World Academy of Science, Engineering and Technology

Authors: Shangfei Lin, Jianping Gan, Gang Wang, Jinhai Zheng

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The impacts of surface waves on coastal upwelling have rarely been examined in a real ocean. We used a coupled sub-mesoscale wave-circulation model to investigate the variability and dynamics of wave effects on the upwelling over a steep shelf east of Hainan. We found that wave effects reduce the along-isobath transport in the upwelling circulation, leading to reductions in vertical shear stress and subsequent cross-isobath upslope transport nearshore. Specifically, during a typical upwelling season, the onshore Stokes transport cumulatively raises (reduces) sea level nearshore (offshore) and geostrophically weakens the upwelling jet. Meanwhile, the offshore anti-Stokes current induced by the Stokes Coriolis force is weaker than the onshore Stokes drift due to wave-modulated turbulent stress. The onshore Stokes drift also interacts with positive (negative) vorticity along the onshore (offshore) flank of the upwelling jet and yields a Stokes vortex force (SVF) that enhances (weakens) the surface offshore Eulerian flow. Consequently, this SVF further raises the sea level nearshore, weakening the onshore pressure gradient force (PGF) and the upwelling jet. The subsequent baroclinic response caused by the wave-modulated density gradient competitively counteracts this barotropic effect. In addition to this dominant geostrophic adjustment, waves influence the cross-shore PGF through set-up by varying radiation stress and correcting the surface boundary pressure in shallow waters. Overall, wave effects reduce the along-isobath transport by ~8.0%, leading to reductions in vertical shear stress and subsequent bottom onshore transport by ~23.0% nearshore. This study highlights the importance of wave impacts on upwelling over the shelf and reveals the intricate dynamics of a coupled wave-circulation system.

Keywords: upwelling circulation, surface wave, geostrophic adjustment, stokes Coriolis force

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Authors: Olayinka Remilekun Anifowose, Akintoye Emmanuel Oluwatobi, Gbolahanmi Akinola Oladosu

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Ocimum gratissimum is widely recognized as a basil cloven and employed in alternative herbal medicine due to its various phytochemical constituents. This study was conducted to evaluate the phytochemical analysis of ethanolic extract of the Ocimum gratissimum leaf, the acute lethal concentration (96 h LC50) of ethanolic extract of the Ocimum gratissimum leaf exposed to Clarias gariepinus juveniles, and the chronic toxic effects of Pseudomonas aeruginosa in infected Clarias gariepinus juveniles and haemato-biochemical, immunological response, and antipathogenic capacity of treated Clarias gariepinus juvenile with Ocimum gratissimum leaf extract. The phytochemical analysis was carried out using GC-MC scan, the Clarias gariepinus juveniles were exposed to leaf ethanol extract of Ocimum gratissimum by immersion at the rate of 50, 300, 550, 800, 1050 mg/L for 96-hour. Clarias gariepinus juvenile (n = 90) with an average weight of 15.0 ± 0.81 g, and length of 9.0 ± 0.6 cm, were randomly divided into five groups, and four groups were infected with 1ml of TSA broth culture containing 4.5 X 108 CFU Pseudomonas aeruginosa by immersion at the rate of 3ml/L of water, blood was collected for haematology and serum chemistry. The chronic infection was observed for 14 days and treatment start on day-15 with 2% (8.7mg/L), 4% (17.3mg/L), and 8% (34.7mg/L) of LC50 Ocimum gratissimum leaf extract by immersion for 5 days and expose for 3 hours per day. Probit Analysis was used to determine 96-hour LC50 and one-way ANOVA to assess the effect of Ocimum gratissimum treatment by immersion on haematology and serum chemistry. Differences between means were tested at the 5% probability level utilizing Duncan test. A p value less than or equal to 0.05 (p≤ 0.05) was considered significant. Esters represented the major constituent (31.992%), followed by alkaloids (29.78%), phthalates (26.266%), terpenoids (21.593%), and phenols (15.872%). The experimental 96h-LC50 for ethanol extract in C. gariepinus juvenile was 433.48mg/L. The Red blood cell counts of groups treated with 2%, 4% and 8% ethanol extract (6.71±0.14), (5.55±0.07), (4.97±0.37) were significantly higher than the untreated group (4.17±0.22). The white blood cell counts of groups treated with 2% 4% and 8% ethanol extract (3.87±0.13), (3.80±0.12), (4.00±0.23) were significantly lower compared to the untreated group (4.80±0.20. In addition, there was significantly higher (p ≤ 0.05) activity of total protein, albumin, and globulin and significantly reduced (p ≤ 0.05) AST, ALT, and Urea serum concentrations in treated groups compared to the untreated. The survival rate of the group treated with 2% ethanol extract (39.3%) was significantly higher than the groups treated with 4% 8% (27.2%), (21.2) respectively. The results of this study indicate that ethanol crude extract of Ocimum gratissimum exhibited ameliorative effects against Pseudomonas aeruginosa infection in African Catfish.

Keywords: pseudomonas aeruginosa, clarias gariepinus, ocimum gratissimum, ethanol, extract

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Authors: Cil Andrew Echavez, Ephrime Metillo

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Understanding the trophic ecology of skipjack tuna (Katsuwonus pelamis) is critical for the sustainable management of pelagic ecosystems and fisheries. This study integrates stomach content analysis (SCA) and stable isotope analysis (SIA) to investigate size- and site-specific dietary patterns of skipjack tuna in the Zamboanga Peninsula, Philippines. A total of 286 stomachs were analyzed across four coastal sites and two monsoonal seasons. Large individuals primarily consumed teleost fishes and cephalopods, with Engraulidae and Myctophidae dominating the diet. In contrast, small skipjacks exhibited a more diverse and zooplanktivorous diet, heavily reliant on copepods, euphausiids, and fish larvae. These findings were supported by Shannon diversity indices and %IRI values, which confirmed an ontogenetic dietary shift aligned with increasing foraging capacity and prey selectivity in larger individuals. Stable isotope data (δ¹³C and δ¹⁵N) from 18 predator and prey taxa further corroborated these patterns. Isospace and Bayesian mixing models revealed clear isotopic separation between juvenile and adult skipjacks, with large individuals displaying enriched nitrogen values consistent with higher trophic positioning. SIMMR and SIBER analyses showed broader isotopic niches and prey overlaps in adults, while juveniles were more isotopically constrained and reliant on zooplankton. Limited sample sizes restricted the calculation of quantitative ellipse overlaps, but SEAc values and posterior distributions provided robust trophic insights. This dual approach highlights the ecological importance of integrating SCA and SIA for comprehensive diet reconstruction and reinforces the need for spatially informed, life-stage specific fisheries management.

Keywords: skipjack tuna, trophic ecology, stable isotope analysis, stomach content analysis, ontogenetic shift, diet composition, Zamboanga Peninsula

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Authors: Anthony Inder Mazeroll, Carlos Chuquipiondo G.

