Element concentrations in pelagic Sargassum along the Mexican Caribbean coast in 2018-2019

Rosa E. Rodríguez-Martínez ​​1, Priyadarsi D. Roy ​2, Nuria Torrescano-Valle 3, Nancy Cabanillas-Terán 3, 4, Silvia Carrillo-Domínguez 5, Ligia Collado-Vides 6, Marta García-Sánchez 1, 7, Brigitta I. van Tussenbroek 1

The west coast of Africa and some eastern Caribbean islands received unusual large quantities of pelagic Sargassum spp. (S. fluitans (Boergesen) Boergesen and S. natans (Linnaeus) Gallion; hereafter named sargasso) for the first time in 2011 (Gower, Young & King, 2013). In subsequent years, the range of massive sargasso influx extended over the Atlantic Ocean and whole Caribbean Sea. Wang et al. (2019) reported more than 20 million metric tons of sargasso in the open ocean in the peak month of June 2018, when the Great Atlantic Sargasso Belt extended for 8,850 km in total length. Beaching of sargasso has caused havoc to the Caribbean coastal ecosystems. Leachates and particulate organic matter from stranded decaying algal masses depleted the oxygen in near shore waters and reduced visibility of the water column, causing mortality of near-shore seagrasses and fauna (van Tussenbroek et al., 2017; Rodríguez-Martínez et al., 2019). Onshore and near shore masses of sargasso interfered with the seaward journeys of the juvenile turtles (Maurer, De Neef & Stapleton, 2015), affected sea turtle nestings (Maurer, Stapleton & Layman, 2018) and altered the trophic structure of the sea urchin Diadema antillarum in coastal marine systems (Cabanillas-Terán et al., 2019). Massive beachings also enhanced beach erosion (van Tussenbroek et al., 2017). Coastal ecosystem-based tourist industry is one of the major sources of income for the Caribbean countries (Langin, 2018) and the potential socio-economic impacts of ecosystem degradation due to sargasso influx have yet to be assessed.

The Mexican Caribbean coast began receiving massive amounts of sargasso during the late 2014 and it reached a peak in September 2015, when in the northern section of the coast between Cancun and Puerto Morelos an average of ∼2,360 m3 of algae (mixed with sand, seagrasses and other algae) arrived per km of coastline (Rodríguez-Martínez, van Tussenbroek & Jordán-Dahlgren, 2016). During 2016, and 2017, the influxes decreased, increasing again in 2018, when in the peak month May ∼8,793 m3 km−1 of algae (mixed with sand, seagrasses and other algae) were removed from the same shore section (Rodríguez-Martínez et al., 2019). In the tourist beaches, the algae removed from the beach and sea have been disposed in areas that are not properly prepared to avoid leakage of the leachates into the aquifer. In addition, the cleaning efforts have not covered the whole coastline and thousands of tons of sargasso have accumulated annually along the Mexican Caribbean coast.

Like other brown algae, species of Sargassum (including the pelagic ones) have high capacity to absorb metals and other elements (Kuyucak & Volesky, 1988; Davis, Volesky & Vieira, 2000). This high absorption capacity is attributed to the unique mixture of polysaccharides, mainly alginates, in their cell walls (Fourest & Volesky, 1997). At present, the Sargassum spp. are used for different commercial end products, such as fertilizers (Milledge & Harvey, 2016), textiles, paper and drugs (Oyesiku & Egunyomi, 2014), as well as in the production of biogas (Wang et al., 2018). They have also been increasingly used as food for animals and humans, and therefore the high concentrations of contaminants, including heavy metals, may pose potential health risks (Reis & Duarte, 2018). Therefore, it is mandatory to evaluate elemental concentrations to ensure that acceptable levels are maintained in terms of health regulations (e.g., Fourest & Volesky, 1997). Previous studies on metal contents in sargasso, were either based on limited number of samples collected mostly from a single locality (e.g., Nigeria Oyesiku & Egunyomi, 2014; Dominican Republic, Fernández et al., 2017) or in a single season (e.g., Addico & De Graft-Johnson, 2016). Hence, it is unclear how much the metal contents can vary in the algal tissues across sites and seasons and between species.

In this study, we estimate concentrations of 28 different elements in sargasso tissues collected from the Mexican Caribbean coast, covering a linear north-south distance of 370 km. We hypothesize that the elemental contents are variable both in time and space. The determinations of metals and other elements from this study provide an essential baseline data for adequate management and potential uses of sargasso.

Survey Methodology

Study sites

We collected 63 samples of sargasso along the Mexican Caribbean coast, from Contoy Island, at the northern extreme, to Xcalak in the south (Fig. 1). This region receives an average precipitation of ∼1,061 mm y−1 and the sea-surface temperature (SST) ranges from 25.1–29.9 °C (Rodríguez-Martínez et al., 2010). The Yucatan Current, a major branch of the Caribbean Current, transports the pelagic algal masses parallel to the Mexican Caribbean coastline. Easterly trade-winds dominate this region during the summer and mild cold fronts occur during the winter season. Trade-winds transport the superficial waters towards the shore, importing the pelagic masses of sargasso towards the coast.

Figure 1: Sampling sites. Location of the sampling sites of sargasso along the Mexican Caribbean coast between August 2018 and June 2019. Map produced in QGIS 2.18 (http://www.qgis.org) using the following data sources: National Geospatial-Intelligence Agency (base map, World Vector Shoreline Plus, 2004. http://shoreline.noaa.gov/data/datasheets/wvs.html). The location of survey sites was obtained from the present study. Data sources are open access under the Creative Commons License (CC BY 4.0).

The coastal environment consists of beaches, rocky shores, seagrass beds, coral reefs, mangroves, jungle and underground rivers (Hernández-Arana et al., 2015). All these ecosystems provide services to the tourism industry, a crucial component of the regional economy (Spalding et al., 2017). In the karstic Yucatan peninsula, the freshwater aquifer and seawater are constantly interacting; especially near the coast (Hernández-Terrones et al., 2011; Hernández-Terrones et al., 2015). This region has no other major industries besides tourism. At present, this region has the highest number of hotel rooms in Mexico and the number of rooms has increased from 3,206 in 1975 to 100,986 in 2017 (SEDETUR, 2019). Similarly, the resident population grew almost 15-folds, from less than 100,000 in 1970 to 1,501,785 in 2015 (INEGI, 2015). This rapid urban development has caused coastal pollution through influx of nutrients (Carruthers, van Tussenbroek & Dennison, 2005; Hernández-Terrones et al., 2011; Baker, Rodríguez-Martínez & Fogel, 2013; van Tussenbroek et al., 2017), sewage (Metcalfe et al., 2011), and some metals (e.g., Lead, see Whelan III, van Tussenbroek & Santos, 2011) into the coastal ecosystems.

