Commercial Vessels Research Articles

Meta-learning for vessel time series data imputation method recommendation

A missing data problem is inevitable when collecting time series datasets from marine sensors. Due to this, sensor data is not reliable enough to assist decision-making. To impute missing values, a number of methods are available. Choosing the best imputation method, however, is not a trivial task, as it usually involves domain expertise and trial-and-error iterations. Additionally, if imputations are done carelessly, they produce a high error, resulting in incorrect assumptions by stakeholders. In this paper, a meta-learning approach is presented that can be used to extract characteristics of the underlying data, and based on that, a less error-prone imputation method is recommended. Ten commercial ocean-going vessel datasets are used to evaluate our proposed method. A total of 29,527 data samples were generated, comprising 22 inputs and 1 target. The proposed method achieves a weighted F1-Score of 87.5% when utilizing stratified 10-fold cross-validation. Our approach can improve the average imputation score up to 86%, with the worst-case improvement being 5%. This demonstrates that our proposed approach is efficient and effective in recommending the best imputation methods.

Estimates of Western Atlantic Goliath Grouper (Epinephelus Itajara) Bycatch Mortality in Commercial Fisheries of the Southeastern United States From 2002 to 2022

The Atlantic Goliath Grouper (_Epinephelus itajara_) in the southeastern United States is in decline due to increasingly large and persistent red tides, loss of juvenile habitat, and severe cold-weather events. In this paper, we address another source of mortality -- bycatch, focusing on data from NOAA Fisheries logbooks for commercial fisheries operating between 2002 to 2022. We calculate capture related mortality based on known patterns of depth-related barotrauma drawn from the literature and assume that all fish captured at depths greater than 30 m died if unvented prior to release. The overall result suggests that 75% (14,124 of 18,770) of Goliath Grouper captures died from barotrauma, as they either hemorrhaged or were unable to return to the bottom because of increased buoyancy due to expanded gas trapped in the swim bladder. While fishers currently use self-reporting to document these mortalities, this approach often results in biases toward lower capture and a higher survival rate. Thus, we strongly urge the Florida Fish and Wildlife Conservation Commission and the National Oceanic and Atmospheric Administration to quit using logbook data and instead require that fishers use paid observers and remote electronic monitoring on all commercial and charter vessels to ensure more effective, timely and reliable bycatch data for this and other protected species.

Reduction of large vessel traffic improves water quality and alters fish habitat-use throughout a large river

Rivers are increasingly used as superhighways for the continental-scale transportation of freight goods, but the ecological impact of large vessel traffic on river ecosystems is difficult to study. Recently, the temporary maintenance closure of lock and dam systems on the Illinois Waterway (USA) brought commercial vessel traffic to a halt along the river's length, offering a rare opportunity to study the response of the ecosystem before, during, and after an extended pause of this persistent anthropogenic disturbance. We observed improvements in main- and side-channel water quality and a redistribution of fish habitat-use during a months-long, near-complete reduction of large vessel traffic. Over 3600 water quality and 1300 fish community samples indicate that large vessel traffic reduction coincided with a 33 % reduction in turbidity as well as increased use of sampling strata near vessel navigation corridors by sound-sensitive and rheophilic fishes. Gizzard shad (Dorosoma cepedianum), the most abundant species in the system, also expanded their use of these ‘impact’ areas. Though inland waterway transport is an economically- and climate-friendly alternative to trucking and rail for the shipment of freight, our data suggest that intense vessel traffic may have profound physical and biological impacts across a large river. Monitoring and mitigation of ecological impacts of the ongoing expansion of inland waterway transport around the world will be critical to balancing large rivers as both useful navigation corridors and functional ecosystems.

Fishing Rights Procedure at the European Court of Human Rights: Spasov v Romania

In recent years, it has increasingly been recognized that work at sea often raises questions concerning the protection of human rights. This is also the case in the context of fishing. While human rights issues on commercial fishing vessels are gaining attention, fishing activities of individuals and small crews are also connected to human rights—for example, regarding the implementation of fisheries policies. In December 2022, the European Court of Human Rights (ECtHR) ruled in the case of a fisherman from Bulgaria who had worked in Romania’s Exclusive Economic Zone (EEZ) in the Black Sea. Bulgaria and Romania are both members of the European Union (EU), and the EU’s Common Fisheries Policy (CFP) applied to the applicant’s work. He alleged that Romania implemented the CFP incorrectly and, in doing so, violated his human rights. This article analyzes the case of Spasov v Romania, which, as of late 2023, is available on the ECtHR’s website in French. The core issues of the case are placed in the context of the CFP and the relationship between the EU and the ECHR. It will be shown that the ECHR remains a potent tool for the protection of human rights at sea as well, including in the EEZ, where the coastal State exercises jurisdiction within the meaning of Article 1 ECHR.

