World Ocean Research Articles

Molecular phylogeny, morphology and distribution of Amphitetras antediluviana Ehrenberg from the Black Sea and the Sea of Azov

The intriguing large-celled species of Amphitetras antediluviana Ehrenberg was originally described as a fossil species (Ehrenberg, 1840), but later noted in a living state in various regions of the World ocean. Our recent studies revealed that the species has been found for the last decade in significant numbers in many habitats along the coast of the Azov-Black Sea basin. Two strains—the large valves from Laspi Bay, the Black Sea (BL-5_12092019) and the small valves from the Sea of Azov (AZ-12_24122019)—were isolated and analyzed using light and scanning electron microscopy along with molecular-genetic investigation. Specimens of the two populations differ in valve sizes and structure, however, their belonging to the same species was confirmed with the help of molecular analysis. Taxonomic positions of the strains of A. antediluviana isolated from two marine waterbodies were clarified. In addition, we provided a detailed morphological diagnosis of the species with a description of the valve ultrastructure and its elements, as well as geographical distribution and taxonomic history.

Anticorrelation of net uptake of atmospheric CO2 by the world ocean and terrestrial biosphere in current carbon cycle models

Abstract. The rate at which atmospheric carbon dioxide (CO2) would decrease in response to a decrease in anthropogenic emissions or cessation (net zero emissions) is of great scientific and societal interest. Such a decrease in atmospheric CO2 on the centennial scale would be due essentially entirely to transfer of carbon into the world ocean (WO) and the terrestrial biosphere (TB), which are sink compartments on this timescale. The rate of decrease in excess atmospheric CO2 and the apportionment of this decrease into the two sink compartments have been examined in two prior model intercomparison studies, subsequent either to a pulse emission of CO2 or to abrupt cessation of anthropogenic CO2 emissions. The present study examines and quantifies inter-model anticorrelation in those studies in the net rate and extent of uptake of CO2 into the two sink compartments. Specifically, in each study the time-dependent coefficients characterizing the net transfer rate into the two sink compartments (evaluated as the net transfer rate normalized to excess atmospheric CO2 above the pre-pulse amount for the pulse experiment or as the net transfer rate divided by excess atmospheric CO2 above the preindustrial amount for the abrupt cessation experiment) were found to exhibit strong anticorrelation across the participating models. That is, models for which the normalized rate of uptake into the WO was high exhibited low uptake rate into the TB and vice versa. This anticorrelation in net transfer rate results in anticorrelation in net uptake extent into the two compartments that is substantially greater than would be expected simply from competition for excess CO2 between the two sink compartments. This anticorrelation, which is manifested in diminished inter-model diversity, can lead to artificially enhanced confidence in current understanding of the consequences of potential future reductions of CO2 emissions and in the global warming potentials of non-CO2 greenhouse gases relative to that of CO2.

Location-dependent effect of microplastic leachates on the respiration rate of two engineering mussel species.

Microplastics are ubiquitous in the world's oceans and pose serious environmental concerns, including their ingestion and the release of potentially toxic mixtures of intrinsic and extrinsic chemical compounds (i.e. leachates; MPLs). Mussels, as key intertidal bioengineers and filter-feeders are particularly susceptible to both exposure pathways. While the effects of microplastic ingestion have been widely investigated, research on the impacts of MPLs has only recently begun. This study examined the influence of MPLs derived from beached pellets collected in two separate regions, namely France and Portugal, on the respiration rates of two key ecosystem engineers, Mytilus edulis and Mytilus galloprovincialis. Possibly due to distinct mixtures of leached chemicals, unlike Portuguese-MPLs, exposure to French-MPLs significantly decreased the respiration rate of both mussel species. This research provides new insights into the physiological impacts of MPLs on bioengineer species, highlighting the importance of MP source and potential cascading effects at the ecosystem level. While we reported significant effects on mussel respiration after acute MPL exposure, future research should investigate long-term impacts and potential detoxification mechanisms to clarify the effects of MPs on mussel physiological performance and their potential consequences on specie fitness.

