Carbon dioxide removal (CDR) potential in temperate macroalgal forests: A comparative study of chemical and biological net ecosystem production (NEP).

The carbon dioxide removal (CDR) capacity of macroalgae, a crucial component in climate regulation, has gained increasing attention. However, accurately estimating the CDR potential of macroalgae in natural conditions remains challenging, necessitating the use of multiple independent methods to reduce the uncertainties in these estimates. In this study, we compared two methods for estimating net ecosystem production (NEP), a key parameter in determining CDR potential: 1) NEP, derived from seawater carbonate chemistry and 2) NEP, based on photorespiratory measurements using benthic tent incubation.

Identifying the external N and Hg inputs to the estuary ecosystem based on the triple isotopic information (δN, ΔO and δO).

The supply and sources of N and Hg in the Geum estuary of the western coast of Korea were evaluated. Triple isotope proxies (δN, ΔO and δO) of NO combined with conservative mixing between river and ocean waters were used to improve isotope finger-printing methods. The N pool in the Geum estuary was primarily influenced by the Yellow Sea water, followed by riverine discharge (821 × 10 mol yr) and atmospheric deposition (51 × 10 mol yr).

Unraveling prokaryotic diversity distribution and functional pattern on nitrogen and methane cycling in the subtropical Western North Pacific Ocean.

Prokaryotes play an important role in marine nitrogen and methane cycles. However, their community changes and metabolic modifications to the concurrent impact of ocean warming (OW), acidification (OA), deoxygenation (OD), and anthropogenic‑nitrogen-deposition (AND) from the surface to the deep ocean remains unknown. We examined here the amplicon sequencing approach across the surface (0-200 m; SL), intermediate (200-1000 m; IL), and deep layers (1000-2200 m; DL), and characterized the simultaneous impacts of OW, OA, OD, and AND on the Western North Pacific Ocean prokaryotic changes and their functional pattern in nitrogen and methane cycles.

Prediction of Growth Characteristics and Migration Period of (Lepidoptera: Noctuidae) According to Temperature.

In 2019, an outbreak of (Smith) was first reported in Korea. This study aimed to determine the growth rate and feeding amount of by temperature to establish the right time window for its control and management. Linear regression analysis was used to determine the growth period and thermal requirements of .

Muscle Strength Moderates the Relationship between Nutritional Health Risk and Depression in Korean Older Adults.

Background: Little is known about the relationships between muscle strength and nutritional health risk with late-in-life depression. This study aimed to investigate the moderating effect of lower-extremity muscle strength on the relationship between nutritional health risk and depression in Korean older adults. Methods: Data obtained from 5949 women and 3971 men aged ≥ 65 years in the 2020 Korea Longitudinal Study on Aging were used in this study.

Intestinal anti-inflammatory activity of Ulva ohnoi oil in DSS-induced experimental mouse model.

This study was conducted to examine the physiological activity of Ulva ohnoi, some of which may be used for food or natural products but could disturbing coastal ecosystems due to large scale green-tide, to check values of U. ohnoi oil through experimental results. U.

NO dynamics in the western Arctic Ocean during the summer of 2017.

The western Arctic Ocean (WAO) has experienced increased heat transport into the region, sea-ice reduction, and changes to the WAO nitrous oxide (NO) cycles from greenhouse gases. We investigated WAO NO dynamics through an intensive and precise NO survey during the open-water season of summer 2017. The effects of physical processes (i.

Effects of salinity and nutrients on metabolism and growth of Ulva lactuca: Implications for bioremediation of coastal watersheds.

We studied Ulva lactuca to determine its potential for bioremediation of coastal watersheds. We cultured Ulva in orthogonal combinations of two salinities and three nutrient concentrations for six weeks, and then measured its growth, photosynthesis, chlorophyll fluorescence, nitrogen, carbon and phosphorus tissue concentrations, and carbon and nitrogen uptake pathways. Our findings show that Ulva was negatively affected by decreased salinity but these effects were ameliorated by the addition of nutrients to the water, such as would be expected from freshwater runoff during heavy rain events.

