Digna Rueda-Roa

Two U.S. National Estuarine Research Reserves (NERRs), Rookery Bay (Florida) and Jobos Bay (Puerto Rico), experienced hurricanes in September 2017 (Irma and Maria) and 2022 (Ian and Fiona). We quantified mangrove canopy disturbance and recovery using pixel-wise annual land-cover trajectories from 2 m WorldView™ imagery (2017–2024) and monthly Sentinel-2 and Landsat Normalized Difference Vegetation Index (NDVI) time series (2016–2025). Mangrove target areas (MTAs) comprised pixels classified as mangrove in the pre-storm 2017 map and consistent coverage across the subsequent available maps. In 2018, mapped mangrove cover declined to 47% in the southeastern Rookery Bay MTA (sRB-MTA) and 59% in the Jobos Bay MTA (JB-MTA), with most disturbed pixels reclassified as soil. Intermediate mapped classes represented spectral and surface-condition changes rather than discrete ecological states. Despite greater initial loss, mapped mangrove cover reached 90% in the sRB-MTA by 2023, compared with 79% in the JB-MTA in 2023 and 83% in 2024. Recovery was spatially heterogeneous: pixels initially reclassified as mixed low-relief vegetation showed higher recovery percentages by 2023 (sRB-MTA: 92%; JB-MTA: 81%) than those reclassified as coastal water (48% and 23%, respectively). Persistent non-recovery of mangrove class coincided with pre-existing hydrologic stressors in both regions, and unauthorized coastal development in Jobos Bay NERR. Areas that subsequently returned to the mangrove class showed a sharp post-storm NDVI decline, followed by an initial rapid rebound and gradual recovery toward climatological greenness and seasonality by mid-2022. NDVI recovery began earlier in Jobos Bay (November 2017) than in southern Rookery Bay (June 2018). No widespread canopy response was detected following the 2022 storms, consistent with weaker local wind exposure but not excluding other ecological effects. Together, land-cover trajectories and the NDVI resolved complementary canopy recovery patterns without establishing restoration of pre-storm forest structure or ecosystem function.

The Guajira Upwelling System (GUS) is located between 10–12.5° N and 61–75.5° W in the Southern–Central Caribbean Sea. This study examines its spatial and seasonal variability using upwelling indices derived from surface differences in temperature, salinity, density, and absolute dynamic topography between the GUS and a nearby Caribbean region (78–68° W, 10–16° N) not affected by coastal upwelling. Weekly time series from 1998 to 2022 were analyzed. The difference-based indices were compared with Ekman transport, a conventional proxy for upwelling intensity, and with satellite-derived chlorophyll-a to evaluate the phytoplankton response. Seasonal cycles were further examined at four representative grid points along the system. Among the indices, sea surface temperature most effectively delineated the spatial extent and seasonal variability of the GUS. Comparisons with chlorophyll-a revealed a strong upwelling–biomass relationship in the northern sector (east of 73.5° W), whereas productivity in the southern sector was not primarily driven by coastal upwelling. Correlation maps indicated that the weakening of upwelling influence coincided with the region affected by the Magdalena River plume.

Dissolved organic carbon (DOC) in coastal waters is integral to biogeochemical cycling, but global and regional drivers of DOC are still uncertain. In this study we explored spatial and temporal differences in DOC concentrations and stocks across the global coastal ocean, and how these relate to temperature and salinity. We estimated a global median coastal DOC stock of 3.15 Pg C (interquartile range (IQR) = 0.85 Pg C), with median DOC concentrations being 2.2 times higher than in open ocean surface waters. Globally and seasonally, salinity was the main driver of DOC with concentrations correlated negatively with salinity, without a clear relationship to temperature. DOC concentrations and stocks varied with region and season and this pattern is likely driven by riverine inputs of DOC and nutrients that stimulate coastal phytoplankton production. Temporally, high DOC concentrations occurred mainly in months with high freshwater input, with some exceptions such as in Eastern Boundary Current margins where peaks are related to primary production stimulated by nutrients upwelled from the adjacent ocean. No spatial trend between DOC and temperature was apparent, but many regions (19 out of 25) had aligned peaks of seasonal temperature and DOC, related to increased phytoplankton production and vertical stratification at high temperatures. Links of coastal DOC with salinity and temperature highlight the potential for anthropogenic impacts to alter coastal DOC concentration and composition, and thereby ecosystem status.