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The Amazon Basin supports one of the most biodiverse freshwater ecosystems globally, harboring over 3,000 species of fish. Among its many ecological and economic functions, the basin serves as a critical source for the global ornamental fish trade. This industry is particularly important in the Peruvian Amazon, where the capture and export of native fish species for aquaria represent a key source of income for local communities. However, increasing exploitation of wild fish stocks poses significant threats to both biodiversity and socioeconomic stability in the region.Multiple anthropogenic stressors are contributing to the decline of native fish populations. Habitat degradation due to deforestation, mining activities, and agricultural expansion, coupled with the introduction of invasive species, prolonged droughts, and direct overexploitation, are exerting cumulative pressures on aquatic biodiversity. The collapse of fish populations would have profound ecological consequences, as these organisms play vital roles in nutrient cycling and energy flow within freshwater ecosystems. Their decline may therefore result in the destabilization of riverine ecological networks.In response to these challenges, the Amazon Research Center for Ornamental Fishes has initiated a sustainable aquaculture program in collaboration with local fishers and exporters. The objective of this initiative is to provide a viable alternative to wild capture, thereby reducing harvesting pressure on natural populations. A proof-of-concept trial was conducted using Apistogramma “Alto Tapiche” (Family: Cichlidae), a popular ornamental species. Breeding pairs were introduced into small-scale earthen ponds (dimensions: 2 m × 2 m × 1 m) and allowed to reproduce under semi-natural conditions, with no artificial feeding over a six-month period.Upon completion of the six-month rearing period, approximately 200 individuals—ranging from juveniles to adults—were recovered from each pond. This outcome demonstrates the reproductive viability of Apistogramma “Alto Tapiche” under low-intervention aquaculture conditions and highlights the species’ potential for sustainable breeding in controlled environments.This study illustrates the potential of community-based ornamental fish aquaculture to mitigate the impacts of overharvesting on Amazonian biodiversity. By equipping local stakeholders with the knowledge and infrastructure required for responsible breeding, such initiatives contribute to the dual goals of conservation and economic development. Expanding these efforts could enhance the long-term resilience of both aquatic ecosystems and the human communities that depend on them.

Keywords: aquaculture, education, ornamental fishes, sustainable breeding

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Authors: Buddhika S. K. Gamage, Yanchun Bao, Abdellah Salhi, Hongsheng Dai

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Dark vessel activities refer to the intentional disabling or manipulation of a vessel's automatic identification system (AIS) or the complete absence of AIS transmission, often used to evade detection by maritime authorities. These activities are prevalent in illicit operations such as illegal fishing, smuggling of goods and people, drug trafficking, piracy, and unauthorized entry into territorial waters. Dark vessels present a significant threat to maritime security, international trade, and environmental sustainability, particularly in regions with rich marine resources and high volumes of shipping traffic. Without AIS, these vessels become invisible to conventional tracking systems, complicating efforts to monitor and regulate maritime activities. Dark vessel activities go beyond simply disabling AIS; they also involve more sophisticated tactics aimed at evading detection and concealing illicit activities. One of the key techniques used by these vessels is AIS spoofing, where a vessel deliberately falsifies its location, identity, or other critical AIS data. By broadcasting fake signals or manipulating their coordinates, vessels can appear to be in a completely different location or be misidentified as legitimate vessels. This tactic is commonly used in smuggling operations, illegal fishing, and to avoid sanctions in embargoed regions. Spoofing can make it challenging for authorities to track a vessel’s actual movements, as it creates a deceptive picture of maritime traffic, masking suspicious or illegal behaviour. This research proposes a method for detecting dark vessel activity, specifically spoofing through the application of different density-based unsupervised learning models, i.e., DBSCAN (Density-Based Spatial Clustering of Applications with Noise) and Gaussian Mixture Model (GMM) algorithms. By extracting spatial and temporal features from AIS transmissions, DBSCAN and GMM are employed to identify dense clusters representing legitimate maritime traffic. The density-based clustering approach can identify clusters of data points that deviate significantly from their original voyage and depict different shapes of AIS spoofing, such as circular, box, hexagonal, or any irregular shapes. Depicted signals are identified as noise, indicating potential spoofing behaviour. The clustered spoofing AIS reporting results are compared with non-machine learning, deterministic approaches in maritime industry and to best of our knowledge, this is the first paper using this methodology on detecting maritime vessel spoofing. The unsupervised, density-based clustering approach is well-suited to dynamic maritime environments and offers a scalable solution for enhancing maritime domain awareness and countering illicit vessel activities.

Keywords: automatic identification system, dark vessel, density based clustering, spoofing, unsupervised learning

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Authors: Amelia Zhang, Ryan Ellingson, Patrick Krug

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Invasive algae pose a significant threat to marine ecosystems as they smother native algae, impact marine food webs, and reduce biodiversity. Some species in the sea slug genus Placida have been noted to preferentially eat invasive Codium fragile algae over native Bryopsis algae. Codium fragile is a major invasive algal pest that grows a rapid canopy over the water surface and shades out native algae. As there are few marine herbivores that can eat it, the food preferences of Placida sea slugs can be utilized to moderate the overgrowth of this invasive algae. However, it is not known precisely which sea slug species within this genus eat Codium fragile. Many species within this genus also only eat a few species of algae in their diet, making finding the exact sea slug species that eats Codium fragile even more important. This study analyzed DNA and morphological data from sea slug specimens collected from California and New Caledonia, compared them with the data from already-defined species in this genus, delimited species in Placida, and provided accurate and precise molecular data and descriptions of the species within this genus. This study is a revision of the Placida genus phylogenetic tree at an enhanced taxonomic resolution, which will aid future research on the feeding preferences of specific species of sea slug in this genus in the ongoing effort to combat Codium fragile.

Keywords: invasive algea, sea slug, placida genus, DNA

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Authors: Benjamin K. Simpson, Yi Zhang, Romy Vaugeois

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Seal meat is generated as a byproduct from the extraction of seal oil. Protein hydrolysates were prepared from the seal meat using alcalase and subjected to a soft dynamic digestion system and evaluated for nutritional and health benefits. Total amino acid content was estimated for seal meat hydrolysates and their intestinal digests as 568.54 and 384.65 mg/g, respectively, using UPLC. Both the hydrolysates and digests were rich in essential amino acids (EAA), and there were no harmful minerals detected from ICP-MS analyses. Both the gastric and intestinal digests revealed nutritive minerals, i.e., Ca, Fe, Mg, Zn, with their contents of Fe as high as 548 and 602 mg/kg, respectively, which are higher than most meat products. The absorbable Fe²⁺ content remained almost the same during the gastric and intestinal digestion, while the Fe³⁺ content declined considerably in the intestinal digests. The change in Fe²⁺ and Fe³⁺ ions was probably due to the antioxidant activities based on data from 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radicals scavenging. The study provides knowledge on seal meat hydrolysates that suggests that it can be a beneficial health food supplement,

Keywords: seal protein, hydrolysates, enzymatic hydrolysis, digestion

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Authors: Yi Gong, Xiangming Tang, Keqiang Shao

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By directly measuring the average size of bacterial cells (based on forward scatter signals using flow cytometry), the hypothesis that heterotrophic bacterial cell size shifts accompany eutrophication was tested at 26 sites over two years in China. The spatial distribution of mean bacterial size exhibited significant differences (p<0.05) and ranged from 0.509μm to 0.968μm. Generalized additive models (GAMs) were employed to model the size distribution of heterotrophic bacteria, inferring that nutrients were negatively correlated with bacterial size, thus supporting the previous hypothesis that lake eutrophication favors small - sized bacterial cells. Nutrients parameters, including total phosphorus (TP), total dissolved phosphorus (TDP), nitrate (NO3−) and nitrite (NO2−), were found to have non - linear relations with bacterial size, and bacterial size values decreased with all these nutrients parameters, accounting for 31.9% of the total variation of bacterial size. The results indicated that TP availability was clearly more crucial than TDP and NO3− in regulating bacterial size, owing to total phosphorus limitation on bacterial growth. This research enhances the current capacity to predict the responses of bacterial size to changes in the trophic stage of lakes, and provides profound implications for lake management.

