Limited potexvirus diversity in eastern Gulf of Mexico seagrass meadows.

Turtlegrass virus X, which infects the seagrass Thalassia testudinum, is the only potexvirus known to infect marine flowering plants. We investigated potexvirus distribution in seagrasses using a degenerate reverse transcription polymerase chain reaction (RT-PCR) assay originally designed to capture potexvirus diversity in terrestrial plants. The assay, which implements Potex-5 and Potex-2RC primers, successfully amplified a 584 nt RNA-dependent RNA polymerase (RdRp) fragment from TVX-infected seagrasses. Following validation, we screened 74 opportunistically collected, apparently healthy seagrass samples for potexviruses using this RT-PCR assay. The survey examined the host species T. testudinum, Halodule wrightii, Halophila stipulacea, Syringodium filiforme, Ruppia maritima, and Zostera marina. Potexvirus PCR products were successfully generated only from T. testudinum samples and phylogenetic analysis of sequenced PCR products revealed five distinct TVX sequence variants. Although the RT-PCR assay revealed limited potexvirus diversity in seagrasses, the expanded geographic distribution of TVX shown here emphasizes the importance of future studies to investigate T. testudinum populations across its native range and understand how the observed fine-scale genetic diversity affects host-virus interactions.

How do soil processes control the provision of ecosystem services in coastal wetlands?

Coastal wetlands are known for their diverse ecosystems, yet their soil characteristics are often misunderstood and thought to be monotonous. These soils are frequently subjected to saline water saturation, leading to unique soil processes. However, the combination and intensity of these processes can vary considerably across different ecosystems. In this study, we hypothesize that these diverse soil processes not only govern the geochemical conditions in coastal ecosystems but also influence their ability to deliver ecosystem services. To test this hypothesis, we conducted soil analyses in mangroves, seagrass meadows, and hypersaline tidal flats along the Brazilian coast. We used key soil properties as indicators of soil processes and developed a conceptual model linking soil processes and soil-related ecosystem services in these environments. Under more anoxic conditions, the intense soil organic matter accumulation and sulfidization processes in mangroves evidence their significance in terms of climate regulation through organic carbon sequestration and contaminants immobilization. Similarly, pronounced sulfidization in seagrasses underscores their ability to immobilize contaminants. In contrast, hypersaline tidal flats soils exhibit increased intensities of salinization and calcification processes, leading to a high capacity for accumulating inorganic carbon as secondary carbonates (CaCO3), underscoring their role in climate regulation through inorganic carbon sequestration. Our findings show that contrary to previously thought coastal wetlands are far from monotonous, exhibiting significant variations in the types and intensities of soil processes, which in turn influence their capacity to deliver ecosystem services. This understanding is pivotal for guiding effective management strategies to enhance ecosystem services in coastal wetlands.

Microbiomes of Thalassia testudinum throughout the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico are influenced by site and region while maintaining a core microbiome.

Plant microbiomes are known to serve several important functions for their host, and it is therefore important to understand their composition as well as the factors that may influence these microbial communities. The microbiome of Thalassia testudinum has only recently been explored, and studies to-date have primarily focused on characterizing the microbiome of plants in a single region. Here, we present the first characterization of the composition of the microbial communities of T. testudinum across a wide geographical range spanning three distinct regions with varying physicochemical conditions. We collected samples of leaves, roots, sediment, and water from six sites throughout the Atlantic Ocean, Caribbean Sea, and the Gulf of Mexico. We then analyzed these samples using 16S rRNA amplicon sequencing. We found that site and region can influence the microbial communities of T. testudinum, while maintaining a plant-associated core microbiome. A comprehensive comparison of available microbial community data from T. testudinum studies determined a core microbiome composed of 14 ASVs that consisted mostly of the family Rhodobacteraceae. The most abundant genera in the microbial communities included organisms with possible plant-beneficial functions, like plant-growth promoting taxa, disease suppressing taxa, and nitrogen fixers.

Metal and metalloid maternal transfer in a newborn West Indian manatee (Trichechus manatus) two years after the northeastern oil spill disaster of 2019 in Brazil.

