Marine Organisms Research Articles

The effects of polystyrene microplastics on feeding, growth, and trophic upgrading of protozoan grazers

Microplastics have become ubiquitous in the global marine environment, posing substantial influences on marine organism health, food web function and marine ecosystem structure. Protozoan grazers are known for their ability to improve the biochemical constituents of poor-quality algae for subsequent use by higher trophic levels. However, the effects of microplastics on the trophic upgrading of protozoan grazers remain unknown. To address this knowledge gap, the ciliate Euplotes vannus and the heterotrophic dinoflagellate Oxyrrhis marina were exposed to microplastic particles (5 μm) for four days with various concentrations (1–20 mg/L). Both O. marina and E. vannus ingested microplastics. At the exposure level of 20 mg/L, the ingestion rate, growth rate, biovolume, and carbon biomass of E. vannus were significantly decreased by 28.18 %, 32.01 %, 30.46 %, and 82.27 %, respectively, while such effects were not observed for O. marina. The contents of highly unsaturated fatty acids in O. marina and E. vannus on a mixed diet of microplastic particles and green algae significantly reduced by 8.66 % and 41.49 % relative to feeding only on green algae, respectively. Besides, we also observed an increase in the composition of C18:3 (ω-3) and C20:3 (ω-3) concurrence with a significant decrease in C16:0 and C18:0 in E. vannus after 96 h exposure at 20 mg/L. These results indicate that microplastics can weaken trophic upgrading of the nutritional quality by protozoan grazers, which may consequently alter the function of food webs.

Spatial and temporal patterns of floating litter in shallow habitats: Insights from high-tourism tropical areas in Northeastern Brazil

We investigated the composition, quantity, distribution and potential sources of floating litter in the subtidal zones of tropical beaches. Marine sampling sites were selected based on the presence (protected/sheltered) or absence (non-protected) of reefs. Plastic was the most abundant material, and the presence of floating litter from land-based sources was confirmed, which was likely associated with domestic and tourism-related activities, owing to irregular waste disposal. Marine debris was more abundant during the rainy season, and marine beaches had more floating litter than estuarine beaches. Coastal reefs served as a barrier, impeding the transport of marine litter by coastal currents, explaining the greater abundance of floating litter on protected/sheltered marine beaches. Thus, three mechanisms seemed to drive the amount of floating litter in the subtidal zone of the tropical beaches: 1) the availability of floating litter in the water, 2) coastal hydrodynamics favoring the accumulation of floating litter, and 3) a beach’s capacity to retain floating litter. Our study demonstrates that marine litter is an important pollution source in sensitive areas that play a key role as nurseries for marine life, especially in beaches close to reef formations.

A long-term dissolved oxygen prediction model in aquaculture using transformer with a dynamic adaptive mechanism

The prediction of Dissolved Oxygen (DO) in oceans is crucial for the survival of marine life and the management of marine farms. However, due to the inherent instability and uncertainty of DO, prediction models frequently necessitate parameter adjustments, posing challenges to maintaining reliable predictive performance and generalization capabilities. Based on this, a long-term dissolved oxygen prediction model in aquaculture using Transformer with a dynamic adaptive mechanism is proposed in the paper. A multi-scale latent correlation decomposition strategy was devised, merging both time and frequency domain decompositions. This approach proficiently untangles time series exhibiting intricate non-linear cycles, thereby delving deeper into and furnishing a more comprehensive array of feature data. Furthermore, an uncertainty-aware attention mechanism was posited, ensuring accurate pinpointing of pivotal data amidst a highly volatile data environment, thus cementing prediction accuracy. Finally, the incorporation of an adaptive hyperparameter adjustment mechanism enables the model to recalibrate in line with feature insights, bolstering its generalization potential across marine farms in diverse regions. Empirical results show that the model proposed in this study can effectively accomplish high-precision long-term forecasting. When juxtaposed with other models under comparable conditions, its mean squared error significantly diminished by 40.2%, the mean absolute error contracted by 55.4%, and concurrently, the R2 value ascended by 7%. This research proffers a fresh vantage point for long-term marine chemical data predictions and extends robust technical bolstering for refining and augmenting aquacultural strategies.