ISASO2: recent trends and regional patterns of ocean dissolved oxygen change

Abstract. Recent estimates of the global inventory of dissolved oxygen (DO) have suggested a decrease of 2 % since the 1960s. However, due to the sparse historical oxygen data coverage, the DO inventory exhibits large regional uncertainties over the interannual timescale. Using the In Situ Analysis System for O2 (ISASO2), a new Argo DO-based optimally interpolated climatology at https://doi.org/10.17882/52367 (Kolodziejczyk et al., 2023), we have estimated an updated regional oxygen inventory. Over the long term (∼ 1980–2013), comparing the ISASO2 Argo fields with the first-guess World Ocean Atlas (WOA18) built from the DO bottle sample fields extracted from the World Ocean Database 2018 (WOD18), the broad tendency to global ocean deoxygenation remains robust in the upper 2000 m, with −451 ± 243 Tmol per decade. The oxygen decline is more pronounced in the key ventilation areas of the Southern Ocean and North Atlantic, except in the Nordic Seas, where oxygen has increased. Over the shorter timescale of the Argo period (2005–2019), the deoxygenation tendency seems globally amplified (−1211 ± 218 Tmol per decade). However, DO changes exhibit stronger amplitude and contrasting regional patterns. The recent changes in Apparent Oxygen Utilization mainly explain the interannual variability in the ventilation regions. However, Argo DO coverage is still incomplete as global and calibration method development is still in progress. Continuing the monitoring of the seasonal-to-interannual and regional-to-global DO variability from ISASO2 will improve our ability to reduce uncertainties in global and regional DO inventories.

An INDEL genomic approach to explore population diversity of phytoplankton

BackgroundAlthough metabarcoding and metagenomic approaches have generated large datasets on worldwide phytoplankton species diversity, the intraspecific genetic diversity underlying the genetic adaptation of marine phytoplankton to specific environmental niches remains largely unexplored. This is mainly due to the lack of biological resources and tools for monitoring the dynamics of this diversity in space and time.ResultsTo gain insight into population diversity, a novel method based on INDEL markers was developed on Bathycoccus prasinos (Mamiellophyceae), an abundant and cosmopolitan species with strong seasonal patterns. Long read sequencing was first used to characterize structural variants among the genomes of six B. prasinos strains sampled from geographically distinct regions in the world ocean. Markers derived from identified insertions/deletions were validated by PCR then used to genotype 55 B. prasinos strains isolated during the winter bloom 2018–2019 in the bay of Banyuls-sur-Mer (Mediterranean Sea, France). This led to their classification into eight multi-loci genotypes and the sequencing of strains representative of local diversity, further improving the available genetic diversity of B. prasinos. Finally, selected markers were directly tracked on environmental DNA sampled during 3 successive blooms from 2018 to 2021, showcasing a fast and cost-effective approach to follow local population dynamics.ConclusionsThis method, which involves (i) pre-identifying the genetic diversity of B. prasinos in environmental samples by PCR, (ii) isolating cells from selected environmental samples and (iii) identifying genotypes representative of B. prasinos diversity for sequencing, can be used to comprehensively describe the diversity and population dynamics not only in B. prasinos but also potentially in other generalist phytoplankton species.

Seasonal intensification of oxygen minimum zone: linking Godavari River discharge to fall hypoxia in the Bay of Bengal

IntroductionThis study investigates the biogeochemical impact of Godavari River discharge (GRD) on the Bay of Bengal (BoB), focusing on the formation of an intense and shallow oxygen minimum zone (OMZ) near the river mouth during the fall season. Unlike the BoB’s typical intermediate-depth OMZ, this subsurface (~40-200 m) phenomenon is attributed to the interplay of GRD-driven nutrient enrichment, coastal upwelling, enhanced productivity, and subsequent organic matter decomposition.Data and MethodsOur analysis using the Biogeochemical-Argo floats and World Ocean Atlas 2018 data reveals that a clear shoaling and intensification of the OMZ in the fall season. Further, a comparative analysis at two geographically distinct locations highlighted the pivotal role of GRD.Results, Discussion, and ImplicationsThe location directly influenced by GRD exhibited significantly higher chlorophyll-a blooms, net primary production during the southwest monsoon, and pronounced oxygen consumption during the fall compared to the other. Our analysis suggests that GRD fuels primary productivity, leading to organic matter abundance and intense oxygen depletion in the subsurface layers, driving the observed shallow OMZ. Understanding the complex interplay between GRD, stratification, upwelling, and biogeochemical processes is crucial for predicting the impact of altered riverine inputs on coastal ecosystems, greenhouse gas emissions, and the overall health of the coastal BoB.

