The intertidal zone is the realm the place the ocean meets the land between excessive and low tides, and right here seagrasses can kind intensive meadows. These flowering marine crops present crucial habitats, appearing as shelter, nurseries, and feeding and spawning grounds for a various vary of birds, fish and invertebrates. Past their ecological significance, seagrass meadows additionally stabilise sediments and defend coastlines from erosion.

Monitoring the incidence, extent, situation and variety of intertidal seagrass as a key biodiversity variable is crucial for assessing the general well being of native ecosystems.

Present world estimates of seagrass protection don’t differentiate between seagrasses within the intertidal zone and people within the subtidal zone, which stay submerged under the ocean floor.

Nonetheless, a current paper, printed in Communications Earth & Atmosphere, particulars how a workforce of scientists used high-resolution imagery from the Copernicus Sentinel-2 mission to reveal its capability to map intertidal seagrass meadows and their seasonal adjustments throughout continents with consistency and precision.

Their analysis was funded by one in all ESA’s Science for Society initiatives known as Biodiversity of the Coastal Ocean, or BICOME.

Bede Ffinian Rowe Davies from Nantes College in France and lead creator of the paper, mentioned, “Coastal areas, like a lot of the world, are experiencing fast and alarming biodiversity loss. To handle this, it’s essential to develop environment friendly monitoring strategies in order that well timed and acceptable motion could be taken to protect delicate ecosystems.

“Utilizing knowledge from Sentinel-2 throughout the BiCOME venture, we have been capable of reveal important differences due to the season in intertidal seagrass. The peaks in extent shifted by as a lot as 5 months – difficult earlier assumptions that there was little or no seasonal fluctuation.”

As examples, the satellite tv for pc photos displayed above present the adjustments in intertidal seagrass cowl within the Cádiz Lagoon, Spain. One was taken in Might 2018 and the opposite in November 2021.

The satellite tv for pc photos under illustrate adjustments in intertidal seagrass cowl within the Bay of Bourgneuf, positioned north of the Bay of Biscay, off the western coast of France. The picture on the left, from April 2021, reveals sparse intertidal seagrass, whereas the picture on the proper, from September 2021, reveals ample progress.

Victor Martinez-Vicente, BiCOME venture principal investigator, famous, “This examine demonstrates the potential of satellite tv for pc observations to trace adjustments within the extent of pure coastal ecosystems, offering precious insights for indicators within the International Biodiversity Framework. Additional analysis is required to develop long-term satellite-based monitoring programs and datasets to assist world progress towards attaining the framework objectives.”

ESA’s Marie-Helene Rio, added, “These new findings clearly reveal the worth that Sentinel-2 can carry to monitoring intertidal seagrass. We now consider that these intertidal meadows behave in another way to the kind of seagrass that spends most of its life submerged by seawater. This means that earlier estimates, which grouped the 2 sorts collectively, might be deceptive.”

“The analysis paves the way in which to additional monitoring and evaluation of intertidal seagrass meadows utilizing Sentinel-2 knowledge.”

The Sentinel-2 satellites every carry a multispectral imager that takes high-resolution photos of Earth’s land, islands, and inland and coastal waters. And with a big swath width of 290 km, it gives these photos in 13 spectral bands with resolutions of 10 m, 20 m and 60 m.

The third Sentinel-2 satellite tv for pc, Sentinel-2C, was launched on 5 September 2024, and has already delivered its first photos of Earth.