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To examine the effects of substratum types on the growth of Caulerpa okamurae, sand surface and sand burial experiments were conducted. Five assimilators (erect fronds) per replicate were cultured for 15 d on the surface of three different treatments: fine sand (200 μm), coarse sand (600 μm), and no sand (control). Also, three stolons and three assimilators were buried by fine grain or coarse grain sands and incubated for 15 d. In both experiments, other culture conditions included 25°C, 30 μmol photons m-2 s-1, and 16 : 8 h L : D (light : dark). In both experiments, stolon + assimilator-, assimilator-, and stolon-weights were measured. Relative growth rates (RGRs) of stolon + assimilator weights ranged from 0.43 to 1.95% d-1 at no sand and fine sand treatment, respectively. RGRs for the weight of stolon + assimilator and new assimilators were significantly greater on the fine- and coarse sand surface than the control. In the burial experiments, RGRs of stolons (4.28% d-1 at coarse sand and 5.57% d-1 at fine sand, respectively) were significantly greater than those of assimilators (1.38% d-1 at fine sand and 1.82% d-1 at coarse sand, respectively). When stolons were buried, RGRs for assimilators were greater at the fine sand than at the coarse sand treatment. On the other hand, RGRs of buried assimilators for total frond weights and for newly produced stolons were significantly greater at the coarse sands than at the fine sands. In conclusion, C. okamurae grew well with all substrates of sands and showed better growth on fine sands than coarse ones. This result suggests that the growth of stolons and assimilators of C. okamurae is stimulated after stable attachment to the sand substrates by rhizophores. In addition, stolons showed higher growth rates than the assimilators in the sand burial states, indicating that stolons are more tolerant to low light than assimilators of C. okamurae.

Although significant research efforts have been targeted toward conservation and management of endangered terrestrial flora and fauna, attempts have been limited to conserve threatened seaweeds. Silvetia siliquosa is an ecologically and commercially vital brown alga that is uniquely distributed in the Yellow-Bohai Sea and along the southwest coast of Korea. A massive decline in its distribution range and biomass from the mid-1990s onward indicates that this species has become endangered. In the present study, we used nuclear internal transcribed spacer and concatenated mitochondrial cytochrome oxidase I subunit+intergenic spacer to estimate the genetic diversity, population connectivity, and degree of genetic differentiation of S. siliquosa in China and Korea. The molecular results exhibited strikingly low levels of haplotype/ribotype and nucleotide diversity in S. siliquosa populations, with only three mitochondrial haplotypes and nuclear ribotypes detected in 136 and 143 specimens, respectively. The analysis of molecular variance revealed 85%–95% of genetic variance among populations. Population differentiation coefficient (FST) and gene flow (Nm) suggested that two populations (JIN and GWA) along the southern coast of Korea are highly divergent from the others, with weak genetic exchange. No significant genetic differentiation was observed among populations either in China or along the geographically proximate west coast of Korea. Thus, four independent management units were designated for sustainable management: the LII and RUS populations in China, the YEO and CHA populations along the west coast of Korea, and each of the GWA and JIN populations along the south coast of Korea. We suggest that artificial cultivation and transplantation of S. siliquosa are the effective approaches for restoration and conservation.

Korea has a long history of utilizing seaweeds, as the country has a high biodiversity of seaweeds. The abundance and composition of seaweed species have changed over the past decades due to climate change and anthropogenic influences. Some species showed a significant extension of their distribution range to the north while some species declined. Some areas have even become barren ground. Korea has put extensive effort into restoring the seaweed resources in these deforested areas. Korea is one of the most advanced countries in the World in terms of seaweed aquaculture. However, the aquacultured species are mostly limited to three genera, Saccharina, Undaria and Pyropia/Porphyra, which represent 96% of the entire seaweed production in the country. Korea has developed highly advanced cultivation technologies as well as various cultivars using breeding and hybridization technologies for these species. There has also been considerable effort in developing environmentally sustainable aquaculture systems using seaweed cultivation (e. g. integrated multi-trophic aquaculture, nutrient bioextraction and biofloc). This study discusses the current status and challenges of the above mentioned topics in detail. In addition, the present study encourages South and North Korean scientists to collaborate in the study of seaweed resources at the border of these two countries.

