Yasuhiro Suzaki, Noriko Futatsugi, Kotomi Watanabe, Kazuo Fukushima, Ho-Dong Park
The green algae Botryococcus braunii is known for its considerable production of hydrocarbons. Recently, we found B. braunii growing in Lake Shirakoma, which is situated at a high altitude ( 2 , 115 m ) in the Nagano Prefecture, Japan. We examined the nature of lipid production and the niche of B. braunii in the lake by conducting genetic, stable isotopic and lipid compositional analyses on natural and cultured algal strains. Using lipid and genetic analyses, B. braunii from Lake Shirakoma was identified as A race and phylogenetically close to B. braunii Yamanaka ( HM 245352 ) isolated from Lake Yamanaka in the Yamanashi Prefecture. Because both lakes are situated at high altitude and are usually or often covered by ice in winter, these species may have a similar ability to adapt to a cold climate. Lipids and stable isotopic compositions suggested that B. braunii is not consumed by zooplankton in Lake Shirakoma. Natural algal samples contained up to 0 . 045 % of hydrocarbons by weight. Meanwhile, the cultured strain produced up to 12 . 5 % of hydrocarbons by weight. Thus, B. braunii from Lake Shirakoma also has the potential to produce abundant hydrocarbons, when placed under optimum growing conditions.
{"title":"Lipid production of Botryococcus braunii in high-altitude dystrophic Lake Shirakoma, Japan","authors":"Yasuhiro Suzaki, Noriko Futatsugi, Kotomi Watanabe, Kazuo Fukushima, Ho-Dong Park","doi":"10.3739/RIKUSUI.75.161","DOIUrl":"https://doi.org/10.3739/RIKUSUI.75.161","url":null,"abstract":"The green algae Botryococcus braunii is known for its considerable production of hydrocarbons. Recently, we found B. braunii growing in Lake Shirakoma, which is situated at a high altitude ( 2 , 115 m ) in the Nagano Prefecture, Japan. We examined the nature of lipid production and the niche of B. braunii in the lake by conducting genetic, stable isotopic and lipid compositional analyses on natural and cultured algal strains. Using lipid and genetic analyses, B. braunii from Lake Shirakoma was identified as A race and phylogenetically close to B. braunii Yamanaka ( HM 245352 ) isolated from Lake Yamanaka in the Yamanashi Prefecture. Because both lakes are situated at high altitude and are usually or often covered by ice in winter, these species may have a similar ability to adapt to a cold climate. Lipids and stable isotopic compositions suggested that B. braunii is not consumed by zooplankton in Lake Shirakoma. Natural algal samples contained up to 0 . 045 % of hydrocarbons by weight. Meanwhile, the cultured strain produced up to 12 . 5 % of hydrocarbons by weight. Thus, B. braunii from Lake Shirakoma also has the potential to produce abundant hydrocarbons, when placed under optimum growing conditions.","PeriodicalId":35602,"journal":{"name":"Japanese Journal of Limnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69924602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Measurements of nitrogen and phosphorus bioaccumulation in the leaves, stems, rhizomes, and spikelets of reeds ( Phragmites australis ) in the Yatsu Tidal Flat were carried out monthly from June 2013 to January 2014. The reeds increased in length, in stem and rhizome circumference, and in biomass until October. After November, the reeds started to senescence and biomass decreased. Storage of nitrogen and phosphorus in the leaves and stems was higher from August – October than during other months, while storage in the rhizomes ( at 10 cm depth from the sediment surface ) was low throughout the investigation period. Aboveground nitrogen and phosphorus storage in the leaves, stems, and spikelets accounted for more than 90 % of stores of these nutrients in this study.
