Segmentation of Enhalus acoroides seagrass from underwater images using the Mask R-CNN method

Seagrass is a Spermatophyta plant that has many roles, including as a primary producer in the food chain in the waters. Monitoring of seagrass meadows and conditions needs to be done in order to achieve a healthy marine ecosystem. The steps taken in monitoring seagrass are by detecting and segmenting it. The purpose of the study is to implement and get information about the performance of the Mask R-CNN algorithm in detecting and segmenting the Enhalus acoroides. The dataset consists of 500 Enhalus acoroides images that had gone through a color correction and labelling process. The training process was performed with the configuration of 0.001 learning rate, batch size of 4 and some image augmentation was used to avoid overfitting. The optimum weight value was obtained after conducting the learning process with 100 epochs. A confusion matrix was used to evaluate detection performance, and linear regression was used to evaluate the segmentation produced by the model. The model evaluation results showed an accuracy value of 0.9246, a precision value of 0.9507, a recall value of 0.9712 and a correlation coefficient value of 0.8771. The value indicates that the model can detect and segment the seagrass Enhalus acoroides well and accurately.

Effects of Iron-Oxide Nanoparticles (Fe3O4) Released From Synthesized Iron-based Thiourea Catalyst on the Growth, Cell Density, and Pigment Content of Chlorella Vulgaris

This study investigated the effects of Fe3O4 nanoparticles released from synthesized Thiourea catalyst to Chlorella vulgaris as an essential primary producer in aquatic systems. A range of Fe3O4 concentrations (0, 10, 100, 250, 500, 750, and 1000 mg L-1) was applied for the exposure test. Biological parameters of C. vulgaris, including cell density, cell viability, and pigment content were assessed. Bioconcentration factor and bioaccumulation were evaluated for contaminated microalgae. Non-carcinogenic risks were then assessed using target hazard quotient (THQ) for potential human consumptions. Findings showed that C. vulgaris cell numbers increased from 0 to 500 mg L-1 of Fe3O4. Chlorophyll a represented a time-dependent response, and greatest values were detected in 250 and 500 mg L-1 Fe3O4 at 4.2 and 4 mg/g, respectively. Chlorophyll b content showed a time-related manner in exposure to Fe3O4 with the highest values recorded at 250 mg L-1 after 96 h. Moreover, bioaccumulation displayed a dose-dependent response as bioaccumulated iron was in the largest amount at 15000 µg/g dw in 1000 mg L-1, whereas the lowest one was in the control group at 1700 µg/g dw. The bioconcentration factor showed a concentration-relevant decrease in all iron treatments and 10 mg L-1 of Fe3O4 represented the greatest BCF at 327.3611. Non-carcinogenic risks illustrated negligible hazard (THQ < 1) in a dose-response pattern and the largest EDI and THQ were calculated in 1000 mg L-1 at 7.4332E-07 (mg kg-1 day-1) and 1.06189E-09, respectively. In essence, iron is an essential trace element for biological aspects in aquatic systems, but in exceeding concentrations could impose toxicity effects in C. vulgaris populations.

COMMUNITY STRUCTURE AND DIVERSITY OF PHYTOPLANKTON IN LEMUKUTAN ISLAND WATERS, WEST KALIMANTAN

Phytoplankton plays an important role in marine ecosystems as primary producer, as the basis of food chains and the food web, and are widely used as bioindicators to monitor water condition. The study of phytoplankton is the primary interest to explore aquatic resources for blue biotechnology applications in conditions as a live feed, antibacterial, antiviral, antioxidant, pharmaceutical, cosmetics, possibly food and health industry. The study aims to assess the composition, abundance and diversity of phytoplankton community in Lemukutan Island waters of West Kalimantan. The present study found 31 genera of phytoplankton, consisted of Bacillariophyceae (28 genera) and Dinophyceae (3 genera). In term of contribution, Bacillariophyceae were found to be dominant (93.035%) than dinophyceae (6.965%). The abundance of phytoplankton varied between 636.91 to 2034.48 cell.L-1. The diversity index (H’), the evenness (E) index, and the dominance (C) index ranged from 1.959–2.579, 0.582–0.868, 0.094–0.283, respectively. The result showed that the diversity index was moderate, the evenness index was high, and the dominance index was low.

Institutional Innovations in India: An Assessment of Producer Companies as New-Generation Co-operative Companies

There are many types of innovations such as technological, social, product, process, marketing and organizational, and institutional innovation is one type. The producer companies (PCs), which are a case of legal institutional innovation in the Indian domain of primary producer organization are more market-oriented co-operative companies and can help farmers buy and sell more effectively. They have gained currency across India during the past 15 years since the amendment to the Companies Act made this possible in 2003, and India now has thousands of such PCs, with many of them being supported by state agencies. This article examines the uniqueness of these entities as an institutional form wherein principles of co-operation and corporate entity have been combined so that they could be more relevant entities in a globalized and liberalized market environment. It discusses their competitive edge over other forms of producer organizations like co-operative societies in India and farmer companies in Sri Lanka, and new-generation co-operatives in other parts of the world. After discussing some innovations in their governance and management, it concludes by making suggestions for augmenting this institutional innovation for inclusive and sustainable agricultural and rural development.

