Mangrove physiological traits are largely driven by ecogeomorphic conditions and environmental stressors. These traits provide adaptive strategies to enable growth and productivity in challenging coastal and marine settings. Moreover, plant biodiversity is a key component to determine the habitat richness, functioning and larger ecosystem dynamics and has a central role in carbon sequestration processes. The urban mangrove green cover at Carter Road in Mumbai harbors key species like Sonneratia alba Sm., Sonneratia apetala Buch.-Ham., Rhizophora mucronata Poir., and Avicennia marina (Forssk.) Vierh. They were evaluated for essential phytochemicals like proline and chlorophyll in ambient ecosystem conditions. Proline was highest in R. mucronata (22.42 ± 0.40 µmol g-1) and lowest in S. apetala (18.93 ± 0.14 µmol g-1). Chlorophyll a, Chl b, Chla+b and Chl a/b varied significantly at the two positional extremes –landward and seaward, with considerably higher values recorded at the landward edge. Chl a content (mg g-1) at the landward edge ranged from 1.60 ± 0.03 to 1.31 ± 0.12 and were much higher in comparison to the seaward fringe (0.71 ± 0.06 to 0.58 ± 0.02). Positional increments were also observed for Chl b and Chl a+b. Linear mixed effect model was significant for positional distinctiveness of soil carbon parameters like soil organic carbon (SOC%),bulk density and soil strata organic carbon (SOCOrg). The SOC (%) gave maximum values of surface soil (0-10 cm) at seaward (1.41 ± 0.06) and landward (2.08 ± 0.31) positions with corresponding SOCOrg (Mg C ha-1) values of 18.05 ± 1.711 and 22.367 ± 2.35 respectively, indicating significant carbon deposits landwards. The standing biomass carbon for aboveground and belowground biomass was 357.00 ± 33.09 Mg C ha-1 and 99.39 ± 9.21 Mg C ha-1 respectively. Thisstudy provides insights into modulation of Chlorophyll content impacting the ecosystem productivity and its carbon storage propensities.

ABSTRACT Multi-decadal observations and reanalysis products of major ocean circulation systems reveal contrasting trends and complex inter-basin connectivity patterns that challenge traditional conceptualizations of global ocean circulation. Using non-parametric trend analysis, multi-method causality testing, and wavelet coherence techniques, we analyzed volume transport time series spanning 1984-2023 for the Indonesian Throughflow (ITF), Agulhas Current system, and Atlantic Meridional Overturning Circulation (AMOC). The ITF demonstrates statistically significant strengthening, with geostrophic (ITF-G) and salinity (ITF-S) components increasing by 0.79 and 0.28 Sv decade-1, respectively (p<0.05). The temperature component (ITF-T) shows a positive but non-significant trend. Conversely, the AMOC at 26ºN from reanalysis exhibits robust weakening of -1.61 Sv decade-1 (p<0.0001), while satellite-derived Agulhas transport proxies show no significant long-term trends despite substantial interannual variability. Causality analysis reveals four statistically significant pathways linking ITF components to Agulhas variability with lag times of 0-18 months, supported by consensus across maximum cross-correlation, convergent cross mapping, and transfer entropy methods. However, no direct causal connections emerge between either Indo-Pacific system and the AMOC at 26ºN, indicating regional forcing dominance over global-scale coupling on observable timescales. Wavelet coherence analysis identifies dominant annual-scale coupling (0.87-1.30 years) in ITF-Agulhas relationships, with enhanced coherence during major climate events including the 1997-98 El Niño. These findings suggest that contemporary ocean circulation responds primarily to regional forcing mechanisms - intensified Maritime Continent rainfall driving ITF strengthening and weakened North Atlantic convection controlling AMOC decline - rather than operating as a tightly coupled global conveyor belt. The identified statistical relationships provide critical observational constraints for ocean circulation models and highlight the need for sustained monitoring as anthropogenic forcing continues to reshape ocean gateway dynamics.

ABSTRACT Katsuwonus pelamis is a fish resource of high economic value and widely used in the fish processing industry, mainly for canned products. This study aimed to identify the parasitic fauna of Katsuwonus pelamis by morphological methods, to analyze the potential impact on industry and consumers. For the evaluation of parasitological contamination, fifty-three animals were visually inspected and the structures with morphology consistent with parasitic forms were analyzed stereoscopically, microscopically, and by Scanning Electron Microscopy (SEM). Two genera of zoonotic parasites have been found: Anisakis sp. (Nematoda) and Trypanorhyncha gen. sp. (Cestoda). Of the 53 samples analyzed, 96% showed parasite contamination. The most affected organs were the intestine, muscle tissue, and stomach, with 596, 441, and 408 parasites, respectively. These results highlight the importance of sanitary inspection and emphasize the importance of immediate evisceration to avoid the migration of larvae from the viscera to the musculature.