A large-scale oil spill along the northeastern Brazilian coast in 2019-2020 severely impacted primary manatee habitats in Brazil. This study aimed to assess metal and metalloid contamination in a dead manatee calf found following this oil spill. Several elements were detected, including chromium, iron, nickel, lead, and vanadium, which are crude oil components, and thallium, a component of dispersants used to degrade and dissipate crude oil. The presence of these contaminants in the manatee calf is indicative of maternal exposure, metabolism, and newborn transference via placenta and lactation. This is the first report of mother-calf metal transfer in manatees, highlighting the species' vulnerability and potential long-term population dynamics effects, and the first report for several metals and metalloids in these animals, laying the foundation for future research efforts. These findings highlight the urgent need for continued environmental monitoring, ecotoxicological assessments, and conservation initiatives.

Marine heatwaves recurrence aggravates thermal stress in the surfgrass Phyllospadix scouleri.

The surfgrass Phyllospadix scouleri grows in highly productive meadows along the Pacific coast of North America. This region has experienced increasingly severe marine heatwaves (MHWs) in recent years. Our study evaluated the impact of consecutive MHWs, simulated in mesocosms, on essential ecophysiological features of P. scouleri. Overall, our findings show that the plants' overall physiological status has been progressively declining. Interestingly, the indicators of physiological stress in photosynthesis only showed up once the initial heat exposure stopped (i.e., during the recovery period). The warming caused increased oxidative damage and a decrease in nitrate uptake rates. However, the levels of non-structural carbohydrates and relative growth rates were not affected. Our findings emphasize the significance of incorporating recovery periods in this type of study as they expose delayed stress responses. Furthermore, experiencing consecutive intense MHWs can harm surfgrasses over time, compromising the health of their meadows and the services they offer to the ecosystem.

Kinetics of metal and metalloid concentrations in holopelagic Sargassum reaching coastal environments.

Since 2011, the Caribbean Islands have experienced unprecedented stranding of a pelagic brown macroalgae Sargassum inducing damages for coastal ecosystems and economy. This study measures the kinetics of metal trace elements (MTE) in Sargassum reaching different coastal environments. In July 2021, over a period of 25 days, fixed experimental floating cages containing the three Sargassum morphotypes (S. fluitans III and S. natans I and VIII) were placed in three different coastal habitats (coral reef, seagrass, and mangrove) in Guadeloupe (French West Indies). Evolution of biomasses and their total phenolic content of Sargassum reveals that environmental conditions of caging were stressful and end up to the death of algae. Concentrations of 19 metal(loid) trace elements were analyzed and three shapes of kinetics were identified with the MTE that either concentrate, depurate, or remains stable. In the mangrove, evolution of MTE was more rapid than the two other habitats a decrease of the As between 70 and 50 µg g-1 in the mangrove. Sargassum natans I presented a different metal composition than the two other morphotypes, with higher contents of As and Zn. All Sargassum morphotype are rapidly releasing the metal(oid)s arsenic (As) when they arrive in studied coastal habitats. In order to avoid the transfer of As from Sargassum to coastal environments, Sargassum stranding should be avoided and their valorization must take into account their As contents.

Influence of pelagic sargassum influxes on the δ15N in Thalassia testudinum of the Mexican Caribbean coastal ecosystem.

The conservation of Mexican Caribbean Ecosystems (MCE) involves ensuring their capacity to provide resources and ecosystem services to society. Monitoring programs are necessary to establish their management and ensure their sustainability. Thalassia testudinum is the community used to determine anthropogenic influence, in which wastewater is the primary anthropogenic nitrogen source. The extensive amount of pelagic sargassum that enters the area and its decomposition may be additional nitrogen sources in MCE. In the present study, the δ15N in T. testudinum was examined from 2009 to 2019 to infer the nitrogen contribution from pelagic sargassum to MCE. T. testudinum δ15N values showed significant depletion from June/October 2014 to 2019 concerning previous periods. Pelagic sargassum was an alternative nitrogen source, and its leaching reduced T. testudinum δ15N values in MCE.

A risk assessment on Zostera chilensis, the last relict of marine angiosperms in the South-East Pacific Ocean, due to the development of the desalination industry in Chile.

