Management Of Marine Resources Research Articles

Larval dynamics suggest phenological strategies and positive effect of marine protected areas controlling indigenous and non-indigenous crab populations

The early life of most decapod crustaceans takes place in the water column as larvae before they settle in benthic habitats. The spatial and temporal variability in the settling of larval stages offers valuable insights into the potential recruitment of natural populations. To explore this, we studied megalopa assemblages at various segments of coastline on El Hierro and Lanzarote islands, both within and outside the Marine Protected Areas (MPAs) of each island. The study spanned four consecutive oceanographic periods in the Canary Islands (NW Africa), employing light traps for sample collection. The low number of recorded species suggested that light traps exhibit selectivity, particularly for megalopae belonging to Portunidae and Grapsidae. El Hierro, which experienced warmer sea surface temperatures, displayed higher megalopa abundance values than Lanzarote and distinct larval assemblages was observed between these two islands. Similarly, we identified significant variations in abundance and species composition between stratified and mixing seasons. These seasonal differences were influenced by the dominance of Achelous hastatus, Percnon gibessi, and Cronius ruber during the stratified season. In Lanzarote, C. ruber was not recorded during the mixing season, suggesting that the colder conditions there may constrain its reproduction. Interestingly, we observed that species traditionally harvested from the intertidal zone for human consumption (Plagusia depressa) or used as bait for recreational fishing (Pachygrapsus spp. and P. gibessi) exhibited higher megalopa abundances within the MPAs. In contrast, we noted lower megalopa densities of the non-indigenous species C. ruber within the protected areas. These results indicate a positive effect of MPAs controlling indigenous and non-indigenous crab populations. Moreover, the study provides novel data, showing that light traps are suitable for monitoring the temporal occurrence, abundance, and spatial distribution of non-indigenous and commercially exploited species. This is key for adopting an ecosystem-based approach to manage marine resources.

Mapping the distribution and dynamics of coastal aquaculture ponds using Landsat time series data based on U2-Net deep learning model

ABSTRACT The extraction of coastal aquaculture ponds from remote sensing images is affected by the effect of ‘same object with different spectrums’ and ‘different objects with same spectrums’. The U2-Net deep learning network is able to capture more contextual information from different scales to solve this problem and is suitable for salient object detection. This study proposed a remote sensing information extraction model of coastal ponds based on U2-Net deep learning network, completed the remote sensing information extraction of coastal aquaculture ponds in Zhoushan Archipelago from 1984 to 2022, analyzed the spatiotemporal evolution of coastal aquaculture ponds in Zhoushan Archipelago. The results showed that the developed model was more accurate with a precision rate of 96.12%, a recall rate of 95.43%, and an F1-measure of 0.96. During the study period, the area of the aquaculture ponds in the Zhoushan Archipelago demonstrated an increasing trend, expanding from 471.21 hm2 in 1984–3668.55 hm2 in 2022. In addition, over half of the aquaculture ponds had been active for more than 10 years. The method developed in this study is capable of rapidly and accurately mapping coastal aquaculture ponds, and thus is significant for the management of marine resources and promoting sustainable development.

Embracing diversity: enhancing the management of South Africa’s kelp forests in an era of change

Abstract In an era of climate change, South Africa’s kelp forests offer important opportunities for sustainable resource utilization. However, these opportunities also bring risks of over-exploitation. The mismanagement of kelp forests through monistic and exclusionary strategies must therefore be avoided. Emphasizing the value of plural knowledges and cultural norms associated with kelp, here we advocate for inclusive and integrated marine resource management to ensure the resilience of South Africa’s kelp forests and the well-being of coastal communities that depend on them.