ABSTRACT The incidental capture of sea turtles by fishing gear is a significant global threat to sea turtle populations. The increasing demand for seafood and seafood products raises the risk of sea turtle entanglement in fishing gear. Our study documented the encounter rate of sea turtles with fishing gear in Guyana, South America. Semi-structured interviews were conducted with fishers at key landing sites along the coast of Guyana. A total of 76 fishers participated in this study. Most fishers encountered sea turtles in their fishing gear at least once annually during fishing trips. Most turtles were captured in gillnet fisheries, and leatherbacks were the most caught species. Encounters were more frequent in August, aligning with the February-to-August nesting period. Most turtles were alive when encountered on the fishing nets, but the post-release mortality of the turtles is unknown. We also found that fishers knew that sea turtles are an endangered and protected species. However, they doubt that much can be done to prevent sea turtle bycatch without compromising their target catch. Our findings highlight the crucial role of collaboration between scientists, fishery managers, and fishers to understand sea turtle bycatch and develop and implement successful bycatch reduction strategies to conserve sea turtles.

ABSTRACT Geotechnical and environmental studies widely use shallow geophysical imaging methods to indirectly acquire high-resolution subsurface data at a low cost for constructing three-dimensional models. Among these, seismic methods are especially valuable for investigating shallow submerged environments due to their capacity to produce detailed subsurface images. This study analyzes seismic facies patterns based on high-resolution shallow seismic profiles collected during a geotechnical investigation of the continental shelf offshore the Port of Suape, seeking to improve the understanding of the sedimentary and structural evolution of the transitional zone between the offshore and onshore regions of the Pernambuco Basin. The dataset comprises 14 multichannel 2D seismic sections, totaling 6.4 km of survey lines. Integrating sonographic data, borehole logs, sediment samples, and photographs enabled classifying three main types of seabed: (i) homogeneous mud seafloor; (ii) subaqueous dunes with gravel and sand; and (iii) irregular rocky substrate partially covered by sand. Interpretation of the seismic profiles identified five key reflections, including the present-day seabed and four major unconformities, And five seismic facies: (a) Facies I - unconsolidated sandy and muddy sediments (Quaternary); (b) Facies II - sandstones and shales of the Suape Formation (Lower-Middle Albian); (c) Facies III - basal deposits of the Cabo Formation (Barremian-Aptian); (d) Facies IV - carbonate mounds of the Estiva Formation (Cenomanian-Turonian); and (e) Facies V - crystalline basement (Ipojuca Magmatic Suite). Seismic and geotechnical data integrated allowed the reconstruction of stratigraphic layers associated with rift and post-rift phases of the basin. Additionally, a prominent positive seismic anomaly and normal faults trending NW-SE occurred at the basement top, suggesting extensional tectonic activity linked to the South Atlantic Rift.

ABSTRACT São José de Ribamar Bay, located in Maranhão State, is one of the largest estuarine systems in Brazil. This study analyzes tidal and riverine regimes, as well as the spatial and seasonal distribution of physical water properties (salinity, temperature, and density) along the bay. Water-level observations were examined using harmonic analysis, and the annual modulation of tidal amplitude was obtained using the Hilbert transform. Historical discharge data from the Itapecurú and Munim rivers - the main tributaries supplying the bay - were analyzed to determine the climatological pattern of river flow. Salinity and temperature data were collected during four oceanographic surveys conducted along the bay: two during the wet season and two during the dry season. In each season, one survey was performed during spring tides and the other during neap tides. Water-column stratification was assessed based on these measurements. The tidal regime is purely semidiurnal and dominated by the M2 harmonic constituent. Tidal range varies from approximately 6 m during spring tides to 2.5 m during neap tides. Mean river discharge reaches approximately 1,000 m3 s-1 in the wet season and decreases to around 100 m3 s-1 in the dry season. Expressed as a flow ratio, river discharge represents only about 1% of the volume periodically exchanged during the wet season and about 0.1% during the dry season. Increased freshwater input in the wet season promotes a buoyancy flux that strengthens stratification. Consequently, the bay behaves as a well-mixed estuary during the dry season and as a strain-induced, periodically stratified estuary during the wet season.

ABSTRACT The Hunga Tonga Hunga Ha’apai eruption of January 15th, 2022, was a rare geological event, resulting in atmospheric pressure waves being recorded around the world, along with sea level fluctuations. This research aims to analyze the tsunami and pressure waves observed in the Caribbean and adjacent regions, which were generated by this eruption. These kinds of perturbations are uncommon and have not been seen in many occurrences, let alone with global implications. Modern instrumentation in the Caribbean and adjacent regions, including both barometers and sea level stations, provided a unique opportunity to observe and analyze this event. A comprehensive review of the observations recorded in the Caribbean and adjacent regions linking the barometric observations to sea level perturbations, including observations of the lead/lag relative to the barometric pressure spikes and the frequency content of observable sea level perturbations, will be shown in this study. For instance, most of the stations in this study recorded six barometric spikes, of which the first two generated a significant sea level observation. Circumstances complicating observations, such as interference from factors, e.g. a strong cold front and lack of standardization, will also be discussed. This study, which will integrate observations from across the Caribbean and adjacent regions, aims to better understand the nature of this unique event and how it was observed in the region. As such, this research can offer insight into the factors that may influence volcanic tsunamis, which is invaluable for developing tsunami warning and response protocols.