Exploring the Potential of Atlantic Mesopelagic Species Processed on Board Commercial Fishing Vessels as a Source of Dietary Lipids.

This study investigates the use of untapped mesopelagic species as a source of long-chain polyunsaturated omega-3 fatty acids (LC n-3 PUFAs) to meet the growing demand. The challenges faced by commercial fishing vessels, such as varying catch rates and species distribution affecting lipid levels, are addressed. Marine oils were produced post-catch using thermal separation and enzymatic hydrolysis during four commercial cruises, screening approximately 20,000 kg of mixed mesopelagic species. Maurolicus muelleri and Benthosema glaciale were the dominant species in the catch, while krill was the primary bycatch. The lipid composition varied, with B. glaciale having a higher prevalence of wax esters, while triacylglycerols and phospholipids were more predominant in the other species. LC n-3 PUFAs ranged from 19% to 44% of lipids, with an average EPA + DHA content of 202 mg/g of oil. Both processing methods achieved oil recoveries of over 90%. Estimates indicate that the mesopelagic biomass in the Northeast Atlantic could supply annual recommended levels of EPA + DHA to 1.5 million people, promoting healthy heart and brain functions. These findings offer valuable insights for considering mesopelagic species as a potential source of dietary marine lipids, laying the groundwork for further research and innovation in processing and obtaining valuable compounds from such species.

Sea turtle bycatch in Argentina: A qualitative assessment in commercial vessels

Abstract1. The Northern Argentine continental shelf is a sea turtle feeding ground that overlaps with important fisheries. Few studies assessed bycatch impact, especially on commercial vessels. 2. This work documents sea turtles' bycatch, fishery involved, species captured and crew actions. 3. Bycatch in four fisheries were registered at the 107 interviews to fishers conducted between 2021 and 2023, showing the urgency to research bottom trawling for demersal multi‐species. Fishers frequently recognize Caretta caretta, and positive and negative practices towards animals have been documented on‐board. 4. These results will help focus researches on fisheries with the greatest impact on sea turtles in the region. They also underscore the necessity for implementing commercial vessel monitoring programmes and improving on‐board handling practices.

Characterizing Overwater High Ozone Events in the Houston–Galveston–Brazoria Region during the 2021 GO3 and TRACER-AQ Campaigns

Abstract Photochemical modeling outputs showing high ozone concentrations over the Gulf of Mexico and Galveston Bay during ozone episodes in the Houston–Galveston–Brazoria (HGB) region have not been previously verified using in situ observations. Such data were collected systematically, for the first time, from July to October 2021 from three boats deployed for the Galveston Offshore Ozone Observations (GO3) and Tracking Aerosol Convection Interactions Experiment—Air Quality (TRACER-AQ) field campaigns. A pontoon boat and a commercial vessel operated in Galveston Bay, while another commercial vessel operated in the Gulf of Mexico offshore of Galveston. All three boats had continuously operating sampling systems that included ozone analyzers and weather stations, and the two boats operating in Galveston Bay had a ceilometer. The sampling systems operated autonomously on the two commercial boats as they traveled their daily routes. Thirty-seven ozonesondes were launched over water on forecast high ozone days in Galveston Bay and the Gulf of Mexico. During the campaigns, multiple periods of ozone exceeding 100 ppbv were observed over water in Galveston Bay and the Gulf of Mexico. These events included previously identified conditions for high ozone events in the HGB region, such as the bay/sea-breeze recirculation and postfrontal environments, as well as a localized coastal high ozone event after the passing of a tropical system (Hurricane Nicholas) that was not well forecast.

Method for Identification of Aberrations in Operational Data of Maritime Vessels and Sources Investigation.