Into the deep: Exploring the molecular mechanisms of hyperactive behaviour induced by three rare earth elements in early life-stages of the deep-sea scavenging amphipod Tmetonyx cicada (Lysianassidae)

With increasing socio-economic importance of the rare earth elements and yttrium (REY), Norway has laid out plans for REY mining, from land-based to deep-sea mining, thereby enhancing REY mobility in the marine ecosystem. Little is known about associated environmental consequences, especially in the deep ocean. We explored the toxicity and modes of action of a light (Nd), medium (Gd) and heavy (Yb) REY-Cl3 at four concentrations (3, 30, 300, and 3000 μg L−1) in the Arcto-boreal deep-sea amphipod Tmetonyx cicada. At the highest concentration, REY solubility was limited and increased with atomic weight (Nd < Gd < Yb). Lethal effects were practically restricted to this treatment, with the lighter elements being more acutely toxic than Yb (from ∼50 % mortality in the Gd-group at dissolved 689–504 μg L−1 to <20 % in the Yb-group at ca. 2000 μg L−1), which could be a function of bioavailability. All three REY induced hyperactivity at the low-medium concentrations. Delving into the transcriptome of T. cicada allowed us to determine a whole array of potential (neurotoxic) mechanisms underlying this behaviour. Gd induced the vastest response, affecting serotonin-synthesis; sphingolipid-synthesis; the renin-angiotensin system; mitochondrial and endoplasmic reticulum functioning (Gd, Nd); and lysosome integrity (Gd, Yb); as well as the expression of hemocyanin, potentially governing REY-uptake (Gd, Yb). While Nd and Yb shared only few pathways, suggesting a link between mode of action and atomic weight/radius, almost all discussed mechanisms imply the disruption of organismal Ca-homeostasis. Despite only fragmental genomic information available for crustaceans to date, our results provide novel insight into the toxicophysiology of REY in marine biota. The neurotoxic/behavioural effects in T. cicada at concentrations with potential environmental relevance warn about the possibility of bottom-up ecological consequences in mining exposed fjords and deep-sea ecosystems, calling for follow-up studies and regulatory measures prior to the onset of REY mining in Norway.

Metathesis Mastery: Crafting Linear Triquinane Frameworks for Natural Product Synthesis

AbstractOrganic and medicinal chemists have shown great interest in developing simple approaches for creating linear triquinane structures, as they are crucial for synthesizing both natural and synthetic products. Linear triquinane shows various biological characteristics like being commonly used for antitumor, antibacterial, and antimalarial purposes, making it a popular subject of study among synthetic chemists. These come from different sources like marine organisms, plants, and fungi and make up a significant group of sesquiterpenoids. These can be classified as cis‐syn‐cis or cis‐anti‐cis based on the stereochemistry at the ring junction, with cis‐anti‐cis being the most common type and exhibiting significant biological activity. In this review, we summarized different methods using a combination of photothermal and olefin metathesis strategy to construct a triquinane framework by utilizing both traditional heat and microwave radiation. Some commonly used synthetic methods, including metathesis protocol and key reactions like Grignard reaction and Diels–Alder reaction, were utilized together with ring‐closing, ring‐opining, and ring‐rearrangement metathesis to create the linear triquinane core for use in total synthesis of natural products. Additionally, the use of photothermal olefin metathesis along with Hosomi‐Sakurai reaction conditions allows for the creation of intricate polyquinanes, which can be used to produce complex natural compounds and for designing unique molecules theoretically.