In this paper, we investigate the potential of dark sirens by the space-borne atom interferometric gravitational-wave detectors to probe the Hubble constant. In the mid-frequency band, the sources live a long time. The motion of a detector around the Sun as well as in Earth orbit would induce large Doppler and reorientation effects, providing a precise angular resolution. Such precise localization for the GW sources makes it possible to observe the dark sirens with only one potential host galaxy, which are dubbed "golden dark sirens". We construct the catalogs of golden dark sirens and estimate that there are around 79 and 35 golden dark sirens of binary neutron stars (BNS) and binary black holes (BBH) that would be pass the detection threshold of AEDGE in 5 years. Our results show that with 5, 10, and all 79 golden dark BNS tracked by AEDGE one can constrain $H_0$ at 5.5\%, 4.1\%, and 1.8\% precision levels. With 5, 10, and all 35 golden dark BBH one can constrain $H_0$ at 2.2\%, 1.8\%, and 1.5\% precision levels, respectively. It suggests that only 5-10 golden dark BBH by AEDGE are sufficient to arbitrate the current tension between local and high-$z$ measurements of $H_0$., 16 pages, 6 figures, and 1 table. To match the published version

Subhalos at subgalactic scales ($M\lesssim 10^7 M_\odot$ or $k\gtrsim 10^3 \,{\rm Mpc}^{-1}$) are pristine test beds of dark matter (DM). However, they are too small, diffuse and dark to be visible, in any existing observations. In this paper, we develop a complete formalism for weak and strong diffractive lensing, which can be used to probe such subhalos with chirping gravitational waves (GWs). Also, we show that Navarro-Frenk-White(NFW) subhalos in this mass range can indeed be detected individually, albeit at a rate of ${\cal O}(10)$ or less per year at BBO and others limited by small merger rates and large required SNR $\gtrsim 1/\gamma(r_0) \sim 10^3$. It becomes possible as NFW scale radii $r_0$ are of the right size comparable to the GW Fresnel length $r_F$, and unlike all existing probes, their lensing is more sensitive to lighter subhalos. Remarkably, our formalism further reveals that the frequency dependence of weak lensing (which is actually the detectable effect) is due to shear $\gamma$ at $r_F$. Not only is it consistent with an approximate scaling invariance, but it also offers a new way to measure the mass profile at a successively smaller scale of chirping $r_F \propto f^{-1/2}$. Meanwhile, strong diffraction that produces a blurred Einstein ring has a universal frequency dependence, allowing only detections. These are further demonstrated through semianalytic discussions of power-law profiles. Our developments for a single lens can be generalized and will promote diffractive lensing to a more concrete and promising physics in probing DM and small-scale structures., Comment: 21 pages, 15 figures

This study quantified the spatial variation of endophyte infections in wild populations of commercially important Chondrus ocellatus in Korea. We examined the variation of infection across four locations, two tidal heights and life-history stage (gametophyte vs tetrasporophyte). One hundred and fifty fronds were collected from the upper and lower C. ocellatus zones and microscopic examinations were conducted to determine their infection symptoms. Our results showed that the percentage of C. ocellatus populations infected by endophytic algae were very high, ranging from 58 to 99%, in all populations examined. Endophyte infection severity of Hakampo and Manripo populations was significantly greater in the lower Chondrus zones but it was significantly higher in the upper zone of Jungdori population. Tetrasporophytic fronds were more susceptible to infection by endophytic algae than gametophytic fronds. Also, the infection symptoms were more severe in the middle and basal parts of the fronds than in the apical parts. The findings of this study are very informative data for the endophyte abundance in the field population of commercial C. ocellatus.

