Mexico Sea Research Articles

Tropical Cyclones in the GEOS-S2S-2 Subseasonal Forecasts

Abstract This paper analyzes the climatology, prediction skill, and predictability of tropical cyclones (TCs) in NASA’s Goddard Earth Observing System Subseasonal to Seasonal (GEOS-S2S) forecast system version 2. GEOS reasonably simulates the number and spatial distribution of TCs compared to observations except in the Atlantic where the model simulates too few TCs due to low genesis rates in the Caribbean Sea and Gulf of Mexico. The environmental conditions, diagnosed through a genesis potential index, do not clearly explain model biases in the genesis rates, especially in the Atlantic. At the storm scale, GEOS reforecasts replicate several key aspects of the thermodynamic and dynamic structures of observed TCs, such as a warm core and the secondary circulation. The model, however, fails to simulate an off-center eyewall when evaluating vertical velocity, precipitation, and moisture. The analysis of the prediction skill of TC genesis and occurrence shows that GEOS has comparable skill to other global models in WMO S2S archive and that its skill could be further improved by increasing the ensemble size. After calibration, GEOS forecasts are skillful in the western North Pacific and southern Indian Ocean up to 20 days in advance. A model-based predictability analysis demonstrates the importance of the Madden–Julian oscillation (MJO) as a source of predictability of TC occurrence beyond the 14-day lead time. Forecasts initialized under strong MJO conditions show evidence of predictability beyond week 3. However, due to model biases in the forecast distribution, there are notable gaps between the MJO-related prediction skill and predictability, which require further study.

The Role of Atmospheric Rivers Moisture Origin in the Seasonality of Extreme Precipitation in the Eastern United States

Abstract Regional patterns of the seasonal weather and atmospheric moisture origins can impact the seasonal activities of extreme precipitation in the eastern United States (eUS). At many locations, tracks of atmospheric moisture can have different influence on timing of extreme precipitation based on the moisture origin source. In this study we evaluate the contribution of Atmospheric Rivers (ARs), and their moisture origin sources to the distribution and seasonal effectivity of annual maximum precipitation (AMP) across the eUS during 1950–2021. Our results suggest that AR is a dominant mechanism of AMP in the eUS as they contribute to 75% (31,438 out of 41,976) of total AMP events recorded between 1950–2021. The seasonal analysis based on circular density approach shows that spring, summer and fall seasons display strong signals of seasonality of AMP-AR events. The spatial patterns of AMP associated with the four major moisture sources (the Pacific Ocean, the Atlantic Ocean, the combined source of Caribbean Sea and Gulf of Mexico, and the local source of moisture) reinforce the key role ARs play in transporting water vapor to eUS from both oceanic and inland originated moisture. The results additionally highlight the importance of moisture sub-sources (major sources sub-regions) in modulating the seasonality of extreme precipitation in the eUS.

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.

Taxonomic, phylogenetic, and functional diversity of mollusk death assemblages in coral reef and seagrass sediments from two shallow gulfs in Western Cuban Archipelago.

Mollusk death assemblages are formed by shell remnants deposited in the surficial mixed layer of the seabed. Diversity patterns in tropical marine habitats still are understudied; therefore, we aimed to investigate the taxonomic, phylogenetic, and functional diversity of mollusk death assemblages at regional and local scales in coral reef sands and seagrass meadows. We collected sediment samples at 11 sites within two shallow gulfs in the Northwestern Caribbean Sea and Southeastern Gulf of Mexico. All the shells were counted and identified to species level and classified into biological traits. We identified 7113 individuals belonging to 393 species (290 gastropods, 94 bivalves, and nine scaphopods). Diversity and assemblage structure showed many similarities between gulfs given their geological and biogeographical commonalities. Reef sands had higher richness than seagrasses likely because of a more favorable balance productivity-disturbance. Reef sands were dominated by epifaunal herbivores likely feeding on microphytobenthos and bysally attached bivalves adapted to intense hydrodynamic regime. In seagrass meadows, suspension feeders dominated in exposed sites and chemosynthetic infaunal bivalves dominated where oxygen replenishment was limited. Time averaging of death assemblages was likely in the order of 100 years, with stronger effects in reef sands compared to seagrass meadows. Our research provides evidence of the high taxonomic, phylogenetic, and functional diversity of mollusk death assemblages in tropical coastal sediments as result of the influence of scale-related processes and habitat type. Our study highlights the convenience of including phylogenetic and functional traits, as well as dead shells, for a more complete assessment of mollusk biodiversity.

