The maritime industry is undergoing a paradigm shift driven by stringent decarbonization regulations, such as the Carbon Intensity Indicator (CII) and Energy Efficiency Existing Ship Index (EEXI). Despite the proliferation of technical solutions, a conceptual divide persists between emission compliance and the established safety management culture governed by the International Safety Management (ISM) Code. This study employs a comprehensive bibliometric analysis to examine the intellectual structure and evolution of the maritime decarbonization literature. Using a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided selection process, 88 core publications from the Web of Science database were analyzed using R Bibliometrix. Results from the Gompertz growth model suggest a trend toward technical saturation in the literature, pointing to a potential shift toward operational management. Furthermore, factorial and Sankey analyses reveal a significant disconnect between emissions management and Safety Management Systems (SMS), with “human factors” and “safety culture” remaining marginalized as “niche” themes. The findings suggest that decarbonization is currently treated as an external “administrative reporting burden” rather than an organic operational routine. To bridge this gap, this study conceptualizes the pathways for integrating operational emission management into SMS from an ISM Code perspective. Rather than proposing isolated technical data fixes or validated operational software, the study illustrates how fuel inefficiencies can be conceptually evaluated within the Plan-Do-Check-Act (PDCA) cycle. This research provides a baseline for policymakers and ship management companies seeking to align environmental performance monitoring with shipboard safety routines.
The tramp shipping sector, a vital component of global maritime trade, operates in a highly competitive and volatile environment. This study investigates the growth strategies employed by Turkish tramp shipping companies through the integrated Resource-Based View (RBV) and Dynamic Capabilities (DC) perspectives. Despite the strategic importance of the sector, empirical research integrating these theoretical perspectives remains limited, particularly within the Turkish context. Data were collected through semi-structured interviews with managers from ten Turkish tramp shipping firms and analyzed using MAXQDA 2020. The findings indicate that fleet expansion, strategic alliances, and operational efficiency constitute the primary growth strategies adopted by the firms. Sustainable growth depends not only on valuable firm resources but also on the ability to sense market opportunities, seize them effectively, and continuously reconfigure resources in response to changing market conditions. The study also identifies financing constraints and increasing regulatory pressures as major barriers to growth. These findings contribute to the strategic management and maritime management literature by providing an integrated explanation of sustainable growth in tramp shipping while offering practical implications for industry managers.
Brachionus plicatilis is one of the most important live feeds used in marine larviculture, and its nutritional quality directly influences larval growth and survival. Although baker’s yeast (Saccharomyces cerevisiae) is widely used as a cost-effective feed for rotifer production, information regarding the effects of different yeast feeding rates on rotifer fatty acid composition remains limited. This study evaluated the effects of three yeast concentrations LF (0.40 g × 106 ind.-1 day-1), MF (0.55 g × 106 ind.-1 day-1), and HF (0.70 g × 106 ind.-1 day-1) on population dynamics, total lipid content, and fatty acid profiles of B. plicatilis. Rotifers were stocked at an initial density of 200 ind. mL-1 and cultured for 5 days. Population density, egg-carrying individuals, fecundity, and growth rate were monitored at 24-h intervals. At the end of the experiment, rotifers were harvested for total lipid and fatty acid analyses. The highest rotifer density (2294 ± 201 ind. mL-1) and number of egg-carrying individuals (639 ± 64 ind. mL-1) were obtained in the LF group. This group also exhibited the highest egg-carrying ratio (27.8 ± 1.1%) and population growth rate (0.48 ± 0.01 div. day-1). Total lipid content increased markedly from 3.59 ± 1.01% dry weight in the 24-h starved control group to 9.32–10.93% dry weight in yeast-fed rotifers, with the highest value recorded in the 0.40 g × 106 ind.-1 treatment. Yeast supplementation also increased total n-6 polyunsaturated fatty acids from 9.65 ± 1.18% in the control group to 12.48–13.01%, primarily through elevated linoleic acid (18:2n-6) levels. Arachidonic acid (20:4n-6) was detected in the MF and HF groups. In contrast, n-3 polyunsaturated fatty acids, including α-linolenic acid, EPA, DPA, and DHA, were absent in all yeast-fed groups, resulting in n-3/n-6 and EPA/ARA ratios of zero. The results demonstrate that S. cerevisiae effectively enhanced biomass production, reproductive performance, and lipid accumulation in B. plicatilis, with the LF feeding regime yielding the best overall performance among the feeding regimes tested. However, baker’s yeast alone is insufficient to provide the essential n-3 highly unsaturated fatty acids required for marine fish larvae. Therefore, although yeast can serve as an economical biomass-building feed, its application should be combined with marine lipid- or microalgae-based enrichment products to improve the nutritional quality of rotifers for marine larviculture.
This study examined return connectedness and spillover transmission among ten major VLSFO bunker hubs in the post-IMO 2020 era. Using daily log return data from 12 June 2023 to 12 June 2026 and the Diebold–Yılmaz connectedness framework, the study identified the system-wide, directional, net, and pairwise spillovers across key VLSFO bunkering hubs. The baseline results show a Total Connectedness Index of 72.56%, indicating a highly integrated global VLSFO bunker market, and a substantial share of return variation is explained by inter-market spillovers. Singapore emerges as the dominant net transmitter, while Hong Kong, Fujairah, Rotterdam, and Houston also act as important transmission hubs. Santos appears as the largest net receiver, suggesting stronger exposure to shocks originating from other hubs. Pairwise and network results show that the Singapore–Hong Kong–Fujairah axis forms the core of global VLSFO spillover transmission, while the Houston–New York connection and Rotterdam-linked routes represent important regional spillover channels. A complementary 200-day rolling-window analysis further shows that total connectedness varies over time, ranging from 52.75% to 88.80%, indicating that the VLSFO spillover structure is dynamic rather than fixed. These findings provide useful implications for bunker procurement, fuel cost management, and maritime energy risk monitoring by identifying the main transmission hubs and receiver markets in the global VLSFO network.
Mesh size strongly influences catch efficiency and catch composition in trammel-net fisheries. This study evaluated the effects of four different inner panel mesh sizes (18, 22, 26, and 30 mm) on catch efficiency, catch composition, and discard proportions of multifilament trammel nets in Beymelek Lagoon (Antalya, Türkiye). Samples were obtained at four stations monthly from January to December 2019, using the haul-seine (voli) method. Catch per unit effort (CPUE) was analysed using a linear mixed-effects model with mesh size, sampling month, and sampling station as fixed effects and fishing operation as a random effect. Mesh size affected log-transformed CPUE (P <0.001), an effect that represents the combined influence of mesh size and panel position (confounded by the fixed panel order) rather than mesh size alone. Sampling month and station also contributed to variation in catches. Estimated marginal means indicated that the 18-mm mesh had a CPUE significantly lower than the 22, 26, and 30 mm meshes, but the three larger sizes were not significantly different from one another. The weight-based discard proportion was highest at the 18 mm mesh (14.4%) and significantly higher than at the 22, 26 and 30 mm meshes, which did not differ from one another; by number, discard proportions did not differ significantly among meshes once over-dispersion was accounted for. Increasing the inner-panel mesh size from 18 to 22 mm was associated with higher catch efficiency. Both catch efficiency and discard composition should therefore be considered when selecting an appropriate mesh size to support the sustainable management of Mediterranean lagoon fisheries.