On the accuracy of distance estimates by propagation time of sound signals on the arctic shelf

As part of numerical modeling, estimates are made of the accuracy of determining the distance between underwater sources and sound receivers located at a distance of several kilometers from each other in the Kara Sea in the autumn. It is assumed that the main source of possible errors in determining the distance is the lack of accurate data on the vertical profile of the sound speed along the propagation path of acoustic signals. Data from September and November were analyzed, in the interval between which significant changes in the profile take place, when the vertical gradient of sound speed changes from negative to positive values. Characteristic values of sound speed variations were obtained by statistical processing of hydrological data taken from the World Ocean Database. The results obtained are important for analyzing the capabilities of underwater acoustic navigation.

Dissolved Nitrous Oxide and Methane in the Taiwan Strait: Distribution, Seasonal Variation, and Emission

AbstractThe global ocean plays an important role in the overall budgets of nitrous oxide (N2O) and methane (CH4), especially in continental estuaries and shelf areas. Four cruises were conducted between 2021 and 2022, covering the spring, summer, and fall seasons, to study the spatial and seasonal characteristics of N2O and CH4 distributions and emissions in the Taiwan Strait (TWS). The surface N2O and CH4 concentrations gradually decreased from the coast to the open sea, with maximum values (14.3 and 15.6 nmol L−1) occurring near the Jiulong and Minjiang estuaries, respectively. The mean surface N2O concentration (8.2 nmol L−1) was highest in the spring and approximately the same in the summer as in the fall. The mean surface concentrations of CH4 (8.8 nmol L−1) were greater in summer than in spring and fall, probably because of the high freshwater input in summer. Except for several stations in fall, surface waters were oversaturated with N2O and CH4 relative to the atmosphere in other seasons, and the TWS was a net source of atmospheric N2O and CH4 in the spring, summer, and fall. In situ production is the main source of N2O and CH4 in the TWS, with nitrification being the dominant mechanism of N2O production in the TWS. In contrast, physical influences (riverine inputs and water mass mixing) reshape the distributions of N2O and CH4. The annual emissions of N2O and CH4 from the TWS were estimated to be 0.9 × 10−3 ± 2.9 × 10−3 Tg yr−1 and 1.6 × 10−3 ± 3.0 × 10−3 Tg yr−1, respectively. Taken together, the TWS accounts for 0.025% of the surface area of the world's oceans and 0.022% ± 0.07% and 0.017% ± 0.033% of global oceanic N2O and CH4 emissions, respectively.

Mesopelagic Fish Traits: Functions and Trade‐Offs

ABSTRACTFishes inhabiting the mesopelagic zone of the world's oceans are estimated to account for the majority of the world's fish biomass. They have recently attracted new attention because they are part of the biological carbon pump and have been reconsidered as a contribution to food security. Hence, there is an urgent need to understand how environmental conditions and species interactions shape their assemblages, and how they contribute to the functioning of marine ecosystems. Trait‐based approaches are valuable for addressing these types of questions. However, the biology and ecology of mesopelagic fishes are understudied compared to fishes in shallow and epipelagic waters. Here, we synthesise existing knowledge of traits of mesopelagic fishes and relate them to their role in survival, feeding and growth and reproduction, the key functions that contribute to fitness. Vertical migrations, specialised vision and the use of bioluminescence are among the most striking adaptations to the conditions in the mesopelagic realm. Many traits are interrelated as a result of trade‐offs, which may help to understand selection pressures. While morphological traits are straightforward to observe, major knowledge gaps exist for traits that require frequent sampling, assessment under experimental conditions or age determination. The unique adaptations of mesopelagic fishes need to be included in management strategies as well as fundamental research of the habitat.