First occurrence of the invasive jellyfish Phyllorhiza punctata in the Dominican Republic: seasonal trend and invasion in the Atlantic Ocean

The invasive, white-spotted jellyfish Phyllorhiza punctata is reported from the Dominican Republic for the first time, representing a significant range expansion in the Caribbean region. A specimen was sighted and photographically documented in Gina’s Bay, Miches on 20 February, 2024. We compiled 222 existing records of P. punctata in the Caribbean Sea and Gulf of Mexico between 1965 and 2023, revealing a distinct seasonal pattern with most observations occurring from May to October (summer season). The earliest record of P. punctata in the Atlantic dates back to 1940, but sightings became more frequent starting in the 1990s. The introduction and spread of this Indo-Pacific species is attributed to vectors like ballast water discharge, aquarium releases, and oil rig movements. Once established, P. punctata can rapidly proliferate due to its life cycle involving asexually produced medusae. The presence of this invasive jellyfish can potentially impact native species through competition and predation on fish and crustacean larvae, as well as impact fisheries through gear entanglement and pose risks to human activities from stinging incidents. Continuous monitoring and close regional collaboration are needed to evaluate the distribution, abundance, and ecological impacts of this invasive species and, furthermore, to develop appropriate management strategies to mitigate the possible effects of this invader in the Dominican Republic and the Caribbean region.

Local ecological knowledge and perception of the causes, impacts and effects of Sargassum massive influxes: a binational approach

ABSTRACT Coastal communities of the Caribbean Sea and Gulf of Mexico have been affected by atypical influxes of pelagic macroalgae (Sargassum genus) since 2011, entailing ecological, economic and social impacts in need of characterization. We compiled and documented local ecological knowledge (LEK) and perceptions across diverse stakeholder groups from coastal communities in Mexico (Quintana Roo) (n=50 participants) and the United States (Florida) (n=36 participants) through on-site and online interviews and workshops undertaken from January to March of 2022, to understand how the knowledge of this phenomenon varies among communities and to characterize ecological and well-being impacts. Participants in Quintana Roo associated these influxes with both global phenomena (e.g., climate change) and local scale processes (e.g., currents/wind patterns) while Florida participants associated these events more with the latter. The communities in both regions perceived that the economy and the environment were the most impacted well-being categories. While influxes effects were mostly negative (80%) according to Quintana Roo participants (e.g., affected fisheries), Florida participants considered many positive effects of Sargassum (40%) on several well-being and ecological components (e.g., nursery habitat for marine species). In general, the perception of Sargassum as a problem was less pronounced in Florida, and these differences in perception are related to the magnitude of these influxes’ effect on the daily life of these communities. Overall, macroalgae management is still mainly focused on beach cleanup. Documenting LEK is important to delineate scientific research priorities and to provide decision makers with resources to develop efficient public policies and coastal management decisions.