Occurrence, distribution, and potential exposure risk of organophosphate flame retardants in house dust in South Korea.

Concentrations of organophosphate flame retardants (OPFRs), which are used in various plastic products, were analyzed in house dust samples collected from three Korean cities (Suwon, n = 23; Jeonju, n = 20; Kunsan, n = 42). OPFRs, including tris (2-chloroethyl) phosphate (TCEP), tris (2-chloroisopropyl) phosphate (TCPP), and tris (1,3-dichloro-2-propyl) phosphate (TDCPP), were detected in 95%-100% of the samples analyzed, suggesting the widespread use of these compounds in Korea. The levels of TCEP, TCPP, and TDCPP in Suwon, Jeonju, and Kunsan ranged from the limit of quantitation to 46,000, 28,000, and 2400 ng/g, respectively.

Evaluating bloom potential of the green-tide forming alga Ulva ohnoi under ocean acidification and warming.

The occurrence of green-tides, whose bloom potential may be increased by various human activities and biogeochemical process, results in enormous economic losses and ecosystem collapse. In this study, we investigated the ecophysiology of the subtropical green-tide forming alga, Ulva ohnoi complex (hereafter: U. ohnoi), under simulated future ocean conditions in order to predict its bloom potential using photosynthesis and growth measurements, and stable isotope analyses.

Variation in Photosynthetic Performance Relative to Thallus Microhabitat Heterogeneity in Lithothamnion australe (Rhodophyta, Corallinales) Rhodoliths.

Rhodoliths are free-living, coralline algae that create heterogeneous structure over sedimentary habitats. These fragile ecosystems are threatened by anthropogenic disturbances that reduce their size and three-dimensional structural complexity. We investigated how physical disturbance from boat moorings affects photosynthetic performance in the rhodolith Lithothamnion australe.

Distribution and Control of Bacterial Community Composition in Marian Cove Surface Waters, King George Island, Antarctica during the Summer of 2018.

Marian Cove is experiencing some of the most rapid environmental changes in the Antarctic region; however, little is known about the response of bacterial communities to these changes. The main purpose of this study was to investigate the spatial variation of physical‒biogeochemical‒bacterial community features in the Marian Cove surface waters and the environmental parameters governing the spatial variation in the bacterial community composition during the summer of 2018. The Marian Cove surface waters are largely composed of two different characteristics of water masses: relatively low-temperature, -salinity, and -nutrient surface glacier water (named SGW) and relatively high-temperature, -salinity, and -nutrient surface Maxwell Bay water (named SMBW).

Global warming offsets the ecophysiological stress of ocean acidification on temperate crustose coralline algae.

Dramatic increases in the release of anthropogenic CO and global temperatures have resulted in alterations to seawater carbonate chemistry and metabolisms of marine organisms. There has been recent interest in the effects of these stressors on crustose coralline algae (CCA) because photosynthesis and calcification are influenced by all components of carbonate chemistry. To examine this, a mesocosm experiment was conducted to evaluate photosynthesis, calcification and growth in the temperate CCA Chamberlainium sp.

Marine deforestation leads to widespread loss of ecosystem function.

Trophic interactions can result in changes to the abundance and distribution of habitat-forming species that dramatically reduce ecosystem functioning. In the coastal zone of the Aleutian Archipelago, overgrazing by herbivorous sea urchins that began in the 1990s resulted in widespread deforestation of the region's kelp forests, which led to lower macroalgal abundances and higher benthic irradiances. We examined how this deforestation impacted ecosystem function by comparing patterns of net ecosystem production (NEP), gross primary production (GPP), ecosystem respiration (Re), and the range between GPP and Re in remnant kelp forests, urchin barrens, and habitats that were in transition between the two habitat types at nine islands that spanned more than 1000 kilometers of the archipelago.

Latitudinal Distributions and Controls of Bacterial Community Composition during the Summer of 2017 in Western Arctic Surface Waters (from the Bering Strait to the Chukchi Borderland).