Coastal wetlands are vulnerable to accelerated sea-level rise, yet knowledge about their extent and distribution is often limited. We developed a land cover classification of wetlands in the coastal plains of the southern United States along the Gulf of Mexico (Texas, Louisiana, Mississippi, Alabama, and Florida) using 6161 very-high (2 m per pixel) resolution WorldView-2 and WorldView-3 satellite images from 2012 to 2015. Area extent estimations were obtained for the following vegetated classes: marsh, scrub, grass, forested upland, and forested wetland, located in elevation brackets between 0 and 10 m above sea level at 0.1 m intervals. Sea-level trends were estimated for each coastal state using tide gauge data collected over the period 1983–2021 and projected for 2100 using the trend estimated over that period. These trends were considered conservative, as sea level rise in the region accelerated between 2010 and 2021. Estimated losses in vegetation area due to sea level rise by 2100 are projected to be at least 12,587 km², of which 3224 km² would be coastal wetlands. Louisiana is expected to suffer the largest losses in vegetation (80%) and coastal wetlands (75%) by 2100. Such high-resolution coastal mapping products help to guide adaptation plans in the region, including planning for wetland conservation and coastal development.

The presented pilot for the Synthesis Product for Ocean Time Series (SPOTS) includes data from 12 fixed ship-based time-series programs. The related stations represent unique open-ocean and coastal marine environments within the Atlantic Ocean, Pacific Ocean, Mediterranean Sea, Nordic Seas, and Caribbean Sea. The focus of the pilot has been placed on biogeochemical essential ocean variables: dissolved oxygen, dissolved inorganic nutrients, inorganic carbon (pH, total alkalinity, dissolved inorganic carbon, and partial pressure of CO₂), particulate matter, and dissolved organic carbon. The time series used include a variety of temporal resolutions (monthly, seasonal, or irregular), time ranges (10–36 years), and bottom depths (80–6000 m), with the oldest samples dating back to 1983 and the most recent one corresponding to 2021. Besides having been harmonized into the same format (semantics, ancillary data, units), the data were subjected to a qualitative assessment in which the applied methods were evaluated and categorized. The most recently applied methods of the time-series programs usually follow the recommendations outlined by the Bermuda Time Series Workshop report (Lorenzoni and Benway, 2013), which is used as the main reference for “method recommendations by prevalent initiatives in the field”. However, measurements of dissolved oxygen and pH, in particular, still show room for improvement. Additional data quality descriptors include precision and accuracy estimates, indicators for data variability, and offsets compared to a reference and widely recognized data product for the global ocean: the GLobal Ocean Data Analysis Project (GLODAP). Generally, these descriptors indicate a high level of continuity in measurement quality within time-series programs and a good consistency with the GLODAP data product, even though robust comparisons to the latter are limited. The data are available as (i) a merged comma-separated file that is compliant with the World Ocean Circulation Experiment (WOCE) exchange format and (ii) a format dependent on user queries via the Environmental Research Division's Data Access Program (ERDDAP) server of the Global Ocean Observing System (GOOS). The pilot increases the data utility, findability, accessibility, interoperability, and reusability following the FAIR philosophy, enhancing the readiness of biogeochemical time series. It facilitates a variety of applications that benefit from the collective value of biogeochemical time-series observations and forms the basis for a sustained time-series living data product, SPOTS, complementing relevant products for the global interior ocean carbon data (GLobal Ocean Data Analysis Project), global surface ocean carbon data (Surface Ocean CO₂ Atlas; SOCAT), and global interior and surface methane and nitrous oxide data (MarinE MethanE and NiTrous Oxide product). Aside from the actual data compilation, the pilot project produced suggestions for reporting metadata, implementing quality control measures, and making estimations about uncertainty. These recommendations aim to encourage the community to adopt more consistent and uniform practices for analysis and reporting and to update these practices regularly. The detailed recommendations, links to the original time-series programs, the original data, their documentation, and related efforts are available on the SPOTS website. This site also provides access to the data product (DOI: https://doi.org/10.26008/1912/bco-dmo.896862.2, Lange et al., 2024) and ancillary data.