Determination of steroid hormones in sea urchins by microwave-assisted extraction and ultrahigh-performance liquid chromatography tandem mass spectrometry

Marine pollution poses significant threats to ecosystems by contaminating habitats and degrading marine life. This involves the need to develop efficient methodologies to evaluate the compounds that affect marine organisms, such as steroid hormones. The study of the presence of these compounds in marine organisms like sea urchins is very interesting given their role as bioindicators because they feed on algae and are constantly in contact with sediments. Given the low concentrations of steroid hormones in marine environments, it is necessary to develop extraction procedures that allow these pollutants to be extracted and preconcentrated before chemical analyses. Of all the extraction methods, microwave-assisted extraction (MAE) has been used for its many advantages compared to traditional extraction techniques, such as easy sample handling or scarce organic solvents use, and for providing very selective extractions. This study presents the novel MAE optimisation for the extraction of 15 hormones, including five oestrogens, three androgens, four progestogens and three glucocorticoids from sea urchin tissues. The extracted hormones were subsequently determined by high-performance liquid chromatography tandem mass spectrometry. To the best of the authors' knowledge, this approach has not been previously developed. To perform extraction optimisation, different variables were studied following factorial experimental designs. The optimised extraction method showed very appropriate analytical parameters, with limits of detection between 0.21 and 20.4 ng·g-1 for the four families of studied steroid hormones, and recovery extractions over 60 % for most target compounds. After optimisation, the analytical methodology was applied to samples of three different sea urchins species (Arbacia lixula, Paracentrotus lividus, Sphaerechinus granularis) caught in different locations around the Gran Canaria island (Canary Islands, Spain). The results showed the great applicability of the optimised methodology and two target hormones, boldenone and prednisolone, which were quantified in different samples and locations. This indicates the potential of sea urchins as bioindicators of the health of marine ecosystems and of anthropogenic contamination.

Marine thermal fluctuation induced gluconeogenesis by the transcriptional regulation of CgCREBL2 in Pacific oysters

Marine thermal fluctuation profoundly influences energy metabolism, physiology, and survival of marine life. In the present study, short-term and long-term high-temperature stresses were found to affect gluconeogenesis by inhibiting PEPCK activity in the Pacific oyster (Crassostrea gigas), which is a globally distributed species that encounters significant marine thermal fluctuations in intertidal zones worldwide. CgCREBL2, a key molecule in the regulation of gluconeogenesis, plays a critical role in the transcriptional regulation of PEPCK in gluconeogenesis against high-temperature stress. CgCREBL2 was able to increase the transcription of CgPEPCK by either binding the promoter of CgPEPCK gene or activating CgPGC-1α and CgHNF-4α after short-term (6 h) high-temperature stress, while only by binding CgPEPCK after long-term (60 h) high-temperature stress. These findings will further our understanding of the effect of marine thermal fluctuation on energy metabolism on marine organisms.

Machine learning for potential anti-cancer discovery from black sea cucumbers

&lt;p&gt;Despite being an abundant marine organism in Indonesia, black sea cucumbers &lt;em&gt;(Holothuria atra)&lt;/em&gt; is still underutilised due to its slightly bitter taste. This study aims to identify potential anti-cancer compounds from black sea cucumbers using machine learning (ML) to perform drug discovery. ML models were used to predict interactions between compounds from the organism with cancer-related proteins. Following prediction, all compounds were computationally validated through molecular docking. The validated compounds were then screened using absorption, distribution, metabolism, excretion, and toxicity (ADMET) Lab 2.0 to assess their druglike properties. The results showed that ML predicted seven out of 86 compounds were interacted with cancer-related proteins. Computational validation from the results showed that four out of seven compounds demonstrated stable interaction with proteins where only one compound meet the criteria of drug-like compound. The framework of ML and computational validation highlighted in this study shows a great promise in the future of drug discovery specifically for marine organisms. Since computational method only works in prediction realms, wet lab validation and clinical trials are imperative before the drug candidate can be produced as actual anti-cancer drug.&lt;/p&gt;

Repeated marine heatwaves aggravate the adverse effects of nano-TiO2 on physiological metabolism of the thick-shelled mussel Mytilus coruscus

