Distribution of DDTs in the Sediment of Lake Biwa

1992 ◽  
Vol 25 (11) ◽  
pp. 93-98
Author(s):  
K. Kawabe ◽  
A. Maegawa ◽  
S. Yamanaka ◽  
K. Nomura
Keyword(s):  
Vertical Distribution ◽  
Lake Biwa ◽  
Southern Basin ◽  
The Past ◽  
Northern Basin ◽  
The Vertical Distribution

An investigation was carried out to determine the residual tendency of DDT and its derivatives in the sediment of Lake Biwa, Japan, where the banning of DDT took effect some 15 years ago. Of the two basins shaping Lake Biwa, the frequency of detection of DDT was higher in the Northern Basin than in the Southern Basin. In the Southern Basin, the area of DDT detection was more confined than that of DDE detection. Therefore, it is reasonable to assume that DDT has been decomposing more rapidly in the Southern Basin than in the Northern Basin. Based on the profile obtained for the vertical distribution of DDTs, it can be inferred also that the amount of DDT and DDE flowing in from land has been decreasing in the past years. DDT has hardly been decomposing into DDE at the deeper part of the Lake.

Acoustic evaluation of the vertical distribution of dwarf ayu Plecoglossus altivelis altivelis in Lake Biwa

2001 ◽  
Vol 67 (3) ◽  
pp. 430-435 ◽  
Author(s):  
Kunio Shirakihara ◽  
Masahiko Yoshida ◽  
Machiko Nishino ◽  
Yoshimi Takao ◽  
Kouichi Sawada
Keyword(s):  
Vertical Distribution ◽  
Lake Biwa ◽  
Plecoglossus Altivelis ◽  
Acoustic Evaluation ◽  
The Vertical Distribution

Observations on the Vertical Distribution of Eggs and Larvae of Mackerel and other Teleosts in the Celtic Sea and on the Sampling Performance of Different Nets in Relation to Stock Evaluation

1980 ◽  
Vol 60 (2) ◽  
pp. 295-311 ◽  
Author(s):  
A. J. Southward ◽  
B. McK. BARY
Keyword(s):  
Vertical Distribution ◽  
Geographical Pattern ◽  
Spawning Grounds ◽  
The Past ◽  
South West ◽  
Complete Survey ◽  
Celtic Sea ◽  
The Vertical Distribution ◽  
Eggs And Larvae ◽  
Made In

There is some controversy about the strength of the stock of mackerel in the Celtic Sea and off the coasts of Cornwall and Ireland, and it is difficult to find out if the numbers of mackerel in this area have fluctuated in the past (Johnson, 1977; Lockwood & Johnson, 1976; Lockwood, 1978; Coombs, Pipe & Mitchell, 1977,1979, 1980). The earliest complete survey of the south-west spawning grounds was made in 1937–9 (Steven & Corbin, 1939; Corbin, 1947) and was principally designed to show the seasonal and geographical pattern, not provide a basis for stock evaluation. Nevertheless, this survey is the only information we have about the breeding of mackerel in the days before the war when fishing was performed with drift-nets and lines, a period when we can assume exploitation was very much less intense than today when trawls and purse-seines are used. Attempts to use the 1937–9 data for estimation of the pre-war stock have been regarded as giving unsatisfactory results (Walsh, 1976). The data from the 1937–9 surveys were defective because we did not know the influence of the depth of fishing of the nets in relation to the vertical distribution of the eggs, nor the efficiency and catching capacity of the nets for sampling eggs and post-larvae.

The vertical distribution of thin features over the Arctic analysed from CALIPSO observations. Part I: Optically thin clouds

Tellus B ◽  
2011 ◽  
Vol 63 (1) ◽  
Author(s):  
Abhay Devasthale ◽  
Michael Tjernström ◽  
Karl-Göran Karlsson ◽  
Manu Anna Thomas ◽  
Colin Jones ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
The Arctic ◽  
The Vertical Distribution
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