Improving satellite monitoring of coastal inundations of pelagic Sargassum algae with wind and citizen science data

Massive blooms of pelagic Sargassum algae have caused serious problems to coastal communities and ecosystems throughout the tropical Atlantic, Caribbean Sea, and Gulf of Mexico since 2011. Efforts to monitor and predict these occurrences are challenging owing to the vast area impacted and the complexities associated with the proliferation and movement of Sargassum. Sargassum Inundation Reports (SIRs) were first produced in 2019 to estimate the potential risk to coastlines throughout the Intra-American Sea at weekly intervals at 10 km resolution. SIRs use satellite-based data products to estimate beaching risk from the amount of offshore Sargassum (quantified by a Floating Algal density index). Here we examine whether including wind metrics improves the correspondence between the offshore Floating Algal density index and observations of Sargassum along the coastline. For coastal observations, we quantified the percent coverage of Sargassum in photos obtained from the citizen science project "Sargassum Watch" that collects time-stamped, georeferenced photos at beaches throughout the region. Region-wide analyses indicate that including shoreward wind velocity with SIR risk indices greatly improves the correspondence with coastal observations of Sargassum beaching compared to SIR risk indices alone. Site-specific analyses of photos from southeast Florida, USA, and data from a continuous video monitoring study at Puerto Morelos, Mexico, suggest potential uncertainties in the suite of factors controlling Sargassum beaching. Nonetheless, the inclusion of wind velocity in the SIR algorithm appears to be a promising avenue for improving regional risk indices.

Taxonomy and biogeography of living species of the Family Notorotaliidae (Notorotalia, Parrellina, Porosorotalia, Buccella, Cristatavultus)

DNA sequencing shows that species of the genera Notorotalia, Porosorotalia and Buccella form a distinct branch (Notorotaliidae) of Rotaloidea, and cluster as sister to Elphidiidae. In this review we report on the sequencing of three species of Buccella (from the Arctic Ocean, Patagonia and Chile) and one each of Notorotalia (New Zealand) and Porosorotalia (Chile). This information has been combined with all the morphological descriptive information on species of these genera plus the genera Cristatavultus and Parrellina to provide a global synthesis of living species of the Notorotaliidae. We recognize 11 species of the southern hemisphere genus Notorotalia, which has a centre of diversity around New Zealand (8 species). A second southern-hemisphere-restricted genus, restricted to eastern Australia is Parrellina (3 species) although specimens (possibly introduced) have been recorded from the Mediterranean Sea. Cristatavultus has a single species, with a tropical west Pacific distribution.We synonymize Cribrorotalia under Porosorotalia, which has a disjunct distribution with one species in the northwest Pacific and a second around the southern parts of South America. Buccella is the most diverse and widespread genus (16 species recognized) with its greatest abundance in the Arctic Ocean and around subantarctic-temperate South America. Five species of Buccella live in a belt along the west coast of central America, from USA to Peru, with some spillage into the Caribbean Sea and Gulf of Mexico. Two new species of Buccella are recognized: B. dejardini (from South Georgia) and Buccella n. sp. A (from Chile).

Influence of nearby environment on recreational bycatch of sea turtles at fishing piers in the eastern Gulf of Mexico

Incidental bycatch of sea turtles from recreational fisheries is generally undocumented globally. At Gulf of Mexico fishing piers in the USA, bycatch is a source of injury and potential mortality of sea turtles. Recreational sea turtle bycatch has grown substantially over the last 6 yr, especially at the Navarre Beach Fishing Pier (NW Florida); the reasons for the increase and the impacts this has on the recovery of northern Gulf of Mexico sea turtle populations are largely unknown. In particular, the reasons why fishing piers are attracting sea turtles are not well understood or if the environmental context of other nearby habitats contributes to the bycatch. Using GIS, we analyzed potential environmental predictors of total sea turtle bycatch, across green sea turtles Chelonia mydas, loggerhead sea turtles Caretta caretta, and Kemp’s ridley sea turtles Lepidochelys kempii. We collated bycatch and environmental data from 20 Florida Gulf of Mexico fishing piers. We statistically assessed relationships using generalized additive models and selected the best fit model using the information-theoretic approach. We found that tonnage of nearby artificial reefs (based on defined home range and core use areas) and distance to nearest seagrass bed exhibit positive relationships with green sea turtle bycatch. For combined loggerhead and Kemp’s ridley bycatch, area of preserved water, distance to nearest seagrass bed, tonnage of nearby artificial reefs, and latitude of fishing piers were all predictors in the confidence set, but the shape of the relationships is variable and nonlinear. Further examination of sea turtle bycatch, occupancy of piers, and environmental factors pertaining to sea turtles will likely improve mitigation measures for recreational bycatch.