The western Arctic Ocean is experiencing some of the most rapid environmental changes in the Arctic. However, little is known about the microbial community response to these changes. Employing observations from the summer of 2017, this study investigated latitudinal variations in bacterial community composition in surface waters between the Bering Strait and Chukchi Borderland and the factors driving the changes.

Diverse responses of sporophytic photochemical efficiency and gametophytic growth for two edible kelps, Saccharina japonica and Undaria pinnatifida, to ocean acidification and warming.

Ocean acidification and warming represent major environmental threats to kelp mariculture. In this study, sporophytic photochemical efficiency and gametophytic growth of Saccharina japonica and Undaria pinnatifida were evaluated under different pCO levels (360, 720, and 980 ppmv) and temperatures (5, 10, 15, and 20 °C for sporophytes; 15 and 20 °C for gametophytes). Sporophytic photochemical efficiencies of both kelps were significantly greater at 720 ppmv than at 360 and 980 ppmv.

Effect on Colony Growth Inhibition of Soil-Borne Fungal Pathogens by Available Chlorine Content in Sodium Hypochlorite.

Our study investigated the available chlorine content, contact time and difference among strains of each pathogen for sodium hypochlorite (NaOCl) to control chemically against soil-borne fungal pathogens, such as Phytophthora rot by , violet root rot by , and white root rot by , causing die-back symptom on apple trees. As a result, the colony growth of was inhibited completely by soaking over 5 s in 31.25 ml/l available chlorine content of NaOCl.

Facile synthesis of partially oxidized MnO-functionalized carbon cathodes for rechargeable Li-O batteries.

High charging overpotential (low energy efficiency) is one of the most important challenges preventing the use of current nonaqueous Li-O batteries. This study demonstrates direct -incorporation of metal oxides on carbon during synthesis and the associated application to nonaqueous Li-O battery catalysts. The partially oxidized MnO (MnO/MnO)-incorporating carbon cathode shows an average overpotential reduction of ∼8% charge/discharge during 40 cycles in a rechargeable nonaqueous Li-O cell.

Feeding by the newly described mixotrophic dinoflagellate Paragymnodinium shiwhaense: feeding mechanism, prey species, and effect of prey concentration.

To investigate the feeding by the newly described mixotrophic dinoflagellate Paragymnodinium shiwhaense (GenBank accession number=AM408889), we explored the feeding process and the kinds of prey species that P. shiwhaense is able to feed on using several different types of microscopes, including a transmission electron microscope and high-resolution video-microscopy. In addition, we measured the growth and ingestion rates of P.

Paenibacillus aestuarii sp. nov., isolated from an estuarine wetland.

A novel bacterial strain designated CJ25(T) was isolated from the estuarine wetland of the Han river in Korea. Identification of this strain was carried out on the basis of polyphasic taxonomy. The isolate was Gram-staining-positive, rod-shaped, non-pigmented and motile.

Flavobacterium chungangense sp. nov., isolated from a freshwater lake.

A yellow-pigmented, rod-shaped, Gram-staining-negative, aerobic bacterial strain, designated CJ7(T), was isolated from a freshwater lake at Chung-Ang University in Anseong, South Korea. Results from 16S rRNA gene sequence analysis revealed that the isolate was phylogenetically affiliated with members of the genus Flavobacterium. Strain CJ7(T) showed sequence similarity values of 91.

Actibacter sediminis gen. nov., sp. nov., a marine bacterium of the family Flavobacteriaceae isolated from tidal flat sediment.

A yellow-pigmented, Gram-negative, aerobic bacterial strain comprising rod-shaped cells devoid of flagellar and gliding motility, designated strain JC2129(T), was isolated from tidal flat sediment of Dongmak on Ganghwa Island, South Korea. Results from a 16S rRNA gene sequence analysis indicated that the isolate belonged to the family Flavobacteriaceae; the highest level of nucleotide sequence similarity (91.9%) occurred with Polaribacter dokdonensis DSW-5(T).