{"title":"Nitrogen and phosphorus bioaccumulations of Phragmites australis in Yatsu Tidal Flat","authors":"Y. Senga, Shohei Yamauchi","doi":"10.3739/RIKUSUI.76.149","DOIUrl":"https://doi.org/10.3739/RIKUSUI.76.149","url":null,"abstract":"Measurements of nitrogen and phosphorus bioaccumulation in the leaves, stems, rhizomes, and spikelets of reeds ( Phragmites australis ) in the Yatsu Tidal Flat were carried out monthly from June 2013 to January 2014. The reeds increased in length, in stem and rhizome circumference, and in biomass until October. After November, the reeds started to senescence and biomass decreased. Storage of nitrogen and phosphorus in the leaves and stems was higher from August – October than during other months, while storage in the rhizomes ( at 10 cm depth from the sediment surface ) was low throughout the investigation period. Aboveground nitrogen and phosphorus storage in the leaves, stems, and spikelets accounted for more than 90 % of stores of these nutrients in this study.","PeriodicalId":35602,"journal":{"name":"Japanese Journal of Limnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69924585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Miyazako, Shogo Sugahara, Y. Tabayashi, H. Ohshiro, Y. Koyama, Y. Nakashima, H. Kamiya, Y. Seike
We sampled river water from 1 July 2010 to 30 June 2011 in the Hii River. Suspended solids (SS), chemical oxygen demand (COD), total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP) showed increasing trends during floods. In contrast, dissolved silica (DSi) had a decreasing trend during floods. By comparing estimated loading amounts from a loading-flow (LQ) equation and actual loading amounts from multiplying a given day s chemical species and discharge, TN, nitrate and D-Si showed quantitative agreement between the two estimations. However, loading amounts of SS, COD, TOC, TP and phosphate from a linear LQ equation had lower values than those of actual loadings. The reason for such underestimation is an increased concentration of certain chemical species during flooding or high discharge. Therefore, we applied quadratic or cubic LQ equations. After applying the quadratic LQ equation to certain chemical species that showed low coefficients of determination, values improved. For more accurate loading amounts from an LQ equation, we require observation data from periods of high discharge.
{"title":"Comparison of measured and calculated loads using quadratic LQ equation for Hii River flows, eastern Shimane Prefecture, Japan","authors":"T. Miyazako, Shogo Sugahara, Y. Tabayashi, H. Ohshiro, Y. Koyama, Y. Nakashima, H. Kamiya, Y. Seike","doi":"10.3739/RIKUSUI.75.151","DOIUrl":"https://doi.org/10.3739/RIKUSUI.75.151","url":null,"abstract":"We sampled river water from 1 July 2010 to 30 June 2011 in the Hii River. Suspended solids (SS), chemical oxygen demand (COD), total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP) showed increasing trends during floods. In contrast, dissolved silica (DSi) had a decreasing trend during floods. By comparing estimated loading amounts from a loading-flow (LQ) equation and actual loading amounts from multiplying a given day s chemical species and discharge, TN, nitrate and D-Si showed quantitative agreement between the two estimations. However, loading amounts of SS, COD, TOC, TP and phosphate from a linear LQ equation had lower values than those of actual loadings. The reason for such underestimation is an increased concentration of certain chemical species during flooding or high discharge. Therefore, we applied quadratic or cubic LQ equations. After applying the quadratic LQ equation to certain chemical species that showed low coefficients of determination, values improved. For more accurate loading amounts from an LQ equation, we require observation data from periods of high discharge.","PeriodicalId":35602,"journal":{"name":"Japanese Journal of Limnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69924540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Kamiya, Shogo Sugahara, Y. Saga, S. Sato, Y. Nojiri, M. Kishi, A. Fujihara, T. Godo
Water, salt and phosphorus balance of the 19 years was calculated in Lake Shinji, a shallow brackish lake in Japan. Average annual freshwater inflow of 19 years into Lake Shinji was in the range of the 1.25 ～ 2.35 × 10 9 m 3 , the average was 1.77 × 10 9 m 3 . Reverse flow from the Lake Nakaumi located downstream of the Lake Shinji was in the range of 0.32 ～ 0.84 × 10 9 m 3 , the average was 0.49 × 10 9 m 3 , corresponding to 27.7% of the freshwater inflow. Retention time in consideration of the amount of freshwater inflow and reverse flow from the Lake Nakaumi were from