Global climate change is a major trigger of unexpected temperature fluctuations. The impacts of marine heatwaves (MHWs) and nano-titanium dioxide (nano-TiO2) on marine organisms have been extensively investigated. However, the potential mechanisms underlying their interactive effects on physiological processes and metabolism remain poorly understood, especially regarding periodic MHWs in real-world conditions. In this study, the effects of nano-TiO2 (at concentrations of 0, 25, and 250 μg/L) and periodic MHWs on the condition index (CI) and underlying metabolic mechanisms were investigated in mussels (Mytilus coruscus). The results showed that mussels try to upregulate their respiration rate (RR) to enhance aerobic metabolism (indicated by elevated succinate dehydrogenase) under short-term nano-TiO2 exposure. However, even at ambient concentration (25 μg/L), prolonged nano-TiO2 exposure inhibited ingestion ability (decreased clearance rate) and glycolysis (inhibited pyruvate kinase, hexokinase, and phosphofructokinase activities), which led to an insufficient energy supply (decreased triglyceride, albumin, and ATP contents). Repeated thermal scenarios caused more severe physiological damage, demonstrating that mussels are fragile to periodic MHWs. MHWs decreased the zeta potential of the nano-TiO2 particles but increased the hydrodynamic diameter. Additionally, exposure to nano-TiO2 and periodic MHWs further affected aerobic respiration (inhibited lactate dehydrogenase and succinate dehydrogenase activities), metabolism (decreased RR, activities of respiratory metabolism-related enzymes, and expressions of PEPCK, PPARγ, and ACO), and overall health condition (decreased ATP and CI). These findings indicate that the combined stress of these two stressors exerts more detrimental impact on the physiological performance and energy metabolism of mussels, and periodic MHWs exacerbate the toxicological effects of ambient concentration nano-TiO2. Given the potential worsening of nanoparticle pollution and the increase in extreme heat events in the future, the well-being of mussels in the marine environment may face further threats.

One becomes three: An integrative morphological and molecular analysis of the windowpane oyster Placuna (Bivalvia: Pectinida) reveals new species.

For decades, many marine animals have been considered to exhibit cosmopolitan or transoceanic distribution. This situation is prevalent in Asia, where many species were collected and named by American or European experts in the 1700s to early 1900s. Using the windowpane oysters Placuna-a small genus of bivalves with five recognized species-we show that careful analysis is required to reassess the validity of these species. Currently, only two species of Placuna (P. placenta and P. ephippium) widely reported in the Indo-Pacific region have been recorded from Chinese coastal waters. Here, we described two new species of Placuna from China. Placuna vitream sp. nov. can be distinguished from P. placenta by its larger ridge angle. Phylogenetic analysis using five gene fragments fully supported that P. vitream sp. nov. is a sister to the specimen from Singapore identified as P. placenta and more distant from other Placuna species with available molecular data. Besides, based on subfossil shells, we describe Placuna aestuaria sp. nov. that differs from its congeneric species by its broad hinge, medium ridge angle, and nearly straight ridges. Finally, we suggest a combination of hinge structure and ridge angle that can be used for identifying Placuna species and preparing a key to this genus. Our findings of two new species expand the diversity of Placuna and prompt reassessment of the many presumably widely distributed marine species in Asia.

Evaluating the Stages of Environmental Pollution and Vital Indicators in the Qayyarah Refinery Area, Mosul, Iraq

Oil spills can have varying degrees of impact on the aquatic environment depending on factors such as the type of oil spilled, the volume released, and the ecosystem affected because crude oil and refined petroleum contain harmful substances such as hydrocarbons, heavy metals, and toxic chemicals. When released into the water, these substances can have immediate and long-term effects on marine life. This research aims to find the factors affecting the degree of pollution from oil spills on the aquatic environment and the areas adjacent to the Qayyarah refinery in northern Iraq. Combines the fuzzy comprehensive evaluation method and the analytical hierarchy process to evaluate the degree of pollution from oil spill incidents in the areas adjacent to the refinery. The statistical analysis showed that there were statistically significant differences and that the value of the correlation coefficient was positive between exchanged cadmium, residual cadmium, exchanged lead, where the lead exchange rate ranged correlation coefficient at a minimum R² 0.674 and a clear increase in the number of bacteria indicating contamination the total number of bacteria coli, fecal coliform bacteria, and fecal strep bacteria (where the numbers of coliform bacteria ranged 102 × 102- (cells/011 mL, and fecal coliform bacteria were between 160 × 102 cells/011 mL. These rates are environmental and vital indicators of the presence of significant levels of organic pollution and evidence of the presence of microorganisms dangerous to the health of residents and living organisms.