Measurements of dissolved organic carbon (DOC), nitrogen (DON), and phosphorus (DOP) concentrations are used to characterize the dissolved organic matter (DOM) pool and are important components of biogeochemical cycling in the coastal ocean. Here, we present the first edition of a global database (CoastDOM v1; available at https://doi.org/10.1594/PANGAEA.964012, Lønborg et al., 2023) compiling previously published and unpublished measurements of DOC, DON, and DOP in coastal waters. These data are complemented by hydrographic data such as temperature and salinity and, to the extent possible, other biogeochemical variables (e.g. chlorophyll a, inorganic nutrients) and the inorganic carbon system (e.g. dissolved inorganic carbon and total alkalinity). Overall, CoastDOM v1 includes observations of concentrations from all continents. However, most data were collected in the Northern Hemisphere, with a clear gap in DOM measurements from the Southern Hemisphere. The data included were collected from 1978 to 2022 and consist of 62 338 data points for DOC, 20 356 for DON, and 13 533 for DOP. The number of measurements decreases progressively in the sequence DOC > DON > DOP, reflecting both differences in the maturity of the analytical methods and the greater focus on carbon cycling by the aquatic science community. The global database shows that the average DOC concentration in coastal waters (average ± standard deviation (SD): 182±314 µmol C L⁻¹; median: 103 µmol C L⁻¹) is 13-fold higher than the average coastal DON concentration (13.6±30.4 µmol N L⁻¹; median: 8.0 µmol N L⁻¹), which is itself 39-fold higher than the average coastal DOP concentration (0.34±1.11 µmol P L⁻¹; median: 0.18 µmol P L⁻¹). This dataset will be useful for identifying global spatial and temporal patterns in DOM and will help facilitate the reuse of DOC, DON, and DOP data in studies aimed at better characterizing local biogeochemical processes; closing nutrient budgets; estimating carbon, nitrogen, and phosphorous pools; and establishing a baseline for modelling future changes in coastal waters.

An extreme Saharan dust storm (named Godzilla) arrived at the Caribbean region in June 2020, deteriorating the air quality to hazardous levels and unhealthy conditions for sensitive groups of people. Our main objective was to characterize populations at risk for Saharan dust by analyzing distribution and levels of dust events in Puerto Rico, and by conducting an online survey to assess community perceptions on Saharan dust health effects. Three daily satellite aerosols products from 2013 to 2020 were retrieved from the Visible Infrared Imaging Radiometer Suite over Puerto Rico to better understand the patterns, frequency, and seasonality of aerosols. The atmospheric results indicated that extreme values (>99th) of big size aerosols (e.g., Sahara dust) were observed over Puerto Rico on 22 June 2020. A total of 1504 qualified people participated in the survey during the summer of 2020, and it was analyzed with descriptive statistics, frequency analysis, and chi-square tests. 51% of the survey participants were on the age group of 25–44 years old, and 65% of the participants had at least one preexisting health condition (respiratory diseases 27%; cardiovascular diseases 28%). Nearly 90% of the participants indicated that Saharan dust affected the health status of both the respondents and their family members. Irritation of eyes (22%), nose (24%), and throat (23%), as well as breathing difficulties (10%), were the most common symptoms reported. Understanding patients’ health profiles associated with Saharan dust is essential before developing public health strategies to minimize exacerbation of health conditions in Puerto Rico.