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With data from the Copernicus Sentinel-2 mission, researchers have revealed seasonal variations in intertidal seagrass across Western Europe and North Africa. As a key indicator of biodiversity, these new findings offer valuable insights for the conservation and restoration of these vital ecosystems. The intertidal zone is the area where the ocean meets the land between high and low tides, and here seagrasses can form extensive meadows. These flowering marine plants provide critical habitats, acting as shelter, nurseries, and feeding and spawning grounds for a diverse range of birds, fish and invertebrates. Beyond their ecological importance, seagrass meadows also stabilize sediments and protect coastlines from erosion. Monitoring the occurrence, extent, condition and diversity of intertidal seagrass as a key biodiversity variable is essential for assessing the overall health of local ecosystems. Current global estimates of seagrass coverage do not differentiate between seagrasses in the intertidal zone and those in the subtidal zone, which remain submerged below the sea surface. However, a recent paper, published in Communications Earth & Environment, details how a team of scientists used high-resolution imagery from the Copernicus Sentinel-2 mission to demonstrate its ability to map intertidal seagrass meadows and their seasonal changes across continents with consistency and precision. Bede Ffinian Rowe Davies from Nantes University in France and lead author of the paper, said, “Coastal regions, like much of the world, are experiencing rapid and alarming biodiversity loss. To address this, it’s crucial to develop efficient monitoring methods so that timely and appropriate action can be taken to preserve delicate ecosystems. “Using data from Sentinel-2 within the BiCOME project, we were able to reveal significant seasonal variations in intertidal seagrass. The peaks in extent shifted by as much as five months—challenging previous assumptions that there was little or no seasonal fluctuation.” The satellite images below illustrate changes in intertidal seagrass cover in the Bay of Bourgneuf, located north of the Bay of Biscay, off the western coast of France. The image on the left, from April 2021, shows sparse intertidal seagrass, while the image on the right, from September 2021, reveals abundant growth. Victor Martinez-Vicente, BiCOME project principal investigator, noted, “This study demonstrates the potential of satellite observations to track changes in the extent of natural coastal ecosystems, providing valuable insights for indicators in the Global Biodiversity Framework. Further research is needed to develop long-term satellite-based monitoring systems and datasets to support global progress toward achieving the framework goals.” ESA’s Marie-Helene Rio added, “These new findings clearly demonstrate the value that Sentinel-2 can bring to monitoring intertidal seagrass. We now believe that these intertidal meadows behave differently to the type of seagrass that spends most of its life submerged by seawater. This suggests that previous estimates, which grouped the two types together, could be misleading. The research paves the way to further monitoring and assessment of intertidal seagrass meadows using Sentinel-2 data.” The Sentinel-2 satellites each carry a multispectral imager that takes high-resolution images of Earth’s land, islands, and inland and coastal waters. And with a large swath width of 290 km, it provides these images in 13 spectral bands with resolutions of 10 m, 20 m and 60 m. The third Sentinel-2 satellite, Sentinel-2C, was launched on 5 September 2024, and has already delivered its first images of Earth. More information: Bede Ffinian Rowe Davies et al, A sentinel watching over inter-tidal seagrass phenology across Western Europe and North Africa, Communications Earth & Environment (2024). DOI: 10.1038/s43247-024-01543-z This article is republished from PHYS.ORG and provided by the European Space Agency. Explore our blog for insights on the latest research from across the globe. Click here