The impact of microplastics on marine life and ecosystems

The impact of microplastics on marine life and ecosystems

Dietary regulation of gut bacteria in the Pacific oyster Magallana gigas and Mediterranean mussel Mytilus galloprovincialis

Feed composition affects the gut bacterial community in aquatic species, but little is known about how diet type impacts gut microbiota in molluscan bivalves. This study investigates the impact of feed composition on the gut bacterial community in two commercially important bivalves: Pacific oyster Magallana gigas and Mediterranean mussel Mytilus galloprovincialis. Oysters and mussels were fed with two types of marine algae, live Isochrysis galbana (microalgae) and the dried seaweed powder Ulva sp. (macroalgae) under a laboratory condition for two months. The V1–V2 region of the 16S rDNA was sequenced through an Illumina MiSeq platform to compare the gut bacterial community of oysters and mussels at the start and the end of the feeding trial. Feed composition directly impacted both alpha and beta diversities of gut microbiota, but the degree of the impact differed between bivalve species. The difference in the gut bacterial assemblages of oysters and mussels in the pre- and post-feeding trials indicated that the diet type and host species shape the composition of gut bacteria. Spirochaeta was absent in mussel guts during the pre- and post-feeding trials but was present in oysters, revealing host specificity in colonizing gut bacteria. The results suggest that the diet type and host species can significantly impact the gut bacterial community structure. This study confirms that diet can modulate gut microbial composition in marine filter-feeding organisms, but the extent of dietary modulation depends on feed type and host species.

The Chinese Freshwater Jellyfish Unbound

Jellyfish are commonly known as dangerous sea creatures that humans should avoid. Focusing on the newly discovered freshwater jellyfish in the late nineteenth century, this article explores a global history of Craspedacusta sowerbii, a species native to China first noted in nineteenth-century Britain but since traveling the world over. The worldwide distribution of C. sowerbii, as both polyps and medusae, made it a global subject of scientific inquiry. However, no independent study has examined the history behind the origin, circulation, and implication of the freshwater jellyfish and its relationship with marine types. The late nineteenth century was the period when our premodern knowledge of jellyfish transformed from it being purely a marine life to the modern recognition of jellyfish as both marine and freshwater organisms, triggered by the discovery and discussion of the Chinese freshwater jellyfish C. sowerbii among naturalists and philosophers. This article focuses on Arthur de Carle Sowerby’s engagement with C. sowerbii in terms of narratives of evolution, nomenclature, and bioinvasion between 1880 and 1941. I argue that jellyfish, as a lowly form of invertebrates, should be taken more seriously by historians of modern China and historians of biology who are interested in the diverse roles of animals in shaping human–animal interactions in the Anthropocene. While the scientific research of jellyfish’s global bloom abounds, the interpretation of the global rise of jellyfish could benefit from a historically and culturally bound analysis of this classical animal. This is particularly so as scientists recognized the diverse perceptions of jellyfish. The global jellyfish bloom requires historical perspectives on a topic that has hitherto received scant attention from historians of science.

Microalgal biofilm induces larval settlement in the model marine worm Platynereis dumerilii.

A free-swimming larval stage features in many marine invertebrate life cycles. To transition to a seafloor-dwelling juvenile stage, larvae need to settle out of the plankton, guided by specific environmental cues that lead them to an ideal habitat for their future life on the seafloor. Although the marine annelid Platynereis dumerilii has been cultured in research laboratories since the 1950s and has a free-swimming larval stage, specific environmental cues that induce settlement in this nereid worm are yet to be identified. Here, we demonstrate that microalgal biofilm is a key settlement cue for P. dumerilii larvae, inducing earlier onset of settlement and enhancing subsequent juvenile growth as a primary food source. We tested the settlement response of P. dumerilii to 40 different strains of microalgae, predominantly diatom species, finding that P. dumerilii have species-specific preferences in their choice of settlement substrate. The most effective diatom species for inducing P. dumerilii larval settlement were benthic pennate species including Grammatophora marina, Achnanthes brevipes and Nitzschia ovalis. The identification of specific environmental cues for P. dumerilii settlement enables a link between its ecology and the sensory and nervous system signalling that regulates larval behaviour and development. Incorporation of diatoms into P. dumerilii culture practices will improve the husbandry of this marine invertebrate model.