Sensing data from vessel operations are of great importance in reflecting operational performance and facilitating proper decision-making. In this paper, statistical analyses of vessel operational data are first conducted to compare manual noon reports and autolog data from sensors. Then, new indicators to identify data aberrations are proposed, which are the errors between the reported values from operational data and the expected values of different parameters based on baseline models and relevant sailing conditions. A method to detect aberrations based on the new indicators in terms of the reported power is then investigated, as there are two independent measured power values. In this method, a sliding window that moves forward along time is implemented, and the coefficient of variation (CV) is calculated for comparison. Case studies are carried out to detect aberrations in autolog and noon data from a commercial vessel using the new indicator. An analysis to explore the source of the deviation is also conducted, aiming to find the most reliable value in operations. The method is shown to be effective for practical use in detecting aberrations, having been initially tested on both autolog and noon report from four different commercial vessels in 14 vessel years. Approximately one triggered period per vessel per year with a conclusive deviation source is diagnosed by the proposed method. The investigation of this research will facilitate a better evaluation of operational performance, which is beneficial to both the vessel operators and crew.

Life-history traits of an exploited skate: The short-tail yellownose skate Zearaja brevicaudata (Chondrichthyes: Rajiformes).

The short-tail yellownose skate, Zearaja brevicaudata, occurs off southern Brazil and along the Argentine continental shelf, including waters surrounding the Islas Malvinas and the upper slope, and is very frequently caught by trawl fisheries throughout its range. The age, growth, and maturity of Z. brevicaudata were investigated using 204 individuals collected by commercial fishing vessels from northern Argentina, between March 2016 and September 2019. Age was determined on a sample comprising vertebrae from 151 individuals, 60 males, ranging in size from 391 to 956 mm total length (TL), and 91 females, ranging in size from 324 to 1060 mm TL. Maximum ages determined for males and females were 22 and 29 years, respectively. A Bayesian framework was employed with a set of three candidate models to estimate growth parameters (von Bertalanffy, Gompertz, and Logistic). The von Bertalanffy model had the best fit, and the sexes showed undistinguishable growth parameters. For sexes combined, derived growth mean parameters (± S.D.) were L∞ = 1081 mm ± 64.34 mm, k = 0.09 ± 0.01 years-1, and L0 = 248 mm ± 23.52 mm. The age at maturity was estimated at 13.15 and 14.66 years for males and females, respectively.

Mesothelioma among seamen: a systematic review and meta-analysis.

Navy personnel and seafarers live and work 24 h per day in the shipboard environment and they are exposed to asbestos fibers released into the confined spaces aboard ships. We conducted a systematic review and meta-analysis to quantify the mesothelioma risk of seamen working aboard ships, either commercial or naval vessels, as compared to that of the general population. We carried out a literature search in MEDLINE through PubMed and EMBASE, from inception to 31 December 2021, of all studies on seamen working aboard ships, either commercial or naval vessels, characterized by exposure to asbestos and providing mesothelioma risk estimates. The Newcastle-Ottawa Scale was used to assess the quality of the studies included. The pooled standardized mortality ratio (SMR) was computed across eligible studies. The study protocol was registered on PROSPERO and reporting followed the preferred reporting items for systematic reviews and meta-analyses guidelines. A total of 10 studies published from 1990 to 2020 were considered eligible and included in the systematic review and meta-analysis. All the included studies were of good quality, with a median score of seven out of nine. Overall, there were 235 mesothelioma cases/deaths in the included studies versus 115.6 expected, with a pooled SMR of 2.11 (95% confidence intervals, 1.70-2.62), in the absence of a significant between-study heterogeneity ( I2 = 39%, P = 0.11). A more than double excess risk for mesothelioma among seamen working aboard ships emerged from our meta-analysis.

Sığacık Körfezi (Ege Denizi, Türkiye)’nin derin deniz dekapod tür listesi ve körfezden yeni kayıtlar

Decapod crustaceans were sampled monthly from May 2008 to April 2009 using a commercial trawl vessel at depths between 292 and 550 m from Sığacık Bay. 16 species were identified, of which 3 are Brachyura, 5 Caridea, 3 Dendrobranchiata, 1 Polychelida, 1 Astacidea, 3 Anomura. Of these, 4 species (Bathynectes maravigna, Munida intermedia, Pontophilus spinosus, and Processa canaliculata) are new records for Sığacık Bay. Furthermore, all of the previous studies were reviewed on the deep-sea decapod crustaceans of Sığacık Bay, depth range of each species is given.

