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The rapid reduction of the Arctic Sea ice area in recent decades and the increase in the duration of ice-free navigation along the Northern Sea Route is one of the positive consequences of global warming for Russia. At the same time, further retreat of the sea ice may lead to a continuous seasonal open-water period outside the Russian exclusive economic zone (EEZ) with significant economic and geopolitical risks. This work provides estimates of possible changes of the sea ice concentration in the Arctic and the length of the open-water period, including outside the Russian EEZ in the 21st century, based on the CMIP6 climate model ensemble for moderate and aggressive scenarios of anthropogenic impact on the climate. In particular, it is shown that, as early as in the middle of the 21st century, the duration of ice-free navigation outside the Russian EEZ may exceed two and a half months.

Oil spillages on a sea’s or an ocean’s surface are a threat to marine and coastal ecosystems. They are mainly caused by ship accidents, illegal discharge of oil from ships during cleaning and oil seepage from natural reservoirs. Synthetic-Aperture Radar (SAR) has proved to be a useful tool for analyzing oil spills, because it operates in all-day, all-weather conditions. An oil spill can typically be seen as a dark stretch in SAR images and can often be detected through visual inspection. The major challenge is to differentiate oil spills from look-alikes, i.e., low-wind areas, algae blooms and grease ice, etc., that have a dark signature similar to that of an oil spill. It has been noted over time that oil spill events in Pakistan’s territorial waters often remain undetected until the oil reaches the coastal regions or it is located by concerned authorities during patrolling. A formal remote sensing-based operational framework for oil spills detection in Pakistan’s Exclusive Economic Zone (EEZ) in the Arabian Sea is urgently needed. In this paper, we report the use of an encoder–decoder-based convolutional neural network trained on an annotated dataset comprising selected oil spill events verified by the European Maritime Safety Agency (EMSA). The dataset encompasses multiple classes, viz., sea surface, oil spill, look-alikes, ships and land. We processed Sentinel-1 acquisitions over the EEZ from January 2017 to December 2023, and we thereby prepared a repository of SAR images for the aforementioned duration. This repository contained images that had been vetted by SAR experts, to trace and confirm oil spills. We tested the repository using the trained model, and, to our surprise, we detected 92 previously unreported oil spill events within those seven years. In 2020, our model detected 26 oil spills in the EEZ, which corresponds to the highest number of spills detected in a single year; whereas in 2023, our model detected 10 oil spill events. In terms of the total surface area covered by the spills, the worst year was 2021, with a cumulative 395 sq. km covered in oil or an oil-like substance. On the whole, these are alarming figures.

The creation of Exclusive Economic Zones (EEZs) in 1982 gave coastal countries sovereignty over their local tuna resources, whereas the migratory nature of tuna calls for regional management. However, as regional tuna management by Regional Fisheries Management Organisations (RFMOs) does not always facilitate optimal management of local resources by coastal countries, there is a need for an approach that ensures both the achievement of regional management objectives and optimisation of local benefits, i.e., “glocalised” management. To promote “glocal” management measures for the local populations of highly migratory species, (1) the spatio-temporal VAST model was used to estimate abundance indices for the adult regional Eastern Atlantic yellowfin tuna population and its local component in Ivorian waters using catch and effort data and (2) convergent cross mapping was used to examine the causal relationship between changes in abundance at these different spatial scales over time. Convergent cross-mapping detected a causal relationship between general stock dynamics and local dynamics, in the direction from global stock abundances to local resource abundances. This implies that the success of local fishing was closely linked to the general state of the stock. Conversely, we found no evidence of a causal relationship in the direction from local resources to the regional stock. This suggests that local adult dynamics had little or no influence on overall stock dynamics. Based on these results, we propose several criteria to ensure fairer distribution of tuna resources between coastal states and distant water fleets (DWFs).

