Marine Biology Research Articles

A study of enhanced visual perception of marine biology images based on diffusion-GAN

Aiming at the influence of factors such as the special optical characteristics of water bodies on the perceptual quality of generated images, this paper proposes the DifSG2-CCL model for reducing the special optical characteristics of water bodies and the DPL-SG2 model for introducing perceptual loss. Combining the ideas of cyclic consistency and style migration, this paper builds the Underwater Cycle Consistency Loss (U-CCL) module. The DifSG2-CCL model is based on the method of image reconstruction, which converts the underwater image into the style of the land image to reduce the influence of the water body factors. VGG16 is introduced as a perceptual loss into the DPL-SG2 to enhance the visual perception of the image by feature extraction with different layers and tonal weighting. Furthermore, in addition to the already disclosed SA dataset, a T dataset with a resolution of 256 × 256 in 9.366k sheets is provided in this paper. The experimental results show that DifSG2-CCL and DPL-SG2 can effectively enhance the perceptual quality of the images. The unique underwater image generation of DifSG2-CCL produces excellent results in qualitative analysis and reduces its FID value to 8.97. DPL-SG2 is more outstanding in the training of T dataset, and its FID value is reduced to 5.39. Therefore, the U-CCL and VGG16 can be applied as an innovative approach to enhance visual perception of underwater images. The experimental code with pre-trained models will be published shortly at https://github.com/yff0428/DPL-SG2/tree/main.

Highly Enriched Metal Elements in Marine Biological Shells as New Resources for the Sustainable Extraction of Metals

Marine biological shell waste, as a representative renewable resource, can lead to serious environmental problems and resource waste if effective utilization methods are not developed. Therefore, there is an urgent need for innovative solutions to enable the effective recycling and reuse of marine biological shell waste. Although previous studies have explored the applications of marine biological shells in chitin extraction and animal feed production, this study is the first to reveal the possibility of obtaining metal resources from marine biological shells, which is a renewable resource available in large quantities. An analysis of the metal element concentrations in marine biological shells shows that several valuable or important metal elements are present at concentrations that are hundreds of thousands of times higher than in seawater. CaCO3 was identified as the main component for enriching metal elements in marine biological shells. The recovery efficiency of most metal elements from oyster shells could exceed 80%. This study highlights the potential of marine biological shells as a valuable metal resource, offering a sustainable approach to waste management and utilization while alleviating the risk of heavy metal accumulation and environmental pollution associated with traditional composting.

The Interaction Between the BBNJ Agreement and the International Deep Sea Mining Regime: More Questions than Answers?

As the scope of the Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction (BBNJ Agreement) overlaps with what is governed by the international deep sea mining regime, interaction between these two frameworks is inevitable, but the nature and implications of this interaction remain largely unclear. The fact that the ratification process of the BBNJ Agreement coincides with the final phase in the development of rules and procedures for commercial exploitation activities in the field of deep sea mining only raises more questions and speculation. Marine environmental protection is a key component in the regulation of deep sea mining, but the rules and measures provided by the BBNJ Agreement might introduce significant changes that alter the legal context in which the deep sea mining regime currently operates, despite the BBNJ Agreement's overall ambition to promote coherence and the general precept not to “undermine” other legal instruments and relevant bodies. In order to unravel this ambiguous relationship, this article unpacks the principle not to undermine and applies it to the deep sea mining context, thereby demonstrating the issues associated with its interpretation and the consequences this may have. To assess some of the concrete implications in a more pragmatic manner, the article also zooms in on a number of questions and scenarios within the field of area-based management tools, whose relevance will only increase with time.

Exploring Global Research Trends in Mangrove Ecosystems: A Bibliometric Analysis of Key Issues and Future Directions (1996–2022)