High functional vulnerability across the world’s deep-sea hydrothermal vent communities

At the nearly pristine hydrothermal vents of the deep sea, highly endemic animals depend upon bacteria nourished by hydrothermal fluids that emerge as outflows from the seafloor. These animals are remarkable in tolerating extreme conditions, including high heat, toxic reduced sulfide, and low oxygen. Here, we test whether the extreme vent environment has selected for functionally similar species across the world's deep ocean, despite well-established global geographic patterns of high phylogenetic distinctness. High functional redundancy in species pools within regions suggests that the extreme environments select for species with specific traits. Yet, some regions emerge as functional hotspots where species pools with distinct functional trait compositions may represent geological idiosyncrasies of the habitats. Moreover, many species are functionally unique, an outcome of low species richness in a system where the species pool is small at all scales. Given the high proportion of functionally unique species, simulated species extinctions indicate that species losses would rapidly translate to the elimination of functionally irreplaceable species and could tip vent systems to functional collapse. Ocean changes and human-induced threats are expected to significantly impact many vent species as human activities expand in the remote deep sea. The opportunity exists now to take precautionary actions to limit the rates of extinction now ubiquitous in more accessible areas of Earth.

Optical Remote Sensing Methods for Floating Marine Debris Detection – Review and Bibliography Analysis

In the last several decades, the disposal and accumulation of debris in the marine and coastal environment has been one of the biggest and fastest-growing threats to the health of the world's oceans. Marine debris is present in all marine habitats and represents a great danger to global environmental and human health. Therefore, this paper aims to support efforts to achieve Good Environmental Status with respect to marine debris in all oceans and seas. The application of optical remote sensing methods for floating marine debris detection was briefly reviewed and the bibliometric analysis of the professional and scientific literature elaborated upon. In the overview part, previously used marine debris detection methods have been listed. The WoSCC (Web of Science Core Collection) and Scopus databases were considered, and the R Studio Bibliometrix and Biblioshiny software tools used for bibliometric analysis. 209 documents that can be classified into 43 research fields were identified in the two databases. Approximately 20% of the documents were published in two journals: the Marine Pollution Bulletin and Remote Sensing. Marine debris research was mainly published in the USA, Portugal, Italy, the United Kingdom, Germany, and China. A total of 54 countries participated in the publication of documents and it should be emphasized that all countries have shown great interest in international cooperation during the scientific research on marine debris. Scientific research on marine debris was found to have increased significantly since 2017, which is highly important for the protection of the environment and human health.

How mariculture expansion is dewilding the ocean and its inhabitants.

The world's oceans are largely free from intensive farming, but momentum to intensify and expand mariculture-the cultivation of aquatic organisms in the ocean-is growing. Despite optimism that mariculture will create economic and nutritional benefits for humans, it can also generate a host of risks, including environmental degradation, harms to wildlife integrity and welfare, captivity effects, and shifts in how humans view the nonhuman world. Collectively, we refer to these four types of risks as "dewilding." In this systematic review, we searched Scopus and Web of Science for recent literature documenting mariculture's dewilding impacts to organize and collate this evidence under one unified framework. We find that mariculture's dewilding impacts are consistently documented, though often in isolation, and that captivity and conceptual dewilding impacts are recognized as potential harms far less than impacts on the environment and wildlife. Future work examining mariculture's dewilding impacts will be paramount to guiding human decision-making and activity going forward.

Long Distance Transport of Subsurface Sediment‐Derived Iron From Asian to Alaskan Margins in the North Pacific Ocean

AbstractThe international GEOTRACES program has been instrumental in demonstrating how marine sediments are a critical source of dissolved Fe to the world's oceans. Here, we present dissolved iron (dFe) from the GEOTRACES North Pacific GP15 section, which, alongside other sediment‐source tracers (including dissolved δ56Fe, Mn, 228Ra, and particulate Fe), allows for identification of the dFe provenance of three distinct dFe depth maxima at the Alaskan margin. Two of these (shelf and abyssal depths) are of local Alaskan sedimentary origin. The third, a mid‐depth dFe maximum with an absence of 228Ra, is an advected signal that, based on tracer data from Western Pacific GEOTRACES transects and circulation models, must be advected from sedimentary sources on the Asian margin, ∼5,000 km away. This study illustrates the importance of measuring diagnostic sedimentary tracers like radium when assigning local margins as sedimentary sources of marine trace metal budgets.