Methodology

Field collection

Samples were collected between August 2018 and June 2019 from eight different sites along the Mexican Caribbean coast (from north to south): (1) Contoy Island, (2) Blue waters, (3) Puerto Morelos, (4) Cozumel, (5) Mahahual, (6) Chinchorro, (7) Xahuayxol and 8) Xcalak (Fig. 1, Table 1). Fresh sargasso (golden color) thalli floating near the shore (2–20 m) and in the ocean (>5 km from shore) were collected manually and separated in species and morphotypes (S. fluitans III, S. natans I and S. natans VIII) in the laboratory following Schell, Goodwin & Siuda (2015), except for the samples of Contoy Island (CI). The samples collected from CI were frozen before separating the specimens by species and morphotypes, thus, we classified them as Sargassum spp. All the samples were placed in an oven for at least 48 h at 60 °C until completely dry. Special caution was taken to avoid contact between the algal samples and any metal object. Samples were shipped to the Institute of Geology of the National Autonomous University of Mexico for the analysis of element concentrations. We did not remove epibionts from the thalli and analyzed the chemical composition of the algae including attached organisms, as the main interest of this study was to determine the potential contamination hazards and uses of sargasso as collected from the sea, without any specific separation treatment. All surveys were conducted under permit PPD/DGOPA-116/14 granted by SAGARPA (Agriculture, Natural Resources and Fisheries Secretariat) to B.I. van Tussenbroek.

Table 1:
Samples information.
Number of samples collected at eight sites along the Mexican Caribbean coast during 2018–2019. Habitat refers to distance from coast, shore (2–20 m from coast) or ocean (>5 km from coast).

Notes: Sarg sp: Sargassum spp., Sflu III: Sargassum fluitans III, Snat I: S. natans I, Snat VIII: S. natans VIII.

Elemental analysis

Concentrations of 28 different elements were measured in dry samples using a Niton FXL 950 energy dispersive X-ray fluorescence (XRF) containing a 50 kV X-ray tube of Ag and equipped with a geometrically optimized large area drift defector following Quiroz-Jiménez & Roy (2017). Table S1 shows the limit of detection of these elements. The dried samples were processed in the laboratory using a non-destructive sample preparation technique. Approximately 5–7 dry g of each sample was placed in a plastic capsule that has a 4µm thick polypropylene X-ray film on one side and the other side of the capsule was packed with synthetic flexible gauze. The samples were measured in the mining Cu/Zn mode and three different filters using the internal calibration curves previously generated by comparing the results of Niton FXL with a conventional XRF (e.g., Quiroz-Jiménez & Roy, 2017). The results are expressed in parts per million dry weight (ppm DW) after carrying out the analysis in five repetitions in each sample. We used two different geological reference materials (Es-2, organic rich argillite and Es-4, dolostone) for estimation of precision (Kiipli et al., 2000). Except for Mg, all other elements have relative standard deviation (RSD) between <1 and 5%. Mg concentrations show RSD of 26% and it is the least precise among all the analyzed elements. Some advantages of the XRF analysis compared to other methodologies are that small samples are required (∼5 g), the results have high precision, and it is non-destructive, permitting the same sample to be reused for other studies. Also, it is less expensive and faster compared to the use of an ICP-MS. The relatively high limit of detection of XRF for some elements is a disadvantage, and some potentially toxic elements may have been present in low concentrations, but were not measured (e.g., Ni and Co). This technique measures concentrations independent of the chemical state of an element.

Table 2:
Element concentrations median and range.
Element concentrations (ppm DW) of pelagic Sargassum spp. tissue collected from eight localities along the Mexican Caribbean coast between 2018 and 2019. The number of samples with readings above LOD are expressed in % of the total sample size (n = 63).

Notes:
LOD, Limit of detection.

Data analyses

The median of the five readings per element of each sample was calculated and used for further analysis. For each element, the readings below the limit of detection (<LOD; Table S1) were substituted with LOD/ 2–√ for calculation of summary statistics (Celo & Dabek-Zlotorzynska, 2010). Distributions (spread of data and the median values) of the fourteen most commonly found elements (e.g., Al, As, Ca, Cl, K, Mg, Mn, P, Rb, S, Si, Sr, Th and U) in sargasso tissue for each sampling locality are illustrated by dot plots. Differences in the concentration of elements among species and morphotypes were tested using non-parametric ANOVAs based on the Kruskal–Wallis rank procedure. We constructed a heatmap using the data from fourteen elements from Puerto Morelos (location 3, see Fig. 1) to visualize temporal differences in concentration of metals in seven different sampling periods between August 2018 and April 2019. Element concentration values were Z-score-transformed across sampling times and their values above and below the mean were used to generate the heatmap. The Z-value is a dimensionless quantity which is defined by the following equation (Larsen & Marx, 1986):
Z=(X−μ)∕σ
Where X represents an individual raw score that is to be standardized, σ is the standard deviation of the population, and μ is the mean of the population.

All analyses were done in R (R Core Team, 2019) using packages: dplyr (Wickham et al., 2019), ggplot2 (Wickham, 2009), gplots (Warnes et al., 2009), pgirmess (Giraudoux, 2013), reshape (Wickham, 2018), tidyr (Wickham & Henry, 2017), and RColorBrewer (Neuwirth, 2011) A reproducible record of all statistical analyses is available on GitHub (https://github.com/rerodriguezmtz/ElementsSar). This includes all underlying data and R code for all analyses.

Results

The most frequent elements in sargasso tissues, detected in 100% of the samples, were As, Ca, Cl, K, Mn, P, Rb, S, Si, Sr, Th, and U. They were followed in frequency by Mg (92.1% of samples) and Al (58.7% of samples) (Table 2). Other elements were found in fewer samples and they had median concentrations below the LOD: V (28.6% of samples), Zn (12.7% of samples), and Cu, Fe, Mo and Pb, present in 7.9% of samples (Table 2). Ba, Cd, Co, Cr, Ni, Ti, Y, and Zr remained below the LOD in all the samples (See Table S1 for LOD values). Some elements showed more than 5-fold difference between their minimal and maximal concentrations (ppm DW). For example, Cl showed 71.1-fold difference, K exhibited 23.1-fold difference, As had 7.2-fold difference, Si showed 6.5-fold difference and Ca exhibited 5.7-fold difference between their minimum and maximum values (Table 2). Concentrations of P, S and Sr showed the least inter-site variability and the concentrations of Al, As, Cl and K showed the most inter-site variability (Fig. 2).