Effect of non-clustering element C and Mo on irradiation-induced clustering in reactor pressure vessel steels

Commercial reactor pressure vessel steels in nuclear power plant applications contain C and other minor non-clustering elements in addition to the clustering elements of Mn, Ni and Si. However, the effect of such non-clustering elements on irradiation-induced solute clustering in ferritic steels has seldom been addressed. Herein, we reveal that a commercial RPV steel and its Fe-Mn-Ni-Si model alloy with coarse/fine grains subjected to ion irradiation exhibits different irradiation-induced clustering, particularly in chemistry, mean size, and number density of irradiation-induced MnNiSi-clusters. The different chemical compositions of the clusters indicate different thermodynamics in driving solute clustering in RPV steel and its model alloy. The different number density and size evolutions of the clusters indicate different kinetics in governing irradiation-induced clustering. The presence of C and Mo, as non-clustering elements, is primarily responsible for the different clustering behaviors of Ni, Mn and Si in the two materials exposed to ion irradiation. The research finding is of significant implication for modelling and fundamental understanding irradiation-induced clustering in commercial RPV steels.

Irradiation microstructures and hardening in commercial nuclear reactor pressure vessel steels at high extended life fluence

Nuclear reactor lifetimes up to and beyond 80 years may be limited by nano-scale Cu-Mn-Ni-Si precipitates (CRPs and MNSPs) that form under neutron irradiation in pressure vessel (RPV) steels, resulting in hardening and ductile to brittle transition temperature increases, or embrittlement. Here, Atom Probe Tomography (APT) is used to characterize precipitation in nine actual RPV steels, irradiated in the ATR-2 test reactor, to a high fluence 1.38 × 1020 n/cm2 at 292 °C and 3.68 × 1012 n/cm2 s. APT quantifies the relation between a wide range surveillance alloy Cu, Ni, Mn, and Si contents and the corresponding precipitate volume fractions, number densities, sizes, and compositions. The precipitate volume fraction (fp) is dominated by the dissolved steel Cu and Ni contents. Irradiation hardening shows the expected dependence on the √fp. The APT results also provide an opportunity to evaluate flux effects by direct comparisons with corresponding archival data from low flux surveillance irradiations. Most notably, this work establishes a strong microstructural and mechanistic foundation for the new data-driven Odette, Wells, Almirall, and Yamamoto (OWAY) model to predict high fluence RPV steel embrittlement.

Novel computer vision tools applied to marine recreational fisheries spatial planning

Successful marine spatial planning relies on understanding patterns of human use, with accurate, detailed, and up-to-date information about the spatial distribution of fishing effort. In commercial vessels, tracking systems like the vessel monitoring system (VMS) or the automatic identification system (AIS) have helped to maintain and enhance the biodiversity of areas by generating large sources of positional data that served for commercial marine spatial planning. However, there is no regulation regarding location systems such as VMS or AIS for marine recreational fishing boats. Obtaining spatial data on marine recreational fishing can be difficult and time-intensive given the widespread and variable nature of the fleet. Remote cameras and computer vision systems are increasingly used to overcome the cost limitations of these conventional methods. Here we show a novel high-resolution and low-cost tracking system based on photo time-lapses and state-of-the-art computer vision algorithms, including deep learning, to automatically classify and obtain precise trajectories of fishing and cruising boats in coastal areas. Our method contributes to the automatic surveillance of marine protected areas by providing an image-based tool for automatic, real-time monitoring. Our method also allows for determining the intensity and spatial-temporal distribution of recreational fishing effort, important to defining the sustainability of the activity and coastal areas. We finally discuss the opportunities and limitations of computer vision tools applied to marine recreational fisheries spatial planning.

A framework for multidisciplinary science observations from commercial ships

Abstract Science Research on Commercial Ships (Science RoCS) is a grassroots multi-institution group of scientists, engineers, data managers, and administrators seeking to further research opportunities by equipping commercial vessels with suites of maritime appropriate scientific sensors operated autonomously on regular ship routes with minimal crew intervention. Science RoCS aims to foster cooperation between the shipping industry and scientific community at a level that will be transformative for societally relevant ocean science, promote cross-disciplinary ocean science through simultaneous observation of the air/sea interface and water column, and spur a technological revolution in observational oceanography by developing new turnkey, maritime-industry-appropriate scientific equipment whose data streams can be used to stimulate innovations in oceanic (physical, chemical, and biological) understanding and forecasting. We envision a future where scientific data collection on commercial ships is the new industry standard, providing repeat measurements in undersampled, remote regions, on scales not otherwise accessible to the scientific community.

