. Satellites, aircraft, and drones can map the extent of seagrass meadows but capturing all the data required still entails measurements on-site.
One practical option for protecting seagrasses with satellite is a monitoring system based on the Internet of Things (IoT) – this would involve taking frequent sensor readings over extended periods of time, with small amounts of data sent from sensors over a wide area.
By the very nature of seagrass meadows, they could be in difficult-to-reach or remote areas. This means protecting seagrasses with satellite require IoT devices that need a connectivity system that is both robust and offers constant access. It should also require little maintenance and very few or no manual visits.
LoRa®, short for Long Range, meets all these requirements. This is a low-power, terrestrial wireless platform for IoT. Transceivers configured with these LoRa devices are embedded into end nodes, or sensor devices, such as temperature or oxygen sensors. These capture data on the seagrass meadows’ environment and transmit it to gateways, which in turn send it over the air to the network.
For remote monitoring of seagrass meadows over extended areas, LoRa® offers a number of advantages of terrestrial connectivity technologies such as 4G and fibre. Without the need for fixed mobile cells, these inexpensive devices can be deployed rapidly over a wide area, ideal for use in extensive seagrass meadows and cutting capital costs. It also cuts operational costs compared to cellular technologies such as Narrowband IoT (NB-IoT). With these devices consuming a lot of power, frequent battery replacements are required, ruling them out for deployment in remote areas.
LoRaWAN® (Long Range Wide Area Network) is an open-source network architecture standardized for LoRa devices and developed by the LoRa Alliance. This becomes even more useful when combined with satellite access.
Many seagrass meadows may be out of range of terrestrial networks. This means that connectivity for IoT monitoring in remote locations is best served by satellite.
The technique has been demonstrated by a solution deployed by EchoStar Mobile, which offers LoRa coverage across Europe using a large, high-capacity satellite. Using this method, data on parameters such as water levels, salinity, temperature and dissolved oxygen would be collected by IoT sensors sited in seagrass meadows and then sent to a LoRa module and then to the satellite. It is then retransmitted to the Internet via an Earth station and a LoRaWAN® compatible network infrastructure.
One of the advantages of protecting seagrasses with satellite is that it offers a real-time view of a whole continent’s seagrass habitats, giving the chance of novel insights about the development of seagrasses.
Satellite-enabled IoT offers great advantages in the struggle to understand and protect seagrass meadows. With any time, anywhere access to current field data, researchers have a powerful tool with which to protect these vital natural resources.