Pengaruh Green Marketing Communication terhadap Green Behaviour (Studi Kasus Pemberdayaan Penggunaan Kantong Plastik pada konsumen Alfamart di Kota Bandung)

Plastic waste is a major problem in environmental pollution, both on land and at sea. Indonesia is ranked second in producing plastic waste in the world's oceans. The Ministry of Environment and Forestry stated that plastic waste generated from 100 retail stores or members of the Indonesian Retailers Association (APRINDO) reached 10.95 million pieces of plastic waste within one year. The Ministry of Environment and Forestry (KLHK) created a paid plastic bag policy to address the plastic waste problem. The aim of this research is to determine the influence of green marketing communication on green behavior regarding empowering the use of plastic bags among Alfamart consumers. The data collection technique used was purposive sampling which is included in non-probability sampling with a total of 100 respondents who had used paid plastic bags at Alfamart in Bandung City aged 17 years and over. The empirical data in this research was collected using a one-shot study approach and then processed and analyzed using simple regression using SPSS version 26. The results of the research show that green marketing communication has a positive effect on green behavior. Therefore, Alfamart management can prioritize improving all the indicators that make up green marketing communication because it is hoped that this can have a positive impact on green behavior.

New Insights into the Mechanisms of Toxicity of Aging Microplastics.

Nowadays, synthetic polymer (plastic) particles are ubiquitous in the environment. It is known that for several decades microplastics (MPs) have been accumulating in the World Ocean, becoming available to a large variety of marine organisms. Particularly alarming is the accumulation of aging plastic particles, as the degradation processes of such particles increase their toxicity. The diverse display of negative properties of aging MPs and its effect on biota are still poorly understood. In this study, in vitro experiments modeling the interaction of pristine and UV-irradiated aging polypropylene (PP) fragments with hemocytes and mitochondria of bivalve mollusks Mytilus sp. were performed. The appearance of free radicals in the environment was recorded by spectral characteristics of indicator dyes-methylene blue (MB) and nitroblue tetrazolium (NBT). It was found that due to photooxidation, aging PP fragments sorbed more than threefold MB on their modified surface compared to pristine samples of this polymer. Using NBT, the formation of reactive oxygen species in seawater in the presence of pristine and photoactivated PP was recorded. It was also found that photodegraded PP fragments largely stimulated the development of lipid peroxidation processes in mitochondrial membranes and reduced the stability of hemocyte lysosome membranes compared to pristine PP fragments. In general, the results obtained concretize and supplement with experimental data the previously stated hypothesis of toxicity of aging MPs.

Delivering scientific evidence for global policy and management to ensure ocean sustainability

AbstractLife depends on the ocean, with societal health, cultural systems and national economies reliant on ocean processes and resources. As ocean resources are used, and humans continue to drive climate change, the benefits from the ocean to society are being diminished. Science must meet the needs of policy and deliver to decision makers the information and tools for identifying pathways that support continued delivery of the benefits society derives from the ocean, whilst minimising impacts. This is crucial if the world’s nations are to meet the goals and targets they have set under international agreements. Here, we outline how a global assessment that focuses specifically on the ocean, the World Ocean Assessment, is linking science to the governments of the world and their policies within an internationally mandated framework. In doing so, we identify key elements that are needed for facilitating engagement by decision makers and uptake of knowledge, and the pathways taken by the assessment in implementing them. We also provide insights into the evolution that the World Ocean Assessment has undertaken over its first three cycles to progress its goal of enhancing the scientific basis of policymaking. We identify the challenges in delivering science to policy at a global scale and the work that still needs to be done in filling gaps to achieve a coordinated, comprehensive mechanism for connecting science with policy and ensuring future sustainability of the ocean.

Tracing troubles: Unveiling the hidden impact of inorganic contamination on juvenile green sea turtle

Human activities and climate change have negatively affected the world's oceans, leading to a decline of 30 to 60 % in coastal ecosystems' biodiversity and habitats. The projected increase in the human population to 9.7 billion by 2050 raises concerns about the sustainability of marine ecosystem conservation and exploitation. Marine turtles, as sentinel species, accumulate contaminants, including trace elements, due to their extensive migration and long-life span. However, there is a lack of data on the degree of contamination and their effects on marine turtles' health. This study focuses on assessing in-situ inorganic contamination in juvenile green sea turtles from La Réunion Island and its short-term impact on individual health, using conventional biomarkers and proteomics. The goals include examining contamination patterns in different tissues and identifying potential new biomarkers for long-term monitoring and conservation efforts. The study identified differential metal contamination between blood and scute samples, which could help illuminate temporal exposure to trace elements in turtle individuals. We also found that some conventional biomarkers were related to trace element exposure, while the proteome responded differently to various contaminant mixtures. Immune processes, cellular organization, and metabolism were impacted, indicating that contaminant mixtures in the wild would have an effect on turtle's health. Fifteen biomarker candidates associated with strong molecular responses of sea turtle to trace element contamination are proposed for future long-term monitoring. The findings emphasize the importance of using proteomic approaches to detect subtle physiological responses to contaminants in the wild and support the need for non-targeted analysis of trace elements in the biomonitoring of sea turtle health.