{"title":"The mechanism and rate of re-sedimentation of phosphorus released from the sediment during the summer months in shallow brackish lakes","authors":"H. Kamiya, Shogo Sugahara, Y. Saga, S. Sato, Y. Nojiri, M. Kishi, A. Fujihara, T. Godo","doi":"10.3739/RIKUSUI.76.139","DOIUrl":"https://doi.org/10.3739/RIKUSUI.76.139","url":null,"abstract":"Water, salt and phosphorus balance of the 19 years was calculated in Lake Shinji, a shallow brackish lake in Japan. Average annual freshwater inflow of 19 years into Lake Shinji was in the range of the 1.25 ～ 2.35 × 10 9 m 3 , the average was 1.77 × 10 9 m 3 . Reverse flow from the Lake Nakaumi located downstream of the Lake Shinji was in the range of 0.32 ～ 0.84 × 10 9 m 3 , the average was 0.49 × 10 9 m 3 , corresponding to 27.7% of the freshwater inflow. Retention time in consideration of the amount of freshwater inflow and reverse flow from the Lake Nakaumi were from","PeriodicalId":35602,"journal":{"name":"Japanese Journal of Limnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69924870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Based on quantitative survey data of 108 rivers and 724 freshwater sites collected during a national census of river environments, we determined the frequency distribution of total invertebrate biomass (total biomass) of riffl es. We also examined the spatial pattern of total biomass by classifying sites according to channel gradient, bed substrate, and region. The median value of total biomass (in wet-weight) among all sites was 19.56 g m for spring-winter and 10.04 g m for summer-autumn. These values were similar to those previously reported for Japanese rivers, but were several times higher than those reported for rivers from other countries. The total biomass was lowest for sites with gentlest gradient classes (<1/3200) and larger for sites with steeper channel classes of up to 1/800-1/400. The total biomass was also lowest for sites with the fi nest substrate classes (silt, sand: <2 mm) and was larger for sites with coarser substrate classes up to small cobbles (5-10 cm). Total biomass was also larger for sites in southwestern regions (especially, Chugoku, Shikoku, Kyushu) than in northeastern regions (especially, Tohoku, Kanto, Hokuriku) with 2.7-6.6 fold differences in median values between these regions. Many taxa showed a high preference (i.e., disproportionately higher occurrence and abundance) for the slope and substrate classes with larger total biomass, and there was also a positive correlation between their own density and total biomass. These patterns were most conspicuous for net-spinning caddisfl y taxa, which are likely to contribute signifi cantly to the total biomass. According to habits of these taxa, bed characteristics such as amount of interstices and bed stability are likely to be factors controlling total biomass. A positive correlation between total biomass and number of genera
基于全国河流环境普查中108条河流和724个淡水站点的定量调查数据，确定了河流无脊椎动物总生物量(总生物量)的频率分布。此外，我们还根据河道坡度、河床底物和区域对样地进行了分类，研究了总生物量的空间格局。各样地的总生物量(湿重)中值春冬季为19.56 g m，夏秋季为10.04 g m。这些数值与之前报道的日本河流相似，但比其他国家河流的数值高出几倍。坡度最小的样地(<1/3200)总生物量最低，坡度较大的样地(> 1/800-1/400)总生物量最高。总生物量在基质类型较细的场地(淤泥、砂:<2 mm)也最低，而在基质类型较粗的场地(小鹅卵石(5-10 cm))则较大。西南地区(特别是中国、四国、九州)的总生物量比东北地区(特别是东北、关东、北陆)的总生物量大，中位数相差2.7 ~ 6.6倍。许多类群对总生物量较大的坡类和底类表现出高度偏好(即不成比例的高发生率和丰度)，其自身密度与总生物量也存在正相关关系。这些模式在对总生物量有重要贡献的纺网飞类中最为明显。根据这些类群的习性，间隙量和床层稳定性等床层特征可能是控制总生物量的因素。总生物量与属数呈正相关
{"title":"Describing benthic invertebrate communities in Japanese rivers using national environmental census data: spatial distributions of total biomass and major taxa","authors":"Sohei Kobayashi, Fumikazu Akamatsu, S. Nakanishi, Yoshinori Yajima, Junji Miwa, Kunihiko Amano","doi":"10.3739/RIKUSUI.74.129","DOIUrl":"https://doi.org/10.3739/RIKUSUI.74.129","url":null,"abstract":"Based on quantitative survey data of 108 rivers and 724 freshwater sites collected during a national census of river environments, we determined the frequency distribution of total invertebrate biomass (total biomass) of riffl es. We also examined the spatial pattern of total biomass by classifying sites according to channel gradient, bed substrate, and region. The median value of total biomass (in wet-weight) among all sites was 19.56 g m for spring-winter and 10.04 g m for summer-autumn. These values were similar to those previously reported for Japanese rivers, but were several times higher than those reported for rivers from other countries. The total biomass was lowest for