Keywords: bacterial size, flow cytometry, GAMs, lake eutrophication

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Authors: Zhen Shen, Yi Gong, Keqiang Shao, Xiangming Tang

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Over the past six decades, Northwestern China has experienced a significant climatic transition from a warm-dry to a warm-wet regime, potentially destabilizing lake ecosystems and altering their biogeochemical functions. However, the mechanisms underlying microbial community responses to such shifts remain poorly characterized. This study investigates the long-term effects of climate-induced environmental changes on microbial diversity, ecological stability, and functional adaptation in Lake Bosten, the largest inland lake in China’s arid northwest. A multi-scale approach was employed, combining: (1) Trend analysis of six-decade (1958–2022) meteorological and limnological data; (2) Decadal field surveys (2013–2022) using amplicon and metagenomic sequencing to track microbial community dynamics; (3) Mesocosm experiments to validate field observations and assess microbial resilience under controlled conditions. Results revealed that the warm-wet climate reduced total nitrogen and salinity, correlating with increased bacterial and eukaryotic diversity but decreased microbial network complexity and ecological stability. Major taxonomic shifts included increased Verrucomicrobiota (+15.6%) and Cryptomycota (+22.4%), alongside declines in Firmicutes (−7.7%) and Phragmoplastophyta (−9.4%). Despite structural reorganization, functional redundancy maintained microbial resilience. Metagenomic analyses indicated elevated potential for key biogeochemical processes, including nitrification, assimilatory nitrate reduction, methane oxidation, and dissimilatory sulfur reduction. These findings highlight a critical trade-off between diversity and stability, emphasizing functional compensation as a key microbial adaptation strategy. This study provides novel insights into climate-driven microbial ecological cascades, demonstrating how functional redundancy sustains critical ecosystem processes despite compositional and stability losses. The results offer a predictive framework for microbial community responses under future climate scenarios.

Keywords: climate warm-wet, ecological stability, functional redundancy, lake Bosten, microbial community

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Authors: Magdi Osman Ahmed Elfaki

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This study assesses the sustainability of marine aquaculture at the National Aquaculture Group (NAQUA) in Al Lith, Saudi Arabia, focusing on environmental, economic, and social dimensions. Field analyses confirmed that water quality parameters, including dissolved oxygen, nutrient levels, and pH, stayed within acceptable ranges for marine life. Sediment testing showed minimal accumulation of heavy metals, and biodiversity surveys revealed stable benthic habitats near aquaculture zones. Economically, NAQUA produces over 100,000 tonnes of seafood annually, providing significant employment for 4,000 workers and contributing to rural development. The study demonstrates that, with effective management, large-scale aquaculture can support food security, rural employment, and environmental conservation. These findings offer valuable insights for policymakers and investors looking to scale sustainable aquaculture under Saudi Arabia’s Vision 2030.

Keywords: marine aquaculture, sustainability assessment, Red Sea ecosystems, integrated coastal management

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Authors: Alicia Clark, Robert Leaf

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Knowing the distribution of ages within a fish stock is absolutely critical for effective and sustainable fisheries management. Current methods to determine age often involve labor-intensive manual counting of annuli on calcified structures like otoliths or fish scales. These traditional methods are subject to reader bias and error, can be time-consuming, and are challenging to apply efficiently for high-throughput screening of the thousands of samples often required for robust stock assessments. The aim of this study was to develop and validate an automated image analysis system to recognize and count annuli on scales taken from Gulf Menhaden (Brevoortia patronus). B. patronus were taken from scientific samples collected at the state marine fisheries of Texas, Louisiana, Mississippi, and Alabama. These specimens had a selection of 8 to 10 scales taken and mounted on microscope slides and assigned a unique serial number. Slides were photographed under a dissecting microscope. The file name of each photographed scale was assigned a unique code with the serial number. The digital photographs were entered into a database, and a program written in R was generated to help establish landmarks and transects. Over 1200 fish scales were digitized, and transects were manually determined. An algorithm, written in the R language, was then employed to extract the gray scale intensity profile along the designated transect line for each scale image, generating data representing optical density changes versus position along the aging axis. Subsequently, a pattern recognition algorithm was developed and applied to these intensity profiles. This algorithm utilized signal-processing techniques, such as peak detection analysis on smoothed data, to objectively identify and enumerate putative annuli based on predefined criteria corresponding to optical density shifts associated with annual growth patterns. To validate the accuracy and precision of the algorithmic counts, results were compared against reference ages determined from manual annuli readings from the same fish for a representative subset of [N = 100] samples. The algorithm-derived annuli counts exhibited a strong positive correlation and high agreement with reference fish scales, demonstrating the method's accuracy in comparison to manual counting. Precision analysis indicated high repeatability with a low coefficient of variation. This work demonstrates that the developed automated image analysis system, combining land marking with algorithmic interpretation of transect data, can provide objective and efficient age estimates for the fish Gulf menhaden from scale images. This approach offers a promising tool to augment and potentially replace manual methods, thus increasing throughput and consistency in generating the crucial age data needed for informed fisheries for better stock assessments and management.

Keywords: automated image analysis, Brevoortia patronus, gulf menhaden, scale aging

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Authors: Khouloud Bouhali

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This study examines the dietary composition and sex ratios of the blue crab Callinectes sapidus in Mellah Lagoon (area: 865 ha, average depth: 3.5 m, temperature: 10-30.2 °C, salinity: 25-34.8 ‰), located in the far east of Algeria. The analysis was conducted on a sample of 287 individuals out of 935 (carapace length ranging from 63 to 179 mm). The results demonstrated significant seasonal variation in diet. In spring, arthropods constituted the largest dietary component (%IRI = 43.71%), followed by mollusks (%IRI = 22.45%). In summer, arthropods remained dominant (%IRI = 45.14%), with the ‘unspecified’ category comprising 43.31%. A notable shift towards teleost fish consumption occurred in autumn, contributing 34.25% to the diet. In winter, the ‘unspecified’ category prevailed at 46.21%, followed by plantae (%IRI = 20.38%). Full stomachs were more frequent in spring (75%) compared to winter. The seasonal variation in digestive vacuity was most pronounced in summer (Cv = 42.42%) and autumn (Cv = 45.74%). The sex ratio exhibited a female bias throughout the year, with a decrease in the ratio from 0.68 in spring to 0.22 in winter, deviating significantly from expected values in both autumn (χ² = 12.30) and winter (χ² = 25.81). This study underscores that C. sapidus is a generalist and opportunistic feeder, with dietary composition and sex ratios closely linked to prey availability and environmental conditions across different seasons, thereby highlighting the species' ecological impact in Mellah Lagoon.

