Search Results (19)

Coral reefs provide environmental goods and services that support biodiversity and people but face diverse threats. To assess the human factors that might be influencing the status of Cuban coral reefs, we collected and analyzed data from three sources: observations made on a research cruise that circumnavigated Cuba’s waters, expert knowledge, and updated published information. Our results show that small-scale fisheries are predominant among human factors influencing Cuban coral reefs, with more than 97% of the fishing incidents detected in situ during the expedition. Many Cuban reefs are heavily fished, have low levels of contamination, and enjoy high legal protection but experience inadequate enforcement. Tourism occurs on many reefs but could be sustainably increased based on its role in supporting enforcement and compliance and reducing fishing pressure. Densities of marine debris were generally lower in Cuban waters than other Caribbean locations and even lower within protected areas. Many human factors are likely acting synergistically, making management a challenge. This is the first at-sea comprehensive visual survey of human factors in Cuban waters and evaluation of marine debris on Cuba’s reefs, establishing a baseline for future assessments. These findings highlight potential human impacts that must be addressed to safeguard the health of Cuba’s marine ecosystem. Full article

Summer processes in sea ice and their influence on the ridge action of structures in industrial areas are still rarely studied but of high interest. This article analyses data from two expeditions, the multidisciplinary GoNorth 2023 in the Arctic and the NPI Fram Strait 2024 cruise, combined with detailed analysis along the ridge keel and calculation of limit stress on vertical structures. The ice ridges were investigated by drilling cross-sections and sampling cores for temperature, salinity and density measurements. The keel depth ranged from 3.0 m to 4.8 m and the sail height ranged from 0.3 m to 0.9 m. The mean density and salinity of the ridge samples in 2023 were 899 kg/m³ and 2.2 ppt, respectively, and the mean salinity in 2024 was 2.0 ppt. The average constant temperature in the keel was −1.7 °C in 2023 and −1.6 °C in 2024. The upper limit of the strength of ridged ice on a vertical structure of 7.2 m in width ranged from 3.1 to 4.1 MPa. These results contribute to the knowledge of summer consolidation processes and are useful for statistical analysis of ice ridge loads exerted on offshore structures by drifting ice ridges. Full article

We show that analyzing archived and future multibeam backscatter and bathymetry data, in tandem with regional environmental parameters, can help to identify polymetallic nodule fields in the world’s oceans. Extensive archived multibeam transit data through remote areas of the world’s oceans are available for data mining. New multibeam data will be made available through the Seabed 2030 Project. Uniformity of along- and across-track backscatter, backscatter intensity, angular response, water depth, nearby ground-truth data, local slope, sedimentation rate, and seafloor age provide thresholds for discriminating areas that are permissive to nodule presence. A case study of this methodology is presented, using archived multibeam data from a remote section of the South Pacific along the Foundation Seamounts between the Selkirk paleomicroplate and East Pacific Rise, that were collected during the 1997 Foundation–Hotline expedition on R/V Atalante. The 12 kHz Simrad EM12D multibeam data and the other forementioned data strongly suggest that a previously unknown nodule occurrence exists along the expedition transit. We also compare the utility of three different backscatter products to demonstrate that scans of printed backscatter maps can be a useful substitute for digital backscatter mosaics calculated using primary multibeam data files. We show that this expeditious analysis of legacy multibeam data could characterize benthic habitat types efficiently in remote deep-ocean areas, prior to more time-consuming and expensive video and sample acquisition surveys. Additionally, utilizing software other than specialty sonar processing programs during this research allows an exploration of how multibeam data products could be interrogated by a broader range of scientists and data users. Future mapping, video, and sampling cruises in this area would test our prediction and investigate how far it might extend to the north and south. Full article