The red alga Chondria crassicaulis has a wide‐ranging bioactive chemical composition and is used as a local foodstuff, representing a potentially new cultivar in Korea. The cultivation techniques were developed by examining the monthly changes in frond weight in a field population of C. crassicaulis from November 2016 to October 2017. For seedling production, temperature and irradiance effects on the attachment and growth of vegetative propagules of C. crassicaulis were evaluated. In addition, effects of day length and salinity on the propagule growth were examined. C. crassicaulis is a year‐round species with a maximum frond wet weight of 817 mg observed in July 2017, as seawater temperature increases to 20°C. The attachment of vegetative propagules was significantly affected by temperature and irradiance, with maximal values detected at 20–25°C and 60 µmol photons m⁻² s⁻¹. The relative growth rates of vegetative propagules of C. crassicaulis were the highest at 20–25°C, 60 µmol photons m⁻² s⁻¹, and a salinity of 25 psu. In conclusion, due to its tremendous tolerance under variable environmental conditions, the vegetative propagules of C. crassicaulis can be used as seedlings for mass cultivation.

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 pCO2 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. Female gametophytes of both kelps grew significantly better at 360 ppmv than at higher pCO2 levels. The growth of U. pinnatifida gametophytes was significantly greater at 20 °C than at 15 °C, while no significant difference was observed for the growth of S. japonica. These results indicate that increased pCO2 stimulated sporophytic photochemical efficiency while inhibited gametophytic growth of these kelps, which might negatively affect their seedling cultivation. U. pinnatifida exhibited higher productivity in warmer ocean than S. japonica.

Juvenile sporophytes and gametophytes of Ecklonia stolonifera were incubated in combinations of three pCO₂ levels (360, 720 and 980 ppmv) and two temperatures (10 and 15°C for sporophytes; 15 and 20°C for gametophytes) to examine potential effects of climate change on photosynthesis and growth. Sporophytes had significantly higher maximum quantum yields (Fᵥ/Fₘ) and maximum relative electron transport rates (rETRₘₐₓ) at 720 ppmv than 360 and 980 ppmv. Also, these parameters were significantly lower at higher temperature of 15°C than at 10°C. Growth of female gametophytes was maximal at 360 ppmv rather than enriched pCO₂ levels. Female gametophytes had significantly lower growth at higher temperature of 20°C than at 15°C. These results indicate effects of elevated pCO₂ varied between generations: stimulating sporophytic photosynthesis and inhibiting gametophytic growth. Ocean acidification and warming would constitute a grave threat to seedling cultivation of E. stolonifera caused by growth inhibition of gametophytes at high pCO₂ levels and temperatures.

To examine optimal growth conditions of the edible green alga Caulerpa okamurae, thalli of this species were cut into erect frond (3 cm long) and stolon (5 cm long) fragments. They were cultured in combinations of four temperatures (15, 20, 25, and 30 °C), three irradiances (20, 40, and 80 μmol photons m−2 s−1), four daylengths (8, 12, 16, and 24 h), and seven salinities (15, 20, 25, 30, 35, 40, and 45 psu). After 12 days, maximal relative growth rates (RGRs) for erect fronds (6.78% day−1) and stolons (7.02% day−1) occurred at 25 °C and 40 μmol photons m−2 s−1. At 30 °C, growth differences were found; negative growth for erect fronds and positive growth for stolons, with an average RGR of 1.96% day−1. A daylength of 16 h and salinity of 30 psu were needed for maximal growth of erect fronds and stolons. Stolon exhibited a greater tolerance to high and low temperatures and low salinity than erect fronds. Thalli weight of C. okamurae was increased by increments of stolon length, new erect fronds, and new ramuli. In conclusion, C. okamurae should be cultivated in summer with high seawater temperature (25 °C) and long daylength, in waters of 30 psu, and at a water depth providing 40 μmol photons m−2 s−1. These physiological and growth pattern data are informative for the successful development of commercial cultivation of C. okamurae.

