scholarly journals Observations of the climate in the southern part of the north basin of Lake Biwa, Japan by a meteorological station mounted on a buoy

2003 ◽  
Vol 64 (2) ◽  
pp. 103-112 ◽  
Author(s):  
Yasuaki OKUMURA ◽  
Shuichi ENDOH
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michio Kumagai ◽  
Richard D. Robarts ◽  
Yasuaki Aota

AbstractAn autonomous underwater vehicle (AUV) was deployed in Lake Biwa from 2000 to 2012. In December 2009, ebullition of turbid water was first found in the deepest area (> 90 m) of the North Basin. Follow-up investigations in April and December 2010 and January 2012 confirmed the existence of benthic vents similar to the vents observed in other deep lakes. Importantly, vent numbers per unit travel distance in Lake Biwa dramatically increased from only two vents (0.37 vents km−1) in December 2009 to 54 vents (5.28 vents km−1) in January 2012, which could be related to recent tectonic activity in Japan, e.g., the M9.1 Tohoku earthquake in March 2011 and slow earthquakes along the Nankai Trough from 2006 to 2018. Continuous back-up investigations from 2014 to 2019 revealed additional benthic vents in the same area. The sudden increase in benthic vent activity (liquid and gaseous ebullitions) have significant potential to alter lake biogeochemistry and, ultimately, degrade Japan’s major drinking water source and may be a harbinger of major crustal change in the near future.


2006 ◽  
Vol 29 (4) ◽  
pp. 1913-1920 ◽  
Author(s):  
Osamu Mitamura ◽  
Hiroto Maeda ◽  
Yasushi Seike ◽  
Kunio Kondo ◽  
Naoshige Goto ◽  
...  

2020 ◽  
Vol 37 ◽  
pp. 1-5
Author(s):  
Fernando Carvalho ◽  
Daniela A.S. Bôlla ◽  
Viviane Mottin ◽  
Suelen Zonta Kiem ◽  
Jairo J. Zocche ◽  
...  

The greater round-eared bat, Tonatia bidens (Spix, 1823), is a medium-sized phyllostomid bat distributed in the north of Argentina, Paraguay and Brazil. The diet and foraging patterns of this species are poorly known. We analyzed the composition of the diet of a population of T. bidens and how the temperature influences the consumption of vertebrates and invertebrates. To describe diet composition, we conducted weekly collections of food scrap from two monospecific night-perches. Data of temperature for the study period were taken from the meteorological station installed 300 m from the collection perches. The influence of temperature was evaluated using generalized linear models (GLMs) with negative binomial distribution. Tonatia bidens consumed 28 taxons (204 records), being at least 17 Artropods and 11 Passeriformes birds. Temperature explained a greater proportion of vertebrate abundance (R2 = 0.23) than invertebrate (R2 = 0.16) or to both pooled (R2 = 0.11). The relation with temperature was positive with invertebrates and negative with the vertebrates. The diet of the population of T. bidens comprised mainly invertebrates, which were the most frequent and diverse taxa. Data suggests that T. bidens has a diverse diet, with proportion of the item’s consumption varying temporally. Environmental factors, such as the temperature presented on this work, seems to be good proxies for the dietary traits of this species.


2019 ◽  
Vol 28 (1) ◽  
pp. 79-86 ◽  
Author(s):  
V. K. Khilchevskyi ◽  
S. M. Kurylo ◽  
N. P. Sherstyuk ◽  
M. R. Zabokrytska

This article provides characteristic of the chemical composition of atmospheric precipitation on the territory of Ukraine and its potential impact on the environment and water bodies. In Ukraine, the rainfall is 650 mm/year in the northwest of the country (mixed forests), up to 300 mm/year in the south (steppe zone), in the Ukrainian Carpathians - up to 1,600 mm/year. Acidity of atmospheric precipitation (pH) on the territory of Ukraine according to monitoring meteorological stations is 5.9-6.3. Minimum values of mineralization of atmospheric precipitation are observed in a zone of mixed forests in the north of the country. In particular, according to the weather station of Teteriv, the mineralization of atmospheric precipitation is 27.0 mg/l. In forest-steppe and steppe zones, this rate gradually increases to 35-45 mg/l, reaching a maximum in the steppe zone at the Askania-Nova meteorological station (82.4 mg/l). In the chemical composition of atmospheric precipitation, anion predominates sulfates, and among cations - magnesium. Anthropogenic component of the total mineralization of atmospheric precipitation, calculated for the first time on the territory of Ukraine (meteorological station Kobelyaki) by comparison with the regional natural background, is 69%. Concentration of sulfate ions (8-24 mg/l) in atmospheric precipitation on the territory of Ukraine shows a high level of pollution with sulfur, which corresponds to IV-V levels o environmental pollution. It is noted that with increasing concentrations of sulfates in atmospheric precipitation a tendency towards a decrease in the pH in the water of Svityaz Lake is projected. Current research shows that at high concentrations of sulfates in atmospheric precipitation, the risk of falling individual rains with low pH (so-called acid rains) increases. Waters of high concentration of organic matter and low mineralization of water are widely distributed on the territory of Ukraine (catchments of Polissya and the Carpathian region): up to 100 mg/l in the meadows and up to 30 mg/l in the flood period. Often, the pH of water in them is 6-6.5 and precipitation of acidic precipitation can significantly affect their hydroecological state. The obtained results on the influence of chemical composition of atmospheric precipitation on water objects have a diagnostic character. For more specific results, special synchronized studies of the chemical composition of the water of experimental water reservoirs with sampling ofatmospheric precipitation are required.


2011 ◽  
Vol 16 (3) ◽  
pp. 215-221 ◽  
Author(s):  
Iwaki Maho ◽  
Hida Yoshifumi ◽  
Ueno Ken’ichi ◽  
Saijyou Mayumi

Zootaxa ◽  
2011 ◽  
Vol 2874 (1) ◽  
pp. 1 ◽  
Author(s):  
ROBIN J. SMITH ◽  
HORST JANZ ◽  
ICHIRO OKUBO

Sampling between 1999 and 2007 of the recent ostracod fauna of Lake Biwa, an ancient lake located in Japan, produced ten Cyprididae and one Ilyocyprididae species. One Cyprididae species, belonging to the genus Ilyodromus is described herein, Ilyodromus intermedius Okubo n. sp., and Bradleytriebella lineata (Victor & Fernando, 1981c) is redescribed. One Cyprididae species is a new record for Japan, namely Stenocypris malayica Victor & Fernando, 1981a, while seven others are new records for Lake Biwa. The family Ilyocyprididae is represented by only one species in Lake Biwa, Ilyocypris salebrosa Stepanaitys, 1960. The Lake Biwa population of this species is the first record of males and they are described in this paper. Including this study, forty ostracod species have now been reported from Lake Biwa. Most species (70%) were found at depths of less than 1 meter. Only four species were found below 44 m, the mean depth of the north basin.


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