Sub-seasonal to seasonal drivers of regional marine heatwaves around Australia

As marine heatwaves (MHWs) become more intense and longer lasting due to global warming, understanding the drivers and impacts of these events is crucial for effective marine resource management. This study investigates the influence of El Niño Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD), Southern Annular Mode (SAM), Sub-Tropical Ridge High (STRH), and Madden Julian Oscillation (MJO) on sea surface temperature (SST) anomalies and MHWs around Australia. The aim of this research is to improve our understanding of the drivers of MHWs on sub-seasonal to seasonal (S2S) timescales, which bridges the gap between short-term weather and interannual to long-term climate variability. By analysing SST anomalies and MHWs characteristics during specific driver phases, a simple MHW hazard index is developed. Our findings support previous research indicating that La Niña plays a role in driving MHWs off the coast of Western Australia and reveals a previously unrecognised connection between ocean warming off Queensland and Tasman Sea low-pressure systems associated with the negative phase of the STRH. Our research emphasizes the importance of considering multiple drivers and their compounding effects on MHWs by showing significant changes to typical La Niña MHW patterns with the additional influence of the MJO. By considering drivers acting in the S2S timescale, forecasts can more accurately capture the timing, intensity, and spatial extent of MHW events within a season. These improved forecasts can enhance the ability of marine managers to adapt and allocate resources based on evolving climate conditions, enabling effective implementation of harm minimisation strategies.

Emerging issues in fisheries science by fisheries scientists.

The current epoch in fisheries science has been driven by continual advances in laboratory techniques and increasingly sophisticated approaches to analysing datasets. We now have the scientific knowledge and tools to proactively identify obstaclesto the sustainable management of marine resources. However, in addition to technological advances, there are predicted global environmentalchanges, each with inherent implications for fisheries. The 2023 symposium of the Fisheries Society of the British Isles called for "open and constructive knowledge exchange between scientists, stakeholders, managers and policymakers" (https://fsbi.org.uk/symposium-2023/), a nexus of collaborative groups best placed to identify issues and solutions. Arguably, the Centre of Environment, Aquaculture and Fisheries Science (Cefas) and their Scientific Advice for Fisheries Management (SAFM) Team sit at the centre of such a network. SAFM regularly engages with managers and stakeholders, undertakes scientific research, provides fisheries advice to the UK government, and are leading experts within the International Council for the Exploration of the Sea (ICES). As such, this paper is an opinion piece, linked to individual authors specialisms,that aims to highlight emergingissues affecting fisheries and suggest where research efforts could be focused that contribute to sustainable fisheries.

Power and participation: A systematic review of marine protected area engagement through participatory science Methods

Marine Protected Areas (MPAs) are a critical part of the marine resource management community’s toolbox in seeking a sustainable and vibrant global ocean system. The processes of community engagement with MPAs, however, are rooted in pre-existing power dynamics inherent in environmental governance systems and influenced by historical contexts of colonialism. Marine governance has historically operated in a top-down manner, imposing exclusionary forms of conservation on local communities without affording them equitable power in the process. Meaningful engagement of community members in MPAs has been suggested as one of the key enabling conditions that drive successful marine protection. Specifically, participatory science methods have the potential to engage local communities, elevate local voices and expertise, and strengthen both local communities and scientific learning. This systematic scoping review assesses the peer-reviewed literature to understand the quality and nature of participatory science methods that have been used to engage communities in MPAs. The review highlights that, while participatory science methods are not uncommon in MPAs, they seldom challenge existing power dynamics. The results of this review show that power in MPA processes related to participatory science is generally retained by conventional researchers and MPA managers. Based on these findings, the authors provide recommendations to marine resource management researchers and practitioners to help the ocean governance community support greater power sharing with local communities through equitable and locally appropriate participatory science methods.

Different roles of the Amazon-Orinoco barrier on the genetic structure of two sardine genera from the Western Atlantic Ocean

Three sardine species of Harengula and one of Opisthonema (Clupeiformes, Clupeidae) are known in the Western Atlantic, where the Amazon-Orinoco plume has been recognized as a major biogeographic barrier, albeit permeable to larger and generalist species. Here we used mitochondrial cox1 gene DNA sequences to check the lineage delimitation of both genera, testing the influence of the Amazon-Orinoco barrier (AOB) and marine provinces on their phylogeographic structure. Results indicate that the two genera are differently affected by the AOB, including cryptic speciation in Harengula and population structure in Opisthonema. Harengula show a broad distribution in the Brazilian Province (BRA) distinct from H. clupeola and H. jaguana from the Greater Caribbean Region (GCR). Divergence time between Harengula from the GCR vs. BRA was estimated as about 2.4 Mya, which coincides with the period of increasing sediment and freshwater discharge of the Amazon River in the Atlantic. Results also indicate the existence of a single species of Opisthonema, albeit with population structuring related to the marine provinces. Since species of both genera are relevant to artisanal fisheries and the maintenance of oceanic ecosystems, these results may help in fisheries management of these important marine resources.