ABSTRACTAmid escalating global climate change and environmental degradation, mangrove ecosystems face challenges like rapid biodiversity loss, intensified human activities, invasive alien species, and recurrent natural disasters. This highlights the urgent necessity for more research and informed conservation strategies. Our study meets this need by using advanced bibliometric techniques to analyze mangrove research trends, evolution, and gaps from 1996 to 2022. It aims to bridge the knowledge gap by providing a comprehensive understanding of mangrove research dynamics, interdisciplinary integration, geographical distribution, and future research priorities. The study presents a thorough analysis of over 14,534 multidisciplinary scientific publications covering ecology, forestry, oceanography, and environmental management. Our findings, based on both quantitative and qualitative methods, show that: (1) The 26‐year mangrove research is split into two phases: 1996–2008 as the initial exploration stage and 2009–2022 as the significant leap stage.in. The literature volume surged, especially in 2009 when the article count leaped from 32 to 543, signaling the start of rapid growth in mangrove research; (2) These studies reflect interdisciplinary integration, drawing from environmental science, marine/freshwater biology, ecology, oceanography, plant science, and molecular biology, with a particular emphasis on marine and freshwater biology, environmental science, and ecology; (3) China and the US lead, with 3,246 and 2,671 publications, making up 22.33% and 18.38%, respectively. India is third with 1719 publications (11.83%). Brazil, Australia, Germany, and others follow closely, jointly expanding mangrove research and deepening understanding of conservation management; (4) Current mangrove research centers on key areas like conservation, management, and restoration, climate adaptation, biodiversity, sediment analysis, and blue carbon assessment. In the future, we need to bolster mangrove research, focusing on climate change response, carbon cycle mechanisms, and exploring more potential emerging blue carbon. Socially, blue carbon management should be enhanced, along with mathematical modeling and prediction capabilities. Interdisciplinary and international collaborations must be deepened. This study combines traditional bibliometric review with modern visual analysis tools to conduct metrics‐perspective network metrics, clustering, and visualization of the mangrove literature, showing its novelty. It offers the latest, in‐depth insights, serving as a valuable reference for scholars, managers, and governments, facilitating sustainable management and advancing Nature‐based Solutions.

Assessing Anthropogenic Impacts on Coral Reefs Using Local and Expert Knowledge in the Semporna Priority Conservation Area, Sabah, Malaysia

ABSTRACTThe Semporna Priority Conservation Area (PCA), located on the southeast coast of Sabah, Malaysia, spans 7680 km2 within the Sulawesi Sea and is part of the Coral Triangle, known for its rich marine biodiversity. Despite its ecological significance, the area faces multiple anthropogenic threats. The study aimed to (1) evaluate reef health by assessing live coral cover, indicator fish and invertebrate density in six locations in Semporna; (2) examine the survey team's threat rankings with the vulnerability factors perceived by experts; and (3) compare vulnerability scores for 10 identified threats. Underwater surveys were conducted using the Reef Check methodology, supplemented by in situ observations from SCUBA divers and boat attendants in May–June 2017. Marine biologists or scientists familiar with Semporna assessed coral reef vulnerability factors based on scales, frequency, functional impact, resistance, recovery time and certainty towards different threats. The main threats identified include fish bombing, marine debris, commercial fishing and artisanal fishing. Results indicate reef degradation, particularly from destructive fishing practices, and highlight differences between local observations made by the field team and expert assessments gathered through interview surveys. Tourism activities were significant in the Centre to Southwest and Northeast to Southwest regions, necessitating site‐based management. This integrated approach provides a comprehensive understanding of threats in the Semporna PCA and underscores the importance of combining empirical data with local insights to guide management prioritisation and develop effective conservation strategies, such as establishing new marine protected areas.

The effects of ocean warming and elevated CO2 on the feeding behavior and physiology of two sympatric mesograzers.

The effects of ocean warming and elevated CO2 on the feeding behavior and physiology of two sympatric mesograzers.

Solid waste research in Scopus (2002-2023): A study based on the Peru scientific production

Objective. In this study, we performed a bibliometric analysis of the Peruvian scientific production of solid waste.Methodology. A bibliometric analysis was conducted based on records indexed in the Scopus database from 2003 to 2023. The bibliometric indicators examined were productivity by journals, productivity by institutions, productivity by authors, most cited articles, and co-occurrence of terms.Results. Many journals and international conferences oriented from marine biology to ecological engineering stood out among the sources with the highest productivity. Three institutions stood out: Universidad Privada del Norte, Pontificia Universidad Católica del Perú, and Universidad San Ignacio de Loyola. There is a group of public universities that stood out, such as Universidad Nacional de Ingeniería, Universidad Nacional Mayor de San Marcos, Universidad Nacional Agraria La Molina, Peru, and Universidad Nacional del Centro del Perú. A small group of leading authors was observed: De-la-Torre, G.E., Vázquez-Rowe, I.; Marin, M.V., and Ziegler-Rodriguez, K. The most cited articles were related to the energetic use of agricultural waste, contamination by personal protective equipment waste during the COVID-19 pandemic, solid waste management in Latin America, environmental impact and public health of plastic waste related to COVID-19, and waste management evaluation and optimization. The co-occurrence map of terms revealed eight thematic clusters: (1) intersection between agriculture and waste management, (2) chemical processes in waste reduction, (3) waste management in aquatic environments, (4) intersection between agriculture and waste management with emphasis on approaches, practices and strategies, (5) agro-industrial waste, (6) impact of solid waste on air and water pollution, (7) social perspectives on environmental issues, and (8) eco-efficiency in the construction sector.Conclusions. Peruvian research on solid waste strongly focuses on agriculture, given that these issues were highlighted in three of the eight thematic clusters identified.