Figure 2: Spatial variability in element concentrations.
Concentration of fourteen most frequent elements (ppm algal DW) in tissues of sargasso collected at eight sites along the Mexican Caribbean coast in 2018–2019. Note differences in scale of the Y-axis. Each dot corresponds to the median of the five XRF readings per sample. Color of the dot represents the sargasso species/morphotype. The horizontal black lines correspond to the median for each site. The dotted blue line corresponds to the limit of detection of the XRF equipment. A, Aluminum; B, Arsenic; C, Calcium; D, Chlorine; E, Potassium; F, Magnesium; G, Manganese; H, Phosphorus; I, Rubidium; J, Sulphur; K, Silicon; L, Strontium; M, Thorium; N, Uranium. Figure 1 and Table 1 have the site and sample details.

Among the potentially toxic elements, only As (median contents of 24–172 ppm DW) and Mn (median contents of 40–139 ppm DW) were present in all the samples (Table 2). Of all samples, 86% presented As concentrations above the maximum allowable concentration for seaweeds to be used as animal fooder under European regulations (40 ppm DW; EU, 2019), and 100% of the samples were above the maximum allowable concentration for agricultural soils in Mexico (22 ppm DW; NOM-147-SEMARNAT-SSA1-2004). Approximately 5% of our samples showed Cu concentrations above maximum tolerable level of dietary minerals for sheep (25 ppm DW) and cattle (100 ppm DW) (McDowell, 1992). Other potentially toxic elements (e.g., Mo, Pb and Zn) were detected in only 8–13% of the samples and they had median concentrations below the toxic limits for agricultural soils (see Table 2 and Table S2).

Concentrations of As, Ca, Cl, K, Mn, Rb and Si varied significantly among sargasso species/morphotypes (Fig. 2, Kruskal–Wallis test, p < 0.05; Table 3). As, Cl, K and Rb were significantly higher in Sargassum natans VIII compared to S. natans I. The concentrations of Ca and Si were significantly lower in S. natans VIII than in S. fluitans III and S. natans I. Similarly, the concentration of Mn was higher in S. natans I compared to S. fluitans III and S. natans VIII (Table 3). Contents of Al, Mg, P, S, Sr, Th and U did not vary significantly among species and morphotypes (KW, p > 0.05; Table 3). We did not compare the concentrations of Cu, Fe, Mo, Pb and Zn statistically among the species/morphotypes as their medians remained <LOD.

Table 3:
Elements concentrations in sargasso morphotypes.
Median and range (in parenthesis) of elements (ppm DW) in three sargasso species/morphotypes collected from eight localities along the Mexican Caribbean coast in 2018–2019. P values show summary of statistical analyses using Kruskal–Wallis H test (bold if significant) and the last column shows results of multiple comparison test.

Notes: LOD, limit of detection.

The concentrations of fourteen different elements (i.e., Al, As, Ca, Cl, K, Mg, Mn, P, Rb, S, Si, Sr, Th and U) in sargasso collected at Puerto Morelos in seven different sampling periods, from August 2018 to April 2019, showed considerable variability (Fig. 3). This inconsistent pattern indicates absence of any seasonal tendency in the elemental concentrations.

Figure 3: Temporal variability in element concentrations.
Variability in concentration of fourteen different elements (ppm DW) in sargasso collected at Puerto Morelos between August 2018 and April 2019. Z-score transformations were applied to values of each element across all the sampling periods and their intensities above and below the mean are represented on the heatmap by red and yellow colors, respectively, as shown on the color key bar.

Discussion

The sargasso tissues from the Mexican Caribbean had more As, Cu and Mn and less Cd, Cr, Pb and Zn compared to the chemical compositions of the algae biomass from Nigeria, Ghana and Dominican Republic (Table 4). Most striking was the high variability of element concentrations detected both in space (different sites along the coast) and time (different sampling months). This variability is likely partially due to the pelagic nature of the sargasso, as a result of increased uptake when exposed to areas rich in metals. It is unlikely that heavy metals were absorbed in near-shore waters of the Mexican Caribbean because this area lacks these elements in high concentrations, due to absence of major industrial, mining or heavy agricultural activities in the region. In addition, the absorption of metals by Sargassum thunbergii under experimental conditions was only clearly noticeable after ≥3 d exposure (Wu et al., 2010), whereas the residence time of sargasso in near-shore Mexican waters is usually in the order of hours when it is transported from the Yucatan Current towards the shore. Thus, the sargasso tissues likely acquired the heavy and trace elements before entering the Mexican coastal waters. Different contaminants are released into the ocean, some as point sources and others more continuous, in different parts across the North Equatorial Recirculation Region of the Atlantic Ocean (NERR) and the Wider Caribbean Region (as a result of long-range transport). Fernandez, Singh & Jaffé (2007) recognized the discharge of sewage, mineral extracts, fertilizer and pesticide used in the agricultural sector as the principal pollution sources. The pelagic masses of sargasso might have been exposed to these contaminants depending on its trajectory in the ocean. The metal sequestration also involves complex mechanisms of ion exchange, chelation, adsorption, and ion entrapment in polysaccharide networks of the algae (Volesky & Holan, 1995). This ion entrapment, in turn, depends on the affinity of some divalent metals to alginates (Haug, 1961), and pH of the seawater also influences absorption of metals (Davis, Volesky & Vieira, 2000). Alginates are often characterized by the proportion of mannuronic (M) and guluronic (G) acids present in the polymer (M:G ratio), which may vary among and within species. For example, Mn concentration was higher in S. natans I, whereas Ca and Si concentrations were higher in S. fluitans III and S. natans I, and the concentrations of As, Cl, K and Rb were higher in S. natans VIII than in S. natans I. Variations in the metal concentrations among the sargasso species and morphological forms may be explained by different concentrations in their tissues, but also by differences in calcifying epifauna, such as bryozoans, tube polychaeta, and crustose coralline algae (Weis, 1968; Huffard et al., 2014). Large differences in concentrations of Si (447–2,922 ppm DW) could be explained by different abundance of diatoms and silicoflagellates present in the samples (Takahashi & Blackwelder, 1992).

Table 4:
Element concentrations in different studies.
Comparison of element concentration in sargasso from the Mexican Caribbean coast and other studies in different parts of the world.

Notes:
a Oyesiku & Egunyomi, 2014 (mean and SD).
b Fernández et al., 2017 (range).
c Addico & De Graft-Johnson, 2016 (range).
d This study (range).