Seagrasses, which are considered among the most ecologically valuable and endangered coastal ecosystems, have a narrowly limited distribution in the south-east Pacific, where Zostera chilensis is the only remaining relict. Due to water scarcity, desalination industry has grown in the last decades in the central-north coasts of Chile, which may be relevant to address in terms of potential impacts on benthic communities due to their associated high-salinity brine discharges to subtidal ecosystems. In this work, we assessed ecophysiological and cellular responses to desalination-extrapolable hypersalinity conditions on Z. chilensis. Mesocosms experiments were performed for 10 days, where plants were exposed to 3 different salinity treatments: 34 psu (control), 37 psu and 40 psu. Photosynthetic performance, H2O2 accumulation, and ascorbate content (reduced and oxidized) were measured, as well as relative gene expression of enzymes related to osmotic regulation and oxidative stress; these, at 1, 3, 6 and 10 days. Z. chilensis showed a decrease in photosynthetic parameters such as electron transport rate (ETRmax) and saturation irradiance (EkETR) under hypersalinity treatments, while non-photochemical quenching (NPQmax) presented an initial increment and a subsequent decline at 40 psu. H2O2 levels increased with hypersalinity, while ascorbate and dehydroascorbate only increased under 37 psu, although decreased along the experimental period. Increased salinities also triggered the expression of genes related to ion transport and osmolyte syntheses, but salinity-dependent up-regulated genes were mostly those related to the reactive oxygen species metabolism. The relict seagrass Z. chilensis has shown to withstand increased salinities that may be extrapolable to desalination effects in the short-term. As the latter is not fully clear in the long-term, and considering the restricted distribution and ecological importance, direct brine discharges to Z. chilensis meadows may not be recommended.

Environmental degradation of the Mexican Caribbean reef lagoons.

Insufficient attention to the large volumes of wastewater produced by expansive tourism and urban development in the north of the Mexican Caribbean has increased concerns on the ecological and economic sustainability of this important tourist destination, which is currently threatened by massive arrivals of pelagic Sargassum. Comparing environmental descriptions for sites exposed to contrasting anthropogenic pressure and before and during massive Sargassum tides, uncovered significant shifts in the environmental conditions in the last 20 years, from oligotrophic to mesotrophic-eutrophic conditions. The most significant changes were observed in the north, for habitats exposed to high anthropogenic pressure. Accordingly, the severe threat that massive Sargassum beaching currently represents for the survival of Caribbean coral reefs cannot be considered the only driver of reef eutrophication in the Mexican Caribbean, as the habitat degradation documented here has an important contribution from anthropogenic fertilization.

Heterozostera nigricaulis from the south-East Pacific coast of Chile: First insights into its physiology and growth.

A short stretch (27°S and 30°S) along the coast of Chile is habitat for the seagrass Heterozostera nigricaulis. The seagrass is classified as endangered and grows only clonally, but there are no data on its physiology and growth. However, this information is important to gain insights into its acclimation potential and how disturbances may affect them. We therefore studied H. nigricaulis at 27° and 30°S, and determined their growth and physiology among seasons and depths over one year. Biomass was higher at 27° than at 30°S, and was always higher in summer than in autumn and winter. Increased photosynthesis supported growth in summer, and in winter carbonic anhydrase activity was in place to maintain these evergreen meadows. Our results suggest that these seagrass meadows are adapted to local conditions, which, together with their asexual reproduction, could make them more vulnerable to disturbance. Therefore, our results serve as a basis for future studies on seagrass growth dynamics, and are important for protection and management plans.

First record of Phytomyxid infection of the non-native seagrass Halophila stipulacea in Puerto Rico.

Halophila stipulacea is an invasive seagrass in the Caribbean Sea that also harbors a phytomyxid endoparasite. Phytomyxean parasites are known to cause disease in agricultural crops and are documented to form galls in some seagrass species. Here we make the first report of phytomyxid infection of Halophila stipulacea in the Bahía de Jobos in Salinas, Puerto Rico. We found phytomyxid infected H. stipulacea at 3 of 5 sites examined; expanding the documented range of the Marinomyxa marina phytomyxid infection by almost 400 km from where it was first documented in 2018. Presence of the endoparasite has not impeded H. stipulacea dispersal and continued expansion of H. stipulacea will likely spread both the host seagrass and the endoparasite.

Changes in the Rhizosphere Prokaryotic Community Structure of Halodule wrightii Monospecific Stands Associated to Submarine Groundwater Discharges in a Karstic Costal Area.