The objective of this study was to examine the effects of temperature and light intensity on growth of female gametophytes of Eisenia bicyclis and Ecklonia cava and responses of these female gametophytes to Fe addition and daylength. Female gametophytes of each species were cultured at four temperatures (10, 15, 20, and 25°C) and under a combination of four light intensities (10, 20, 40, and 80 μmol photons/(m 2 ·s)) with two temperatures (15 and 20°C for E i. bicyclis; 20 and 25°C for E c. cava) to clarify their optimal growth conditions. Growth and maturation of female gametophytes of these two species under a combination of five Fe-EDTA concentrations (0, 1, 2, 4, and 8 μmol/L) and three daylengths (10, 12, and 14 h) were also examined. The growth of E i. bicyclis gametophyte was maximal at approximately 15–20°C, 20 μmol photons/(m 2 ·s), Fe-EDTA concentration of 8 μmol/L and daylengths of 12–14 h. While E c. cava gametophytes showed optimal growth at approximately 20–25°C, 20 μmol photons/(m 2 ·s), Fe- EDTA concentration of 8 μmol/L and daylength of 14 h. Maturation of gametophytes was enhanced at Fe-EDTA concentration of 4 μmol/L for E i. bicyclis and at 2 μmol/L for E c. cava. In conclusion, optimal growth temperatures and Fe-EDTA concentrations for maturation of E i. bicyclis and E c. cava gametophytes were different. Higher optimal growth temperature for E c. cava gametophytes may contribute to its wider geographical distribution compared to E i. bicyclis which has restricted habitats in Korea. This suggests that addition of Fe ion could be used to recover beds of these two species in barren grounds of Korea.

Silvetia siliquosa is an ecologically and commercially important brown alga that is harvested from its natural habitats, but its population has recently been diminishing along the Korean coast. To develop new techniques for algal population restoration, we tested two newly developed transplantation methods (using polyethylene ropes and natural rock pieces) at two study sites, Gwanmaedo and Yeongsando, on the southwest coast of Korea, from May to November 2014. The transplants on polyethylene ropes showed significantly greater survival, maturity, and growth than those on natural rocks at both study sites. Newly recruited juveniles (

Understanding the evolutionary processes that have created diversity and the genetic potential of species to adapt to environmental change is an important premise for biodiversity conservation. Herein, we used mitochondrial trnW-L and cox3 and plastid rbcL-S data sets to analyze population genetic variation and phylogeographic history of the brown alga Sargassum fusiforme, whose natural resource has been largely exterminated in the Asia-Northwest Pacific in the past decades. Phylogenetic trees and network analysis consistently revealed three major haplotype groups (A, B, and C) in S. fusiforme, with A and B distributed in the Japan-Pacific coast. Group C consisted of three subgroups (C1, C2, and C3) which were distributed in the Sea of Japan, the Yellow-Bohai Sea, and East China Sea, respectively. Isolation-with-migration (IM a) analysis revealed that the three groups diverged approximately during the mid-Pleistocene (c. 756-1,224 ka). Extended Bayesian skyline plots (EBSP) showed that groups A and B underwent relatively long-term stable population size despite a subsequent rapid demographic expansion, while subgroups C2 and C3 underwent a sudden expansion at c. 260 ka. FST and AMOVA detected low population-level genetic variation and high degrees of divergence between groups. The cryptic diversity and phylogeographic patterns found in S. fusiforme not only are essential to understand how environmental shifts and evolutionary processes shaped diversity and distribution of coastal seaweeds but also provide additional insights for conserving and managing seaweed resources and facilitate predictions of their responses to future climate change and habitat loss.