The Cosmonaut Sea is one of the least accessed regions in the Southern Ocean, and our knowledge about the fish biodiversity in the region is sparse. In this study, we provided a description of demersal fish diversity in the Cosmonaut Sea by analysing cytochrome oxidase I (COI) barcodes of 98 fish samples that were hauled by trawling during the 37th and 38th Chinese National Antarctic Research Expedition (CHINARE) cruises. Twenty-four species representing 19 genera and 11 families, namely, Artedidraconidae, Bathydraconidae, Bathylagidae, Channichthyidae, Liparidae, Macrouridae, Muraenolepididae, Myctophidae, Nototheniidae, Paralepididae and Zoarcidae, were discriminated and identified, which were largely identical to local fish occurrence records and the general pattern of demersal fish communities at high Antarctic shelf areas. The validity of a barcoding gap failed to be detected and confirmed across all species due to the indicative signals of two potential cryptic species. Nevertheless, DNA barcoding still demonstrated to be a very efficient and sound method for the discrimination and classification of Antarctic fishes. In the future, various sampling strategies that cover all geographic sections and depth strata of the Cosmonaut Sea are encouraged to enhance our understanding of local fish communities, within which DNA barcoding can play an important role in either molecular taxonomy or the establishment of a dedicated local reference database for eDNA metabarcoding analyses. Full article

Luxury cruise ships are high-end passenger ships with facilities on board for the leisure and entertainment of passengers, so the comfort of luxury cruise ships is a matter of great concern. In this paper, a finite element model of a new polar exploration cruise ship is established, and the wet modes of the whole ship are calculated using the virtual mass method and compared with the principal frequencies of the excitation forces to initially verify the rationality of the design of the structural vibration characteristics of the whole ship. The admittance matrix of the vibration velocity to excitation force was calculated by a frequency response analysis, and the vibration velocities at the stern plate and main engine foundations were tested during sailing. Then, the obtained propeller and main engine excitation forces were loaded into the finite element model; the vibration velocities of each compartment were calculated and compared with the compartment vibration velocity test values. The errors were within the engineering allowable range, verifying the accuracy of the excitation forces. The propeller and main engine excitation forces were loaded separately on the finite element model to calculate the vibration velocity of each cabin, and the contribution of the two excitation sources to the vibration velocity of each cabin was analyzed. It was found that the contribution of the excitation source to the cabin response was related to the relative position between the cabin and the excitation source. When the cabin was located in the cabin adjacent to or directly above a certain excitation source, the contribution of the excitation source to the cabin response was greater. When the cabin was farther away from both excitation sources, the contribution of the propeller excitation was greater. This provides a targeted reference for the preliminary vibration assessment and later vibration control of the new polar expedition cruise ship. Full article

Three deep-sea tardigrade species were identified from the sediment samples collected during the four German–Russian joint deep-sea cruises that were conducted in the North-Western Pacific: Coronarctus sonne sp. nov., Moebjergarctus okhotensis sp. nov., and Angursa cf. bicuspis. Specimens of those species were collected at depths between 1700 and 5410 m. The new species Coronarctus sonne sp. nov. belongs to the Cor. tenellus group of species on the basis of morphological traits such as the short cephalic appendages and heteromorphic claws. The structure of the secondary clavae and two points, with an accessory point and a primary point simultaneously on the internal and external claws on legs IV, are significant characteristics distinguishing Coronarctus sonne sp. nov. from other described species. Moebjergarctus okhotensis sp. nov. is characterized by having cephalic cirri with the long smooth portion of the scapus and annulated scapus only in the basal portion, the structure of the male and female reproductive system, and differences in the sizes of some structures compared to the other described species. An analysis of the results of four deep-sea expeditions indicates a patchy distribution of tardigrades in the North-Western Pacific. Full article