Keywords: callinect sapidus, diet composition, sex ratio, Algeria, invasive spieces

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Authors: Feng Xing, Wei Quanhui, Liao Weimin, Peng Shitao, Liu Liankun

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In this study, a two-dimensional multiphase VOF model based on a finite volume solver was developed to comprehensively investigate the oil intercepting process and performance of existing typical structural oil containment booms (single skirt, double skirts, ramp and L-type), with a focus on utilizing in the inland waters. Through analyzing the flow field characteristics including pressure, velocity and vorticity distribution in front of different structural oil barriers, the evolution patterns of the oil slick morphology in front of the barriers and the main mechanisms inducing oil containment failure are explored. The oil intercepting performances of different structural oil barriers are compared, characterized by using the critical failure velocity and the threshold oil blocking capacity as the main indicators. The numerical simulation results indicate that under the selected inland water conditions, the oil intercepting performance of the L-shaped oil boom surpasses other types but with the disadvantages of being subjected to significantly larger hydrodynamic forces and overturning moments. The ramp-type oil boom has a good anti-flow effect but obviously poor oil intercepting performance in small spill conditions.

Keywords: oil spill, inland waters, oil containment boom, multiphase VOF model, oil intercepting performance

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Authors: Lamiae El Hadri, Farid Boushaba, Mimoun Chourak

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Tsunamis are among the most destructive natural hazards, posing significant threats to coastal populations and infrastructure. They are primarily triggered by undersea earthquakes, which generate powerful waves capable of traveling over 800 km/h and reaching heights of tens of meters upon landfall. The devastating impact of the tsunami highlights the urgent need for accurate prediction and mitigation strategies. Numerical modeling has become essential for improving tsunami forecasting, hazard assessment, and early warning systems. Several numerical models are widely used to simulate tsunamis generated by seismic sources. COMCOT (Cornell Multi-grid Coupled Tsunami Model) solves the shallow water equations using finite difference methods, making it effective for both near-field and far-field tsunami simulations. GeoClaw also uses finite difference methods with adaptive mesh refinement, allowing high-resolution modeling of tsunami propagation and inundation. Tsunami-HySEA applies finite volume methods and GPU-based parallel computing, providing high accuracy and efficiency for complex wave dynamics. In the western Mediterranean, the Alboran Sea is at risk of tsunamis from the Averroes Fault, a NW-SE strike-slip fault capable of generating waves up to 6 meters high within 30 minutes of a seismic event. Tsunami-HySEA simulations reveal the rapid onset of tsunami waves that could affect densely populated coastal areas. On the Atlantic coast, the Gulf of Cadiz remains a major source of tsunami risk, with the 1755 Lisbon tsunami demonstrating the region’s vulnerability. Effective mitigation strategies require high-resolution modeling, real-time monitoring, and coordinated emergency response to protect at-risk coastal communities.

Keywords: Tsunami, Earthquake, Numerical models, Coastal hazard mitigation

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Authors: Maria Rosilene Sabino, Maria do Rosário Cabrita, Ana de Jesus Mendes, Tiago Pinho

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Ports play a vital role in global trade, driving economic growth and development in their respective regions and countries. As key nodes in international supply chains, they offer sea-land connections and a range of value-added services. However, the maritime industry is undergoing imperative transformations driven by the adoption of advanced technologies to improve efficiency and competitiveness, as well as by regulatory requirements demanding sustainable practices to reduce the environmental impacts caused by port activities. The digital and sustainable transformation in ports is not only about incorporating technologies; it also highlights the need for a paradigm shift and new governance models that facilitate the strategic alignment of the actors that make up the port ecosystem. Thus, open and sustainable innovation emerges as an essential strategy for seaports to address these pressing issues collaboratively, involving port authorities, logistics operators, technology providers, policymakers, and the port community. While the literature references some case studies of ports within innovation ecosystems, such as those in Rotterdam, Valencia and Barcelona, there is a lack of evidence regarding open innovation practices in ports. This research aims to analyse open and sustainable innovation practices in Portuguese seaports. Specifically, the study seeks to identify best practices, challenges, and factors that influence the innovation strategies in the Portuguese maritime sector, as viewed by its managers, with the goal of enhancing efficiency and sustainability. The research is conducted through semi-structured interviews with port managers and industry stakeholders. The study reveals that some Portuguese ports, notably the Port of Sines, have adopted digital platforms, alternative fuels, and smart port programs; nevertheless, others encounter obstacles due to regulatory restrictions, funding limits, and a fragmented approach to innovation. The research indicates that collaborative governance frameworks, public-private partnerships, and data-informed decision-making are essential for expediting sustainable and digital transformation. This work contributes to the wider debate on maritime innovation by providing a comparative perspective between ports in Portugal and their European peers. It provides policymakers and port authorities with strategic suggestions to strengthen the role of open and sustainable innovation ecosystems in the process of developing a more environmentally resilient and competitive port industry. This research is in line with the topics that will be discussed at the Maritime Transport Conference, as it discusses current trends in port digitalisation, sustainable maritime strategies, and the changing role of innovation in port development.

Keywords: open innovation, maritime transport, sustainable ports, digital transformation

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Authors: Barbara Fontainha, Ana Mendes, Tiago Pinho

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The global urgency to mitigate greenhouse gas (GHG) emissions has catalyzed the implementation of strict environmental regulations in the maritime sector, which currently emits a significant amount of CO₂ in its operations. The Carbon Intensity Indicator (CII), established by the International Maritime Organization (IMO), has emerged as an essential tool in the sector's decarbonization strategy, establishing quantifiable metrics for reducing the carbon intensity of naval operations. However, the effective application of the CII transcends ships, having a direct impact on ports, since they function as critical nodes in the global logistics chain. The relevance of this research lies in the long-term impacts of implementing the CII in ports, considering the implementation and expansion of the CII standard to make up the framework of environmental metrics and policies in ports, and the main challenges and opportunities for ports for the competitiveness and sustainability of the sector. Understanding the context and situation in which ports operate provides a clear path to understanding the framework that the standard will need to establish in order to be effective. Analyzing the challenges and opportunities associated with the adoption of the IIC in ports offers valuable insight into the future of prospective implementation in ports, with a view to formulating public policies and business strategies aligned with global emission reduction objectives. The research carries out a literature review, acknowledging the scarcity of studies available on the subject. It then presents a qualitative investigation based on an analysis of the perceptions of four port managers. Based on the interviews, an inductive analysis is carried out that highlights the main challenges and opportunities of port decarbonization. Using the PESTEL/SWOT strategic approach, the macro-environmental and strategic factors influencing this transition are examined, offering a comprehensive view of the associated challenges and opportunities. The findings of this research sought to elucidate advances in knowledge about the Carbon Intensity Indicator, as the results showed that the implementation of standard in ports will face challenges such as modernization costs and the decommissioning of smaller ports, where government funding and incentives could mitigate these obstacles. However, rapid adaptation to the CII will offer competitive advantages for ports, attracting shipowners who prioritize decarbonization. Ports that invest in sustainable technologies will also add value to their activity, gaining a competitive advantage over their competitors. The proposed strategies aim to convert challenges into sustainable advantages, reduce risks and improve operational efficiency, since the CII drives this transformation, requiring cooperation between authorities, shipowners and stakeholders. The study concludes that although the adoption of the CII in ports represents a significant step in the transition towards more sustainable maritime operations, its application in ports and the adoption of port environmental policies will face structural, financial and regulatory challenges. This study reinforces the importance of a multidimensional approach to CII adoption, which considers not only the technical and operational aspects, but also the political, economic and social factors involved.

