I am Mark from CyanoLakes, and I am writing to tell you more about our application for monitoring water quality and harmful algal blooms in coastal waters using satellite imagery. I’m going to be answering a few common questions that will hopefully enlighten those who are not familiar with satellite imagery and the advantages it provides.
Why use satellites?
Thousands of satellites orbit the earth daily, with cameras pointing down and collecting millions of images every day. A few of these satellites have special cameras designed for monitoring the health of the earth and environmental change, using precise measurements of the visible and near infrared spectrum (or the colour spectrum). The data these cameras collect can be turned into information for management and monitoring. The advantage with using satellites is that they are unaffected by weather (being in space) and they don’t require any manual interventions besides for being kept in orbit by occasional adjustments from the mission team. This means they collect consistent datasets that can be used to track long-term changes in the environment, while also alerting to sudden unforeseen changes thanks to very fast data procession and provisioning.
When it comes to coastal marine management, satellites can be used for a number of important applications. The first one, is to detect any harmful algal blooms that often occur in coastal marine lagoons, bays and upwelling systems. Satellites can alert to the presence of a bloom, and be used to track its movement and eventual die-off. This can allow decision makers to alert locals to the danger it may present for shellfish poisoning. Besides for algal blooms, satellites can be used to effectively monitor outflows from lagoons and river mouths with high turbidity, which may be an indicator for poor water quality. This information can be used to inform tourist activities, like helping tour operators select clear water dive sites based on current conditions. Another example is monitoring sewage outflow pipes, that could pose a risk to coastal populations depending on the current and weather. Water clarity can alert desalination plants of high turbidity water that would require additional filtration of their source water. Lastly, satellites can monitor changes in things like seagrass beds, and marine forests, in an effort to assist conservation efforts.
Is it reliable?
Much can be said about the skepticism surrounding satellites measuring changes on the ground, and especially in oceans, lakes or rivers. But technological advancements now allow very precise measurements of the colour spectrum, which in turn leads to better estimates for parameters such as chlorophyll-a, turbidity, suspended particulate matter, and even detection of specific types of algae (e.g. distinguishing between cyanobacteria and algae). In general, although it is still advised to confirm any measurements made by satellite with local samples, satellite data is reliable and trustworthy, and if not as good, then at least half as good, as any measurement made on the ground (or in the water). And because satellites collect so much data, it is easy to learn how to spot errors that may be a result of cloud or atmospheric conditions, and can be later ruled out as anomalies.
For the MarcoSouth Project, CyanoLakes is providing high and medium resolution satellite imagery for twelve coastal African sites to assist in their management. To view the page, visit https://online.cyanolakes.com/marcosouth/
Mark Matthews (firstname.lastname@example.org)