A brown filamentous endophyte, Mikrosyphar zosterae, occasionally appears as an epiendophyte of seagrass in Europe and North America. In the present study, M. zosterae was first isolated from wart-like spots of the red alga Chondrus ocellatus and identified by morphological features and molecular analysis. The production of wart-like spots M. zosterae on the host C. ocellatus fronds was confirmed using Koch’s postulates and in mixed culture of the two species. Neither hypertrophic nor hyperplastic cells of host C. ocellatus were found in the wart-like spots which differed from gall composition in other species. Wart-like spot formation by brown filamentous M. zosterae on the red macroalgal fronds is reported for the first time. In the culture, three morphological types of M. zosterae were observed, which were heterotrichous, pseudoparenchymatous and monostromatic prostrate thalli. Phaeophycean hairs and reproductive organs (both unilocular and plurilocular sporangia) of M. zosterae were also observed in the culture. In conclusion, M. zosterae is a causative agent producing wart-like spots on Chondrus fronds, which is a new record in red seaweeds and was confirmed in the laboratory culture for the first time.

Aim Oceanic currents are among the most pervasive hydrodynamic features in shaping community dynamics, population connectivity and phylogeographical structure of intertidal species. Here, we test whether population structure and biogeographical gradients of genetic diversity in the brown alga Sargassum thunbergii are correlated with oceanic currents in the north-west Pacific (NWP). Location North-west Pacific (25.07°N–43.36°N). Methods Nuclear internal transcribed spacer-2 and mitochondrial cox3 sequences were obtained from 835 and 810 individuals of S. thunbergii respectively. Parsimony networks and phylogenetic trees (maximum parsimony and Bayesian inference) were constructed to evaluate phylogeographical structure. Pairwise FST estimates and analyses of molecular variance (AMOVA) at various hierarchical levels (latitude, longitude, marine provinces, biogeographical basins and zoogeographical zones) were conducted to elucidate population genetic differentiation. migrate software was used to estimate the number of migrants between adjacent populations. Results Several lines of evidence indicate that S. thunbergii is characterized by shallow population structure. Geographical distances do not correlate with population pairwise genetic differentiations. The corridor/stepping-stone model-based coalescent analyses reveal high levels of asymmetric gene flow among S. thunbergii populations, with the numbers of migrants largely corresponding to the directions of oceanic current systems in the NWP. Genetic signatures also indicate that Jeju Island, Korea might act as a transition zone for dispersal of S. thunbergii in the NWP driven by the Kuroshio Current, thus facilitating subsequent transportation northward into the Sea of Japan and the Yellow-Bohai Sea. Main conclusions Population genetic homogeneity in S. thunbergii was mainly structured by oceanic currents rather than palaeoclimatic events. Our study illustrates an important phylogeographical case of how coastal hydrodynamic factors contributed to population connectivity and geographical shifts of genetic diversity for marine organisms without a pelagic stage.