Climate-Provenance Effect on the Organic Matter Enrichment of the Chang 9 Source Rocks in the Central Ordos Basin, China

The Upper Triassic Chang 9 organic-rich sediments have been considered as effective hydrocarbon source rocks for the Mesozoic petroleum system in the Ordos Basin. Previous studies on the Chang 9 member mostly focused on the influence of their paleoproductivity and paleoredox conditions on the organic matter (OM) enrichment, whereas there are few studies on the influence of the paleoclimate condition and sediment provenance on the OM enrichment. In this study, a series of geochemical analyses was performed on the Chang 9 core samples, and their hydrocarbon generation potential, paleoclimate condition, and sediment provenance were assessed to analyze the effect of paleoclimate-provenance on OM enrichment. The Chang 9 source rocks are characterized by high OM abundance, type I−II OM type, and suitable thermal maturity, implying good hydrocarbon generation potential. Based on the C-values and Sr/Cu ratios, the paleoclimate condition of the Chang 9 member was mainly semihumid. In addition, the Th/Co vs. La/Sc diagram and negative δEuN indicate that the Chang 9 sediments were mainly derived from felsic source rocks. Meanwhile, the paleoweathering intensity of the Chang 9 member is moderate based on moderate values of CIA, PIA, and CIW, which corresponds to the semihumid paleoclimate. The relatively humid paleoclimate not only enhances photosynthesis of the primary producer, but also promotes chemical weathering intensity, leading to suitable terrestrial clastic influx to the lacustrine basin, which is beneficial for OM enrichment.

Spatial and Ontogenetic Patterns in the Trophic Ecology of Juvenile Bull Sharks (Carcharhinus leucas) From the Northwest Gulf of Mexico

A combination of stomach content and stable isotope (δ13C, δ15N, and δ34S) analyses were used to characterize and examine spatiotemporal and ontogenetic trends in the feeding ecology of juvenile bull sharks (Carcharhinus leucas) captured in estuaries throughout the northwest Gulf of Mexico (GoM) between 2013 and 2016. Shark diets were dominated by fish prey taxa [&gt;98% index of relative importance (%IRI)], and of those identified to the family level, two families comprised greater than 50% IRI, Mugilidae (mullets: ∼32%) and Sciaenidae (drums and croakers: 27%). Clupeidae (herrings: 14%) and Ariidae (sea catfishes: 15%) also contributed substantially to the diet of juvenile sharks, though consumption of Ariidae increased as consumption of Clupeidae decreased in juvenile sharks larger than 893 mm Fork Length (FL) (∼1 year old). Values of δ15N increased significantly with shark size, indicating a shift toward larger or higher trophic level prey with increasing shark size. Latitudinal and temporal trends in δ13C and δ34S suggest isotopic variation occurred in correspondence with shifts in primary producer assemblages and environmental drivers of sampled estuaries. These results highlight the importance of teleost prey resources along the freshwater-marine continuum in the diet of juvenile bull sharks, as well as the utility of natural tracers in tracking ontogenetic trends in feeding ecology.

Comparison of selenium-induced antioxidant responses and bioaccumulation in two strains of the halotolerant alga Dunaliella salina

Selenium water pollution is an increasing environmental problem that requires investigation of cellular responses of aquatic primary producer organisms, especially algae. Industrial wastewater with selenium contamination is often coupled with high salinity (60–70). In this study, the biochemical responses of two strains of the halotolerant alga (Dunaliella salina Hoze-soltan and Dunaliella salina CCAP 19/18) to different selenium concentrations were evaluated. Although at high selenium concentrations both strains showed lipid peroxidation and cell number reduction, Dunaliella salina Hoze-soltan was less affected. Higher selenium tolerance in this strain might be attributed to the better activity of resistance responses like proline, total reducing sugar, superoxide dismutase (SOD) and peroxidase (POX), even at the high selenium concentrations. Catalase (CAT) had no significant role for protection against selenium toxicity as its activity declined in both strains with rising selenium concentration. Both strains accumulated selenium intracellularly, but the accumulation was about three-fold higher in Dunaliella salina Hoze-soltan than in the other strain. It can be concluded that Dunaliella salina Hoze-soltan may be a better candidate for selenium bioremediation of a high salinity environment. The data obtained from this study could be useful for improvement of algal ability for high efficiency selenium bioremediation in hypersaline environments.

Revisiting the sedimentary record of the rise of diatoms

Diatoms are a major primary producer in the modern oceans and play a critical role in the marine silica cycle. Their rise to dominance is recognized as one of the largest shifts in Cenozoic marine ecosystems, but the timing of this transition is debated. Here, we use a diagenetic model to examine the effect of sedimentation rate and temperature on the burial efficiency of biogenic silica over the past 66 million years (i.e., the Cenozoic). We find that the changing preservation potential of siliceous microfossils during that time would have overprinted the primary signal of diatom and radiolarian abundance. We generate a taphonomic null hypothesis of the diatom fossil record by assuming a constant flux of diatoms to the sea floor and having diagenetic conditions driven by observed shifts in temperature and sedimentation rate. This null hypothesis produces a late Cenozoic (∼5 Ma to 20 Ma) increase in the relative abundance of fossilized diatoms that is comparable to current empirical records. This suggests that the observed increase in diatom abundance in the sedimentary record may be driven by changing preservation potential. A late Cenozoic rise in diatoms has been causally tied to the rise of grasslands and baleen whales and to declining atmospheric CO2 levels. Here we suggest that the similarity among these records primarily arises from a common driver—the cooling climate system—that drove enhanced diatom preservation as well as the rise of grasslands and whales, rather than a causal link among them.