Environmental DNA metabarcoding: Current applications and future prospects for freshwater fish monitoring.

Environmental DNA metabarcoding: Current applications and future prospects for freshwater fish monitoring.

Parasites: The Hidden Hitchhikers of Cephalopods

Cephalopods (cuttlefish, squid, octopus, and nautilus) are remarkable marine creatures with extraordinary features like high intelligence, impressive camouflage abilities, blue blood, and three hearts. Yet, beneath the waves, they face a hidden threat from microscopic parasites. Parasites can wreak havoc on cephalopods, causing wounds that lead to infections, stomach aches that affect their appetite, and changes in their behavior. Luckily, cephalopods have a defense squad in their blood that battles these invaders. It is not all doom and gloom—parasites can help scientists uncover areas of the ocean where cephalopods travel and whether these areas are facing threats such as pollution and climate change. Scientists can examine the relationship between cephalopods and their parasites, helping cephalopods all over the world stay as healthy as possible. Dive into this thrilling underwater world, as we embark on an adventure to solve the mysteries of cephalopods and their secret hitchhikers.

Learning Marine Biology Quantitative Skills Through Computational Thinking

Increased technological advances within marine biology requires professionals to become versed in interdisciplinary computer-based skills. Computational thinking (CT) is a contemporary concept used in educational settings across the globe to meet this need. CT has been incorporated into many curricula; however, incorporation strategies are vague and result in specific challenges for post-secondary marine science educators. We developed a framework to support an intervention which incorporated CT into learning marine biology quantitative skills for students in an introductory marine science course at a small liberal arts university in the northeastern United States through a quasi-experimental action research design. We assessed student participant content knowledge through two assessments, student artifacts and a self-perception survey. Results indicate that the intervention was successful in overall participant knowledge gains in both quantitative marine biology skills and computational thinking. Our research design may shed light on how post-secondary institutions may address student range of computational thinking skills within marine science to better support sustainability practices and promote equity and present its applicability to other settings.

Reconfiguration and dynamics of clamped fibers under finite-amplitude surface gravity waves

We investigate the behavior of a flexible stem completely submerged under a surface gravity wave of finite amplitude using fully resolved direct numerical simulations. By varying the rigidity of the stem over ten orders of magnitude, we explore its motion in the drag-dominated regime with realistic air and water properties. Our findings reveal two distinct structural responses of the stem depending on the ratio between its natural frequency (fnat) and the wave frequency (fwave). For fnat/fwave≫1, the stem maintains on average a straight configuration and exhibits streamwise oscillations in phase opposition with the wave, moving symmetrically with respect to the vertical direction. Conversely, for fnat/fwave≪1, the stem reconfigures under the influence of the Stokes drift, bending forward and breaking the symmetry, and exhibits oscillations that are more coherent with the surrounding flow field. Resonance is observed when fnat≈fwave. These results provide insights into the dynamics of slender vegetation and manmade structures in wave fields, offering valuable implications for marine biology and engineering. Published by the American Physical Society 2025

Counting of Underwater Static Objects Through an Efficient Temporal Technique

Counting marine species is a challenging task for biologists and marine experts. This paper presents an efficient temporal technique for counting underwater static objects. The proposed method employs deep learning techniques to detect objects over time and an efficient spatial–temporal algorithm to track them, allowing for accurate counting of objects within a given area. The technique is designed to handle various challenges that arise in underwater environments such as low visibility, object occlusion, and water turbulence. The approach is validated through experiments conducted on the surveyed data of Nephrops norvegicus. Nephrops is considered one of the main commercial species in Europe. Nephrops spend most of their time inside the burrows. Burrows tracking and counting are the only ways to monitor this species. This paper proposed a technique to accurately count underwater static objects using their spatial–temporal values by minimizing false positives. The proposed technique has potential applications in marine biology, environmental monitoring, and underwater surveillance.

