Assessment of carrying capacity and management practices for Litopenaeus vannamei industrialized aquaculture based on an ecosystem model

Highlights: • An ecosystem model was developed for the indoor industrialized aquaculture system. • Model captured shrimp growth and nutrient dynamics (nitrogen, phosphorus). • The system's carrying capacity was assessed based on the discharge standard. • Evaluated feed quality, water exchange and tailwater treatment effects on system. • Tailwater treatment maximized carrying capacity and minimized nutrient discharges. Abstract: The sustainability of indoor industrialized aquaculture is challenged by resource limitations and environmental constraints. Thus, an integrated ecosystem-level assessment is essential to conserve water resources, improve production efficiency, and enhance the sustainability of the system. In this study, an ecosystem model for a Litopenaeus vannamei industrialized aquaculture system was developed to simulate shrimp growth, and its effects on nitrogen and phosphorus dynamics were examined. This study assessed the carrying capacity of the system, overall benefits, and the effects of management practices by integrating model simulations with discharge standards for nitrogen and phosphorus in tailwater. The results revealed a carrying capacity of 409 ind·m−2 for juvenile shrimp (body length: 4.24 ± 0.37 cm). Compared with the current stocking density (880 ind·m−2), the yield and economic benefit decreased by 53.5 % and 71.5 %, respectively. A simulation of management practices indicated that the carrying capacity could be increased to 449 ind·m−2, 593 ind·m−2, and 1193 ind·m−2 by enhancing feed quality, increasing the water exchange rate, and adopting tailwater treatment technology, respectively. Notably, adopting tailwater treatment technology would increase current stocking density to 1193 ind·m−2 and produce an increase of 33.5 % in economic benefit, a reduction of 26.2 % in tailwater discharge per unit yield, and 48.2 % and 49.0 % reductions in the discharge of total nitrogen and total phosphorus in tailwater, demonstrating water conservation and pollution control. This study provides a theoretical foundation and practical references for the standard discharge of tailwater and efficient resource utilization in L. vannamei industrialized aquaculture systems

Generative artificial intelligence and marine ecological monitoring

To meet the needs of the future, marine environmental monitoring must develop methods to efficiently combine and utilise data from a diverse range of sources (e.g., satellite imagery, sensor networks, acoustic data). Generative Artificial Intelligence (GenAI) is uniquely suited to aid with this by enabling the synthesis and integration of heterogeneous and often incomplete data. Its ability to learn underlying statistical patterns supports data fusion, imputation, and enhanced interpretation across sources. GenAI also introduces novel modelling approaches to tackle ecological uncertainties and improve predictive insight. Here, we present a comprehensive overview of GenAI applications in marine ecological monitoring, emphasising its potential to improve data quality control, automate species identification, and support the creation of digital twins. We also highlight key research challenges, such as managing model bias and ensuring system transparency, and outline future directions for integrating GenAI into sustainable marine ecological monitoring and management

A Comparison Between the (μ+ λ) and (μ, λ) Genetic Algorithm

For genetic algorithms, there are many strategies to choose individuals: general, and elitist. The general approach is the simplest approach, in which the algorithm replaces the whole current population by the offspring generated so far. In the elitist strategy, parents and offspring compete for survival. With the elitist approach, only the best individuals are selected from the current generation. In this article, we compare the results of the non-elitist genetic algorithm, and the elitist genetic algorithm improved with the parenting fitness. Results show that the elitist genetic algorithm improved with parenting fitness outperforms the non-elitist one in 93% cases

On the importance of Mongolian cyclones to East Asian dust storms

In East Asia, dust storms typically occur in spring with adverse impacts on socio-economic activities, loss of life, and climate. Mongolian cyclones that form downstream of the Altai-Sayan Mountain have been known for some time as drivers of spring dust storms in East Asia. The passage of Mongolian cyclones primarily induces dust-emitting winds in the Gobi Desert, leading to dust emissions and favoring the subsequent transport of dust aerosols across Northern China. Herein, the relative contributions of Mongolian cyclones to dust emissions in the Gobi Desert and subsequent dust storm activity in Northern China are assessed from a climatological perspective for the first time in this dissertation. Furthermore, this study provides the first evidence that dust activity in the Taklamakan Desert, which is located in the west of the Gobi Desert, is also supported by Mongolian cyclones. This assessment aims to illustrate the importance of Mongolian cyclones in generating spring dust storms across East Asia

High trophic plasticity in the mixotrophic Mastigias papua-Symbiodiniaceae holobiont: implications for the ecology of zooxanthellate jellyfishes

