The seasonal abundance and vertical distribution of the <3-μm phytoplakton in the north basin of Lake Biwa

1986 ◽  
Vol 1 (2) ◽  
pp. 207-221 ◽  
Author(s):  
Toshi Nagata
Keyword(s):  
Vertical Distribution ◽  
Lake Biwa ◽  
Seasonal Abundance ◽  
The North

scholarly journals Increasing benthic vent formation: a threat to Japan’s ancient lake

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michio Kumagai ◽  
Richard D. Robarts ◽  
Yasuaki Aota
Keyword(s):  
Lake Biwa ◽  
Autonomous Underwater Vehicle ◽  
Tohoku Earthquake ◽  
Water Source ◽  
Tectonic Activity ◽  
Drinking Water Source ◽  
Sudden Increase ◽  
The North ◽  
Slow Earthquakes ◽  
Near Future

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.

Seasonal changes in carbon and nitrogen productivity in the north basin of Lake Biwa, Japan

2006 ◽  
Vol 29 (4) ◽  
pp. 1913-1920 ◽  
Author(s):  
Osamu Mitamura ◽  
Hiroto Maeda ◽  
Yasushi Seike ◽  
Kunio Kondo ◽  
Naoshige Goto ◽  
...  
Keyword(s):  
Seasonal Changes ◽  
Lake Biwa ◽  
Carbon And Nitrogen ◽  
The North ◽  
Nitrogen Productivity

Studies of the Biting-habits of African Mosquitos. An Appraisal of Methods employed, with special Reference to the twenty-four-hour Catch

1954 ◽  
Vol 45 (1) ◽  
pp. 199-242 ◽  
Author(s):  
A. J. Haddow
Keyword(s):  
Vertical Distribution ◽  
Special Reference ◽  
Geometric Mean ◽  
Seasonal Abundance ◽  
Central Tendency ◽  
Valuable Method ◽  
Different Seasons ◽  
Working Out ◽  
Different Levels ◽  
Biting Behaviour

It is felt that the 24-hour catch presents a valuable method of studying the biting-behaviour of mosquitos in the field, and further that conclusions concerning seasonal abundance, vertical distribution and times of biting-activity must be based on catches of this type if serious errors of interpretation are to be avoided.The time-divisions of the catch should not exceed one hour, and even shorter intervals may be desirable. Timing should be related to the actual times of sunrise and sunset. Where possible, a series of consecutive catches should be carried out, and a shift system must be carefully considered in relation to the particular series projected.Usually the results from different levels above ground should be treated separately in working out biting-cycles, and this may also apply to results from different seasons or different localities. Further, while in some instances the summation of long series of catches seems permissible, in others it is not, and in these detailed analysis of the figures may be necessary before consistent behaviour-patterns become apparent.In cases where a measure of the central tendency is to be employed, the geometric mean as modified by C. B. Williams appears to be the most suitable.

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