An invasive species of seagrass has been on a steady march across the world, taking over ecosystems well beyond its native waters of the Red Sea, Persian Gulf and Indian Ocean. Scientists have long wondered when it would reach the waters off the coast of Florida. Florida International University scientists say that day has arrived. Florida International University marine scientist Justin Campbell has positively identified Halophila stipulacea growing in Crandon Marina and nearby areas of Biscayne Bay. It is the first time this non-native species has been found in waters along the continental United States. The study appears on the preprint server bioRxiv. “I think this species could pose a considerable threat,” Campbell said. “There are several reports of it being able to outcompete native seagrasses in other areas across the Caribbean. It is plausible that this could also be true for seagrasses here in South Florida.” A marina worker first noticed the seagrass last month and reached out to Campbell, who conducted tests to determine the species. Halophila stipulacea first started spreading its distribution with the opening of the Suez Canal in the late 1800s, hitching rides on the anchors and other parts of boats. By the early 2000s, it was found in the Caribbean.   Field photographs of H. Stipulacea inside Crandon Marina (Key Biscayne, Florida) (a,b). Close-up detail of samples collected inside the marina, structure and leaf cross veins (c,d). Credit: Matthew White (a,b) and Justin Campbell (c,d). Healthy seagrass meadows are vital for healthy oceans. They are nursery habitats for commercially and economically important fish as well as shrimp, stone crabs, scallops and other crustaceans and shellfish. Seagrasses are a primary food source for sea turtles, manatees and other marine herbivores. And for the health of the planet, seagrasses are really good at sucking carbon emissions out of the air and storing that carbon long-term. While scientists are still working to understand possible impacts from the invasive species entering waters around the U.S., early research suggests some fish species may avoid the shorter seagrass when scouting nursery locations and local sea turtles in the Caribbean avoid eating the invasive seagrass, preferring native species as part of their regular diets. While most species of seagrass are on the decline from warming waters and other human-induced impacts, Halophila stipulacea has the unique ability to grow quickly and adapt to different conditions including salinity levels, temperature and light availability. Just a small piece can float through water and grow. Once it settles into soil, it can take hold easily and grow at a variety of depths. While most seagrass species require shallower depths to attain sunlight, Halophila stipulacea has been observed flourishing at depths of 60 feet or more. “The arrival of yet another invasive species to Florida is a reminder that all of our earth is interconnected and that human actions have the power to change the planet, for good or bad,” said James Fourqurean, co-author of the research and director of the Coastlines and Oceans Division in FIU’s Institute of Environment. Fourqurean has studied seagrasses, especially those in Florida, for more than 40 years. A foremost expert, he is one of the lead scientists in the International Blue Carbon Working Group, as well as scientific representative to the International Blue Carbon Policy Working Group—both dedicated to the recognition and preservation of seagrass meadows, mangroves and tidal salt marshes as critical contributors to slowing the rise of CO2 in the atmosphere. “Given the importance of seagrasses to a healthy South Florida, we now need to do what we can to limit the spread of this invasive species and be wary of disruptions to the natural order it may cause,” Fourqurean said. Stipulacea has a very different appearance and structure than the native seagrasses in South Florida and throughout the Caribbean. At least 19 Caribbean islands have reported this seagrass growing in nearby waters and, in some cases, overtaking meadows of native grass. “We don’t know whether Stipulacea provides similar ecological benefits as compared to our native species,” Campbell said. “Our seagrass meadows here are some of the most pristine and well-protected in the Western Hemisphere. They are iconic and emblematic. We certainly don’t want to lose them.” So how long has this non-native species been in South Florida? It is hard for Campbell to say, but based on the current distribution, he believes it first started taking root several years ago. It had gone unnoticed because, to the casual observer, it can be difficult to distinguish from native vegetation, he said. Crandon Marina can accommodate medium and large sized sailboats, likely capable of travel to and from areas where Stipulacea is well-established. This is one possible and likely way the non-native seagrass reached Biscayne Bay. With other large marinas in the region, Campbell said surveys and monitoring should be expanded now that this invasive species is confirmed to be in South Florida. More information:Justin E. Campbell et al, First record of the seagrass Halophila stipulacea (Forskkal) Ascherson in the waters of the continental United States (Key Biscayne, Florida), bioRxiv (2024): DOI: 10.1101/2024.09.02.610701 This article is republished from PHYS.ORG and provided by the Florida International University. Explore our blog for insights on the latest research from across the globe. Click here