Advancing Sustainable Marine Exploration: Highly Efficient Photonic Radar for Underwater Navigation Systems under the Impact of Different Salinity Levels

The exploration of underwater environments for applications like environmental monitoring, scientific research, and surveillance has propelled the significance of underwater wireless navigation. Light waves have emerged as a promising solution, offering the potential to achieve the required data rates and propagation speeds. However, underwater optical wireless navigation faces challenges, particularly limited range. This research investigates a novel FMCW (frequency-modulated continuous wave)-based photonic radar system’s efficacy in detecting underwater vehicles across diverse salinity levels and distances. Numerical simulation evaluations reveal distinct signal-to-noise ratios (SNR) and detected power peaks corresponding to varying salinity levels, demonstrating the system’s sensitivity. At 5 g/L salinity, the detected power peaked at −95 dBm, decreasing to −105 dBm at 15 g/L. SNR analysis indicates robust detection within a 4 m range, with challenges emerging at extended ranges and higher salinity. Despite these challenges, the system shows promise for near-range underwater navigation, contributing to sustainable marine exploration by enhancing the accuracy and efficiency of underwater monitoring systems. This advancement aligns with the goals of sustainable development by supporting the protection of marine ecosystems, promoting scientific understanding of underwater environments, and aiding in the sustainable management of marine resources.

Sequential Treatment Application Robot (STAR) for high-replication marine experimentation

Marine organisms are often subject to numerous anthropogenic stressors, resulting in widespread ecosystem degradation. Physiological responses to these stressors, however, are complicated by high biological variability, species-specific sensitivities, nonlinear relationships, and countless permutations of stressor combinations. Nevertheless, quantification of these relationships is paramount for parameterizing predictive tools and ultimately for effective management of marine resources. Multi-level, multi-stressor experimentation is therefore key, yet the high replication required has remained a logistical challenge and a financial barrier. To overcome these issues, we created an automated system for experimentation on marine organisms, the Sequential Treatment Application Robot (STAR). The system consists of a track-mounted robotic arm that sequentially applies precision treatments to independent aquaria via syringe and peristaltic pumps. The accuracy and precision were validated with dye and spectrophotometry, and stability was demonstrated by maintaining corals under treatment conditions for more than a month. The system is open source and scalable in that additional treatments and replicates may be added without incurring multiplicative costs. While STAR was designed for investigating the combined impacts of nutrients, warming, and disease on reef-building corals, it is highly customizable and may be used for experimentation involving a diverse array of treatments and species.

Analysis of Integrated Coastal Zone Management in Guatemala

Integrated coastal zones management is a process that seeks to improve the quality of life in coastal communities based on the use of natural resources while respecting ecosystems and biodiversity. This study takes the laws and regulations that were considered most important and the articles of each one that are considered most appropriate for coastal management, in accordance with the national legal and institutional framework applicable to the management and management of marine and coastal resources of Guatemala. . The role of the institutions that are essential for the iczm process is made known. Finally, training and information strategies and the importance of citizen participation are analyzed. Keywords: Integrated coastal management; Coastal zones; iczm Decalogue.