An investigation on the distribution dynamics of kiddi prawn, Parapenaeopsis stylifera (H. Milne Edwards, 1837) along southwest coast of India, using multi-dimensional approach

Along India's southwest coast, the kiddi prawn (Parapenaeopsis stylifera) supports a substantial fishery, known as "karikady fishery" due to its high demand in domestic and international markets. Following implementing "mechanised fishing prohibition," catch fluctuations observed in P. stylifera catches sparked widespread social unrest among stakeholders, who feared that unharvested prawns would be lost to the fishery when these prawns moved away from the coast during the monsoon season. The study derived scientific evidence for to distributional idiosyncrasy of the species with spatial distribution tracking, understanding the correlation of species movement and maturity with environmental parameters, and tracking the individual cohorts through population parameter analysis. Data for the study were collected from commercial vessels, experimental surveys, and analyses was supported by GIS software and SPSS foftware. 18 cruises in the RV Silver Pompano and 3 cruises in RV Matsyakumari at five depths (10, 30, 50, 70, 90 m) were conducted during 2016–2019 off Kerala, southwest coast of India and, and a spatial analysis of the experimental trawling data contributed to evaluating the impact of the environment on the distribution of the species. The study revealed that increased salinity has a statistically significant impact on the expansion of the species, as indicated by geographical data. P. stylifera prefers to settle in areas with high salinity and low temperatures, according to geographical studies. This study not only established that the perception that species migrate away from the coast is rational, but it also established that there is no resource loss as a result of the 'Monsoon trawl ban,' because current fishing methods are capable of catching the larger prawns that have migrated to deeper waters. The study reaffirmed the usefulness of "monsoon trawl ban" in ensuring the long-term viability of the "karikadi" fishery along the southwest coast by assisting in species recruitment during the monsoon season.

Sulfide stress cracking (SSC) of a commercial Q345 pressure vessel steel in a wet H2S environment

The steel Q345 is extensively used in pressure vessels with low and medium pressure because of good mechanical properties and low cost. Good resistance to sulfide stress cracking (SSC) is required for the pressure vessel steel, but the SSC behavior of the Q345 has received little attention. This work investigated the SSC behavior of the Q345 in a wet H2S environment. The microstructure contained the irregular various-sized polygonal-like ferrite grains plus a carbon-rich degenerate pearlite banded structure. The Q345 had high ductility but failed to pass the SSC tests. The SSC cracking involved hydrogen embrittlement. The SSC preferentially occurred at the carbon-rich degenerate pearlite banded structure. The elimination of the carbon-rich degenerate pearlite banded structure is necessary to improve the SSC resistance of the Q345 pressure vessel steel.

Distribution, abundance, and density of harbor porpoises in Hood Canal, Washington

AbstractHarbor porpoises (Phocoena phocoena) are the only cetaceans routinely sighted in Hood Canal, a narrow fjord that comprises the western edge of Puget Sound, Washington, USA. Harbor porpoises are sensitive to anthropogenic sounds, including noise from recreational and commercial vessel traffic, and the United States Navy, which conducts military training and testing within Hood Canal that can include underwater sound sources. This study was funded as part of the Navy monitoring program to assess potential impacts of naval activities on cetaceans. We conducted vessel‐based line‐transect surveys for harbor porpoises in Hood Canal in 2022–2023 to derive seasonal estimates of abundance and density. We carried out surveys over 37 days and surveyed the entire canal twice per season totaling 2,176 km of on‐effort track line. We recorded 809 on‐effort harbor porpoise groups and 1,385 individuals. Seasonal abundance estimates were lowest in winter (308 animals, 95% CI = 189–503) and gradually increased through spring and summer to a peak of 1,336 animals (95% CI = 826–2,160) in fall. Overall porpoise density was highest in central Hood Canal, an area that includes a designated United States Navy training range, though porpoise sightings were notably absent in a 21‐km2 area adjacent to the naval submarine base within this otherwise high‐density region. Though we collected only a single year of data, these results suggest that harbor porpoise abundance in Hood Canal increased significantly since it was last estimated (2013–2015). The notable seasonal fluctuation of harbor porpoise abundance suggests Hood Canal may host a larger percentage of the overall Washington Inland Waters stock during the fall season, raising important management considerations.