Seagrass meadows are essential for the health of our oceans. They provide vital habitats for marine life, improve water quality, and store significant amounts of carbon. Unfortunately, these vital ecosystems are in decline. Here at Project Seagrass, we are on a mission to restore seagrass meadows to help create a healthier world and protect against the impacts of climate change. To achieve this, we are partnering with Tandem Ventures to develop an underwater seagrass seed harvester to help us to more efficiently collect seagrass seeds and scale up the restoration process.  In order to do this, we need your help. We need to raise £30,000 to design, develop, and test this innovative new technology. Supporting our Crowdfunder will make seagrass restoration faster, more efficient, and scalable. Donate Today The Problem Currently, seagrass seed collection relies on divers using scissors – a slow and labour-intensive process. This bottleneck limits large-scale restoration efforts. We need to invent a new and radically better method this summer, while the seagrass is producing seeds. Time is ticking! Our Solution: The Underwater Seagrass Seed Harvester Key Features Automated Operation: Operates far more efficiently, reducing the need for manual labour. Efficient Collection: Gently harvests seeds without damaging the seagrass beds. Boat-Towed Design: Causes minimal disturbance to the seabed while covering large areas quickly. Adjustable: Key elements of the design can be adjusted to most efficiently collect Seagrass seeds in differing environments. Open-Source Design: Thoroughly documented and shareable plans, allowing replication and application worldwide. Join Us in Making a Difference We need to raise £30,000 to make this vision a reality. If we meet our target, the £30,000 will be allocated as follows: £6,500 for design, research and prototyping £15,000 for building the seagrass seed harvester £2,500 for documentation, and £6,000 for testing and iteration. Your support is crucial for the future of our oceans. By backing this project, you’re investing in innovative technology and a healthier planet. Together, we can restore seagrass meadows and protect marine life for generations to come. Donate via our Crowdfunder. Donate Today

Scientists from The University of Western Australia have partnered with Indigenous rangers on a seagrass restoration project in Gathaagudu (Shark Bay) to help moderate climate change and conserve biodiversity. Dr. Elizabeth Sinclair and Professor Gary Kendrick, from UWA’s School of Biological Sciences and Oceans Institute, were co-authors of the paper published in Ocean & Coastal Management. “Solutions that integrate western science and Traditional Ecological Knowledge are key to improving restoration outcomes,” Dr. Sinclair said. Researchers partnered with Malgana Aboriginal Corporation Rangers on a program that included On Country workshop-based knowledge sharing in north-west Western Australia, with a focus on seagrass restoration. Malgana Elder, Auntie Pat Oakley said managing and caring for a living and dynamic Country are at the heart of well-being for all Indigenous Peoples. “The global rate of seagrass decline continues largely due to human activities, including the widespread impacts from climate change,” Professor Kendrick said. “Reversing this decline by restoring seagrass ecosystems and the benefits they provide is challenging and can take decades, even when human impacts are reduced.” The program found with the right resourcing and logistics, there are opportunities to support training workshops that develop expertise in seagrass restoration activities in Shark Bay. Sean McNeair, Malgana man and ranger coordinator, said field-based restoration workshops helped people reconnect with Country through two-way knowledge sharing. “We need to empower the Malgana Aboriginal Corporation Rangers and local Indigenous-led businesses to schedule restoration activities that help build seasonal local economies and increase the ability to restore seagrass at larger scales,” Dr. Sinclair said. More information: Elizabeth A. Sinclair et al, Healing country together: A seagrass restoration case study from Gathaagudu (Shark Bay), Ocean & Coastal Management (2024). DOI: 10.1016/j.ocecoaman.2024.107274 Journal information can be found here: Ocean and Coastal Management This article is republished from PHYS.ORG and provided by the University of Western Australia.