Keywords: carbon intensity indicator, decarbonization, maritime transport, port

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Authors: Lima Gilvan, Castro Marcela, Mendes Ana, Santos Alexandre, Pinho Tiago

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Unmanned Aerial Vehicles (UAVs) have emerged as pivotal instruments in modern maritime port operations, offering a safe and efficient alternative for data collection in hazardous environments. Their application spans equipment and structural inspections, firefighting, rescue, and security missions, thereby streamlining ship inspections, critical mission planning, and comprehensive infrastructure assessments. Despite their increasing use, the literature on UAV integration in maritime ports remains limited and fragmented. This study conducts a rigorous bibliometric analysis and qualitative literature review to consolidate and clarify the strategic advantages of UAV implementation within the seaport industry. The research is structured around three primary objectives: identify the strategic benefits that drive the adoption of UAV technology—such as enhanced decision-making and resource management; define the management areas where UAVs prove most beneficial, including safety and security, environmental monitoring and operational efficiency; and document the tangible benefits realized post-implementation, such as cost savings, increased productivity, and improved overall performance. Findings indicate that UAVs significantly enhance critical operational domains within maritime ports. Their capacity to deliver comprehensive, real-time data on air quality, water pollution, and ecological impacts enables proactive monitoring and effective management strategies. In addition, the advanced imaging and sensing technologies integrated into UAV systems support timely and accurate data acquisition, which in turn strengthens decision-making processes across corporate management, environmental policy, and strategic planning. These technological advantages not only bolster operational efficiency but also ensure alignment with sustainability goals and regulatory compliance. The conclusions drawn from this study highlight the transformative potential of UAV technology in addressing the multifaceted challenges of maritime port management. By consolidating dispersed scholarly work, the research creates a robust informational foundation that is of value to both academic and industry professionals. Furthermore, the insights gained are directly relevant to the innovation in maritime technologies and sustainable port management. The study advocates for the broader integration of UAVs as a strategic asset in modernizing maritime operations and enhancing competitiveness in a rapidly evolving global market. Beyond these immediate applications, the study underscores the need for further exploration of UAV technology across diverse geographic regions and port environments. As ports increasingly embrace digitalization and artificial intelligence (AI) integration, the evolution of "smart ports" is creating an ecosystem conducive to wider UAV applications. Future research should investigate how AI-driven analytics, automation, and interconnected digital systems can enhance UAV operations, enabling seamless coordination with existing maritime logistics and security frameworks. Additionally, expanding the scope of UAV studies across different port infrastructures will provide valuable comparative insights, fostering global best practices and optimizing UAV deployment strategies in maritime industries. In summary, the research not only elucidates the operational and strategic advantages of UAV adoption but also provides a framework for future studies and policy development. Consolidating existing literature into a comprehensive resource ensures that maritime ports remain at the forefront of technological advancement and sustainable practice, aligning with current industry needs and the forward-looking agenda.

Keywords: maritime ports, strategic advantages, technology efficiency, unmanned aerial vehicle

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Authors: Zi Yang, Erzheng Fang

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The concept of polarization originated in optics and has been extensively developed and applied in fields such as electromagnetism and seismology. With the advent of vector sensors, this concept has been introduced into acoustics. However, research on acoustic polarization phenomena in underwater acoustics remains relatively scarce. Therefore, this paper explores the principle of polarization in the underwater acoustic vector field and proposes a method for DOA (Direction of Arrival) estimation based on underwater polarization. The propagation of sound waves in liquids is exclusively attributed to longitudinal waves. In traditional underwater acoustic research, it is common that polarization phenomena in the sound field are not considered. However, with the advent of vector sensors, signal processing in the sound field has transitioned to vector information processing of particle velocity. In this case, multiple sound waves of the same frequency are in the vector sound field. The synthesized particle velocity vector will generally no longer be longitudinal. Due to energy oscillations caused by instantaneous reaction intensity, the occurrence of energy polarization in certain sound fields may be observed. This study proposes a method to analyze the polarization phenomenon in underwater acoustic vector fields. Firstly, the study establishes the basic model of the polarization phenomenon in an acoustic vector field, illustrates the time evolution of a bivariate signal in a three-dimensional representation, and elucidates the physical significance underlying this phenomenon. Subsequently, the polarization ellipse in the acoustic vector field and its characterization parameters are derived theoretically and extended to three-dimensional space. The major and minor axis values and the inclination angle of the ellipse describe its trajectory, while the polarization degree quantifies the statistical stability of the polarization ellipse trajectory in space. These parameters provide a visual representation of the signal polarization characteristics. Building on this, this paper introduces polarization into the traditional research on underwater acoustic vector field target azimuth estimation and proposes an improved MUSIC algorithm based on polarization weighting. For single-frequency signals, as the signal-to-noise ratio increases, the polarization value also increases. Based on this observation, we construct a polarization weighting function, apply polarization weighting to the covariance matrix of the hydrophone input signal, and use the MUSIC algorithm to estimate the target azimuth of the weighted signal. The simulation results show that the polarization weighting function effectively suppresses noise without altering the signal characteristics, thereby yielding a more accurate target azimuth estimate. Finally, field experiments are conducted, and the results align with theoretical expectations, validating the effectiveness of the proposed method. Based on the results of this paper, it is clear that different acoustic signals in the underwater sound field exhibit distinct polarization characteristics, including the shape of the polarization ellipse and the degree of polarization. A comprehensive analysis of these characteristics can be effectively used to improve the traditional MUSIC algorithm, thus yielding more accurate target direction estimates and providing important technical support for the practical development of underwater acoustics.

Keywords: direction of arrival estimation, MUSIC algorithm, polarization, polarization characteristics, polarization model

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Authors: Yuanyuan Tan, ErZheng Fang

Abstract:

The noise power received by the sound pressure and vibration velocity channels of the underwater vector sensor array is not equal. The ASMusic beamforming method solves this problem by adding a virtual source in the signal subspace while also increasing computational complexity. GPUs are adept at performing parallel computing tasks with simple logic and high computational complexity, making them suitable for computing frequency domain vector ASmusic beamforming. From the simulation experiment results, it can be seen that the GPU parallel structure has higher computational efficiency compared to the CPU, and the acceleration ratio is significantly improved.