Fine‐scale diet data reveal spatial variation in predator–prey interactions in Norwegian fjords

Abstract Predator–prey interactions in time and space determine stock productivity, making them an important consideration when managing marine resources, rebuilding stocks or considering reopening a fishery. We analysed fine‐scale diet data from surveys conducted in 2009–2010 and 2018–2019 in three fjords in northern Norway with geostatistical models investigating how predation varied in space, time and between predator species. Our focus prey species was northern shrimp (Pandalus borealis), valuable both as a commercial resource and a major food source for other important species like Atlantic cod (Gadus morhua). Diet composition of fish predators differed clearly between fjords. While predator species and size were good predictors of shrimp predation, the relationships with bathymetry, prey density and geospatial variables were complex. Our study indicates that predation of forage species, such as shrimp, varies spatially in heterogenous fjord ecosystems. Shrimp consumption was not highest in the fjord with highest predator density, indicating a higher dependency of cod on shrimp in specific areas. Realized predation is a complex combination of predator and prey densities and predator ecology that differed in each of the three fjords. Synthesis and applications. Ignoring spatial variations in predator–prey interactions may lead to an inaccurate perception of stock productivity, suboptimal management and possibly unsustainable management targets. We recommend spatially explicit assessment and management for fish stocks where predator–prey interactions vary substantially in space, such as fjords and reefs.

Ocean governance in practice: A study of the application of marine science and technology research techniques to maritime law enforcement in Taiwan

The research looks into the relationship between technology, international law, and marine policy in Taiwan, specifically looking at how these three factors interact to influence the way the maritime environment is monitored, understood, and regulated. The research explores how cutting-edge innovation has improved sustainable marine resource management by reshaping data collecting, analysis, and decision-making via a comprehensive literature review and case studies focused on Taiwan. The impact of international law, and UNCLOS in particular, on the standards and technologies used in marine resource management is a significant topic covered in the paper. Q&A sessions with experts in maritime policy, technology, and international law provide a qualitative analysis of the current state of marine affairs in Taiwan. The research shows that technology has revolutionized the way Taiwan oversees and monitors its marine environment. More effective and cooperative ocean governance has resulted from the rise of evidence-based decision-making made possible by technological advancements. An example of the regulatory impact of international law is UNCLOS, which sets standards for the sustainable management of marine resources and directs the use of technology. In spite of geopolitical obstacles, Taiwan is well-positioned for successful marine conservation and sustainable resource use thanks to its all-encompassing approach, which is based on continuing conversations and partnerships and is in line with worldwide technological advances and changing regulatory frameworks. This study highlights the interconnected nature of technology, international law, and marine policy, and how these factors influence Taiwan's strategy for preserving marine resources for the future.

EKONOMI, KEAMANAN DAN DAMPAK LINGKUNGAN DARI PENURUNAN KEJAYAAN MARITIM

Maritime collapse is a complex phenomenon that affects countries around the world. The economic, security and environmental impacts of maritime collapse have far-reaching implications. This research identifies key causal factors, such as exploitation of marine resources, maritime security instability, infrastructure inadequacy, corruption and climate change, and proposes solutions that include sustainable management of marine resources, enhanced maritime security, infrastructure investment, combating corruption and adapting to climate change. In conclusion, holistic efforts are needed to address the issue of Maritime Glory Collapse and ensure economic, national security and environmental sustainability in an increasingly important maritime era.

Analysis of Policy Strategy for Empowerment of Fisherman in Teluk Village, Labuan Sub-District, Pandeglang Regency

The community empowerment approach is sought to provide guidance for the sustainability of the livelihoods and lives of the fishing communities of Teluk Village, Labuan District, Pandeglang Regency, especially after being hit by the tsunami (22/12/2018) and the Covid-19 pandemic. Ecosystem preservation also requires commitment from stakeholders. The policy strategy is the government's task that needs to be analyzed, while the community has strong social capital, as a form of survival in facing opportunities, challenges and threats in the management of marine and fishery resources. This study aims to analyze the policy strategy for empowering fishermen in Teluk Village, Labuan District, Pandeglang Regency. The key theory used is the concept of strategy according to Hunger-Wheelen (2003: 9), through observing the external environment to describe opportunities and threats, then observing the internal environment of the organization to describe strengths and weaknesses known as Strengths, Weaknesses (weaknesses). Opportunities (opportunities), and Threats (threats). The approach used in this research is descriptive qualitative. Through this approach it is intended to be able to take a full picture of various phenomena that aim to describe, summarize various conditions, various situations or various social realities of empowering the fishing community in Teluk Village, Labuan District, Pandeglang Regency. The results of the study show that the policy strategy for empowering fishermen in Teluk Village refers to strengthening the internal and external sources of the Pandeglang Regency Maritime Service organization, including efforts in the field of empowering fishermen by carrying out various fisheries business development programs, carrying out fishermen technical guidance for business groups with fishermen. Furthermore, monitoring and evaluation, as well as carrying out reports. The suggestion that the researchers put forward is to increase various efforts to empower fishermen in the Bay Village by encouraging fishermen's involvement in accessing various institutional fishermen empowerment programs and revitalizing various facilities and infrastructure that require development and repair due to the tsunami disaster.