Sargasso samples from the Mexican Caribbean coast contained essential macro-elements for plants, like Ca (23,723–136,146 ppm DW), K (1,990–46,002 ppm DW), Mg (<2,915–13,662 ppm DW), P (228–401 ppm DW) and S (9,462–24,773 ppm DW), in addition to various micro-elements. Similar properties have been found in other Sargassum spp., making them adequate as complementary fertilizers as they enhance growth, seed germination and photosynthesis of crop plants on mineral-depleted soils (Sathya et al., 2010; Kumari, Kaur & Bhatnagar, 2013; El-Din, 2015). Some micro-elements found in sargasso from Mexico, such as Cu, Mn, Mo and Zn, are micronutrients in low concentrations, but they are potentially toxic when present in high concentrations. In this study, we detected the presence of Cu (<8–540 ppm DW) and Mo (<1–7 ppm DW) in 7.9% of the samples, Zn (<2–17 ppm DW) in 12.7% of the samples and Mn (40-139 ppm DW) in all the samples. Cu concentrations exceeded safely limits recommended for agricultural soils by several countries in 5% of the samples (see Table S2). Similarly, about 8% of our samples contained Mo concentrations above the maximum level established for agricultural soils by Canada (i.e., 2 ppm DW), but these were below the limits established by Austria and Poland (i.e., 10 ppm DW). Mn content was above 100 ppm DW in 22% of the samples, considered toxic for some plant species, but acceptable for others that can tolerate Mn up to 5,000 ppm DW (Howe, Malcolm & Dobson, 2004). Pb (<2–3 ppm DW) could be detected only in 7.9% of the samples, due to the limitation related to LOD of XRF analysis, and its concentration always remained below the toxic levels. Arsenic is of concern for the usages of sargasso as complementary fertilizer for crop plants. Limits of total As allowed for agricultural soils are between 15–50 ppm DW depending on the country (Table S2) (Belmonte-Serrato et al., 2010), thus, continuous application of sargasso (with total As between 24–172 ppm DW) may cause accumulation of As in the soils above allowable levels. High concentrations of As in soil may be toxic for the plants themselves, as it interferes with photosynthesis and other metabolic processes (Påhlsson, 1989; Ruiz Huerta & Armienta Hernández, 2012).

Sargasso could also be considered as animal fodder due to the presence of micro- and macro-elements, in addition to proteins, fibers and other components (Marín et al., 2009; Carrillo et al., 2012). However, approximately 86% of the samples had total As concentrations above the maximum level (40 ppm DW) allowable in Europe for animal feed materials derived from seaweed (EU, European Union). The toxicity of As depends on its chemical form, with inorganic As (trivalent state As III and pentavalent state As V) considered toxic (e.g., Yuan et al., 2007, Circuncisão et al., 2018), thus, even if total As concentrations are below 40 ppm DW, it is recommendable to carry out As speciation studies before using sargasso as animal fodder.

The (occasional) high contents of potentially toxic metals in sargasso is also a serious threat for the environment. The Mexican Caribbean coast has already received millions of tons of algae since late 2014. This accumulation over time, in addition to eutrophication and organic matter accumulation (Carruthers, van Tussenbroek & Dennison, 2005; Hernández-Terrones et al., 2011; Baker, Rodríguez-Martínez & Fogel, 2013; van Tussenbroek et al., 2017), is also a potential source of metal contamination for this region, even though levels of some potentially toxic elements like Cu, Mo, Zn, Mn and Pb were low. The sargasso removed from Mexican Caribbean beaches is presently deposited at abandoned limestone quarries, near the coast, without any treatment. The Yucatan Peninsula has a highly porous karst aquifer that is the only source of freshwater in the region. The pollutants from near surface deposits can easily infiltrate into the aquifer causing accumulation of As and other potentially toxic metals in the groundwater. Considering that water from the aquifer flows into the ocean through underground rivers, all these metals and excessive nutrients will eventually reach the marine environment (Carruthers, van Tussenbroek & Dennison, 2005; Metcalfe et al., 2011; Baker, Rodríguez-Martínez & Fogel, 2013). Prevention and mitigation measures are urgently needed to ensure that the massive influx of sargasso does not harm the coastal ecosystems and the tourism-based economy of countries located in the vicinity of the Great Atlantic Sargassum belt, including the Mexican Caribbean. The analyses of different specimens collected over longer periods and from different locations is required to obtain reliable information about metal contents in tissues.

Conclusion

In countries affected by the Great Atlantic Sargassum belt, the accumulation of decomposing sargasso on shores has harmed the coastal ecosystems, tourism-based economy and general human well-being. The Mexican Caribbean coast has received millions of tons of sargasso since late 2014, and our study concludes that the massive influx might contribute with potentially toxic elements to the coastal ecosystems, including the aquifer. We observed relatively higher values of As, Cu and Mn and lower values of Cd, Cr and Pb compared to similar studies in countries affected by the Sargassum belt. Cu, Mo, Zn, Mn and Pb were present in lower contents but their accumulation over time might be a potential source of contamination in this region. Total arsenic in most samples exceeded the limit established for usage as animal fodder in Europe and for agricultural soil in several countries. Further studies on As speciation are required before using sargasso in food industries to determine if it complies with guidelines of international institutions and organizations (i.e., FAO, WHO). Chemical analysis should also be conducted using other methodologies such as an ICP-MS, with better limit of detection, before evaluating sargasso usages in food, pharmaceutical and agricultural industries. Governments and industries have the financial strengths, as well as the moral and legal responsibilities, to carry out regular analyses of specimens collected over long periods and from different locations required for obtaining reliable information about metal contents in the tissues of sargasso due to its unpredictable variability.

Supplemental Information

Limits of Detection (LOD) of the analyzed elements in Niton FXL energy dispersive XRF (ppm = mg/kg) and Toxic metals and trace elements maximum levels permitted by different countries in agricultural soils (ppm = mg kg−1). nr: no reported

Additional Information and Declarations

Competing Interests : The authors declare there are no competing interests.

Author Contributions

Rosa E. Rodríguez-Martínez conceived and designed the experiments, analyzed the data, prepared figures and/or tables, authored or reviewed drafts of the paper, and approved the final draft.

Priyadarsi D. Roy, Nuria Torrescano-Valle and Nancy Cabanillas-Terán conceived and designed the experiments, performed the experiments, authored or reviewed drafts of the paper, and approved the final draft.

Silvia Carrillo-Domínguez, Ligia Collado-Vides, Marta García-Sánchez and Brigitta I. van Tussenbroek conceived and designed the experiments, authored or reviewed drafts of the paper, and approved the final draft.