Based on multibeam bathymetric data and high-resolution shallow sub-bottom profiles acquired during China’s 10th Arctic Scientific Expedition Cruise in 2019, a sediment wave field was found on the western slope of the Chukchi Rise, in the Arctic Ocean. This sediment wave field developed on the lower slope with water depths of between 1200 m and 1800 m and stretched 15 km in the downslope direction. It comprised several parallel sediment waves, with wavelengths ranging from 700 m to 3400 m and wave heights from 12 m to 70 m. In the vertical direction, well-stratified deposits, tens of meters thick, were affected by sediment waves, which exhibit asymmetric waveforms and upslope migration trends. The morphological and seismostratigraphic characteristics of the sediment waves suggested their genesis as a result of the interaction between the bottom current and seafloor morphology, which was also supported by hydrographical data adjacent to the sediment wave field. It was infered that this bottom current was related to the Arctic Circumpolar Boundary Current, which many researchers suggest flows through the study area. Full article

Within the framework of the expedition research “Complex studies of the Antarctic marine ecosystem in the areas of the transport and interaction of water masses in the Atlantic sector of Antarctica, the Scotia Sea and the Drake Strait” (cruise 87 of the R/V “Academik Mstislav Keldysh”, 7 December 2021–5 April 2022), the distribution of gas-geochemical fields of methane in the Bransfield Strait was studied in detail for the first time. The connection of the methane distribution in water with the complex hydrological regime of the strait has been revealed. Elevated values of methane concentrations brought to the Bransfield Strait in the warm current flow from the Bellingshausen Sea have been established. Low concentrations of methane also mark the cold waters of the Weddell Sea, which carry out the transit of water masses into the Atlantic Ocean. The research was carried out within the framework of the theme FWMM-2022-033 “Integrated environmental studies of the Southern Ocean” AAAA17-117030110035-4 and international obligations of the Russian Federation as a party to the Antarctic Treaty and the Convention on the Conservation of Antarctic Marine Living Resources. Full article

Arctic sea ice concentration (SIC) has been studied extensively using passive microwave (PM) remote sensing. This technology could be used to improve navigation along vessel cruise paths; however, investigations on this topic have been limited. In this study, shipborne photographic observation (P-OBS) of sea ice was conducted using oblique-oriented cameras during the Chinese National Arctic Research Expedition in the summer of 2016. SIC and the areal fractions of open water, melt ponds, and sea ice (A_w, A_p, and A_i, respectively) were determined along the cruise path. The distribution of SIC along the cruise path was U-shaped, and open water accounted for a large proportion of the path. The SIC derived from the commonly used PM algorithms was compared with the moving average (MA) P-OBS SIC, including Bootstrap and NASA Team (NT) algorithms based on Special Sensor Microwave Imager/Sounder (SSMIS) data; and ARTIST sea ice, Bootstrap, Sea Ice Climate Change Initiative, and NASA Team 2 (NT2) algorithms based on Advanced Microwave Scanning Radiometer 2 (AMSR2) data. P-OBS performed better than PM remote sensing at detecting low SIC (< 10%). Our results indicate that PM SIC overestimates MA P-OBS SIC at low SIC, but underestimates it when SIC exceeds a turnover point (TP). The presence of melt ponds affected the accuracy of the PM SIC; the PM SIC shifted from an overestimate to an underestimate with increasing A_p, compared with MA P-OBS SIC below the TP, while the underestimation increased above the TP. The PM algorithms were then ranked; SSMIS-NT and AMSR2-NT2 are the best and worst choices for Arctic navigation, respectively. Full article