Mitochondrial genome structure and composition in 70 fishes: a key resource for fisheries management in the South Atlantic

BackgroundPhylogenetic gaps of public databases of reference sequences are a major obstacle for comparative genomics and management of marine resources, particularly in the Global South, where economically important fisheries and conservation flagship species often lack closely-related references. We applied target-enrichment to obtain complete mitochondrial genomes of marine ichthyofauna from the Brazilian coast selected based on economic significance, conservation status and lack of phylogenetically-close references. These included sardines (Dorosomatidae, Alosidae), mackerels (Scombridae) croakers (Sciaenidae), groupers (Epinephelidae) and snappers (Lutjanidae).ResultsCustom baits were designed to enrich mitochondrial DNA across a broad phylogenetic range of fishes. Sequencing generated approximately 100k reads per sample, which were assembled in a total of 70 complete mitochondrial genomes and include fifty-two new additions to GenBank, including five species with no previous mitochondrial data. Departures from the typical gene content and order occurred in only three taxa and mostly involved tRNA gene duplications. Start-codons for all genes, except Cytochrome C Oxidase subunit I (COI), were consistently ATG, whilst a wide range of stop-codons deviated from the prevailing TAA. Phylogenetic analysis confirmed assembly accuracy and revealed signs of cryptic diversification within the Mullus genus. Lineage delimitation methods using Sardinella aurita and S. brasiliensis mitochondrial genomes support a single Operational Taxonomic Unit.ConclusionsTarget enrichment was highly efficient, providing complete novel mitochondrial genomes with little sequencing effort. These sequences are deposited in public databases to enable subsequent studies in population genetics and adaptation of Latin American fish species and serve as a vital resource for conservation and management programs that rely on molecular data for species and genus-level identification.

Dominant species of squid in the waters of Western Kalimantan and Northern Java identified by DNA barcoding method

Squid resources in Indonesia have high economic value, and their exploitation tended to increase due to declining fish resources in many waters. Previous research mentioned that 21 squid species were identified in Indonesian waters. However, many researchers argued that the identification of cephalopod morphology, especially squids, was challenging, and that is why supporting methods were needed, one of which was DNA analysis. The study aimed to determine the type and distribution of squid in the western waters of Kalimantan and northern Java using the DNA barcoding method on the COI gene. Squid samples were collected from six locations, consisting of Tanjung Pinang, Bangka Belitung (Babel), Kalimantan Barat (Kalbar), Muara Angke, Pekalongan, and Lamongan. The analysis results showed that Uroteuthis chinensis was present in all sampling locations except Tanjung Pinang, where Uroteuthis edulis and U. sibogae were found. The results of this study are very important in the management of squid resources because they can contribute to the sustainable management of marine resources and the maintenance of the sustainability of marine ecosystems.