Light Color Regulation of Photosynthetic Antennae Biogenesis in Marine Phytoplankton.

Photosynthesis in the world's oceans is primarily conducted by phytoplankton, microorganisms that use many different pigments for light capture. Synechococcus is a unicellular cyanobacterium estimated to be the second most abundant marine phototroph, with a global population of 7 x 1026 cells. This group's success is partly due to the pigment diversity in their photosynthetic light harvesting antennae, which maximize photon capture for photosynthesis. Many Synechococcus isolates adjust their antennae composition in response to shifts in the blue:green ratio of ambient light. This response was named Type 4 chromatic acclimation (CA4). Research has made significant progress in understanding CA4 across scales, from its global ecological importance to its molecular mechanisms. Two forms of CA4 exist, each correlated with the occurrence of one of two distinct but related genomic islands. Several genes in these islands are differentially transcribed by the ambient blue:green light ratio. The encoded proteins control the addition of different pigments to the antennae proteins in blue versus green light, altering their absorption characteristics to maximize photon capture. These genes are regulated by several putative transcription factors also encoded in the genomic islands. Ecologically, CA4 is the most abundant of marine Synechococcus pigment types, occurring in over 40% of the population oceanwide. It predominates at higher latitudes and at depth, suggesting that CA4 is most beneficial under sub-saturating photosynthetic light irradiances. Future CA4 research will further clarify the ecological role of CA4 and the molecular mechanisms controlling this globally important form of phenotypic plasticity.

Signature of the western boundary currents in local climate variability.

The western boundary currents are characterized by narrow, intense ocean jets and are among the most energetic phenomena in the world ocean. The importance of the western boundary currents to the mean climate is well established: they transport vast quantities of heat from the subtropics to the midlatitudes1, and they govern the structure of the climatological mean surface winds2-6, precipitation4-6 and extratropical storm tracks7-13. Their importance to climate variability is much less clear, as the tropospheric response to extratropical sea surface temperature (SST) variability is generally modest relative to the internal variability in the midlatitude atmosphere12-14. Here we exploit novel local analyses based on high-spatial-resolution data to demonstrate that SST variability in the western boundary currents has a more robust signature in climate variability than has been indicated in previous work. Our results indicate that warm SST anomalies in the major boundary currents of both hemispheres are associated with a distinct signature of locally enhanced precipitation and rising motion anomalies that extend throughout the depth of the troposphere. The tropospheric signature closely mirrors that of ocean dynamical processes in the boundary currents. Thus, the findings indicate a distinct and robust pathway through which extratropical ocean dynamical processes influence local climate variability. The observational relationships are also reproducible in Earth system model simulations but only when the simulations are run at high spatial resolution.

DC_OCEAN: an open-source algorithm for identification of duplicates in ocean databases

A high-quality hydrographic observational database is essential for ocean and climate studies and operational applications. Because there are numerous global and regional ocean databases, duplicate data continues to be an issue in data management, data processing and database merging, posing a challenge on effectively and accurately using oceanographic data to derive robust statistics and reliable data products. This study aims to provide algorithms to identify the duplicates and assign labels to them. We propose first a set of criteria to define the duplicate data; and second, an open-source and semi-automatic system to detect duplicate data and erroneous metadata. This system includes several algorithms for automatic checks using statistical methods (such as Principal Component Analysis and entropy weighting) and an additional expert (manual) check. The robustness of the system is then evaluated with a subset of the World Ocean Database (WOD18) with over 600,000 in-situ temperature and salinity profiles. This system is an open-source Python package (named DC_OCEAN) allowing users to effectively use the software. Users can customize their settings. The application result from the WOD18 subset also forms a benchmark dataset, which is available to support future studies on duplicate checks, metadata error identification, and machine learning applications. This duplicate checking system will be incorporated into the International Quality-controlled Ocean Database (IQuOD) data quality control system to guarantee the uniqueness of ocean observation data in this product.