Field Study Permissions
The following information was supplied relating to field study approvals (i.e., approving body and any reference numbers):

All surveys were conducted under permit PPD/DGOPA-116/14granted by SAGARPA (Agriculture, Natural Resources and Fisheries Secretariat) to Brigitta I. van Tussenbroek.

Data Availability
The following information was supplied regarding data availability:

Data is available at https://github.com/rerodriguezmtz/ElementsSar.

Funding
The authors received no funding for this work.

Acknowledgements

Special thanks to Elisa Vera Vázquez, for collecting sargasso samples from Puerto Morelos and Manta México Caribe A.C. for providing samples from Blue Waters and Isla Contoy. We also want to thank CEMIE-Oceano for the samples at Cozumel. Gabriela González López provided logistic help during fieldwork and in laboratory and Irma Gabriela Vargas-Martinez helped in XRF analysis. The authors claim no conflict of interest with this work.

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SOURCE: https://peerj.com/articles/8667/  Published February 26, 2020

 

FRANCE – Plan Sargasses II : le Gouvernement s’engage pour quatre ans auprès des collectivités locales

Pour pérenniser l’appui de l’État aux collectivités locales pour faire face au phénomène des sargasses, le Gouvernement vient d’adopter un second plan interministériel pour la période 2022-2025. Il est doté de près de 36 millions d’euros pour 4 ans. Ce budget traduit une augmentation de près de 30 % des financements de l’État.

Ce plan national prévoit 26 mesures pour mieux connaître, prévenir et lutter contre ce phénomène naturel. Il constitue un socle de priorités, de financements et de principes de gestion des sargasses, qui fera l’objet d’une déclinaison territoriale et opérationnelle avec les collectivités, en cours de concertation locale, dans les territoires les plus concernés (Martinique, Guadeloupe et Îles du Nord). Il permettra de mobiliser 3 millions d’euros, incluant des financements internationaux, pour la recherche amont consacrée à la compréhension et la prédiction de la prolifération des algues sargasses, et 3 millions d’euros pour des actions de recherche appliquée, en matière de valorisation des algues collectées notamment.

Les crédits nationaux, principalement gérés par les préfets et les agences régionales de santé, permettront d’appuyer les collectivités dans la durée, en particulier pour prendre en charge le ramassage des algues en mer comme à terre, et assurer leur transport et leur stockage. Les crédits à destination des collectivités ont ainsi été augmentés de 75 % dans ce second plan, et le taux de subvention porté à 50 % pour les actions qui étaient auparavant financées à 30 %.

Ce plan fait suite au premier plan national de prévention et de lutte contre les sargasses, lancé par l’État en octobre 2018. En octobre 2019, une conférence internationale a été organisée sous l’égide du Premier ministre, notamment pour mobiliser la recherche des différents pays concernés.

Le phénomène d’échouages des algues sargasses sur le littoral des Antilles et de la Guyane est un phénomène aux conséquences négatives très importantes, en matière sanitaire et environnementale ainsi que pour l’économie des îles concernées, notamment sur le secteur touristique. Il gagne au fil des années en nombre d’échouements et en intensité.

sargasses-martinique-guadeloupe-saintmartin-saintbarth-marie-galante-france

Contact(s)

EMAIL: secrétariat.presse@mer.gouv.fr

TEL : 01 44 49 85 24

TEL : 0155558424

 

 

Telecharger ICI le dossier de presse

Source : https://www.enseignementsup-recherche.gouv.fr/ du 17 mars 2022

Invita Comuna solidarense a segunda jornada de limpieza de sargazo

Invita Comuna solidarense a segunda jornada de limpieza de sargazo

Autoridades municipales convocaron a la sociedad en general a participar en la segunda jornada de limpieza de sargazo que se realizará este sábado 9 de abril, de 7 a 10 de la mañana, en las playas de las calles 10, 12, 14 norte, El Recodo y Punta Esmeralda.

De acuerdo con Lourdes Várguez Ocampo, directora de Zofemat Solidaridad, dicha jornada de limpieza se realizará cada sábado, y busca concientizar a la población de que todos podemos contribuir a mantener los arenales del municipio en buen estado.

Playa del Carmen – Sargazo

Agregó que, al mismo tiempo, se busca que “todos pongan su granito de arena”, para que se mantengan limpios los arenales durante este periodo vacacional, que a su vez transcurrirá en el marco de los primeros arribos atípicos de la temporada de sargazo.

Asimismo, recomendó a la ciudadanía interesada a acudir a los arenales con sombrero o gorra, así como con botellas de agua para mantenerse hidratados durante las actividades.

Sargazo Mexico Riviera Maya

Cabe mencionar que el pasado sábado se logró la convocatoria de alrededor de 500 trabajadores de diferentes secretarías del Ayuntamiento y ciudadanía en general y miembros de asociaciones civiles.

Fuente: INFOCARIBE 8 de Abril 2022

¿Quieres ir de vacaciones « pagadas »? Quintana Roo ofrece 9 mil pesos por recoger sargazo

No hay restricciones de edad, pues hay personas de 65 años que han ido a solicitar el empleo en esa actividad.

A una semana de que empiecen las Vacaciones de Semana Santa 2022, autoridades de Quintana Roo ofrecen 9 mil pesos a quienes retiren sargazo de Playa del Carmen.
Créditos: Cuartoscuro

A una semana de que inicien las Vacaciones de Semana Santa 2022, autoridades del estado de Quintana Roo ofrecieron 150 vacantes con un pago de 9 mil pesos al mes más prestaciones para quienes recojan sargazo en Playa del Carmen.

“Para esta contratación de personas que quieran ser parte del equipo de la Zofemat, pueden venir a las oficinas de la Zofemat que están en el palacio municipal nuevo, en la avenida 125, el sueldo es de nueve mil pesos mensuales, cuatro mil 500 a la quincena con prestaciones”, dijo Lourdes Várguez Ocampo, directora de la Zona Federal Marítimo Terrestre (Zofemat).

Estos trabajadores se sumarán a otros 50 que realizan labores para evitar que el sargazo llegue a las playas, donde desde hace dos semanas comenzó a agudizarse la invasión de la alga.

La directora de la Zofemat señaló que no se exigen requisitos de edad ni de condición física para quienes quieran trabajar realizando el retiro de los desechos, por lo que lanzó el llamado a toda la población.

“No nos dejamos llevar por la edad o la imagen física, la otra vez contratamos a un señor de 65 años y es un señor súper fuerte, nos rinde muchísimo », añadió Várguez Ocampo.

Esta semana, una previa a las Vacaciones de Semana Santa 2022, comenzó a instalarse la barrera anti sargazo por parte de los elementos de la Secretaría de Marina (Semar), para que las personas puedan disfrutar de las playas sin que tengan que padecer la plaga.