An international team of researchers discovered that coastal urban seagrass ecosystems can significantly reduce human bacterial pathogens, including those with widespread antibiotic resistance, in marine bivalves—a vital food source for people around the world. The study, published Aug 2 in the journal Nature Sustainability, sheds light on the significant role seagrass meadows play in their ecosystems. Not only do they serve as crucial habitats for marine life and contribute to biodiversity and clearer waters, but they also act as natural filtration systems, reducing bacterial pathogens in the surrounding waters. This is important because the current economic burden of human infectious diseases in marine environments is estimated at $12 billion annually. Furthermore, the looming threat of antimicrobial resistance, projected to cause over 300 million deaths and cost the global economy $100 trillion, underscores the urgency of such natural interventions. “Our paper presents the first evidence that coastal urban seagrass ecosystems can reduce human bacterial pathogens, several with known widespread antibiotic resistance, in a food source that has the potential to support over half of global seafood production and consumption,” said Joleah Lamb, assistant professor at the University of California, Irvine, Charlie Dunlop School of Biological Sciences, who led the research with Drew Harvell, professor emerita of ecology and evolutionary biology at Cornell. The team analyzed mussels deployed by Washington’s Department of Fish and Wildlife Mussel Watch across 20 Puget Sound beaches with varying seagrass presence. Mussel gills from locations with seagrass showed a 65% reduction in bacterial pathogens compared with those from places without seagrass. Phoebe Dawkins performs seagrass health surveys in Puget Sound. Credit: Cornell University This study adds to Lamb and Harvell’s previous work showing 50% reductions in pathogenic bacteria in Indonesia seagrass meadows, and suggests that intact seagrass ecosystems in both tropical and temperate waters could play a vital role in ensuring safer seafood and enhancing public health. “Seagrasses have untapped potential to contribute to the chain of survival for humans and our coastal biodiversity,” Harvell said. “Seagrass meadows are prime feeding grounds for wild birds and shelter crabs, oysters, mussels and sea stars, and so the role of lower bacteria has yet unmeasured benefit for wildlife as well as humans.” Harvell’s Cornell research team of postdocs, graduate students and undergraduates has been studying the health of seagrass and drivers of decline in the San Juan Islands and Friday Harbor Labs for over a decade. The Cornell-based research team for this project included not only Lamb, but also Phoebe Dawkins, then a graduate student in Harvell’s lab, and undergraduate Evan Fiorenza ’17. The potential applications of this research are vast, Lamb said. As global food demand accelerates, securing safe and sustainable seafood from a healthy ocean is critical. Seagrass meadows, which are already recognized for their high-value services such as nutrient cycling, carbon sequestration and shoreline protection, now present an added layer of public health benefits. The study’s model estimates that 1.1 billion people currently live within 50 kilometers of seagrass ecosystems, highlighting the immediate opportunity to integrate these natural infrastructures into urban planning and conservation strategies. This research aligns with numerous global sustainability initiatives, including the U.N. Decade of Ocean Science for Sustainable Development and the U.N. Decade on Ecosystem Restoration. It provides timely evidence to inform policies and commitments aimed at reversing the decline of seagrass ecosystems, which are disappearing at an alarming rate of 7% per year. The study’s implications extend beyond immediate public health benefits, Lamb said, offering a blueprint for sustainable urban development that leverages nature’s powers to address global challenges. Lamb has called for a concerted effort from policymakers, urban planners and conservationists to recognize and harness the benefits of seagrass ecosystems. “As ecosystems continue to decline globally, there is an urgent need to invest in environmental conservation and assess the value of ecosystem services,” she said. “By doing so, we can make significant strides in addressing the biodiversity and climate crises while simultaneously improving human health and food security.” This research was supported by the Sea Doc Society, a program of the Karen C. Drayer Wildlife Health Center at the School of Veterinary Medicine at the University of California, Davis; the University of California, Irvine; and The Nature Conservancy. https://www.youtube.com/watch?v=Mt3za0G6ack&t=56s Credit: Video produced by Bob Friel and the SeaDoc Society. Narrated by SeaDoc Society Science Director Joe Gaydos. More information: Phoebe D. Dawkins et al, Seagrass ecosystems as green urban infrastructure to mediate human pathogens in seafood, Nature Sustainability (2024). DOI: 10.1038/s41893-024-01408-5 Journal information: Nature Sustainability  This article is republished from PHYS.ORG and provided by the Cornell University.