Water Management and Protection from Space with Pléiades Neo

Applying new satellite technology solutions, our partner DHI frequently monitors critical habitats worldwide and keeps track of remote, vast, dynamic and inaccessible areas in high spatiotemporal detail.

Here they show an example from Florida, US where our new Airbus’ Pléiades Neo data was applied to derive key parameters to underpin conservation management efforts.

Florida’s coastal waters are some of the most productive and diverse ecosystems, often dominated by submerged aquatic vegetation (SAV). SAV includes a taxonomically diverse group of macroalgae and seagrasses that lives below the water surface in coastal and estuarine waters in large meadows, or smaller patches. The health of aquatic vegetation is a key indicator of the ecological status and environmental state of ocean and estuarine waters.

They provide critical functions which are difficult to replace, such as:

• Habitats, spawning grounds and food for many different marine species
• Adding oxygen to the water and remove excess CO2
• Improve water quality by absorbing excess nutrients
• Stabilise sediment and reduce erosion.

One of Florida’s most endangered species, the manatee, rely almost entirely on the extensive beds of seagrass and freshwater aquatic vegetation in the estuaries and freshwater lakes, springs and rivers. As the manatee’s primary food source, healthy and abundant SAV communities are a precondition to their survival – however Florida’s SAV communities are increasingly under threat, not least because of human disturbance and climate change. A record high 1,001 manatees died in 2021, largely due to starvation caused by loss and degradation of aquatic vegetation. As a result, Florida Wildlife officials started a campaign feeding starving manatees with lettuce in early 2022.

Due to the nature of their important ecosystem functions, up-to-date knowledge about SAV abundance, distribution, health and growth dynamics is critical, in order to assess the impacts of management efforts, identify degraded communities and monitor overall marine health. However, SAV communities are also highly fragmented in both time (in some locations changes occur within days and in others over weeks or months) and place (organised into many different heterogenous patches of individual communities) which makes SAV monitoring a challenging task. Traditionally, a combination of diver observations, photos and/or video recordings, to determine e.g., spatial coverage and species composition, have been used to monitor SAV habitats. However, these techniques are time consuming, labour intensive and highly limited in their spatial extent and thus unable to fully capture the spatiotemporal dynamics.

With its twice-daily revisit time, Pléiades Neo data can be applied to continuously map and monitor all Florida’s fragile coastal ecosystems, thus providing up-to-date insights into the growth and dynamics of SAV communities at scale.

Furthermore, with a 30 cm resolution, Pléiades Neo data provides new opportunities for assessing qualitative SAV parameters, such as detecting and mapping impacts of propeller scars. These scars, caused by motorboats, are extremely detrimental to SAV communities across Florida’s coastal areas, and in order to underpin conservation efforts, it is vital to have comprehensive and up-to-date information on the areas where these scars occur as well as how they develop over time.

As seen from the illustrations below, Pléiades Neo 30cm data can be used to map and monitor these scars as they develop – thus providing authorities with a timely tool to evaluate threats and assess mitigation needs. In combination with the satellite-derived bathymetry data, the most vulnerable shallow water areas with exposed aquatic vegetation can also be easily identified and protected.

Lastly, Pléiades Neo data can be used to monitor objects, such as individual boats and manatees as illustrated in the example below from the inner Crystal River estuary. Using novel deep learning technology, such assessments can be conducted accurately, timely and at scale, for comprehensive monitoring of boat traffic density and dynamics as well as population assessments of manatees or other marine species (e.g., basin wide assessments of whales or whale sharks).

Image 1: Propeller scars of Sandy Hook as seen from the Pléiades Neo satellite image (right)

Image 2: Numerous propeller scars identified across the Crystal River region and an example of damaged vegetation mapping (top right)

Image 3: Vessels and manatees detected in the inner Crystal River estuary through the use of deep learning technology and Pléiades Neo data