 

Fuente : radio formula 7 de Abril 2022

Exposure to emissions from Sargassum seaweed washed up on the shore: ANSES reiterates its recommendations and adds to them

2018 Martinique Sargasses récoltées par l'armée Française
2018 Martinique Sargassum collected by the French Army

In 2015 ANSES was asked to conduct an expert assessment on gaseous fumes emitted by decaying Sargassum seaweed. In March 2016, the Agency recommended implementing measures to protect the general public and workers in charge of collecting, transporting and processing Sargassum seaweed, from exposure to the hydrogen sulfide (H2S) produced during its decay. An update of this assessment, including a revision of the toxicological profile of H2S and a summary of the ecology, accumulation, chemistry and decomposition of Sargassum seaweed, led the Agency to additionally recommend the immediate implementation of measures to prevent the risk of exposure to the heavy metals found in seaweed – arsenic and cadmium in particular – which could be hazardous to human health and to the environment.

Puerto Morelos Mexico 2022
Sargazo Puerto Morelos Mexico 2022

Since August 2014, coastal regions of the Caribbean and French Guiana have experienced successive waves of accumulated Sargassum seaweed on their coasts. Despite clean-up efforts, the seaweed continues to decompose on the shore. This decomposition produces hydrogen sulfide (H2S) gas, which can sometimes be detected in high concentrations. Reports by physicians in conjunction with health effects perceived by people exposed to H2S, as well as complaints from the general public regarding unpleasant odours, have increased sharply.

The Ministries of health, the environment and labour therefore asked ANSES to conduct an expert assessment of the gases produced by decaying Sargassum seaweed and emitted into the ambient air in the Caribbean and in French Guiana. An opinion published in March 2016 presented the initial findings and recommendations of the Agency. It emphasised the necessity of collecting the seaweed without delay and recommended that measures be taken to protect the workers in charge of collecting, transporting and processing the seaweed. It also recommended that the local population be informed that the seaweed should not be handled.

The Agency pursued its work by examining the ecology of Sargassum seaweed, as well as its chemistry, biodegradation profile and the kinetics of H2S emissions and that of other substances, especially during decay of the seaweed following its accumulation on the shore.

Sea-turtle died in sargassum
Sea-turtle died in sargassum

The Agency’s recommendations

The conclusions of the expert assessment published today have led the Agency to reiterate the recommendations to be implemented regarding preventive measures for the health risks of exposure to H2S:

limit exposure by the general public, by regularly collecting the seaweed accumulated on the coast, by marking off collection sites, and by informing the population of the health risks of exposure to H2S;
limit worker exposure through use of H2S detectors, mechanical means of collection whenever possible, personal protective equipment, training and informing workers about the risks of exposure to H2S and implementing a traceability system for work that exposes workers.

2015 Cancun, Mexico (@Notimex)

In addition, the expert assessment published today reveals that Sargassum seaweed has a high capacity for accumulating heavy metals – arsenic and cadmium in particular – which may pose a risk to human health and to the environment. Therefore, the Agency recommends prohibiting any possible food or feed uses of this seaweed until more in-depth studies can be conducted on the heavy metal contamination of seaweed.

@Noticiario Barahona Republica Dominicana 2015

The Agency also recommends pursuing research on:

  • exposure linked to accumulated Sargassum seaweed and effects on human health;
  • the toxicity of H2S, in particular the effects of chronic exposure to low doses of H2S;
  • the indirect environmental and health impact of accumulated Sargassum seaweed (seaweed composition, presence of heavy metals);
  • the proliferation of seaweed and its accumulation on dry land in the French départements in the Americas.
2022 Mayaro Trinidad sargassum

To read : 2019 Cancun hotel creates exotic cocktail with a side of Sargasso

 

Download PDF from ANSES 2017 : See ANSES’s amended OPINION and REPORT on gaseous fumes emitted by decaying Sargassum seaweed in the Caribbean and in French Guiana (in French)

 

Playa del Carmen Prisoners Can Reduce Jail Time By Cleaning Seaweed Off Beaches For Tourists

There’s a pretty good chance that Cancun beaches in general will be filled with massive amounts of seaweed in the coming weeks. As reports indicate that large amounts of the foul smelling seaweed known as sargassum are slowly, but steadily making their way towards the shore. In Playa del Carmen authorities are trying to come up with creative ways to build up enough manpower to clean the local beaches. One of these solutions that they’ve come up with involves giving minor infractors the possibility of picking up sargassum as a form of community service. Doing so in an effort to avoid jail time.

The initiative that is allowing people to avoid jail time contemplates will only apply to those who have committed “administrative infractions”. These administrative infractions are things like urinating in public, littering and consuming alcoholic beverages, on public roads. To put it simply, pretty much all of the minor infractions that tend to land rowdy tourists in the slammer, will now be payable through this form of community service.

It’ll ultimately be up to the judge whether a particular infraction can be paid in this manner. Local judges approved of this form of punishment in recent weeks. It was actually the Zomefat (the organization responsible for cleaning the beaches) that proposed this idea to Playa del Carmen judges. The director of the Zomefat institute, Lourdes Vargues Ocampo, had this to say about the initiative.

“We talked to the civic judges a week ago to propose this initiative of having people do community service instead of having to pay other types of fines. The decision to approve the initiative was made unilaterally. Many judges showed a keen interest in this idea.”

This Type of Community Service Eliminates Potential Fines or Jail Time
The director of Zomefat would go on to clarify that as things stand right now folks who opt to provide this community service will not be charged extra fines, or have to spend time behind bars to further pay their debt to society. The judges have the power to assign a specific amount of community service hours to infractors. Which they must complete in order to be properly released. There have already been quite a few people that have chosen this route. Lourdes Vargues made those numbers public saying,

“Sunday we had 15 people, (doing community service), Monday there were 11, and Tuesday there were 7. In doing this type of work they are able to meet the sanctions that the judges impose on them. This is not a form of forced labor. These people are not criminals, they are just folks who commited minor infractions.”

There Are Other Ways To Join A Brigade To Clean Up The Beaches
You don’t necessarily have to commit a crime to be on a brigade responsible for cleaning up beaches. In fact, infractors who are part of these brigades are the ones wearing the bright orange vests. To distinguish themselves as community service workers. While the rest of the folks also picking up Sargassum may very well be getting paid for the job that they’re doing.