Extreme Winter Precipitation Regimes in Eastern North America: Synoptic-Scale and Thermodynamic Environments

Abstract We define extreme precipitation regimes (EPRs) during the eastern North American winter based on widespread and persistent heavy precipitation, using ERA5 precipitation data from 1979 to 2020. We find 62 EPRs and analyze their synoptic-scale and thermodynamic environments. EPRs impact most of eastern North America with heavy precipitation, especially from Louisiana to Quebec, and generally last for 5–8 days. They are associated with an anomalously strong 500-hPa trough–ridge over western–eastern North America that travels slowly eastward, favoring intrusions of moist, tropical air into eastern North America, and a strong baroclinic zone from the central United States to Atlantic Canada. They are also characterized by high frequencies of cyclones in the midwestern United States, anticyclones over eastern Canada and the subtropical Atlantic, and atmospheric rivers (ARs) in eastern North America. Precipitation is maintained by large moisture influxes, primarily from the Gulf of Mexico and Caribbean Sea, from the EPR start to the time midway through the EPR period. The influxes are often associated with ARs feeding into cyclones, where the moisture falls as precipitation. We also categorize EPRs based on the spatial anomaly correlation (AC) of synoptic-scale weather patterns between individual EPRs and the EPR composite. High AC EPRs have similar but stronger 500-hPa features over North America, greater moisture flux from the Gulf of Mexico and inland precipitation over eastern North America, farther inland cyclone track, higher frequency of subtropical Atlantic anticyclones, and lower EPR-to-EPR variability than low AC EPRs. Significance Statement Cool-season extreme precipitation regimes (EPRs) often lead to flooding and other impacts and represent a significant forecast challenge. We define and analyze EPRs during the eastern North American winter to obtain a better understanding of their associated meteorological conditions. We also categorize EPRs into two distinct categories to capture the variability among EPRs. EPRs generally last 5–8 days and are associated with slowly moving large-scale weather patterns favoring intrusions of moist, tropical air into eastern North America, a strong temperature contrast, and frequent cyclones in the midwestern United States with anticyclones to the north and south. The intrusions of moist, tropical air are often associated with atmospheric rivers (ARs) that deposit their moisture in cyclones as precipitation.

Historical observations of zooplankton groups in Mexican waters of the Gulf of Mexico and Caribbean Sea

Historical observations of zooplankton groups in Mexican waters of the Gulf of Mexico and Caribbean Sea

Role of Winds in Interrupting the Formation of Coastal Hypoxia

Enrichment of nutrients is believed to lead to coastal hypoxia which have become a seasonal phenomenon over large river estuarine areas such as the Mississippi River-Northern Gulf of Mexico and Changjiang-East China Sea. A similar nutrient enrichment process exists in the Pearl River. However, hypoxia occurs only as episodic events over a relatively small area. We hypothesize that frequent wind events play the interruptive mechanism in preventing the seasonal formation of bottom hypoxia. We used 29 years’ time series data of dissolved oxygen (DO) and winds in the Hong Kong coastal waters to test the hypothesis. Our results show that bottom DO at 3 stations in southern waters of Hong Kong occasionally drops below the hypoxic level (2 mg/L), lasting only for less than one month in summer. Episodic hypoxia events appear to occur more frequently in recent years, but bottom DO does not show a significantly decreasing trend. The wind speed of 6 m/s appears to be a threshold, above which a wind event could destroy water column stratification and interrupt the formation of low-oxygen (DO <3 mg/L) water mass. The wind events above the threshold occur 14.3 times in June, 14.2 times in July and 10.0 times in August during 1990-2018. This explains why episodic events of hypoxia hardly occur in June and July, and only occasionally in August. The frequency of such the above-threshold events appears to show a decreasing trend during 1990-2018, which coincides with an increasing occurrences of episodic hypoxia events in recent years.