Belowground seagrass associated microbial communities regulate biogeochemical dynamics in the surrounding sediments and influence seagrass physiology and health. However, little is known about the impact of environmental stressors upon interactions between seagrasses and their prokaryotic community in coastal ecosystems. Submerged groundwater discharges (SGD) at Dzilam de Bravo, Yucatán, Mexico, causes lower temperatures and salinities with higher nutrient loads in seawater, resulting in Halodule wrightii monospecific stands. In this study, the rhizospheric archaeal and bacterial communities were characterized by 16S rRNA Illumina sequencing along with physicochemical determinations of water, porewater and sediment in a 400 m northwise transect from SGD occurring at 300 m away from coastline. Core bacterial community included Deltaproteobacteria, Bacteroidia and Planctomycetia, possibly involved in sulfur metabolism and organic matter degradation while highly versatile Bathyarchaeia was the most abundantly represented class within the archaeal core community. Beta diversity analyses revealed two significantly different clusters as result of the environmental conditions caused by SGD. Sites near to SGD presented sediments with higher redox potentials and sand contents as well as lower organic matter contents and porewater ammonium concentrations compared with the furthest sites. Functional profiling suggested that denitrification, aerobic chemoheterotrophy and environmental adaptation processes could be better represented in these sites, while sulfur metabolism and genetic information processing related profiles could be related to SGD uninfluenced sites. This study showed that the rhizospheric prokaryotic community structure of H. wrightii and their predicted functions are shaped by environmental stressors associated with the SGD. Moreover, insights into the archaeal community composition in seagrasses rhizosphere are presented.

Green turtles shape the seascape through grazing patch formation around habitat features: Experimental evidence.

Understanding how megaherbivores incorporate habitat features into their foraging behavior is key toward understanding how herbivores shape the surrounding landscape. While the role of habitat structure has been studied within the context of predator-prey dynamics and grazing behavior in terrestrial systems, there is a limited understanding of how structure influences megaherbivore grazing in marine ecosystems. To investigate the response of megaherbivores (green turtles) to habitat features, we experimentally introduced structure at two spatial scales in a shallow seagrass meadow in The Bahamas. Turtle density increased 50-fold (to 311 turtles ha-1 ) in response to the structures, and turtles were mainly grazing and resting (low vigilance behavior). This resulted in a grazing patch exceeding the size of the experimental setup (242 m2 ), with reduced seagrass shoot density and aboveground biomass. After structure removal, turtle density decreased and vigilance increased (more browsing and shorter surfacing times), while seagrass within the patch partly recovered. Even at a small scale (9 m2 ), artificial structures altered turtle grazing behavior, resulting in grazing patches in 60% of the plots. Our results demonstrate that marine megaherbivores select habitat features as foraging sites, likely to be a predator refuge, resulting in heterogeneity in seagrass bed structure at the landscape scale.

Seagrass density correlates with burrow abundance and size in the Zebra Mantis Shrimp (Stomatopoda: Lysiosquillidae) / La densidad de los pastos marinos se correlaciona con la abundancia y el tamaño de las madrigueras de los camarones mantis cebra (Stomatopoda: Lysiosquillidae)

Introduction: Mantis shrimps are ecologically and economically important organisms in marine ecosystems. However, there is still a lack of information about their habitat, in particular, their burrows. Objective: To analyze how dense and sparse mantis shrimp burrows differ in abundance, size, sediment grain size, and water quality. Methods: We counted burrows in 10 x 10 m2 random plots in sparse and dense seagrass (ten plots per density), around Barrang Lompo Island, South Sulawesi, Indonesia. Sampling took place at spring low tide from August to September 2017. Results: Two mantis shrimp species were observed: Lysiosquillina maculate and L. sulcata. Dense and sparse seagrass burrows did not differ in wall grain size or water parameters, both inside and outside of the burrows (P > 0.05). Similarly, there was no correlation between burrow depth and diameter in either dense (P > 0.05; r= 0.27) or sparse (P > 0.05; r= 0.33) seagrass. However, larger burrows tend to occur in denser beds, but there were more burrows in denser seagrass (t-test, P < 0.05). Conclusions: There seems to be a preference for dense seagrass beds, especially by larger mantis shrimps. The correlation between shrimp burrow abundance and seagrass density highlights the importance of conserving the quality as well as the extent of seagrass habitat.