ABSTRACT Marine pigments are more commonly used in food, pharmaceuticals, aquaculture and cosmetics industries. Marine pigments have a significant economic importance, constituting a multimillion-dollar industry that is still growing. Considering this, we decided to conduct a descriptive study of the photosynthetic pigments in surface sediments from the continental shelf and slope of 14 sites located in the northwestern Gulf of Mexico, obtained during October-November 2012. These pigments were analyzed using high-performance liquid chromatography. At least one pigment was detected in 10 of the samples examined, and a total of six pigments were identified, including three photosynthetic pigments and three chlorophyll-a degradation products: pheophorbide-a, pyrophaeophytin-a and phaeophytin-a. The pigments with the highest concentration were β-carotene and pheophorbide-a. Significant pigment concentrations were observed in inshore areas exposed to the influence of river discharge (Bravo and Soto La Marina) and Laguna Madre. The pigment composition and concentration were influenced by depth, temperature, salinity, and nickel concentration. Finally, a correlation between Ni, an indirect hydrocarbon contaminant marker, and pigment concentrations was observed. A deeper understanding of marine pigments certainly will fuel advances in biotechnology and bioengineering. We find it crucial to recognize the interactions between marine pigments and other ecosystem components. Despite pigment diversity, exploration in this field is still in its first stages, with many marine compounds awaiting further exploration.

ABSTRACT The waterline position derived from publicly available satellite imagery has been an increasingly used method to acquire high spatial-temporal scale and enough data to study shoreline behavior. In this study, to enhance the understanding of shoreline behavior and evolution of beach systems adjacent to Babitonga bay inlet, SC, Brazil, the CASSIE platform was used to generate ~40 years of satellite-derived waterline position data. Shoreline behavior and evolution of these systems were investigated through Hovmoller diagram interpretation, beach systems sectorization and shoreline change rate of the identified sectors. The Hovmoller diagram was drawn up using the annual average shoreline position. The beach systems sectorization was made up with the Hovmoller diagram interpretation allied to Hierarchical Clustering analysis. The shoreline change rate of each sector was conducted for the average transect data that make up the sectors. Results revealed the occurrence of sedimentary pulses on Enseada and Forte beaches, which starts at headland and propagates along Enseada beach and Forte-Capri beach system. Also, significant erosion trends were identified on the border of Ponta do Sumidouro and Forte beach, at second sector of Forte-Capri beach system, with Linear Regression Rate (LRR) of -4.11 m/year (CI = ±0.59 m/year), at the second and third sector of Pontal-Itapoá beach system with LRR of -1.61 m/year (CI = ±0.31 m/year) and -0.90 m/year (CI = ±0.18 m/year), respectively. The remaining sectors embodying beach environments were classified as stable state.

ABSTRACT Advances in high-resolution satellite sensors and merged multi-sensor ocean colour products have improved the detection of submesoscale features and enhanced the continuity of ocean surface measurements. This has enabled more detailed observations of chlorophyll-a (chl-a) growth rates, biomass and biogeochemical fluxes. Chl-a, a photosynthetic pigment in marine autotrophs, is used as a proxy for phytoplankton biomass and primary productivity. The accurate estimation of surface chl-a via remote sensing is key to improving coastal ocean process modelling. We compared chl-a products from sensors of multiple spatial resolutions, including Sentinel-3 Ocean and Land Colour Imager (OLCI), the Moderate Resolution Imaging Spectroradiometer (Aqua) (MODIS Aqua), the Visible Infrared Imaging Radiometer Suite (VIIRS) on Suomi NPP and the Ocean Colour Climate Change Initiative (OC-CCI) V6 product to two in situ datasets (M1 and C1) in Monterey Bay, California, USA. Sentinel-3 consistently performed well under the Inverse Modelling Technique - Neural Network chl-a algorithm, performing slightly better at station M1 R M 1 2 = 0 . 85 , R C 1 2 = 0 . 80. The Ocean Colour for MERIS algorithm performed better at offshore station M1 R M 1 2 = 0 . 87 and yielded no matchups at C1. MODIS Aqua and VIIRS performed poorly R M 1 , M O D I S 2 = 0 . 32 , R M 1 , V I I R S 2 = 0 . 02 , R C 1 , M O D I S 2 = 0 . 08 , R C 1 , V I I R S 2 = 0 . 25, likely inhibited by calibration to global as opposed to regionally adapted datasets. OC-CCI, though blended for greater continuity, produced fewer matchups at a higher accuracy R M 1 , O C - C C I 2 = 0 . 66 , R C 1 , O C - C C I 2 = 0 . 63 than MODIS Aqua or VIIRS alone, but still less so than Sentinel-3 OLCI. All sensors either over- or under-estimated chl-a at all concentrations, apart from OC-CCI, likely due to the complex coastal optical properties of the area. Our results highlight the need for regional algorithm development and show the potential effectiveness of Sentinel-3 and OC-CCI products for future submesoscale process studies.