Surface Pathways Connecting the South and North Atlantic Oceans

AbstractThe North Brazil Current (NBC) is considered a bottleneck in the South Atlantic, responsible for carrying upper‐ocean waters into the North Atlantic. This work explores the surface pathways connecting the NBC and 26°N in the North Atlantic. To identify said pathways, we use observational trajectories from surface drifters in conjunction with transition path theory applied on a Markov chain. The pathways are computed as ensembles of paths transitioning directly between the NBC and 26°N. Our results suggest that there are two dominant surface pathways: The first is the traditional pathway through the Caribbean Sea and Gulf of Mexico, carrying waters to the Florida Current, while the second is a direct route east of the Caribbean supplying waters to the Antilles Current and basin interior. The latter is composed of multiple pathways that are collectively more probable than the traditional pathway.

An Integrated Observing Effort for Sargassum Monitoring and Warning in the Caribbean Sea, Tropical Atlantic, and Gulf of Mexico

An Integrated Observing Effort for Sargassum Monitoring and Warning in the Caribbean Sea, Tropical Atlantic, and Gulf of Mexico

Insights from a Survey of Texas Gulf Coast Residents on the Social Factors Contributing to Willingness to Consume and Purchase Lionfish

Indo-Pacific lionfish (Pterois volitans and P. miles) are the first marine teleost to become established in the Western Atlantic Ocean, Caribbean Sea, and Gulf of Mexico. Lionfish have been labeled a global conservation issue and pose major threats to local economies. To test whether commercial harvest of lionfish is a socially accepted management approach in Texas, we measured the components of an environmental behavior intention model with survey responses of Texas Gulf Coast residents (n = 420). Regression analyses of survey responses indicate that individuals were significantly more willing to consume lionfish if they had a high level of concern for the environmental problems posed by the invasive species and were more knowledgeable about the fish. Participation in an educational program that addresses lionfish was also found to be associated with greater willingness to consume lionfish among those who are moderately to highly concerned about the issue. The originality of this study is related to its contribution in identifying social factors that contribute to an individual’s willingness to consume lionfish. Insights from this study demonstrate the attitudinal and behavioral mechanisms that can be addressed to increase acceptance of using consumption as a sustainable management strategy to combat marine fish invasions.

Satellite remote sensing of pelagic Sargassum macroalgae: The power of high resolution and deep learning

In recent years, massive blooms of pelagic Sargassum have occurred in the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico, and satellite imagery have been used operationally to monitor and track the blooms. However, limited by the coarse resolution and other confounding factors, there is often a data gap in nearshore waters, and the uncertainties in the estimated Sargassum abundance in offshore waters are also unclear. Higher-resolution satellite data may overcome these limitations, yet such a potential is hindered by the lack of reliable methods to accurately detect and quantify Sargassum in an automatic fashion. Here, we address this challenge by combining large quantities of high-resolution satellite data with deep learning. Specifically, data from the Multispectral Instrument (MSI, 10–20 m), Operational Land Imager (OLI, 30 m), WorldView-II (WV-2, 2 m), and PlanetScope/Dove (3 m) are used with a deep convolution neural network (DCNN) to extract Sargassum features and quantify Sargassum biomass density or areal coverage. By utilizing the U-net architecture and the pre-trained weights from the VGG16 model, the DCNN (i.e., the VGGUnet model) can extract Sargassum features while discarding other confusing features (waves, currents, phytoplankton blooms, clouds, cloud shadows, or striping noise). For Sargassum biomass estimated from OLI and MSI images, results indicate an accuracy of ~92% and 90%, respectively, when evaluated using images from the same sensor. When Sargassum areal coverage is estimated from WV-2 and Dove images, there is an accuracy of ~98% and 82%, respectively. When different sensors are cross-compared, OLI reveals ~30% more Sargassum biomass than MODIS from 14 OLI images collected in the Caribbean Sea (path/row: 001/050) for their commonly viewed observable areas, and ~ 180% more Sargassum biomass than MSI (N = 15, path/row: 001/050); such differences appear systematic (R2 = 0.98 and 0.73, respectively). Compared to the quasi-simultaneous MSI, OLI, and MODIS images, Dove shows higher Sargassum coverage. Higher-resolution sensors tend to observe more Sargassum because they can detect smaller-scale features that are missed by the coarser-resolution sensors, although the difference varies with time and location. The morphological characteristics of Sargassum features from these high-resolution data are also reported to facilitate management actions. The findings here not only fill the knowledge gaps and coverage gaps from previous studies, but more importantly pave the road toward operational monitoring and tracking Sargassum features in nearshore waters.