Introducción: Los camarones mantis son organismos ecológica y económicamente importantes en los ecosistemas marinos. Sin embargo, aún falta información sobre su hábitat, en particular sobre sus madrigueras. Objetivo: Analizar cómo difieren las madrigueras de los camarones mantis en su abundancia, tamaño, tamaño de grano de los sedimentos y calidad del agua. Métodos: Contamos las madrigueras en parcelas de 10 x 10 m2 al azar (diez parcelas por densidad) en pastos marinos densos y poco densos, alrededor de la isla de Barrang Lompo, Sulawesi del Sur, Indonesia. Resultados: Se observaron dos especies de camarones mantis: Lysiosquillina maculata y L. sulcata. El tamaño de grano de las paredes de las madrigueras y los parámetros de agua, tanto dentro y fuera de la madriguera no variaron (P > 0.05). Tampoco hubo correlación entre la profundidad y el diámetro de las madrigueras, tanto en praderas densas (P > 0.05; r= 0.27), como no densas (P > 0.05; r= 0.33). Sin embargo, las madrigueras más grandes tienden a aparecer en las praderas densas, además había más madrigueras en pastos densos (t-test, P < 0.05). Conclusiones: Parece haber una preferencia por las praderas marinas densas, especialmente en los camarones mantis de mayor tamaño. La correlación entre la abundancia de madrigueras de camarones y la densidad de pastos marinos pone de manifiesto la importancia de conservar la calidad del hábitat de los pastos, así como su extensión.

Accumulation and fluxes of potentially toxic elements in a large coastal lagoon (southern Gulf of Mexico) from 210Pb sediment chronologies.

Three 210Pb-dated sediment cores were used to evaluate the contamination degree and flux ratios of potentially toxic elements (PTEs; As, Cd, Cr, Cu, Ni, Pb, V, and Zn) in seagrass meadows from the northern margin of Términos Lagoon (TL), southern Gulf of Mexico. The sediments displayed minor Cd, Ni, V, and Zn enrichments but moderate to strong enrichment by As. Results from a chemometric analysis revealed that: 1) salinization and grain size, along with 2) the terrigenous inputs are the major factors influencing the PTEs accumulation. The historical trends of PTEs flux ratios nearly follow the large-scale land-use changes around TL, linked to the growth of the Mexican oil industry in the area since the 1970s. Our findings showed the critical role of seagrass meadows as PTEs sinks. This information is useful for decision-makers to develop restoration projects for a vulnerable site within the largest coastal lagoon ecosystem in Mexico.

Temporal variations in the level of chlordecone in seawater and marine organisms in Martinique Island (Lesser Antilles).

The present study, conducted in the Galion Bay in Martinique, aims to highlight the temporal and seasonal variations of chlordecone contamination (an organochlorine pollutant) in the ambient environment (seawater) and also in the marine organisms in three main coastal marine habitats (mangroves, seagrass beds and coral reefs). To this end, two methodologies were used to measure and compare the chemical contamination of seawater during 13 months (spot samplings and POCIS technique). In parallel, concentrations of chlordecone and isotopic ratios (C and N) were carried out on marine organisms, collected during two contrasting climatic periods (dry and rainy), to evidence seasonal variations. The results showed that the contamination of seawater displayed significant variations over time and depended on environmental factors such as water flows, which imply dilution and dispersion phenomena. Concerning the marine organisms, the level of contamination varied considerably between the two seasons in seagrass beds with higher levels of contamination during the rainy season. Reef organisms were more moderately affected by this pollution, while mangrove organisms showed a high level of chlordecone whatever the season. Finally, isotope analyses highlighted that bioamplification along marine food webs occurs at each season and each station.

Coastal degradation impacts on green turtle's (Chelonia mydas) diet in southeastern Brazil: Nutritional richness and health.