세계 인구의 2/3 이상이 해안에 살고 있으므로 연안역 개발 은 불가피하며, 인간 활동에 기인한 암반조간대 생태계도 심각 한 교란에 직면해 있다. 이러한 암반조간대에 서식하는 해조류 는 연안생태계의 중요한 일차생산자로서 영양염과 탄소순환 에 기여하고 있으며, 어류 및 무척추동물을 포함한 다양한 해양 생물의 은신처, 산란장 및 먹이장으로서 중요한 기능을 수행한 다(Lindstrom, 2009; Wan et al., 2009; Whitaker et al., 2010; Ja niak and Whitlatch, 2012; Perkol-Finkel et al., 2012; Satheesh and Wesley, 2012). 이외에도, 해조류 군집은 해양에 유입 되는 유기 및 무기 오염물질을 제거하는 생물여과자(bio filter) 로써 역할을 하지만, 반대로 서식지 환경(교란, 혹은 오염)의 변 화됨에 따라 군집구조가 바뀌기 때문에(Lemieux and Cusson, 2014), 연안의 환경상태의 안정도를 평가하는 생물지표자로 도 이용된다(Worm et al., 2000; Piazzi and Cinelli, 2001; Orfanidis et al., 2003; Rindi and Guiry, 2004; Wells et al., 2007; Scherner et al., 2013). 연안생태계에서 형태와 구조적 복잡성 및 종다양성을 가진 해 조류 군집은 해양생물의 종다양성을 증가시키는 생물공학자 (bioengineer)의 역할을 하며, 환경오염의 경고자로서 관심이 증대되고 있다(Feely et al., 2004; Pandolfi et al., 2011; PerkolFinkel et al., 2012; Satheesh and Wesley, 2012). 최근에 온실가 스인 CO2의 증가로 인한 수온 상승과 CO2 농도 증가에 따른 해 양산성화, 그리고 조식동물의 증가로 인하여 연간 4억 6천만 톤 의 탄소를 흡수하는 해중림이 지속적으로 감소되고 있어(Harley et al., 2012; Muraoka, 2004; Ordonez et al., 2014), 해중림 복원에 대한 연구가 많이 수행되고 있다(Whitaker et al., 2010; Perkol-Finkel et al., 2012). 따라서, 지구온난화와 연안의 환경 상태 변화를 반영하는 지표생물인 해조류의 종다양성과 군집구 조 변화에 대한 자료 축적이 매우 중요한 시점이다(Orfanidis et al., 2001; Diaz-Pulido et al., 2011; Roleda et al., 2012). 해조류 군집지수에 기초한 해양국립공원의 생태학적 평가 오지철·최한길·김철도·안중관*

Effects of environmental factors on the zoospore release and germling growth of Chaetomorpha linum were examined. Zoospore release and germling growth experiments were carried out under a combination of temperatures × irradiances, and a single factor of irradiances, salinities, daylength and nutrients (nitrogen, phosphorus). Zoospore release was maximal under condition of 20℃ × 100 μmol photons m −2 s −1 in a factorial experiment (temperatures × irradiances), at 100 μmol photons m −2 s −1 in irradiance experiment and at 34 psu in salinity conditions. After 24 days in culture, germling growth was maximal at 25℃ × 100 μmol photons m −2 s −1 in temperatures × irradiances and at normal seawater (34 psu) in salinity. Germling growth is faster at higher irradiance under same temperature condition and it increased with increasing daylengths (8−16 h). Chaetomorpha linum grew in wide range of N and P concentrations. The growth of germling was maximal at 50 μM PO₄ 3− and 40 μM NH₄ + . Germling growth was more effective under nitrogen addition than phosphorus addition in culture. In conclusion, optimal environmental conditions for zoospore release were 20℃, 100 μmol photons m −2 s −1 , and 34 psu. In addition, the optimal germling growth was observed at 25℃, 100 μmol photons m −2 s −1 , 34 psu, 16 h, 50 μM (PO₄ 3− ) and 40 μM(NH₄ + ).

In this paper, we test the performance of templates in detection and characterization of Spin-orbit resonant (SOR) binaries. We use precessing SEOBNRv3 waveforms as well as {\it four} numerical relativity (NR) waveforms to model GWs from SOR binaries and filter them through IMRPhenomD, SEOBNRv4 (non-precessing) and IMRPhenomPv2 (precessing) approximants. We find that IMRPhenomD and SEOBNRv4 recover only $\sim70\%$ of injections with fitting factor (FF) higher than 0.97 (or 90\% of injections with ${\rm FF} >0.9$).However, using the sky-maxed statistic, IMRPhenomPv2 performs magnificently better than their non-precessing counterparts with recovering $99\%$ of the injections with FFs higher than 0.97. Interestingly, injections with $\Delta \phi = 180^{\circ}$ have higher FFs ($\Delta \phi$ is the angle between the components of the black hole spins in the plane orthogonal to the orbital angular momentum) as compared to their $\Delta \phi =0^{\circ}$ and generic counterparts. This implies that we will have a slight observation bias towards $\Delta \phi=180^{\circ}$ SORs while using non-precessing templates for searches. All template approximants are able to recover most of the injected NR waveforms with FFs $>0.95$. For all the injections including NR, the error in estimating chirp mass remains below $, Comment: 27 pages, 15 figures. Abstract shortened due to word limit