Variations in grain size, clay mineral composition, and stable isotopes (δ¹³C and δ¹⁵N) are closely linked to the sedimentary facies that reflect mineralogical and geochemical modification during the retreat and advance of the Larsen ice shelf. A whole round core of marine sediment (EAP13-GC17, 236 cm below the sea floor) was collected on the northwestern Larsen B embayment of the Antarctic Peninsula during a marine geological expedition (the ARA13 Cruise Expedition by the Korea Polar Research Institute, 2013). Four sedimentary facies (U1–U4) were clearly distinguishable: bioturbated sandy mud (open marine, U1), laminated sandy mud (sub–floating ice shelf, U2), sandy clay aggregates (deglacial, U3), and muddy diamictons (sub-glacial, U4), as well as interbedded silty. Clay minerals, including smectite, chlorite, illite, and kaolinite, were detected throughout the core. An increase in the clay mineral ratio of smectite/(illite + chlorite) was clearly observed in the open marine condition, which was strongly indicated by both a heavier isotopic composition of δ¹³C and δ¹⁵N (−24.4‰ and 4.3‰, respectively), and an abrupt increase in ¹⁰Be concentration (~30 times). An increase in the average values of the crystal packet thickness of illite (~1.5 times) in U1 also indicated sediments transported in open marine conditions. Based on the clay mineral composition in U1, the sediments are likely to have been transported from the Weddell Sea. The clay mineralogical assessments conducted in this region have significant implications for our understanding of paleodepositional environments. Full article

During the summers of 2011 and 2012, two scientific cruises were carried out over the Arctic Ocean aiming at the determination of the aerosol chemical composition in this pristine environment. First, mass spectrometry was applied to study the concentration and gas/particle partitioning of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes. Experimental and modelled data of phase partitioning were compared: results demonstrated an equilibrium between gas and particle phase for PAHs, while n-alkanes showed a particle-oriented partitioning, due to the local marine origin of them, confirmed by the extremely low value of their carbon preference index. Moreover, the inorganic and organic ions (carboxylic acids and amines) concentrations, together with those of elemental carbon (EC) and organic matter (OM), were analyzed: 63% of aerosol was composed of ionic compounds (>90% from sea-salt) and the OM content was very high (30.5%; close to 29.0% of Cl⁻) in agreement with n-alkanes’ marine signature. Furthermore, the amines’ (dimethylamine, trimethylamine, diethylamine) concentrations were 3.98 ± 1.21, 1.70 ± 0.82, and 1.06 ± 0.56 p.p.t.v., respectively, fully in keeping with concentration values used in the CLOUD (Cosmics Leaving OUtdoor Droplet)-chamber experiments to simulate the ambient nucleation rate in a H₂SO₄-DMA-H₂O system, showing the amines’ importance in polar regions to promote new particle formation. Finally, high resolution mass spectrometry was applied to determine trace elements, including Rare Earth Elements (REEs), highlighting the dominant natural versus anthropic inputs for trace metals (e.g., Fe, Mn, Ti vs. As, Cd, Ni) and possible signatures of such anthropic activity. Full article

Nitrous oxide is a trace gas with two global environmental effects: it depletes stratospheric ozone and contributes to the greenhouse effect. Oceans are one of the most significant nitrous oxide sources; however, there are ocean areas whose contributions to the nitrous oxide budget are not yet well studied. The Southern Ocean and the Arctic Ocean feature strong winds and portions that are covered by sea ice. These intense environmental conditions and the remoteness of these regions hamper fieldwork; hence, very limited data are available on the distributions and the source and sink characteristics of nitrous oxide. Using data from the 4th Chinese National Arctic Research Expedition and the 27th Chinese National Antarctic Research Expedition, the first global-scale investigation of the surface water N₂O distribution pattern, the factors influencing the N₂O distribution and the air-sea N₂O flux are discussed in this study. The results show that the tropical and subtropical regions (30° N–30° S) exhibit significant source characteristics, with a maximum air-sea flux of approximately 21.0 ± 3.9 μmol·m⁻²·d⁻¹. The high air-sea flux may result from the coastal influences and high wind speeds in certain areas. The distribution patterns of N₂O in the sub-polar regions (30° N–60° N, 30° S–60° S) transition from oversaturated to approximate equilibrium with the atmosphere, and the boundaries generally correspond with frontal structures. The distributions of N₂O in the high-latitude Southern Ocean and Arctic Ocean (>60° N and 60° S) exhibit contrasting patterns. With the exception of the continental shelf hotspot, the Arctic Ocean surface water is undersaturated with N₂O; in contrast, the high-latitude Southern Ocean along the cruise track is oversaturated with N₂O. The high-latitude Southern Ocean may act as a N₂O source, with a maximum air-sea N₂O flux of approximately 9.8 ± 0.5 μmol·m⁻²·d⁻¹ at approximately 60° S, whereas the air-sea N₂O flux of the Arctic Ocean is close to zero due to the low wind speed conditions at these latitudes. Full article