The Zomefat organization seems to be incredibly understaffed. So much so that they are offering a 9,000 MXN ( around 450 dollars) monthly salary to anyone willing to work cleaning up Playa del Carmen beaches alongside minor infractors. That may not seem like much to a lot of people. To put things into context though, the average salary that a Mexican worker makes is around 7,000 MXN per month. With a slight increase over the average salary, and the addition of community service workers Zomefat is hoping to create at least another 50-person team to clean up Playa del Carmen beaches.

Source: The Cancun Sun April 2022

Cenotes reciben “daño colateral” por arribazón de sargazo

Cenotes reciben "daño colateral" por arribazón de sargazo
Cenotes reciben « daño colateral » por arribazón de sargazo

Según datos presentados por un especialista en Planeación Turística Sustentable, los cenotes del municipio de Puerto Morelos, donde se ubica la denominada “Ruta de los cenotes”, estarían recibiendo un importante “daño colateral” ante la arribazón de sargazo a las playas del destino.

Diego Armando Casas Beltrán, catedrático de una maestría relacionada con el tema en la Universidad del Caribe (UniCaribe), explicó como es que la macro alga ha afectado a los cenotes, a través de una investigación realizada en el Centro de Investigación Científica de Yucatán (CICY).

Te Puede Interesar: Han recalado 18 mil 905 toneladas de sargazo a Quintana Roo

El informe de Casas Beltrán tiene lugar a unos días del inicio de las vacaciones de Semana Santa, y ante la amenaza del arribo masivo de sargazo a las costas de la entidad, que ya dejado sentir la magnitud del daño, según las autoridades han recalado casi 19 mil toneladas de esta alga.

Por medio del detallado estudio efectuado por el investigador, éste demostró que la afectación por esta alga marina ha impactado de forma indirecta a los cenotes de Puerto Morelos, los cuales han recibido la carga de los bañistas que han dejado de ir a las playas.

Cenote Riviera Maya

En su conferencia denominada “El arribo de sargazo en Puerto Morelos y sus impactos sobre la actividad turística en la ruta de los cenotes”, el investigador señala que un 59 por ciento de los residentes de ese municipio ha dejado de ir a la playas durante los meses de arribo de sargazo, principalmente por los malos olores que desprende su descomposición y por las picaduras de pulgas marinas que se alojan en la algas.

La investigación de Casas Beltrán, señala que de esos bañistas que dejaron de visitar las playas, un 56 por ciento optó por visitar cenotes, 46 por ciento zonas arqueológicas y 42 por ciento parques temáticos, y ante este incremento de la ocupación de bañistas en los cenotes, se ha registrado un cambio en la química del agua, registrando incrementos en los niveles de nitrito y nitrato.

No obstante, el profesor aclaró que lo anterior no significa que haya contaminación en los cenotes, pero sí se demuestra que el desplazamiento de bañistas de las playas está impactando indirectamente a estos cuerpos de agua.

Y no solo los cenotes han resultado dañados, pues el catedrático de la Maestría en Planeación Turística Sustentable señaló que el arribo de sargazo también ha impactado al relleno sanitario, toda vez que 4 mil 400 toneladas de algas fueron trasladadas a éste, reduciendo su vida útil; sin contar que es un residuo cargado de sales y metales pesados, que se filtran al subsuelo y contaminan el manto freático.

El investigador señaló que, aun cuando el gobierno de Quintana Roo invirtió en 2019 más de 3.2 millones de pesos en la contratación de 4 mil 400 trabajadores para retirar el sargazo, ese año sólo se atendieron las playas de Isla Mujeres, Cancún, Cozumel, Solidaridad Puerto Morelos y Tulum; mientras que el 90 por ciento de la costa quintanarroense no fue atendida.

Source: TN Turquesa News Abril 2022

Can you eat Sargassum?

𝗖𝗮𝗻 𝘆𝗼𝘂 𝗲𝗮𝘁 𝗦𝗮𝗿𝗴𝗮𝘀𝘀𝘂𝗺?
𝗖𝗮𝗻 𝘆𝗼𝘂 𝗲𝗮𝘁 𝗦𝗮𝗿𝗴𝗮𝘀𝘀𝘂𝗺?

Since this weed yearly hits almost all the coasts in the region many have been looking for ways to use it. For instance as animal fodder, compost or biogas/fuel. Unfortunately sargassum contains accumulated arsenic substances and other nasty stuff. It is also very salty. On Bonaire we experimented with sargassum compost to grow tomatoes, spinach and warmoes. Sadly the plants took up the toxins and were thus not suitable for consumption. Research continues on Bonaire and in the region. For now the highest priority is to keep sargassum from damaging the most vulnerable parts of the island.

Also, do not try this at home. This maniac did not really eat it 🙂

Source: Mangrove Maniacs – Bonaire Lac restoration project – 21/03/2022

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Mexico : Seaweed Season Begins As Sargassum Washes Up On Beaches In Playa del Carmen And Tulum

First Major Deposit Is A Concern For Tourists And Businesses

The first major deposit of sargassum arrived in Playa del Carmen and several other popular tourist spots including Tulum on Friday night. It’s estimated that around eighty tonnes of the unpleasant seaweed were left on the beaches.

Sargassum algae covers the popular vacation beach of Playa Del Carmen in Mexico, 21 of August 2018
Sargassum algae covers the popular vacation beach of Playa Del Carmen in Mexico, 21 of August 2018

Tourists and hoteliers woke on Saturday morning to the unpleasant sight of masses of sargassum on the beaches of Playa del Carmen. Several of the most popular resort’s beach areas were heavily affected, prompting staff in the establishments to jump to work on removing it. Puerto Aventuras also received significant deposits of seaweed.

The timing is rough for Playa del Carmen. The placement of sargassum barriers to protect its beaches was delayed last week after poor weather prevented the Navy from getting to work. The barrier was due to be placed this week instead, but not soon enough to prevent the masses of brown from covering the shoreline.

Riviera Maya, Mexico - July 27, 2018. Mexican male worker shows a wheel barrow full of problem Sargassum seaweed as he cleans up a beach on the caribbean coast in Mexico.
Riviera Maya, Mexico – July 27, 2018. Mexican male worker shows a wheel barrow full of problem Sargassum seaweed as he cleans up a beach on the caribbean coast in Mexico.

The removal process is not easy once it’s on the beach. The workers have to be careful not to cause beach erosion with their methods. In this case, they pulled the majority of the sargassum to the streets near the beach and collected it there, preventing any damage to the beach. It’s not easy work, but the presence of sargassum greatly impacts the business of Cancun, Playa del Carmen, and Tulum.

Patches of Sargassum seaweed on a Tulum beach in Mexico
Tulum, Mexico – 7 August 2018: Two men are cleaning Sargassum seaweed from the beach.