Phenomenological investigation of organic modified cements as biocompatible substrates interfacing model marine organisms.

Organic modification can generally endow inorganic materials with novel and promotional characteristics to fit into new functionalities. In this paper, new cement-based composite materials, with Portland cement as the substrate and polyacrylamide (PAM, alone) and PAM/chitosan as the functional components mixed with cement (bulk modified) or served as the surface coating (surface modified), were prepared and engineered as sampling substrates for biofilm and coral co-culture. In comparison to the bulk modified substrate and pure cement material, the surface modified substrate showed a balanced mechanical property, considering both bending and compressive strengths and distinctive surface features toward facilitating biofilm and coral growth, as characterized by spectroscopic, morphological, mechanical, and biofilm and coral co-culture experiments. We, thus, believe that the as-prepared surface modified substrate has the very potential to be applied as a substitute/alternative for the conventional cement material in the construction and engineering of artificial facilities with ecological protection functions.

The effectiveness of crab apartment to shelter egg berried female of blue swimming crab (Portunus pelagicus) in Rembang, Central Java, Indonesia

Abstract Blue swimming crab is an Indonesian fishery commodity with high economic value for export to America, Asia, and Europe. The increase in crab fishing activities every year results in diminishing stocks in nature, in addition to predator attacks around spawning areas. The purpose of this study was to determine the growth of blue swimming crabs and identify types of fish in the crab apartment shelters in Rembang Regency, Central Java Province, from March to May 2023. The egg berried female crabs were put in a floating apartment for three months and monitored every 2 weeks to determine the growth of the hatched crab eggs. Our observations showed as many as 50 egg berried female crab with with an average size of 8–10 cm and a weight of 40–65 g. There were other marine organisms found in the shelter, including rabbit fish, shrimp, small crabs, and therapon-perch. Rabbit fish and therapon-perch often result in reduced juveniles. Therefore, add and installing shelter is highly recommended to the entry of these fish. This study found crab apartment brings positive impacts on the survival of hacthing crabs and protected them from the threat of predatory fish.

Tracking suspended particulate organic matter biochemistry from glacial meltwater runoff to coastal waters of an Antarctic fjord

Increased glacier melting runoff in Antarctica involves intensification of freshwater, nutrients, sediments and organic matter inputs from land to the sea, which is impacting coastal ecosystems. Basic environmental characteristics of water and biochemical composition of suspended particulate organic matter (POM) both in the proglacial melting runoff system (PROGLARS) of Collins Glacier and marine surface waters of Collins Bay was studied based on organic biopolymers and molecular level analysis of amino acids (AAs), to discern among sources and degradation state in the two environments. Hierarchical Clustering Analysis revealed that PROGLARS stations and marine stations form two distinct groups in terms of water physicochemical characteristics and suspended POM biochemical composition. These differences are the consequence of low restricted contribution of freshwater from Collins Glacier runoff into the coastal-marine environment. Our results evidenced low concentrations of terrestrial suspended POM in marine waters of Collins Bay mainly attributed to low meltwater inputs between the 1st and 7th of February 2018. In terms of macromolecular composition, the predominance of proteins, denote the labile nature of suspended POM in the two environments. Suspended POM in Collins Bay is labile, poorly degraded, representing a protein supplemented food resource, with high energetic value and easily assimilated by heterotrophic marine organism. AAs composition supported less degraded suspended POM derived from marine phytoplankton in surface waters of Collins Bay, whereas, great degradation of suspended POM in the proglacial runoff system of Collins Glacier. Changes in the biochemistry of suspended POM caused by glacial melting and retreat, may affect food features and availability, the productivity of ecosystems, and ultimately, the capacity of Antarctic fjords to act as carbon sinks and climate regulators. Considering low influence of Collins Glacier meltwater in coastal marine waters of Collins Bay, due to the relatively slow retreat of Collins Glacier and low development of its meltwater runoff system, the results of our work are relevant as baseline information for comparison with other Antarctic fjords. Further knowledge about meltwater runoff and suspended POM input dynamics in Antarctic coastal ecosystems, is critical, particularly in areas prone to undergo increased glacier melting in the following decades.