Specht, C.; Specht, M.; Cywiński, P.; Skóra, M.; Marchel, Ł., and Szychowski, P., 2019. A new method for determining the territorial sea baseline using an unmanned, hydrographic surface vessel. Journal of Coastal Research, 35(4), 925–936. Coconut Creek (Florida), ISSN 0749-0208. This article discusses a method of determining a territorial sea baseline, which establishes the boundary of maritime zones (inland waters, territorial sea, contiguous zone, and exclusive economic zone) of a coastal state. So far, only approximately 200 of the 430 sea borders have been delimited, which is less than half of all boundaries. The reason behind that omission (apart from the legal, technical, and measurement-related aspects) is the issue of baseline measurement methodology. The aim of this study was to develop a method for determining a territorial sea baseline using an unmanned hydrographic vessel in a 400-m-long water body with a sandy bottom. The measurements were performed with a small, unmanned surface vessel with a global navigation satellite system (GNSS) receiver (Trimble R10) installed with a miniature singlebeam echo sounder (SonarMite BTX). These devices enabled measurements by the hydrographic method in the coastal zone at a depth below 1 m. The measurements involved determining the internal border of the territorial sea and creating a bathymetric chart with isobaths using geodetic software. To verify the results of tests conducted with an unmanned vessel, an additional (reference) measurement was taken in the same water body by the geodetic method with a GNSS receiver and a position accuracy of 2–3 cm (p=0.95), which involved developing a digital terrain model by the “stop and go” method. The geodetic measurements were conducted on the same sounding lines as those of an unmanned hydrographic vessel—by the direct measurements performed with a geodesist in water at a depth of 0 to 1 m.

Lagrangian dispersal models are valuable tools for understanding the transport mechanisms and distribution of larvae in space and time. These models primarily use high-quality physical oceanographic data from hydrodynamic ocean models to simulate the advection and connecting pathways of larvae. The paper seeks to achieve the following objectives 1) to establish the dispersal patterns of larval anchovies and sardines spawned in South Africa’s coastal marine protected areas (i.e., inshore of the 200 m isobath), and 2) to assess the impact of model resolution on the dispersal patterns by comparing outputs of a 3-km-grid coastal and regional ocean community model, and the 8-km-grid global ocean physics reanalysis product. We demonstrate that the model yields more structured patterns than sporadic patterns obtained from the global reanalysis. The model shows relatively shorter residence times (i.e., < 5 days) and transport confined to the inshore area of the Agulhas Current. The high variability of dispersals observed off the west coast is attributable to the significant differences in mean kinetic energy between the model and global reanalysis. This finding directly impacts transport and potential connectivity along coastlines: global reanalysis data overestimated local retention and subsequent recruitment variability. Our findings indicate that a model grid size of 3 km or smaller may be more appropriate for studying the dispersal patterns of anchovies and sardines in the South African coastal zone. These findings add to the growing knowledge of the importance of including sub-mesoscale processes in Lagrangian analysis for dispersal studies of coastal species.

The Burdwood Bank (BB) is a subantarctic area, where two of the three Marine Protected Areas (MPA) of the Argentinean Exclusive Economic Zone are located: Namuncurá I, and Namuncurá II. The area is characterized by a high biodiversity of benthic invertebrates and teleost fishes; however, the available information on oviparous chondrichthyans is scarce. The aim of this study is to explore the potential reproductive use that oviparous chondrichthyans could make of the area based on the presence of egg-laying grounds. Additionally, we aim to provide an updated checklist of the species that inhabit the BB. Samples of specimens and egg capsules collected in four research cruises carried out between 2016 and 2018 were analyzed. Six skate species were found in both MPAs: Amblyraja doellojuradoi, Bathyraja albomaculata, B. brachyurops, B. macloviana,B. scaphiops, and Psammobatis rudis; whereas B. cousseauae, and B. magellanica were found exclusively in Namuncurá I, and B. multispinis in Namuncurá II. Here we report, for the first time, the presence of egg-laying grounds for five chondrichthyan species in the BB area: A. doellojuradoi, B. brachyurops, B. macloviana, B. scaphiops, and P. rudis. The results obtained highlighted the importance of the region for the conservation of oviparous chondrichthyans found in the southern Patagonian shelf.

The most used temperature and salinity climatology for the world ocean, including the Indian Ocean, is the World Ocean Atlas (WOA) (Antonov et al 2006, 2010; Locarnini et al 2006, 2010) because of the vast amount of data used in its preparation. The WOA climatology does not, however, include all the available hydrographic data from the Indian Exclusive Economic Zone (EEZ), leading to the potential for improvement if the data from this region are included to prepare a new climatology. We use all the data that went into the preparation of the WOA ( Antonov et al 2010; Locarnini et al 2010), but add considerable data from Indian sources, to prepare new annual, seasonal, and monthly climatologies of temperature and salinity for the Indian Ocean. The addition of data improves the climatology considerably in the Indian EEZ, the differences between the new North Indian Ocean Atlas (NIOA) and WOA being most significant in the Bay of Bengal, where the patchiness seen in WOA, an artifact of the sparsity of data, was eliminated in NIOA. The significance of the new climatology is that it presents a more stable climatological value for the temperature and salinity fields in the Indian EEZ.