ADL-Net: attention-driven densenet-LSTM network for underwater images classification

Abstract Imaging in marine environment is a challenging task due to several reasons, including light variations, color distortions, noise, and limited datasets, which causes inaccurate target classification problems. This paper presents a methodology for image classification in marine biology and environmental research. We proposed the Attention-Driven DenseNet-LSTM Network (ADL-Net), aiming to improve classification accuracy of underwater imagery. Initially, feature extraction is performed using multi-levels of DenseNet201, which excels in hierarchical feature extraction, offering stability and rapid convergence. In the next stage, two modified attention mechanisms are designed: the squeeze and excitation operations are used to refine channel-specific feature responses, while the convolutional block attention module refines attention for both channels and spatial dimensions. These attention mechanisms help the model to highlight important features and minimize distractions. Additionally, a Bi-directional Long Short-Term Memory layer is integrated to capture spatial dependencies and improve classification robustness. Various training strategies are used to find the best parameter tuning. Our method demonstrates excellent performance when tested on fish datasets: LifeCLEF 2015 and Fish4Knowledge, achieving accuracies of 98.02%, and 99.52%, respectively. These findings underscore ADL-Net's potential for enhancing automated underwater image classification, advancing research in marine ecology.

Bio-inspired Octopus-mimicking Soft Robotic Grasping System

Octopus-inspired soft robots have emerged as a promising field of research, drawing inspiration from the remarkable dexterity and adaptability of this marine creature. Their ability to manipulate objects in complex environments, coupled with their soft, compliant bodies, offers significant advantages over traditional rigid robots. This paper provides a comprehensive overview of recent advancements in the design and development of octopus-inspired soft robots, focusing on shape control, grasping strategies, and potential applications. This paper presents a comprehensive review of recent advancements in biomimetic robotic design, focusing on octopus-inspired soft robots and soft grippers. This paper discusses various shape control algorithms and modeling methods for octopus-inspired soft manipulators, highlighting their applications in highly flexible and complex grasping tasks. The paper explores grasping planning strategies for soft grippers, such as force equilibrium and minimum grasping force control, to achieve precise grasping of diverse objects. Furthermore, this paper present various design schemes based on soft materials and actuation techniques, including tendon-driven and pneumatic actuation, each with its own structural and performance advantages. This paper provides theoretical support and practical guidance for the further development and optimization of octopus-inspired soft robots.

Isolation, Characterization and Identification of Bioluminescent Bacteria from Indian Squid (Uroteuthis duvaucelii)

Bioluminescence, the capacity of living creatures to produce light through chemical processes, has been a topic of scientific fascination for many years. Bioluminescence is of great importance in the marine environment, since it facilitates diverse ecological interactions. Bioluminescent bacteria establish symbiotic partnerships with marine creatures, such as squids, octopus, dinoflagellets, various fishes like anglerfishes, etc. In order to use bioluminescent bacteria as a biosensor, the samples of Indian Squid were gathered from local fish market located in Ganesh Peth and Camp area of Pune district, Maharashtra. This study was performed to isolate and characterize potential bioluminescent bacteria which can be used as biosensors in food and brewing industry for food analysis. In this study, 608 colonies with blue color and 873 colonies with green color bioluminescence were isolated from Indian squid using sea water agar. The bacterial strains AB28 and ABG67 were selected for further analysis, which required comparing them with the information provided in Bergerys handbook for their characterization. Additionally, their identification was carried out using 16S rRNA. The bioluminescent strains that were isolated and identified were Shewanella seohaensis and Shewanella hafniensis, respectively.

Creating a scientific picture book of marine organism with natural history illustration: A case study in Japan

In recent years, global concern has grown regarding the degradation of marine ecosystems. Humanity has greatly benefited from the oceans, underscoring the constant need for restoration and conservation of marine ecosystems. International cooperation is essential for protecting the oceans, with Japan, an island nation surrounded by the sea, playing a crucial role in marine environmental conservation. For the sustainable use of marine resources and the preservation of marine environments, comprehensive measures are important. Particularly, marine biology education for the next generation holds great importance. Here, we report a detailed case study on the creation of a scientific picture book about marine organisms in Japan and its feedback. The book explores the theme of mutual symbiosis among marine organisms, aiming through illustrations and storytelling to help children understand the complexities of marine life. It focuses on the symbiotic relationship between hermit crabs and sea anemones. The picture book was developed based on scientific literature survey and specimen observation. Positive feedback from readers highlights how effectively the picture book conveys educational content on marine biology, suggesting the potential of science picture books as powerful tools in educational outreach and environmental conservation efforts. This report discusses the creative process, the educational impact of the picture book, and offers valuable insights into the use of visual arts and narrative in science education.