This study evaluated the influence of environmental degradation on the nutritional value of the main marine macrophytes consumed by green sea turtles (Chelonia mydas) in areas with different degrees of urbanization. Macrophyte assemblages in the highly urbanized area (HUa) showed lower richness compared to the lightly urbanized area (LUa) (Mann-Whitney U test: 10.0 ± 3.6 SD genera and 11.9 ± 4.2 taxa per transect vs. 20.1 ± 7.0 genera and 23.5 ± 9.2 taxa per transect) respectively. Also, diet was poorer with 4.0 ± 1.6 genera per turtle (vs. 8.5 ± 4.0 in HUa) and less diverse with Shannon index of diversity = 0.45 ± 0.29 (vs. 0.64 ± 0.46 in LUa). Body condition was similar in both areas. About half of individuals were classified as having normal body condition, 14-15% as underweight and 23-34% as being emaciated. Fibropapillomatosis prevalence (χ2 = 8.720; n = 222; df = 1; p = 0.003) was higher in the HUa but, in affected animals, severity was marginally non-significant (χ2 = 5.721; n = 82; df = 2; p = 0.057). Significant differences in energy content (kcal) were detected between areas in both summer (S) and winter (W). All ANOVAs on total lipids (F = 22.15 [S] and 30.39 [W]), total water-soluble proteins (F = 327.65 [S] and 64.42 [W]) and total carbohydrates (F = 70.90 [S] and 27.62 [W]) showed high significance (p < 0.001). Carotenoids concentration yielded significant results for Halodule in summer and Hypnea in winter (ANOVAs, F = 39.42 and 13.07, respectively). For both, tests revealed that concentration was higher in LUa than HUa. High levels of phycobiliproteins and proteins in this area probably reflect nitrogen accumulation. Frequency and severity of fibropapillomatosis suggest that urbanization-caused alterations in species diversity and in chemical composition of marine plants affect green turtles' health. LIGHT ABSTRACT: The use of coastal areas by humanity is widespread and increasing. The impacts caused to the coastal environment, be it terrestrial, estuarine or marine, are important and affect numerous species. Our study evaluated the influence of environmental degradation on the nutritional value of the main algae eaten by the green turtle, one of the very few marine megaherbivores (those herbivores with body mass above 10 kg). Diet in the highly urbanized area was richer in proteins, lipids and carbohydrates (sugars) and lower in carotenoids (photosynthetic and photoprotectant pigments in algae and plants; precursors of vitamin A involved in oxygen transport in animals-animals do not synthetize such molecules). High levels in phycobiliproteins (photosynthetic pigments present in some algae) and proteins in the highly urbanized area probably result from organic pollution and nitrogen accumulation in coastal waters. Nitrogen compounds dissolved in water are a threat to vertebrates due to its toxicity and negative effects on the immune system. Our results suggest that algae chemical composition and severity of fibropapillomatosis (tumors caused by a herpesvirus in green sea turtles) are directly related through environmental alterations caused by urbanization.

Mollusk death assemblages in 210Pb-dated marine sediment cores reveal recent biotic changes in the Gulf of Guanahacabibes, NW Cuba.

We investigated stratigraphic changes in mollusk death assemblages and geochemistry in sediment cores from four seagrass beds and one unvegetated site in the Gulf of Guanahacabibes (GG), NW Cuba. There was a transition from mangrove to seagrass beds, associated with sea level rise ∼6000 years ago. Sediment accumulation rates during the last century showed a general rise, but increased sharply after ∼1980, likely because of human activities. The GG displayed overall high mollusk γ-diversity, and our estimate of 189 species is biased toward the low end. High ß-diversity was driven by inter-site differences in grain size, vegetation cover, and nutrient input. Spatial heterogeneity within the basin influenced downcore abundance and diversity metrics, highlighting the influence of local drivers. Herbivorous gastropods dominated in seagrass beds and suspension feeder bivalves were dominant on sandy bottom. In the top parts of cores, species richness declined at two sites that were subject to high, human-mediated bulk sedimentation rates and eutrophication. Conservation measures are needed to preserve this hotspot of marine diversity.

Selection of parameters for seagrass management: Towards the development of integrated indicators for French Antilles.

Seagrass beds are increasingly impacted by human activities in coastal areas, particularly in tropical regions. The objective of this research program was to study seagrass beds characteristics under various environmental conditions in the French Antilles (FA, Caribbean Sea). A total of 61 parameters, from plant physiology to seagrass ecosystem, were tested along a gradient of anthropogenic conditions, distributed across 11 sites and 3 islands of the FA. A selection of 7 parameters was identified as relevant for the monitoring of seagrass meadows in the framework of public policies. They combined "early warning indicators" (e.g. nutrients and some trace metals) and long-term responding parameters (e.g. shoot density) adapted to management time scales. The ecological status of seagrass meadows was evaluated using a PCA. This work is a first step towards monitoring and management of seagrass meadows in the FA.