Seasonal variability in the marine seaweed community structure was examined in the intertidal zones at nine study sites in Hallyeohaesang National Park, on the southern coast of Korea from March to October 2014. A total of 145 seaweeds were indentified, comprising 15 green, 41 brown and 89 red algae. Coarsely branched seaweeds were the dominant functional group, comprising 58.95% in species number, whereas filamentous, sheet, thick leathery, crustose and jointed calcareous forms comprised 2.63-17.72% each. The seaweed biomass averaged 358.00 g dry wt/m2 and it was maximal at Somaemuldo (847.64 g dry wt/m2) and minimal at Gamam (56.51 g dry wt/m2). Based on biomass, the dominant and subdominant seaweeds were Ulva australis at Gamam, Sargassum thunbergii at Sangju, Ulva australis and S.fulvellum at Neukdo, S.horneri at Dala-Bijindo-Somaemuldo, S. thunbergii at Dapo, and Corallina pilulifera at Songdo. Community indices were as follows: dominance index (DI), 0.43-0.71; richness index (R), 8.26-16.50; evenness index (J`), 0.36-0.54; and diversity index (H`), 1.57-2.19. In conclusion, we found that both biomass and the community structure of seaweeds in Hallyeohaesang National Park were similar to those in other studies of the Southern Sea along the Korean peninsula, and that Hallyeohaesang National Park is a relatively favorable habitat for seaweeds. Future studies should examine the changes in seaweed composition and biomass as they relate to climate change and environmental pollution.

To examine the effects of increased CO₂ concentration and seawater temperature on the photosynthesis and growth of forest forming Ecklonia cava (Laminariales, Phaeophyta), sporophytic discs and gametophytes were cultured under three pCO₂ concentrations (380, 750, 1000 ppm), four temperatures (5, 10, 15, 20℃ for sporophytes; 10, 15, 20, 25℃ for gametophytes), and two irradiance levels (40, 80 μmol photons m ?2 s ?1 ) for 5 days. Photosynthetic parameter values (ETR max , E k , and α) were generally higher as sporophytic discs were grown under low temperature and increased CO₂ concentration at 750 ppm. However, photosynthesis of Ecklonia sporophytes was severely inhibited under a combination of high temperature (20℃) and 1000 ppm CO₂ concentration at the two photon irradiance levels. The growth of gametophytes was maximal at the combination of 380 ppm (present seawater CO₂ concentration) and 25℃. Minimal growth of gametophytes occurred at enriched pCO₂ concentration levels (750, 1000 ppm) and high temperature of 25℃. The present results imply that climate change which is increasing seawater temperature and pCO₂ concentration might diminish Ecklonia cava kelp beds because of a reduction in recruitments caused by the growth inhibition of gametophytes at high pCO₂ concentration. In addition, the effects of increased temperature and pCO₂ concentration were different between generations - revealing an enhancement in the photosynthesis of sporophytes and a reduction in the growth of gametophytes.

2 of Ulva frond, hole areas ranged from 0.37 to 5.94 cm 2 , and between 4.9 and 36.2 holes were observed. Fourteen residential animal species were observed at the three evaluated sites, 75.0 (Haseom) to 408.7 individuals 100 g -1 Ulva (Pohang) per site. The dominant residential species at each site differed with Amphithoe sp. at Haseom, Monodonta spp. at Pohang, and Pagurus sp. at Woedo. The growth (frond area, wet weight) and hole number of Ulva fronds, and the number of residential animals were significantly greater in samples collected from the sheltered shore than the wave-exposed shore of Seongsan. The present results showed U. australis grew well at sheltered shores and had more holes on the fronds due to abundance of residen- tial animals. The dominant residential animals (crabs, gammaridea, and snails) were similar in the Ulva populations of sheltered and wave-exposed shores, but greater species diversity was observed at the exposed shore (18 species ver. 11 species). In conclusion, U. australis is a keystone species providing habitat to various invertebrates and frond holes are positively correlated to the number of residential animals.