Keywords: GPU, ASMusic, vector array, parallel computing, beamforming

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Authors: Bo Hu, Xingchao Yu, Sijia Wang, Jintong Gao, Bowen Shi, Haoyang Zhang

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In the design and application of underwater sound absorption coatings, it is an important technical approach to broaden their performance and applications by introducing holes on the surface of the coating and embedding sensors. Therefore, considering the influence of different hole parameters on the acoustic performance is of great significance in studying the sound absorption coating. To address this issue, this paper establishes a model of a sound absorption coating with surface holes based on the finite element method. The effect of various hole parameters on the performance of large rubber-coated samples is investigated by measuring the sound absorption coefficient and average sound absorption coefficient. The results indicate that compared to hole depth, increasing hole area has a smaller influence on the sound absorption coefficient. Additionally, the influence on the coating's absorption ability can be efficiently minimized by placing the bigger end of the conical holes closer to the incident wave.

Keywords: rubber material, sound absorption coating, sound absorption performance, surface holes

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Authors: Roksana Malec, Magdalena Bełdowska, Mariusz Sapota, Anna Dziubińska, Bartłomiej Wilman, Adam Woźniczka, Ryszard Kornijów

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Due to intensive human activity, especially in the second half of the 20th century, a significant amount of chemical elements has been extracted from the Earth's natural deposits. Some of these elements have no beneficial role in living organisms and are toxic. Ideally, such toxic elements would not be present in our natural environment. However, this is not the case, nor will it ever be, as these elements naturally occur on our planet and have been further introduced into the ecosystem through industrial use. There are also chemical elements that are essential or even necessary for the proper development of animal and plant organisms. However, at elevated concentrations, these elements become highly toxic. Thanks to regulations introduced in many European countries at the turn of the 20th and 21st centuries, emissions of toxic elements from anthropogenic sources have significantly decreased. Nevertheless, their concentrations in the natural environment have not declined proportionally. It is therefore crucial to understand their pathways and circulation in the environment, particularly in marine ecosystems, as fish and seafood often serve as key sources of these elements for humans. While numerous scientific studies have examined the concentrations of toxic elements (e.g., Hg, Pb, Cd, Zn, Cu, As, Se) in sediments and commercially significant fish species, there is a notable lack of data on their transfer through individual links in the trophic network, especially among small, non-commercial fish. Moreover, there is limited information in the scientific literature regarding the concentrations of technology-critical elements, some of which are or could potentially be highly toxic to living organisms. The purpose of this research is to investigate the role of small, non-commercial fish in the transfer of toxic elements within the marine trophic network, using the southern Baltic Sea as a case study. The Puck Lagoon has been selected as the research area.

Keywords: toxic elements, trophic web, marine ecosystem, mercury

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Authors: Angelica M. Darunday

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Illegal, unreported, and unregulated (IUU) fishing represents a severe threat to marine ecosystems, depleting fish stocks and jeopardizing the livelihoods of coastal communities. The Philippines, recognized as the center of the center of marine shore fish diversity, is facing IUU fishing risk despite ongoing national and local initiatives to curb it. However, assessment of IUU fishing threats has not been done yet in many coastal areas, including the entire Region 9. Thus, this study evaluated the response of the coastal local government unit of Talusan, Zamboanga Sibugay in Region 9 to IUU fishing using five indicators namely, enforcement team fully operational; information, education and communication (IEC); local government unit (LGU) fisheries compliance audit score; IUU fishing data collection and analyses; and IUU fishing reduction plan implemented following the Philippine IUU Fishing Index and Threat Assessment Tool (I-FIT Tool). Data were collected through social survey, key informant interview, and focus group discussion with participants from various stakeholders such as fisherfolk, vessel owners, LGUs, enforcement teams, academic institutions, people organizations, among others. The findings revealed a lack of necessary resources and coordination to address IUU fishing effectively. This deficiency has led to the persistence of illegal fishing practices, undermining efforts to protect marine ecosystems. The assessment of enforcement and management efforts to combat IUU fishing revealed significant challenges, with each component scoring 4 (Very High), resulting in a total score of 20/20. This score highlights critical issues that hinder effective enforcement. Specifically, 100% of respondents (N= 376) reported that no local or composite enforcement team has been organized, and existing enforcement efforts remain non-operational. Furthermore, 100% of respondents noted the absence of regular IEC campaigns on IUU fishing, severely limiting community awareness and involvement. In terms of financial accountability, the Fund Control Account (FCA) score was alarmingly low, ranging from 0%, indicating poor financial management and oversight in addressing IUU fishing. Additionally, 100% of respondents identified the lack of systematic data collection, archiving, or analysis of relevant information, which undermines evidence-based decision-making. Finally, 100% of respondents indicated the absence of a concrete IUU fishing reduction or enforcement plan, further demonstrating the municipality’s limited capacity to address the issue. These findings confirm that enforcement mechanisms are not yet fully operational and immediate intervention is needed. Several recommendations were proposed by respondents, emphasizing the need for strengthening law enforcement, specifically through enhanced patrolling, surveillance, and the integration of modern technologies, such as remote sensing, to monitor and track illegal fishing activities more effectively. There was also a strong call for implementing the Bantay Dagat program in all coastal barangays to ensure community-based monitoring and enforcement. The findings of this study are useful in improving the existing response measures of the LGU and stakeholders in addressing IUU fishing in Talusan. Moreover, this study contributes to the SDG 14.4 Target, which aims to regulate fishing, eliminate IUU fishing, and conserve marine ecosystems for sustainable fisheries.

Keywords: illegal fishing, IUU, IUU fishing, SDG 14.4

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Authors: Norlika D. Moti, Judy Ann H. Fernandez, Angelica M. Darunday, Frandel Louis S. Dagoc, Maria Theresa M. Mutia, Hilly Ann Roa-Quiaoit, Daisy Lou L. Polestico, Armi G. Torres