К ВОПРОСУ ОБ ОПРЕДЕЛЕНИИ ПРОМЫСЛОВОГО ЗАПАСА АНТАРКТИЧЕСКОГО КРИЛЯ EUPHAUSIA SUPERBA В РАЙОНЕ АНТАРКТИЧЕСКОГО ПОЛУОСТРОВА ПО ДАННЫМ ТРАЛОВЫХ УЛОВОВ КОММЕРЧЕСКИХ СУДОВ

Background. The assessment of the density and total biomass of the Antarctic krill aggregations has been conducted based on the commercial catches by the fishing and krill harvesting trawlers (supertrawlers) “Konstruktor Koshkin” (“Design Engineer Koshkin”) in 2006 and “More Sodruzhestva” (“Commonwealth Sea”) in 2017 in the Bransfield Strait (FAO Subarea 48.1). Relevance. Recommencement of the Russian krill harvesting necessitates timely strategical characterization of the krill aggregations with regard to their prospective exploitation. This work is aimed at the identification of the density and biomass of the Antarctic krill aggregations in 2006 and 2017, which have been calculated by the volumetric (net) method based on the catches by the commercial vessels in the Bransfield Strait. Methods. A midwater rope trawl of the 74/600 m design with the mesh size 20 mm in the krill-targeting insertion was used as a fishing gear. Estimation of the biomass was done using the isoline method. The catchability coefficient was considered to be 1. Mapping of the biomass density values was conducted with Golden Software Surfer 9 and QGIS 2.18.16. Confidence intervals for the average variation were calculated with 95 % probability. Results. The decrease in the average density of the krill biomass at the harvesting sites in the Bransfield Strait in 2017 (18.0±0.23 g/m3) as compared to 2006 (32.5±0.40 g/m3) has been identified; it resulted from the krill aggregations scattering over the increased area. The total krill biomass in the aggregations in 2006 and 2017 was 2678.3±65.07 thousand t and 2743.1±68.70 thousand t, respectively. Conclusion. Based on the commercial trawl catches, the volumetric method allows for the expedient estimation of the density and biomass of the krill aggregations with the size composition optimal for their exploitation. Taking into consideration that the commercial trawls capture the relatively large-sized krill preferred by the krill-dependent predators, the volumetric method makes it possible to estimate the volume of their food reserves. Exploitable krill stock in the aggregations in the Bransfield Strait in 2017 remained virtually unchanged as compared to that of 2006 and amounted to 2.7 million t.

The bycatch estimate of threatened marine megavertebrates in Moroccan fleets operating in the Mediterranean Coast

This study addresses the information gaps by a descriptive analysis of bycatch of vulnerable species (i.e. seabirds, sea turtles, seals, marine mammals, sharks and rays’ species) in in Moroccan Mediterranean area. The present study is one of the first researches to provide an evaluation of the bycatch of different threatened species in relation with fishing activities. The bycatch monitoring was conducted on board commercial fishing vessels operating in the Mediterranean coast of Morocco from March 2019 to Jun 2022. A total of 2203 days at sea observations, a total of 5792 questionnaires were performed to collect information on the interactions between these groups of vulnerable species and the three main vessels groups operating in the country (i.e. trawlers, long liners and purse-seiners). Considering all threatened taxa of monitored vulnerable species, sharks and rays had the highest percentage with 93% of the total bycatch in number. They are the most threatened by fishing among the megafaunas. The bycatch rate of common dolphins made up more than 0.03%. For sea turtles and sea birds it’s less than 0.02 %. Those estimates rates could underestimate the real rates in comparison to the quantities caught by the target species. Despite the incidental captures of those species were very low, there is an urgent need for their conservation given their crucial role in the ecosystems. Finally, some mitigations trials were proposed and additional research will be implemented to improve knowledge on bycatch estimates, fully understanding fisheries practices and achieves the goal of bycatch-reduction in these fisheries