Deep-Sea Carbonates Are a Reservoir of Fossil Microbes Previously Inhabiting Cold Seeps

Carbonates are globally distributed particularly around deep-sea cold seeps. The embedded microbes are fossil records of the past bioprocess but metagenomes of the carbonates have not been fully studied. In this study, we report microbial community structures and genomes of dominant species in cold-seep carbonates from the South China Sea (SCS) and Gulf of Mexico (GoM). The carbonates contained both anaerobic microbes represented by methane oxidizing archaea (ANME) and aerobic ammonia-oxidizing archaea (AOA). The samples from GoM were mostly composed of small microbial groups, indicating heavy degradation of the fossil microbes. The composition of the carbonate communities differed from that of cold seep sediments, suggesting alteration of cold-seep microbial structures during formation and weathering of carbonates. Extraction of 18S rRNA genes from metagenomic reads revealed prevalence of fungal species in the carbonates of the GoM. Genome binning resulted in 10 genomes for dominant prokaryotic species. The ANME genomes showed a short genetic distance to the relatives from the current cold seep sediments; the AOA genomes were affiliated with alpha ecotype dominating deep-sea sediments. Our study reports the genomes in ancient carbonates and sheds lights on microbial role in formation and bioweathering of carbonates.

Downhole Fluid Analysis During Wellbore Sampling at High Temperatures Using a Pyroelectric Array Spectrometer

While the world is transitioning into a greener and less-carbon-rich energy source, the fact remains that there is a growing need for exploration and production of hydrocarbons in previously untapped resources. These frontier reservoirs, while extremely hot, are prolific and make the footprint of the exploration activity much smaller than shallower drilling, which would require many more wells to deliver the same amount of hydrocarbon. These frontier wells, classified as high-pressure/high-temperature (HP/HT) wells, are defined as wells with reservoir or bottomhole temperatures higher than 300°F and which require pressure-control equipment with a rating above 10,000 psi. HP/HT wells can be found offshore in the North Sea and Gulf of Mexico, or on land—as seen recently in the Gongola Basin. Fluid identification, which is a critical process in fluid sampling, continues to be a challenge in temperatures above 350°F. At temperatures up to 450°F, fluid identification is currently achieved by bubblepoint and compressibility measurements, which cannot quantitatively measure contamination levels of the subject sample fluid. A possible solution to this problem would involve using pyroelectric detectors in the process of estimating a property of a downhole fluid. The method and apparatus in this approach involves exposing a fluid to modulated light downhole and sensing changes in the intensity of infrared radiation from the downhole fluid, to estimate the level of filtrate contamination and other properties. The pyroelectric detector senses changes in the intensity of light by con-verting the transient changes in temperature of its detector and performs the spectroscopic fluid analysis by optically filtering the light allowed to impinge on it, converting the changes in temperature of the pyroelectric detector to a signal which can then be used to estimate the property of the downhole fluid. If successfully implemented, this would enable the wireline-logging industry to develop an optical fluid analyser capable of quantitatively measuring fluid contamination levels in high-temperature (greater than 300°F) environments. Theory Pyroelectric infrared detectors (PIR) convert the changes in incoming infrared light to electric signals. Pyroelectric materials are characterized by having spontaneous electric polarization, which is altered by temperature changes as infrared light illuminates the elements. Pyroelectric detectors (Fig. 1) are thermal detectors, meaning they produce a signal in response to a change in their temperature. Below a case temperature (Tc) known as the Curie point, ferroelectric materials such as lithium tantalate exhibit a large spontaneous electrical polarization. If the temperature of such a material is altered, for example by incident radiation, the polarization changes. This change in polarization may be observed as an electrical signal when electrodes are placed on opposite faces of a thin slice of the material to form a capacitor. When the polarization changes, if the external impedance is comparatively high, the charges induced in the electrodes can be made to produce a voltage across the slice. The sensor will only produce an electrical output signal when the temperature changes; that is, when the level of incident-radiation changes.