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Illegal, unreported, and unregulated (IUU) fishing poses a significant threat to marine biodiversity, fisheries sustainability, and coastal livelihoods in the Philippines. While various enforcement mechanisms exist, persistent governance gaps and data deficiencies undermine strategic interventions. The 2023 Philippine IUU Fishing Assessment Report highlights a 0% evaluation for Region 9, indicating a critical data gap that prevents effective risk assessment. This study addresses that gap by assessing the vulnerability of the coastal waters of Olutanga, Zamboanga Sibugay, in Region 9 to IUU fishing. A mixed-methods approach was employed, integrating the IUU Fishing Index and Threat Assessment Tool (I-FIT) developed by BFAR and USAID, along with stakeholder workshops, social surveys, direct observation, and secondary data analysis. Fieldwork was conducted in 14 coastal barangays of Olutanga from December 2024 to January 2025. Stakeholder workshops included representatives from Local Government Units (LGUs), the Municipal Agriculture Office, Fisherfolk Organizations, Bantay-Dagat, and the Philippine National Police (PNP), focusing on governance and enforcement challenges. Additionally, a social survey of 367 respondents provided insights into resource availability, economic conditions, illegal fishing activities, and enforcement effectiveness. The study also evaluates fisheries vulnerability based on eight key indicators: (V1) fisheries resource availability and coastal habitat quality, (V2) ex-vessel selling price of species commonly targeted by illegal fishers, (V3) overcapacity of fisheries, (V4) physical configuration of shoreline and islands, (V5) weather and ocean condition impact on seaborne interventions, (V6) LGU budget allocation for fisheries and coastal resource management (CRM), (V7) clear boundaries and jurisdiction for enforcement, and (V8) illegal fishers supported by third-party influential people or groups. The findings indicate severe fish stock depletion, with 90.46% of respondents rating stocks as poor and 82.29% reporting deteriorating coastal habitat conditions. High fisher density (74.93%) intensifies competition for dwindling resources, while patrol operations are frequently disrupted by extreme weather conditions (100%), further weakening enforcement. Local government support for fisheries management remains entirely inadequate (100%), and municipal boundary conflicts hinder jurisdictional enforcement. Notably, 83.93% of respondents acknowledged external actors facilitating illegal fishing, exposing systemic governance vulnerabilities. These findings underscore the urgent need for targeted policy reforms, increased funding, and stronger enforcement mechanisms to combat IUU fishing in Olutanga and similar unassessed regions. This study contributes to broader efforts in sustainable fisheries governance by providing localized vulnerability assessments that inform national and international strategies against IUU fishing. Furthermore, this study supports the Sustainable Development Goal Target 14.4, which aims to effectively regulate harvesting and end overfishing, IUU fishing and destructive fishing practices and implement science-based management plans.

Keywords: IUU fishing index and threat assessment tool (I-FIT), fisheries sustainability, SDG 14.4, IUU fishing

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Authors: Judy Ann H. Fernandez, Norlika D. Moti, Angelica M. Darunday, Shekinah L. Ogoc, Frandel Louis S. Dagoc, Maria Theresa M. Mutia, Hilly Ann Roa-Quiaoit, Daisy Lou L. Polestico, Armi G. Torres

Abstract:

Illegal, unreported, and unregulated (IUU) fishing is a significant threat to marine ecosystems, fish stocks, and the livelihoods of coastal communities. It undermines conservation efforts, disrupts food security, and causes major economic losses for legitimate fishing industries. IUU fishing practices include using destructive fishing methods, operating without licenses, exceeding quotas, and failing to report catches accurately. In the Philippines, despite national and local efforts to address this issue, IUU fishing persists due to regulatory challenges, economic pressures, socio-cultural factors, and weak monitoring, control, and surveillance systems. In particular, the current status of IUU fishing in Region 9 remains unassessed. Thus, this study aims to assess the prevalence of IUU fishing in Alicia, Zamboanga Sibugay in Region 9 using the Philippine IUU Fishing Index and Threat Assessment Tool (I-FIT Tool), identify critical hotspots, and propose strategies to combat IUU for sustainable fisheries management. The research adopts a mixed-methods approach, integrating quantitative social survey data with qualitative insights from key informant interviews, focus group discussions, and field observations. Perspectives from fisherfolk, vessel owners, local government units (LGUs), enforcement teams, academe, people organization, and other stakeholder representatives were incorporated to provide a comprehensive analysis of the prevalence of IUU fishing. Geospatial analysis and mapping of IUU fishing hotspots were conducted using QGIS. The findings revealed 10 types of IUU fishing violations in the municipal waters, with most violators originating from the local community, though some came from neighboring municipalities. Destructive practices, such as using Danish seines, trawling, fine mesh nets, explosives, and toxic substances, were prevalent and caused significant degradation of marine habitats. In 2024, poison cyanide fishing (locally known as Tubli, Lanate, or Lagtang) was the most widespread practice, reported by 86% of the respondents, followed by compressor cyanide fishing and dynamite fishing (Bomba), both by 84% of the respondents. These practices were observed across all 20 coastal barangays. The study also found that Danish seines, particularly in Barangay Poblacion, were responsible for the highest number of violations in 2024. This active gear drags a weighted net across the seafloor, damaging vital habitats such as coral reefs and seagrass beds. Immediate interventions are needed to address these issues. Several recommendations were proposed by respondents, including strengthening law enforcement through enhanced patrolling, surveillance, and the use of modern technologies like remote sensing. Implementing the Bantay Dagat program in all coastal barangays, promoting awareness campaigns on destructive fishing practices, and fostering alternative livelihoods such as aquaculture and eco-tourism were also suggested. Habitat restoration efforts, including mangrove replanting, coral reef rehabilitation, and establishment of a sanctuary, are essential. Simplifying registration processes and offering incentives for sustainable practices would encourage policy compliance. This study aligns with SDG 14.4 which seeks to regulate fishing, eliminate IUU fishing, and conserve marine ecosystems for sustainable fisheries.

Keywords: fisheries management, illegal fishing, IUU, SDG 14.4

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Authors: Olaniyan, Rotimi, Francis, Abubarkar Mohammed

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Agbabu Water, Oluwa River is used for artisanal fishing, ferrying and domestic activities in Odigbo Local Government Area (OLGA), Ondo State. The river receives bitumen spills and domestic and agricultural wastes, which could adversely impact on the water quality and resident biota. In spite of anthropogenic activities, there is a dearth of information on the limnology and biota of the river. Extensive bitumen spills, as well as uncontrolled discharge of domestic wastes, have pollution implications as they alter prevailing conditions and destroy the habitats of aquatic organisms. The aim of this study was to investigate the physic-chemical parameters of Agbabu Water in order to provide baseline information for effective management. Monthly water samples were collected on the surface of Agbabu water,Oluwa River, for a period of 6 months (June 2024 to November 2024). All physic-chemicals were collected and analyzed according to APHA (2005) standard methods. Results showed that temperature ranged between 26.0-32.0oC, transparency (1.0-8.0 m), alkalinity (14.0-25.0 mg/l), electrical conductivity (18-105 µS/cm), dissolved oxygen (1.2-3.8 mg/l), sulphate (0.0 -4.0mg/l) and total dissolved solids (18-36). The parameters at the downstream (station A) accounted for the bulk of the highest values; there were, however, no significant differences between the stations at P<0.05. The results obtained from the physic-chemical parameters agree with the limits set by both national and international bodies for drinking and fish growth. It was recommended that urgent checks and monitoring by relevant agencies, government representatives, public health practitioners, and community leaders be required.

