Tropical cyclones can severely disturb shallow, continental shelf ecosystems, affecting habitat structure, diversity, and ecosystem services. This study examines the impacts of Hurricane Ian on the Southwest Florida Shelf by assessing water quality, substrate type, and epibenthic and microbial community characteristics at eight sites (3 to 20 m in depth) before and after Ian’s passage in 2022. Hurricane Ian drastically changed substrate type and biotic cover, scouring away epibenthos and/or burying hard substrates in mud and sand, especially at mid depth (10 m) sites (92–98% loss). Following Hurricane Ian, the greatest losses were observed in fleshy macroalgae (58%), calcareous green algae (100%), seagrass (100%), sessile invertebrates (77%), and stony coral communities (71%), while soft coral (17%) and sponge communities (45%) were more resistant. After Ian, turbidity, chromophoric dissolved organic matter, and dissolved inorganic nitrogen and phosphorus increased at most sites, while total nitrogen, total phosphorus, and silica decreased. Microbial communities changed significantly post Ian, with estuary-associated taxa expanding further offshore. The results show that the shelf ecosystem is highly susceptible to disturbances from waves, deposition and erosion, and water quality changes caused by mixing and coastal discharge. More routine monitoring of this environment is necessary to understand the long-term patterns of these disturbances, their interactions, and how they influence the resilience and recovery processes of shelf ecosystems.

Southwest Florida is one of the fastest growing regions in the United States, heavily affected by anthropogenic activities, which may alter the composition of natural seawater. Polluted seawater may thus become a potential risk to coastal human populations and the ecosystem at large. The current study investigated seasonal variations in surface seawater along the Gulf coast of southwest Florida to determine potential anthropogenic inputs and the ecological impacts of heavy metals. Water samples were collected from 14 sampling locations at three different time points (October 2022, January 2023, and March 2023) following Hurricane Ian in September 2022. Samples were analysed for heavy metals (V, Cr, Mn, Ni, Zn, As, Rb, Mo, Cd, Sb, Pb, and U) using an Inductively Couple Plasma Mass Spectrometry (ICP-MS). The metal highest concentrations were found to be as follows, Zn (5096.81 ± 1.09 µg/L), Pb (387.84 ± 1.73 µg/L), Rb (237.46 ± 1.51 µg/L), Ni (131.29 ± 1.09 µg/L), Cr (32. 58 ± 1.29 µg/L), Mn (16.62 ± 1.22 µg/L), Mo (12.96 ± 0.43 µg/L), Cd (3.11 ± 8.87 µg/L), V (8.68 ± 0.76 µg/L), Sb (7.63 ± 0.31 µg/L), As (7.32 ± 0.47 µg/L), U (7.13 ± 0.00 µg/L). The Ecological risk index ranged from 1.01 to 83.75 in October 2022, 2.41–321.77 in January 2023, and 1.05–248.61 in March 2023, indicating high ecological risk due to the presence of heavy metals. Dermal hazard and ingestion indexes assessments were lower than one, indicating that no health risks to humans may result from dermal exposure at this stage. The presence of high concentrations of some heavy metals may be attributed to the impact of pollutants and possibly discharges from Hurricane Ian, thus the need for continuous monitoring. The present study may serve as baseline data for further research efforts to identify the source of these heavy metals in seawater as they may have detrimental effects on marine economically important organisms.

Oysters are important estuarine species, providing numerous ecosystem services, including habitat and filtration. However, natural oyster reefs are declining, largely due to increased coastal development, habitat loss, and water-quality degradation. Despite these declines, little attention is given to understanding the natural stressors experienced by oysters. In Southwest Florida, reefs are predominantly intertidal, exposing oysters to a suite of stressors that may interact to decrease fitness. Yet, spatial and temporal variation in these natural environments is largely understudied. To fill this gap, we monitored five oyster reefs (Crassostrea virginica) across Estero Bay, FL, over two years, measuring oyster performance alongside numerous environmental factors. Oyster condition varied within reefs, among neighboring reefs, and across the estuary, but no single environmental variable consistently explained these patterns. Neighboring reefs separated by only hundreds of meters differed in oyster condition and live cover despite similar water-quality conditions, corresponding instead with fine-scale differences in reef elevation. Across the estuary, the influence of reef elevation was context dependent: greater exposure was associated with favorable oyster condition at one site but increased thermal exposure and reduced live cover at another. Oysters exposed to chronic low salinity also maintained condition and growth comparable to reefs experiencing more moderate salinity regimes, suggesting an important role of environmental history. Collectively, these findings demonstrate that oyster performance emerges from interacting physical and environmental processes operating across multiple scales. Reef-scale morphology, hydrodynamics, and biologically relevant measures of environmental variability may therefore provide more informative indicators of reef condition than broad environmental averages alone.

Microbial communities play a crucial role in coastal ecosystem function, yet their seasonal and spatial dynamics in response to environmental change remain underexplored in tropical and subtropical regions. This yearlong study investigated microbial composition in water, sinking particles, and sediments along an inshore–offshore gradient influenced by the Caloosahatchee River Estuary in southwest Florida. The region has been altered by rapid coastal development and was struck by Hurricane Ian in September 2022. Environmental parameters exhibited significant spatiotemporal variation, shaping microbial beta diversity in all habitats. Sediment communities showed the greatest hurricane-induced disruption but returned to pre-disturbance conditions within six months. Dominant microbial classes included Alphaproteobacteria, Bacteroidia, and Gammaproteobacteria. Biogeochemical cycling taxa displayed strong habitat specificity, such as Desulfobulbia which dominated sinking particles, Desulfobacteria which was abundant in sediments, and Nitrosomonadaceae and Nitrosopumilaceae which were key nitrifiers in water and sediments, respectively. Particle–sediment taxonomic overlap suggests resuspension processes. Several inshore microbial indicators were consistently present across microbial habitats, especially at estuarine sites, suggesting the estuary as a microbial diversity reservoir for the coastal zone. These results highlight the value of long-term microbial monitoring to understand ecosystem change and resilience in dynamic coastal environments.