First release of the European marine omics biodiversity observation network (EMO BON) shotgun metagenomics data from water and sediment samples.

The European Marine Omics Biodiversity Observation Network (EMO BON) is an initiative of the European Marine Biological Resource Centre (EMBRC) to establish a persistent genomic observatory amongst designated European coastal marine sites, sharing the same protocols for sampling and data curation. Environmental samples are collected from the water column and, at some sites, soft sediments and hard substrates (Autonomous Reef Monitoring Structures - ARMS), together with a set of mandatory and discretionary metadata (including Essential Ocean Variables - EOVs). Samples are collected following standardised protocols at regular and specified intervals and sequenced in large six-monthly batches at a centralised sequencing facility. The use of standard operating procedures (SOPs) during data collection, library preparation and sequencing aims to provide uniformity amongst the data collected from the sites. Coupled with strict adherence to open and FAIR (Findable, Accessible, Interoperable, Reusable) data principles, this ensures maximum comparability amongst samples and enhances reusability and interoperability of the data with other data sources. The observatory network was launched in June 2021, when the first sampling campaign took place.

Effect of a polymeric compound layer on jetting dynamics produced by bursting bubbles.

Jetting dynamics from bursting bubbles play a key role in mediating mass and momentum transport across the air-liquid interface, and have attracted widespread interest from researchers across disciplines. In marine environments, this phenomenon has drawn considerable attention due to its role in releasing biochemical contaminants, such as extracellular polymeric substances, into the atmosphere through aerosol production. These biocontaminants often exhibit non-Newtonian characteristics, yet the physics of bubble bursting with a rheologically complex layer at the bubble-liquid interface remains largely unexplored. In this study, we experimentally investigate the jetting dynamics of bubble bursting events in the presence of such a polymeric compound layer. Using bubbles coated by a polyethylene oxide solution, we document the cavity collapse and jetting dynamics produced by bubble bursting. At a fixed polymer concentration, the jet velocity increases while the jet radius decreases with an increasing compound layer volume fraction, as a result of stronger capillary wave damping due to capillary wave separation at the compound interface as well as the formation of smaller cavity cone angles during bubble cavity collapse. These dynamics produce smaller and more numerous jet drops. Meanwhile, as the polymer concentration increases, the jet velocity decreases while the jet radius increases for the same compound layer fraction due to the increasing viscoelastic stresses. In addition, fewer jet drops are ejected as the jets become slower and broader with increasing polymer concentration, as viscoelastic stresses persist throughout the jet formation and thinning process. We further obtain, for the first time, a regime map delineating the conditions for jet drop ejection versus no jet drop ejection in bursting bubbles coated with a polymeric compound layer. Our results may provide new insights into the mechanisms of mass transport of organic materials in bubble-mediated aerosolization processes, advancing our understanding of marine biology and environmental science.

Overlooked tripartite microbial interactions influencing chemical cycling in the ocean.

Overlooked tripartite microbial interactions influencing chemical cycling in the ocean.

Digital Fish Image Segmentation Using U-Net for Shape Feature Extraction

Segmentation of digital images of fish is an important challenge in image processing in the field of marine biology and aquaculture. Extraction of fish shape features through image segmentation can improve accuracy in species identification and fish population monitoring. The U-Net method, which is based on deep learning, has been proven effective in medical image segmentation and is beginning to be applied in fish image segmentation. This study aims to develop a fish digital image segmentation method using U-Net architecture for accurate and efficient fish shape feature extraction. The dataset used consists of 500 fish images of various shapes and sizes collected from various sources. The fish images were processed using a U-Net artificial neural network, which was trained and tested to obtain the best segmentation results, with evaluation using Intersection over Union (IoU). The segmentation results show that the U-Net method can produce precise segmentation, with a high degree of accuracy in extracting fish shape features. Evaluation of the segmentation metrics resulted in an IoU value of 0.88, indicating excellent performance in distinguishing the fish object from the background and accurately mapping the fish shape. The fish digital image segmentation method using U-Net is effective for fish shape feature extraction and can be applied in fish species identification and aquatic ecosystem monitoring.