sites with gentlest gradient classes (<1/3200) and larger for sites with steeper channel classes of up to 1/800-1/400. The total biomass was also lowest for sites with the fi nest substrate classes (silt, sand: <2 mm) and was larger for sites with coarser substrate classes up to small cobbles (5-10 cm). Total biomass was also larger for sites in southwestern regions (especially, Chugoku, Shikoku, Kyushu) than in northeastern regions (especially, Tohoku, Kanto, Hokuriku) with 2.7-6.6 fold differences in median values between these regions. Many taxa showed a high preference (i.e., disproportionately higher occurrence and abundance) for the slope and substrate classes with larger total biomass, and there was also a positive correlation between their own density and total biomass. These patterns were most conspicuous for net-spinning caddisfl y taxa, which are likely to contribute signifi cantly to the total biomass. According to habits of these taxa, bed characteristics such as amount of interstices and bed stability are likely to be factors controlling total biomass. A positive correlation between total biomass and number of genera","PeriodicalId":35602,"journal":{"name":"Japanese Journal of Limnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69923697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Salinity range that freshwater submerged and floating-leaved plants which may overgrow in brackish lakes in Japan were observed","authors":"M. Yamamuro","doi":"10.3739/RIKUSUI.75.113","DOIUrl":"https://doi.org/10.3739/RIKUSUI.75.113","url":null,"abstract":"","PeriodicalId":35602,"journal":{"name":"Japanese Journal of Limnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69924059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The spatial distribution of submerged macrophytes, in terms of biomass and species composition, was surveyed in the south basin of Lake Biwa in September, 2012 using scuba. Submerged macrophytes were observed in 48 out of 52 sampling stations, and 12 species were found in this study. The number of species of submerged macrophytes per site was 4 . 6 ± 2 . 0 . The area with vegetation cover and the total biomass ( dry weight ) during the study period were estimated to be 47 . 6 km 2 and 3264 ± 1445 t, respectively. Although the area with vegetation cover was only 1 km 2 less than in 2007 , total biomass of submerged macrophytes declined by 6360 t during the same period. Biomass of Potamogeton maackianus , Egeria densa , and Ceratophyllum demersum decreased signifi cantly between 2007 and 2012 ( paired Student 2007 and 2012 ( paired Students t -test, P < 0 . 05 , n = 52 ) , 4107 t, 879 t, and 804 t, respectively. Biomass reduction in these three species accounted for 91 % of the entire reduction. The biomasses of the other species also declined, with excepthion of two, Potamogeton malaianus and P. anguillanus
{"title":"Spatial distribution of submerged macrophytes in the south basin of Lake Biwa in the summer of 2012, compared with 2002 and 2007.","authors":"H. Haga, K. Ishikawa","doi":"10.3739/rikusui.75.107","DOIUrl":"https://doi.org/10.3739/rikusui.75.107","url":null,"abstract":"The spatial distribution of submerged macrophytes, in terms of biomass and species composition, was surveyed in the south basin of Lake Biwa in September, 2012 using scuba. Submerged macrophytes were observed in 48 out of 52 sampling stations, and 12 species were found in this study. The number of species of submerged macrophytes per site was 4 . 6 ± 2 . 0 . The area with vegetation cover and the total biomass ( dry weight ) during the study period were estimated to be 47 . 6 km 2 and 3264 ± 1445 t, respectively. Although the area with vegetation cover was only 1 km 2 less than in 2007 , total biomass of submerged macrophytes declined by 6360 t during the same period. Biomass of Potamogeton maackianus , Egeria densa , and Ceratophyllum demersum decreased signifi cantly between 2007 and 2012 ( paired Student 2007 and 2012 ( paired Students t -test, P < 0 . 05 , n = 52 ) , 4107 t, 879 t, and 804 t, respectively. Biomass reduction in these three species accounted for 91 % of the entire reduction. The biomasses of the other species also declined, with excepthion of two, Potamogeton malaianus and P. anguillanus","PeriodicalId":35602,"journal":{"name":"Japanese Journal of Limnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3739/rikusui.75.107","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69924050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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