Sargassum isn’t typical seaweed. It forms miles out to sea in huge floating island-like structures. At sea, it’s massive beneficial. It creates its own ecosystem where thousands of small sea creatures are able to live, as well as providing nutrients for the water in the surrounding area.

The problem with sargassum arrives as it approaches the coastline. These tangles of weed can be kilometers long, formed by tens of thousands of individual weeds intertwined. When they reach the shoreline, they float in the shallows before being left on the beach. When floating in the shallows, they pose a safety threat for young or inexperienced swimmers who have been known to get caught in it. Small fish and other animals can also still be living in the tangle.

Tulum, Mexico - 12 August 2018: workers are removing Sargassum seaweed from the beach at Playa Paraiso with a Barber Surf Rake Beach Cleaner.
Tulum, Mexico – 12 August 2018: workers are removing Sargassum seaweed from the beach at Playa Paraiso with a Barber Surf Rake Beach Cleaner.

Its biggest downside is when it washes up, however. It produces a sulfur-like smell making it extremely unpleasant for any beachgoers nearby and typically leads to many avoiding the beach completely. On a purely aesthetic level, it is detrimental to the atmosphere of the region. The biggest draw of the Mexican Caribbean is the pristine beaches and crystal blue water. The presence of a giant knot of seaweed Changs the water’s color and the white sands are covered and smelly.

Bavaro, Punta Cana, Dominican Republic - 19 December 2018: Workers cleaning sargassum algae on tropical shore. Caribbean ecology problem
Bavaro, Punta Cana, Dominican Republic – 19 December 2018: Workers cleaning sargassum algae on tropical shore. Caribbean ecology problem

The local government spends incredible amounts of money fighting the sargassum. The problem has grown over the past decade as water temperatures increase globally. Global warming will continue to exacerbate the arrival of the seaweed which thrives in warm waters.

Tulum, Mexico - 12 August 2018: workers are cleaning Sargassum seaweed from the beach.
Tulum, Mexico – 12 August 2018: workers are cleaning Sargassum seaweed from the beach.

Barriers are placed at strategic points around the area, and the Navy even collects masses of sargassum at sea before it gets a chance to approach the shore. Several new tactics have been implemented, including the use of drones to oversee the movement of clumps. A hot air balloon company in Miami has even been hired to help with the surveillance effort. Most hotels even have their own designated staff who collect the seaweed that makes it to the beach.

Sargassum algae covers the popular vacation beach of Playa Del Carmen in Mexico, 21 of August 2018
Sargassum algae covers the popular vacation beach of Playa Del Carmen in Mexico, 21 of August 2018

Tourists visiting the region over the next few weeks should check in with their hotels to find out the sargassum situation at that specific location. With as many as 3 million visitors passing through the region over the Easter period, expect hotels and all organizations involved with sargassum prevention to be working at full capacity to ensure an enjoyable experience for everyone.

Source: The Cancun Sun – 21/03/2022

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Trinidad & Tobago : Moderate To Severe Surges of Sargassum To Stay North Of T&T Through May 2022

Thick mats of Sargassum on the beaches of Mayaro on Saturday, February 12th, 2022.
Thick mats of Sargassum on the beaches of Mayaro on Saturday, February 12th, 2022.

Islands north of Trinidad and Tobago and the Southern Windwards are being advised to brace for moderate to severe surges of Sargassum over the next coming months. This is according to the latest Sargassum Sub-Regional Outlook Bulletin published by the UWI Centre for Resource Management and Environment Studies (CERMES), Cave Hill, Barbados.

Through the first quarter of 2022, the Eastern Caribbean experienced moderate to severe influxes of Sargassum, which is forecast to continue through the next several weeks but mainly north of the Southern Windwards. The report noted that the level of Sargassum is expected to remain at moderate to severe levels through March and into April.

There have been 63% less seaweed visible in the Atlantic than last year, as of March 2022, and well below 2018 levels, which were the worst recorded to date.

At least through May 2022, islands across the Eastern Caribbean are set to receive moderate to severe Sargassum influxes, particularly for the Lesser Antilles’ central islands. The surge in seaweed mats has subsided for Trinidad and Tobago, at least until late May.

The prediction graph below illustrates a comparison of 3+ month forecasts using a relative index of Sargassum from processed satellite images by SaWS (USF/MODIS+) and SAMtool (CLS/Sentinel+). Close overlap of the two lines on any one graph indicates that the predictions are similar between the two datasets. (CERMES)
The prediction graph below illustrates a comparison of 3+ month forecasts using a relative index of Sargassum from processed satellite images by SaWS (USF/MODIS+) and SAMtool (CLS/Sentinel+). Close overlap of the two lines on any one graph indicates that the predictions are similar between the two datasets. (CERMES)

The outlook notes

  • Northern Islands (Dominica northward): Mild influxes from now until late April when levels are expected to increase to moderate levels.
  • Central Islands (St. Vincent and the Grenadines to Martinique, including Barbados): Moderate to severe influxes over the next three months, with spikes expected at the end of March and early May.
  • Southern Islands (Grenada and the Grenadines to T&T): Mild to moderate influxes with peaks expected in mid-March and the end of May, with mild levels in between.
    Tourists and tourism business operators have experienced moderate to severe influxes in the past few weeks. The report noted that the sector could expect beaches and bathing areas to be periodically inundated with high quantities of Sargassum in the coming weeks, especially in the middle islands.

Fisherfolk have reported low catches of flyingfish in the past three months, and according to the report, they should expect some disruption at windward landing sites. Beach and shore-side markets in the middle islands will likely require clean-up efforts.

Given the current forecast for the middle islands, consumers can expect continued availability of almaco jacks (amber fish) in the coming months. Beached Sargassum may provide a challenge for leatherback turtles laying eggs during their March to May nesting season.

Sargassum inundation risk as of March 14th, 2022, classifying the risk into three categories: low (blue), medium (orange), and high (red). National Oceanic and Atmospheric Administration (NOAA) and the University of South Florida (USF)
Sargassum inundation risk as of March 14th, 2022, classifying the risk into three categories: low (blue), medium (orange), and high (red). National Oceanic and Atmospheric Administration (NOAA) and the University of South Florida (USF)

As of March 14th, 2022, a report by the National Oceanic and Atmospheric Administration (NOAA) and the University of South Florida (USF) shows varying levels of risk for Sargassum landings across the Lesser Antilles. There is the lowest risk for Trinidad, Tobago, and Barbados, joining much of the Leeward Islands. However, Grenada to Guadeloupe has a moderate to high risk of Sargassum inundating coastlines.

Source: T&T Weather Center 03/17/2022