The trophic ecology of mixotrophic, zooxanthellate jellyfishes potentially spans a wide spectrum between autotrophy and heterotrophy. However, their degree of trophic plasticity along this spectrum is not well known. To better characterize their trophic ecology, we sampled the zooxanthellate medusa Mastigias papua in contrasting environments and sizes in Palau (Micronesia). We characterized their trophic ecology using isotopic (bulk δ13C and δ15N), elemental (C:N ratios), and fatty acid compositions. The different trophic indicators were correlated or anti-correlated as expected (Pearson’s correlation coefficient, rP > 0.5 or < -0.5 in 91.1% of cases, p < 0.05), indicating good agreement. The sampled M. papua were ordered in a trophic spectrum between autotrophy and heterotrophy (supported by decreasing δ13C, C:N, proportion of neutral lipid fatty acids (NLFA:TLFA), n-3:n-6 and increasing δ15N, eicosapentaenoic acid to docosahexaenoic acid ratio (EPA:DHA)). This trophic spectrum was mostly driven by sampling location with little influence of medusa size. Moreover, previous observations have shown that in a given location, the trophic ecology of M. papua can change over time. Thus, the positions on the trophic spectrum of the populations sampled here are not fixed, suggesting high trophic plasticity in M. papua. The heterotrophic end of the trophic spectrum was occupied by non-symbiotic M. papua, whereas the literature indicates that the autotrophic end of the spectrum corresponds to dominant autotrophy, where more than 100% of the carbon requirement is obtained by photosynthesis. Such high trophic plasticity has critical implications for the trophic ecology and blooming ability of zooxanthellate jellyfishe

Post-LGM sedimentation history and deglaciation processes in the southern Gulf of St. Lawrence, Canada

Highlights • Significant influence of the Bølling-Allerød and Younger Dryas on sedimentation. • Buried sediment basins and channels filled by late Pleistocene sediments. • Sedimentation rates >0.4 cm a−1 during deglaciation. • Erosional truncation possibly related to the Holocene RSL lowstand. • Marine sedimentation close to the coast of PEI as early as ∼13.6 ka BP. Abstract During the last glacial period, continents and surrounding shelves in high latitude regions of the Northern Hemisphere were covered by ice sheets. Their retreat after the Last Glacial Maximum resulted in isostatic adjustments of the previously glaciated landmass and post-glacial changes in relative sea level during the late Pleistocene and Holocene. Many questions, however, remain about the timing and impact of the ice retreat and of short-lived climatic events on continental shelf environments. This study aims to reconstruct the sedimentation and deglaciation processes on the continental shelf of the southern Gulf of St. Lawrence (Canada) over the past 14 ka by investigating changes in the sedimentation patterns and paleo-environments. Using information from sub-bottom profiles, sediment cores, and multibeam bathymetry, this study finds that most of the continental shelf was flooded 13.6 ka ago, as evidenced by the presence of Bølling-Allerød marine sediments at a water depth of ∼50 m and ∼15 km off the modern coastline, which also suggests an earlier retreat of the Laurentide Ice Sheet than suggested by previous studies. We estimate sedimentation rates for the Bølling-Allerød of ∼0.4 cm a−1, which increased up to 1 cm a−1 during the Younger Dryas cooling event, likely associated with increased storm-wave activity and sea ice development caused by deteriorating climatic conditions. The presence of an erosional truncation atop Younger Dryas sediments indicates a late Pleistocene-early Holocene relative sea level fall and associated lowstand. Based on our new data, we established a geological model that highlights sedimentation processes since the Last Glacial Maximum and demonstrate the potential impact of short-lived climatic events on the former ice margin during deglaciation

Constraining the drivers of barium isotope composition in marine barite: Insights from Pliocene-Holocene Eastern Mediterranean sapropels

The stable isotopic composition of barium in marine barite (δ138/134Babarite) has been proposed as a proxy for reconstructing past Ba cycling in the oceanic water column. However, whether δ138/134Babarite can also be a proxy for export productivity remains uncertain, particularly in semi-enclosed basins such as the Eastern Mediterranean (EMed). Here we present the first record of δ138/134Babarite extracted from EMed Pliocene to Holocene sapropels from six Ocean Drilling Program (ODP) Sites. Despite strong variability in Ba concentrations (∼400–4000 ppm) and organic carbon content (∼3–25 %)—reflecting varying export productivity levels—the δ138/134Babarite values show limited variation (ranging between 0.02 to −0.16 ‰), even during periods of exceptionally high inferred export productivity (e.g., during late Pleistocene sapropel S5). Consistent δ138/134Babarite values are also observed in sapropel S1 sites located at a wide range of water depths (∼900–3600 m). Well-preserved pelagic barite crystal textures (observed under scanning electron microscopy) and barite sulphur isotope composition similar to seawater (∼21 ‰; Paytan et al., 2004) in the sapropels, suggest that neither partial dissolution in bottom waters nor postdepositional Ba ion-exchange significantly altered the δ138/134Babarite signal. These results suggest that fluctuations in marine productivity had a limited impact on the dissolved Ba pool and its isotopic composition in the EMed upper water column during sapropel deposition. Instead, the EMed δ138/134Ba was likely controlled primarily by the Ba isotope composition of Atlantic Water inflow and local dissolved Ba sources, such as riverine and groundwater inputs, rather than by productivity-driven barite fluxes. This finding highlights that δ138/134Babarite in sedimentary records should not be interpreted as a straightforward proxy for export productivity, particularly in semi-restricted basins