Risk assessment of TBT in the Japanese short-neck clam (Ruditapes philippinarum) of Tokyo Bay using a chemical fate model

2006 ◽  
Vol 70 (4) ◽  
pp. 589-598 ◽  
Author(s):  
Fumio Horiguchi ◽  
Kisaburo Nakata ◽  
Naganori Ito ◽  
Ken Okawa
Keyword(s):  
Risk Assessment ◽  
Ruditapes Philippinarum ◽  
Tokyo Bay ◽  
Short Neck ◽  
Chemical Fate ◽  
Fate Model

Production of asari (Manila) clams, Ruditapes philippinarum, during the period of harvest decrease in the 2000s in the Banzu tidal area, Tokyo Bay

2020 ◽  
Vol 33 ◽  
pp. 14
Author(s):  
Mitsuharu Toba ◽  
Jun Kakino ◽  
Kazuo Tada ◽  
Yutaka Kobayashi ◽  
Hideharu Tsuchie
Keyword(s):  
Field Investigation ◽  
Ruditapes Philippinarum ◽  
Management Style ◽  
Seed Stock ◽  
Tokyo Bay ◽  
Yearly Variation ◽  
Culture Area ◽  
Stock Biomass ◽  
Tidal Area ◽  
High Level

In Tokyo Bay, the harvestable quantity of asari (Manila) clams Ruditapes philippinarum has been decreasing since the late 1990s. We conducted a field investigation on clam density in the Banzu culture area from April 1988 to December 2014 and collected records spanning January 1986 to September 2017 from relevant fisheries cooperative associations to clarify the relationship between the temporal variation in stock abundance and the production activities of fishermen. The yearly variation in clam abundance over the study period was marked by larger decreases in the numbers of larger clams. A large quantity of juvenile clams, beyond the biological productivity of the culture area, may have been introduced as seed stock in the late 1980s despite the high level of harvestable stock. The declines in harvested quantity began in the late 1990s and may have been caused by decreases in harvestable stock despite the continuous addition of seed stock clams. The harvested quantity is likely to be significantly dependent upon the wild clam population, even within the culture area, as the harvestable quantity was not correlated with the quantity of seed stock introduced during the study period. These declines in harvested quantity may have resulted from a decreasing number of operating harvesters due to the low level of harvestable stock and consequently reduced profitability. Two findings were emphasized. A certain management style, based on predictions of the contributions of wild and introduced clams to future stock biomass, is essential for economically-feasible culturing. In areas with less harvestable stock, actions should be taken to maintain the incomes of harvesters while avoiding overexploitation, even if the total harvest quantity decreases.

scholarly journals Seasonal changes in short-neck clam (Ruditapes philippinarum) population and its controlling factors on Sashiki Tidal Flats

2018 ◽  
Vol 73 (1) ◽  
pp. 1-10
Author(s):  
Hiroaki TSUTSUMI ◽  
Tasuku NISHIOKA ◽  
Noboru KITAGAWA ◽  
Yoshihiro FUJIYOSHI ◽  
Moriyuki KOZAKI ◽  
...  
Keyword(s):  
Seasonal Changes ◽  
Ruditapes Philippinarum ◽  
Tidal Flats ◽  
Controlling Factors ◽  
Short Neck

scholarly journals SENSITIVITY OF TROPICAL CYCLONE TRACK TO ASSESSMENT OF SEVERE STORM SURGE EVENT AT TOKYO BAY

2018 ◽  
pp. 5 ◽  
Author(s):  
Sota Nakajo ◽  
Hideyuki Fujiki ◽  
Sooyoul Kim ◽  
Nobuhito Mori
Keyword(s):  
Risk Assessment ◽  
Storm Surge ◽  
Wave Equations ◽  
Tokyo Bay ◽  
Cyclone Track ◽  
Tropical Cyclone Track ◽  
Translation Speed ◽  
Long Wave ◽  
Storm Surge Event ◽  
Surge Height

In total 82 tropical cyclones data was used to determine scenarios of translation speed, minimum central pressure and track for risk assessment of storm surge at Tokyo Bay. The numerical simulation of waves and flows was conducted by solving non-linear long wave equations. The maximum surge height shows that the typhoon passing through along northeast directional track is dangerous for Tokyo Bay. This trend confirms the previous risk assessment was reasonable. However, it has been shown that the typhoon passing through along north directional track is also dangerous although the frequency is low. Especially, it is interesting that the typhoon passing through along northwest directional track causes distinctive resurgence and harbor oscillation.

Regional differences in chemical fate model outcome

Chemosphere ◽  
2004 ◽  
Vol 55 (10) ◽  
pp. 1361-1376 ◽  
Author(s):  
Eva Webster ◽  
Don Mackay ◽  
Antonio Di Guardo ◽  
David Kane ◽  
David Woodfine
Keyword(s):  
Regional Differences ◽  
Chemical Fate ◽  
Fate Model

Application of a 3-D chemical fate prediction model (FATE3D) to predict dioxin concentrations in the Tokyo Bay

2006 ◽  
Vol 70 (4) ◽  
pp. 621-632 ◽  
Author(s):  
Norihiro Kobayashi ◽  
Tomomi Eriguchi ◽  
Kisaburo Nakata ◽  
Shigeki Masunaga ◽  
Fumio Horiguchi ◽  
...  
Keyword(s):  
Prediction Model ◽  
Tokyo Bay ◽  
Chemical Fate
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