As tensions continue to grow across the Taiwan Strait, China is using domestic maritime law to justify an expansion of police power in the international waters of the Taiwan Strait in violation of international law. This Comment will argue that the People's Republic of China has violated the UN Convention on the Law of the Sea (\"UNCLOS\") by implementing non-resource-related police power in waters meant only for resource exploration and management. In comparing the language of China's domestic maritime law with that of UNCLOS, this Comment will show that the People's Republic of China has used domestic law to reinterpret and obfuscate its obligations under UNCLOS. As a result, the freedom of navigation granted by UNCLOS to all States has been restricted by China's policing. To prevent China from using its domestic law to assert increasing control over the Strait, the Tribunal of the Law of the Sea should issue an advisory opinion clarifying the purpose of Exclusive Economic Zones and denouncing China's noncompliance with UNCLOS. Additionally, foreign States should continue to exercise freedom of navigation through the Taiwan Strait and push China to limit its police activity of the Strait.

Over the last few centuries, mapping the ocean seabed has been a major challenge for marine geoscientists. Knowledge of seabed bathymetry and morphology has significantly impacted our understanding of our planet dynamics. The history and scientific trends of seabed mapping can be assessed by data mining prior studies. Here, we have mined the scientific literature using the keyword “seabed mapping” to investigate and provide the evolution of mapping methods and emphasize the main trends and challenges over the last 90 years. An increase in related scientific production was observed in the beginning of the 1970s, together with an increased interest in new mapping technologies. The last two decades have revealed major shift in ocean mapping. Besides the range of applications for seabed mapping, terms like habitat mapping and concepts of seabed classification and backscatter began to appear. This follows the trend of investments in research, science, and technology but is mainly related to national and international demands regarding defining that country’s exclusive economic zone, the interest in marine mineral and renewable energy resources, the need for spatial planning, and the scientific challenge of understanding climate variability. The future of seabed mapping brings high expectations, considering that this is one of the main research and development themes for the United Nations Decade of the Oceans. We may expect a new higher resolution ocean seafloor map that might be as influential as The Floor of the Oceans map.

Biological parameters are critical for the sustainable management of fisheries globally, providing critical insights into population dynamics, ecological interactions, and fish stock resilience. In the Senegalese Exclusive Economic Zone (SEEZ), valuable biological information required for Atlantic bonito stock assessment and implementing effective management measures is either limited or nonexistent. This study aims to address this gap by examining some important biological parameters of Atlantic bonito, one of the most targeted species of small tuna by small‐scale fisheries in the Senegal fishing area. The results reveal important biological aspects, such as the length–weight relationship coefficient (a) of 0.0062 and the rate of weight change with length (b) of 3.2346, which is significantly greater than 3.0. These findings suggest that most fish species exhibit moderately positive allometric growth and an increase in relative body size or weight. The Fulton's condition factor (K) of the combined data ranged 1.18–1.48 (1.34 ± 0.14), suggesting that the fish are well‐nourished in relation to their size. Furthermore, the age of Atlantic bonito in Senegalese waters is approximately 4.6–5 years. The final main growth parameters obtained were Linf = 73.01 cm fork length, with estimated sizes at first maturity (Lm50) for males and females being 42.09 and 38.56 cm, respectively, and 40.75 cm for combined sexes. The results provide important biological aspects for assessing the Atlantic bonito stock, establishing robust harvest control rules (HCRs) for fisheries management, and supporting sustainable fishing for this small tuna for the benefit of coastal communities in the Northeastern Atlantic Ocean. This study provides the Atlantic bonito biological parameters from small‐scale fisheries operating within the SEEZ. This study provides valuable information to support stock assessment studies of Atlantic bonito in SEEZ. By enhancing our understanding of Atlantic bonito biology and ecology in the SEEZ, this work will support broader conservation efforts aimed at protecting marine biodiversity and promoting ecosystem resilience.