Keywords: Agbabu Water, dynamics, Oluwa River, physico-chemical

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Authors: Jason Monty, Nicholas Hutchins, Jelle Will, Isnain Aliman, I. Ketut Utama, Bagus Nugroho

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Hydrodynamic resistance (drag) on a ship accounts for up to 90% of the vessel’s energy consumption. For most common ship geometries the resistance is primarily caused by skin friction drag resulting from the formation of a turbulent boundary layer owing to the relative motion of the ship hull and the water. This drag is increased by biofouling that inevitably grows on the hull during operation. Biofouling is known to increase drag by up to 80%, meaning significant excess fuel is used by fouled vessels, leading to excessive harmful greenhouse gas emissions. The International Maritime Organisation estimates the wasted energy at 7% on average across all ships in operation, taking into account the varying stages of fouling growth on the world’s fleet. This investigation aims to directly measure the impact of fouling on skin friction drag,for the first time, on a ship in operation. Through collaboration with our partners Samudera Indonesia and ITS Surabaya, we have instrumented an operating tanker in Indonesia with a laser Doppler anemometer measuring through a glass window in the flat bottom of the hull. This permits us to make measurements of the turbulent boundary layer to estimate drag accurately. At the same time, we have built a custom photogrammetry rig with unprecedented resolution to acquire a 3D topographical maps of the state of the hull. Therefore, we are able to correlate the measured skin friction drag with the hull state such that predictions can be made for lost fuel due to biofouling and other sources of roughness. Such a predictive capability would allow ship operators to make more informed decisions on hull cleaning and to better understand fuel use patterns. Our preliminary results show that even a freshly cleaned and recoated vessel coming from dry-dock can have a drag penalty exceeding 20% compared to an assumed hydrodynamically smooth hull, already significantly higher than the IMO estimate. Ongoing measurements over multiple years demonstrate the evolution of the hull state and the ship drag change with the onset of biofouling. This paper will present these data, along with the first ever high fidelity boundary layer measurements on an operating vessel. The methodology and challenges of conducting boundary layer measurements at sea and measuring biofouling accurately will also be discussed.

Keywords: boundary layers, ship performance, biofouling, ship drag

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Authors: Mridula G. M., Sai Ganesh Veeravalli, Satya Kiran Raju Alluri, M. V. Ramana Murthy

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India’s 7,500 km coastline is home to nearly 170 million people, contributing significantly to fisheries, tourism, and maritime trade. However, nearly 45% of India’s coastline is eroding, driven by natural processes, climate change, and poorly planned interventions. High-energy waves, rising sea levels and increasing extreme weather events further exacerbate coastal vulnerabilities. Despite the establishment of Coastal Regulation Zones (CRZ) and Integrated Coastal Zone Management (ICZM), micro-level shoreline management remains inadequate, often leading to ineffective and unsustainable coastal protection measures. This study evaluates the effectiveness of implementing shoreline management strategies in India, emphasizing nature-based solutions. Through a comparative analysis of successful and failed interventions, the paper highlights the need for data-driven, adaptive shoreline management policies that integrate scientific modeling, stakeholder engagement, and sustainable engineering practices. As India faces accelerating climate change impacts, the development of resilient shoreline management strategies is imperative for balancing economic growth, environmental sustainability, and coastal community well-being. This paper provides actionable insights for policymakers, engineers, and coastal managers to implement effective, region-specific coastal protection measures, ensuring the long-term sustainability of India's dynamic coastline.

Keywords: coastal management, climate change, coastal policy, nature-based solution

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Authors: Asma Baouham, Seif-eddine Cherif, Siham Sakami

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On November 1, 1755, a catastrophic earthquake and tsunami struck several countries bordering the Atlantic Ocean, including Portugal, Spain, and Morocco, among others. With a magnitude of approximately Mw=7.8, the earthquake triggered devastating tsunami waves, particularly affecting the Moroccan coastline. Extensive damage and fatalities were reported in coastal cities like Agadir, Safi, Sale, and Tangier. Numerous studies have delved into the 1755 earthquake and tsunami, aiming to identify potential sources of the event, we select five typical faults of candidate tsunami scenarios in the Gulf of Cadiz region; namely, the Gorringe Bank fault (GBF), Horseshoe fault (HSF), Marques do Pombal fault (MPF), Gulf of Cadiz fault (CWF) and Portimao Bank Fault (PBF). it utilized the COMCOT (Cornell Multi-grid Coupled Tsunami Model) numerical code, coupled with an initial sea-surface perturbation generated using Okada’s formulae, to simulate the generation, propagation, and inundation of 1755 tsunamis along the Atlantic coasts of Morocco. Overall, this study’s outcomes yield valuable insights into the most impacted Atlantic coastal cities, based on the outputs of the simulation, that include the inundation distances, arrival times at different locations, and wave heights.

Keywords: tsunami, COMCOT, wave heights, inundation distances, arrival times

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Authors: Mohammed M. A., Chado Z. M.

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This study examined the role of latency period on the breeding indices of C. gariepinususingtwo type of synthetic hormones i.e ovaprim and ovatide. Twelve brood stock were sourcedfor this experiment from the federal department of fisheries farm, Kaduna, Kaduna State. Theexperiment was designed to consist six (6) treatment, i.e 1A, 1B, 2A, 2B, 3A, and 3B. Twobroodstock consist of male and female were used for each treatment. Group of treatment ‘’1’’ wereinjected with ovaprim and ovatide at 0.5ml/kg body weight each for eight (8) hrs latency periodbefore stripping. Group of treatment “2” were injected with ovaprim and ovatide at 0.5ml/kgbody weight for ten (10) hrs latency period before stripping. Group ‘3’ were injectedwithovaprim and ovatide at o.5ml/kg body weight for twelve (12) hrs latency period before stripping. The injection was intramuscularly above the lateral line and below the anterior end of thedorsal fin. The fish administered ovaprim at 0.5ml/kg body weight at the latency period twelve (12) hrshad highest number of stripped eggs (53,260) also with highest percentage fertilization (83.57%)(P≤0.05). The fertilization took place at each latency period, but highest percentage fertilizationwas observed at the latency period of twelve (12) hrs with the temperature range of 26ºC- 27ºc.

Keywords: latency period, fertilization, stripping, breeding

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Authors: Kietisak Yokseng, Rachow Khaochumnan, Patchara Pedpradab

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Sponges are biological filtration organisms in the marine environment and are a rich source of bioactive compounds. Inland cultivation presents an alternative method for growing sponges for pharmaceutical purposes. A blue marine sponge (Xestospongia sp.) was collected by hand from Sarai Island, Thailand. The sponge samples were rehabilitated in natural seawater within a 90 m³ cement pond for one month. The system maintained a water flow rate of 180 m/second and salinity levels between 28-30 ppt. After an incubation period, the experimented sponge explants were prepared at the initial size of 1×2 cm and weighed before being attached to the plastic net. The samples were then transferred to the aquarium under a semi-close circulating system operation. Sponges fed with Chaetoceros gracilis. The cultural container material is made of glass, plastic, and polymeric form. Results revealed that the highest sponge growth (1.21 g) was observed in a cultural tank made from glass, while the lowest growth (0.66 g) was recorded in plastic containers. However, the growth differences between container materials were not statistically significant. The results demonstrated that a semi-closed circulating system is suitable for inland sponge cultivation, with optimal growth achieved using glass containers feeding with diatom C. gracilis.

Keywords: xestospongia sp, culture, development, marine sponge

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