Presence of microplastic in target species of small scale fisheries and possible social implications on the local communities

Microplastic ingestion by marine fishes has been of particular interest, as many species are the target of commercial fisheries and, thus, have a strong connection with human health. Consumption of microplastic thru seafood is likely to have harmful effects on people globally but mainly on social groups that highly depend on fisheries for self-consumption. Here, we first aim to characterize the presence of microplastics in species targeted by small-scale fishers; and explore if the fish consumption of microplastic particles is associated with biological factors. Second, we applied semi-structured interviews to small-scale fishers to investigate, from a socio-environmental perspective, the potential social and environmental impacts of contamination by microplastics on the local communities. We found that commercially important fish families regularly contained microplastics in their tissues, and the consumption of microplastics by fish caught through traditional fishing gear depends on traits such as species mobility but the microplastic load also depended on the type of fishing gear used. Species with a wide home range had a higher load of microplastics than fish with a small home range but also seemed to be related to the fishing method. The observed differences in microplastic content on target species are likely to be transferred to humans in a non-random fashion. This work implies that microplastic pollution in commercial fish might represent an environmental and social issue that is not well understood by the fishing community in the Mexican Caribbean, with potential ramifications for marine resource management.

Marine Object Detection using YOLOv4 Adapted Convolutional Neural Network

This research presents an innovative application of the YOLOv4 object detection model for the identification and classification of marine objects within a dataset encompassing seven distinct classes. The study focuses on enhancing the robustness and accuracy of object detection in challenging marine environments, leveraging the unique capabilities of YOLOv4. Pre-processing steps involve resizing raw images, applying data augmentations, and normalizing pixel values to ensure optimal model training. Specifically tailored for underwater scenarios, additional color space transformations address variations in lighting conditions. The model is trained to detect marine objects such as fish, corals, and underwater structures, contributing to advancements in underwater exploration, environmental monitoring, and marine resource management. Experimental results demonstrate the effectiveness of the proposed approach, showcasing YOLOv4's ability to accurately identify and classify marine objects across the specified seven classes. This research not only expands the applicability of YOLOv4 in the marine domain but also provides valuable insights for the development of intelligent systems for underwater object detection.

Harnessing economic tools for Indigenous climate resilience: Insights from Arctic marine resources

Economic tools remain under-used in addressing multiple challenges faced by indigenous communities in the rapidly changing Arctic. While there are multiple explanations for this under-use, perceptions that economic principles diverge from indigenous value systems and are rooted in Western paradigms limit the uptake of these tools to bolster resilience in the face of climate change. Nevertheless, Indigenous communities are expected to integrate their traditional systems with the historically imposed colonial systems of resource extraction to sustain their economies and community wellbeing that are challenged by environmental shifts and socioecological transitions. These changes manifest in resource use, availability and management and affect the ways Indigenous knowledge has traditionally guided resource exploitation decisions and practices. Using select examples, this paper argues that economic approaches to the management of marine resources have the potential to improve the well-being and resilience of indigenous Arctic communities. While more work is needed to tailor economic tools to the specific needs of indigenous people, the integration of resource economics and traditional approaches to resource management holds promise for strengthening Indigenous resilience in the face of the profound challenges posed by climate change.

Efficient 3D real-time adaptive AUV sampling of a river plume front

The coastal environment faces multiple challenges due to climate change and human activities. Sustainable marine resource management necessitates knowledge, and development of efficient ocean sampling approaches is increasingly important for understanding the ocean processes. Currents, winds, and freshwater runoff make ocean variables such as salinity very heterogeneous, and standard statistical models can be unreasonable for describing such complex environments. We employ a class of Gaussian Markov random fields that learns complex spatial dependencies and variability from numerical ocean model data. The suggested model further benefits from fast computations using sparse matrices, and this facilitates real-time model updating and adaptive sampling routines on an autonomous underwater vehicle. To justify our approach, we compare its performance in a simulation experiment with a similar approach using a more standard statistical model. We show that our suggested modeling framework outperforms the current state of the art for modeling such spatial fields. Then, the approach is tested in a field experiment using two autonomous underwater vehicles for characterizing the three-dimensional fresh-/saltwater front in the sea outside Trondheim, Norway. One vehicle is running an adaptive path planning algorithm while the other runs a preprogrammed path. The objective of adaptive sampling is to reduce the variance of the excursion set to classify freshwater and more saline fjord water masses. Results show that the adaptive strategy conducts effective sampling of the frontal region of the river plume.