Situated to the south of New Zealand in the Southern Ocean are the New Zealand Subantarctic Islands, comprising the Auckland, Campbell, Antipodes, Snares and Bounty Islands. Sometimes referred to as the ‘Forgotten Islands’, these island groups are among the most remote and hostile within New Zealand waters. Yet, as they harbour some of the country’s most unique biodiversity and contain some of the world’s least modified landforms, they were recognized in 1998 with the designation of World Heritage Area status. It is not surprising therefore that the Islands have long appealed to visitors wishing to explore and understand the Islands’ rich natural and cultural environments. Typically, fare-paying tourists arrive by sea in small- to medium-sized expedition-style cruise vessels, although in recent years, the number of small vessels, such as yachts and sail boats, has increased. The most recent Conservation Management Strategy (2016) proposes developing and implementing a visitor monitoring programme to determine the effects of visitors on the natural and cultural environment, as well as on the visitor experience itself. However, there is only piecemeal data published on visitor numbers (especially since the mid-1990s) upon which to base visitor monitoring, and there is only limited evidence regarding the range of possible impacts visitors may have, including direct and indirect impact on wildlife, soils, and vegetation. In order to address this gap in knowledge, this case study draws on stakeholder interviews (n = 4), and a range of secondary sources (including visitor statistics from the Department of Conservation, tour operators and other published works) to provide an overview and update on visitation to the Islands, including site-specific data, an assessment of tourist impacts, and how impacts are currently monitored and managed. Full article

Sustainable management of nature-based tourism sites is a pertinent issue in vulnerable Arctic environments. Arctic tourism operators often act collectively to protect their common interests of ensuring the sustainability of tourism sites. Nowadays, information and communication technology (ICT) is increasingly used to support these collaborative efforts, but the remoteness and risks associated with Arctic tourism operations challenge the success of such collective action. This study explores the use of ICT as a management tool for Arctic tourism sites to ensure their sustained quality. Drawing on a case study of an expedition cruise operators’ network in Svalbard, we explore how the use of ICT affects collective action and sustainable management of tourism sites. Our findings show that, through increased noticeability, the creation of artificial proximity and the development of new management practices, ICT can help to overcome the challenges for collective action that are posed by the Arctic environment. The use of ICT results in changes in a network’s relational and normative structures, which can as much add to as detract from the success of collective action. Our study indicates that the successful application of ICT depends on a high level of social capital, in particular norms, to guide interactions between ICT and network actors. Full article

Cruising is a segment of tourism that is increasing at a faster rate than other kinds of leisure travel, especially in the Arctic region. Due to changing environmental conditions in recent years, cruise ships have been able to access more regions of the Arctic for a longer operating season. We investigated the cruiser motivations for polar expedition cruising and the educational dimensions of expedition cruising. Motivations of cruisers were identified using entrance surveys prior to embarking on four separate itineraries (n = 144). We conducted semi-structured interviews, n = 22), made participant observations while on board the vessel for one trip to support survey findings, and followed up with a post-trip survey to assess attitudinal changes (n = 92). We found that, unlike mainstream cruisers, expedition cruisers are motivated by opportunities for novel experience and for learning. Subsequently, the educational programming offered by expedition cruise companies is an important component of the cruise experience. We found that this programming has positively impacted cruiser attitudes, behaviours, and knowledge post-cruise. These findings will encourage cruise companies to improve their educational offerings (i.e., preparedness, program quality, level of engagement) to meet the expectations of their clientele, thereby transferring critical knowledge of environmental stewardship. Full article