To examine the relationship between competition and environmental factors, the germlings of Ascophyllum nodosum (L) Le Jolis and Fucus vesiculosus L. were cultured in monocultures and mixtures of the two species under two different exposure and nutrient levels. Both intra- and inter-specific competition were examined in comparison of the mortality and growth of germlings in monocultures and mixtures of the two species. The mortality of germlings increased with increasing density and emergence periods both in the monoculture and mixtures of the two species, and the mortality of Ascophyllum was significantly higher than that of Fucus both in submerged and emerged treatments. The growth of germlings of both species reduced with increasing density but F. vesiculosus always grew faster than Ascophyllum. The values of log output ratio were more than 0.1, indicating that Fucus ‘won’ in the competitive battles with Ascophyllum under two nutrient- and air-exposure levels. Log output ratio was greater in high than in low nutrients, indicating that the growth of Fucus is more enhanced than that of Ascophyllum in high nutrients. In the present study, the outcome of inter specific competition between germlings of Fucus vesiculosus and Ascophyllum nodosum was slightly altered by duration of emergence and nutrient concentration, but not to such an extent as to change the outcome.

A light scalar dark matter (DM) is allowed in a wide range of the mass and interaction types. We show that the light scalar DM may be probed in a new way from final years of neutron-star (NS) binary inspirals. If the DM interacts with the neutron, its long wave coherence in the background can induce the time-oscillating mass shift, to which the binary inspiral is inherently sensitive. But the sensitivity is found to be significantly enhanced by a large number of gravitational-wave (GW) cycles during year-long highest-frequency measurements in the broadband $f \simeq 0.01-1000$ Hz. The future broadband detector networks including LIGO-band detectors can probe unconstrained parameter space of the light scalar DM., Comment: 12 pages, 3 figures

해양의 연안생태계는 지구에서 종다양성과 생산성이 가장 높 은 곳이며(De Forges et al., 2000), 기초생산자인 해조류는 다 양한 해양 동·식물의 서식처(착생기질, 산란장, 생육장)로서 생 태적 서비스를 제공한다(Lindstrom, 2009). 따라서, 생산자인 해조류의 종별 형태, 크기와 군집에서 개체군 종류, 종조성 및 생물량 등은 이를 이용하는 해양생물의 종다양성과 밀접한 관 련이 있으므로 해조류의 군집구조를 파악하는 것은 연안생태 계의 먹이망을 이해하는데 필수적인 요소이다(Hooper et al., 2005; Lindstrom, 2009). 또한, 해조류의 군집구조는 시·공간 적으로 변화하고 있는 것으로 알려져 있는데, 이는 인간의 직· 간접적인 활동으로 인한 수질환경(부영양화, 수질오염, 퇴적물 증가 등)과 기후 변화(수온상승과 해양산성화 등), 나아가 이러 한 무생물적 환경의 변화로 인한 생물학적 상호작용인 경쟁과 섭식압의 변화 때문이다(Tribollet and Vroom, 2007; Szmant 2002). 환경오염과 부영양화가 심한 해역에서는 해조류의 종 다양성이 감소하여 단순화된 군집구조를 보임으로써 해조류의 종조성과 군집구조는 암반 연안생태계의 환경 상태를 확인하 는 생물학적 지시자(biological indicator)로 활용된다고 하였다 (Wells et al., 2007). 한국의 남해안(부산광역시 해운대전남 해남군 토말)은 리아 스식 해안으로 해류의 변화가 심하고, 해역에 따라 물리적 환 경(수온, 탁도 등)이 달라서, 해역별 해조류의 종조성과 군집구 한국 남해안 정자도의 해조상 및 군집구조 변화 유현일·정보경·박정광·허진석·박미선 ·최한길*