Technology Focus: Offshore Facilities (September 2024)

Offshore wind power involves generating electricity from wind farms located at sea. Because wind speeds are generally higher offshore than on land, these farms produce more electricity for the same amount of installed capacity. Both wind and solar energy are renewable and do not emit carbon, which helps reduce dependence on fossil fuels such as oil and gas. The papers synopsized in this year’s Offshore Facilities feature cover a breadth of related subjects that will be critical to the future of the industry. Automation in the offshore oil and gas industry makes production safer, faster, and more efficient. It reduces human error, improves quality control, and allows real-time monitoring of operations. Machine learning improves offshore industries by enhancing safety, efficiency, and sustainability It tracks and predicts environmental changes, such as oil spills or marine life patterns, aiding in better environmental management and response. Remotely operated vehicles are used in offshore operations to inspect, maintain, and repair underwater infrastructure; the offshore industry uses 3D video imaging technology to provide detailed real-time images of the underwater environment. Corrosion in offshore environments occurs because of factors such as seawater, sea salts, temperature, salinity, and moisture. It is crucial to monitor corrosion because it can lead to major structural failures. Hydrogen can be produced offshore using renewable energy sources such as wind and solar, which do not emit greenhouse gases and help combat climate change. Supply-chain logistics boost efficiency by cutting costs, removing unnecessary steps, and speeding up product delivery. An efficient supply chain can lead to higher revenue, lower operational costs, and better overall performance. Decommissioning is the final stage of an oil or gas project and involves significant technical, economic, social, and environmental challenges. It is a lengthy, costly, and complex process that must be carefully planned and managed to avoid serious problems. Several ideas have come to the surface that show innovative ways to repurpose a decommissioned platform or ways to cut the cost of decommissioning. Recommended additional reading at OnePetro: www.onepetro.org. SPE 217706 Dynamic Simulation of Riser-Gas Handling With a Fixed-Choke Constant Outflow by Zhaoguang Yuan, SLB, et al. OTC 35092 Reducing Carbon Footprint by Using Fiber-Reinforced Polymers in FPSOs by S. Eves, NOV, et al. OTC 35393 Challenges and Approaches to Solutions for Green Decommissioning and Recycling of Offshore Facilities by Carlos Alberto Machado, American Bureau of Shipping, et al.

A generalized numerical model for clonal growth in scleractinian coral colonies.

Coral reefs, vital ecosystems supporting diverse marine life, are primarily shaped by the clonal expansion of coral colonies. Although the principles of coral clonal growth, involving polyp division for spatial extension, are well-understood, numerical modelling efforts are notably scarce in the literature. In this article, we present a parsimonious numerical model based on the cloning of polyps, using five key parameters to simulate a range of coral shapes. The model is agent-based, where each polyp represents an individual. The colony's surface expansion is dictated by the growth mode parameter (s), guiding the preferred growth direction. Varying s facilitates the emulation of diverse coral shapes, including massive, branching, cauliflower, columnar and tabular colonies. Additionally, we introduce a novel approach for self-regulatory branching, inspired by the intricate mesh-like canal system and internode regularity observed in Acropora species. Through a comprehensive sensitivity analysis, we demonstrate the robustness of our model, paving the way for future applications that incorporate environmental factors, such as light and water flow. Coral colonies are known for their high plasticity, and understanding how individual polyps interact with each other and their surroundings to create the reef structure has been a longstanding question in the field. This model offers a powerful framework for studying these interactions, enabling a future implementation of environmental factors and the possibility of identifying the key mechanisms influencing coral colonies' morphogenesis.