Large-scale and long-term distribution of corals in the gulf of Mexico and Caribbean Sea of Mexico and adjacent areas: Corals distribution in Mexico and adjacent areas

Hard coral distribution varies across temporal and geographical scales. Distribution of scleractinian corals was analyzed in 59 reefs in the Gulf of Mexico and Caribbean Sea of Mexico in two seasons 27 years apart. Data was collected by photography along 20 meter long transects placed at 10 m depth intervals over a 0–50 m depth range. Abundance data was generated by sampling 31 random points in each photographic image. A total of 62 hard coral species were identified. Overall abundance decreased by 67.17% between the two sampling periods. Abundance values were highest at Cozumel Island in the first period and at Chinchorro Bank in the second. Most (91%) of the sampling sites exhibited declines in abundance ranging from 2 to 99.25%. Different scleractinian species experienced declines from 3.72 to 98.7%, although Tubastrea coccinea increased by 16.6% and Porites astreoides by 1430.3%. Based on the Importance Value Index, dominance was highest for Manicina areolata (10.07%) in the first period and Orbicella annularis (10.49%) in the second. Species richness decreased at 67.79% of the sites and diversity at 57.62% of them; however, average diversity values varied minimally between the two periods (3.22–3.14 Bits/Ind.). In both periods, coral species exhibited peaks of higher richness and diversity at the sampled oceanic reefs in the Caribbean Sea. Analysis of site association with the Bray–Curtis index showed strong affinities among sites in the Gulf of Mexico and among those in the Caribbean Sea, although in the latter some differentiation existed between oceanic and coastal reefs. Non-metric scaling analysis showed species spatial distribution to be in well-defined groups that remain intact in both periods.

Monitoring pelagic Sargassum inundation potential for coastal communities

ABSTRACT Pelagic Sargassum is a buoyant macroalgae that forms rafts at the ocean surface and serves as a biologically rich habitat for hundreds of diverse marine species. Since 2011, massive blooms of Sargassum have occurred in the tropical Atlantic and swept through the western tropical Atlantic, Caribbean Sea, and Gulf of Mexico. These recurring annual events have caused significant disruptions to coastal communities throughout the region, negatively impacting human health, tourism, fishing, navigation, and nearshore ecosystems. We present here the Sargassum Inundation Report (SIR), a product that uses satellite-based methodology to estimate and predict the future coastal inundation of pelagic Sargassum. Results from one year of SIRs show strong spatiotemporal differences in the potential of coastal inundation across the Intra-American Seas, and provide a comprehensive method for assessing its geographic distribution and temporal variation. Comparisons of SIRs to opportunistically collected photographs indicate a qualitative concordance between satellite and in situ observations. This work highlights the value of satellite observations, basin-wide and seasonal monitoring, and emphasises the need for sub-regional and weekly forecasting. SIRs show considerable promise as a tool that can eventually incorporate improved spatiotemporal resolution Sargassum imagery, ocean circulation, wind, and wave conditions to forecast the movement of Sargassum into coastal areas.