STUDY ON THE FORMATION OF LARGE SCALE ANOXIDATION AND OUTSIDE WATER INTRUSION IN URANOUCHI BAY

浦之内湾大规模氧化及外部水入侵的形成研究

基本信息

批准号：
04650465
负责人：
MUNEKAGE Yukihiro
金额：
$ 1.02万
依托单位：
KOCHI UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04650465/
关键词：
Anoxidation DO production and consumption Intrusion Vertical mixing DO budget daylight hours DO consumption by hydrogen sulfide migration of dinoflagellate 亜表層部の貧酸素化異常気象プランクトンによるDO消費赤潮 DO消費速度密度流物質収支海水交換

项目摘要

In Uranouchi Bay, strong anoxic water mass was formed in the bottom and subsurface layrs in summer. A large number of cultured yellowtail fish were killed.(1)Anoxic water in the bottom grew with the development of pycnocline from June to September, and disappeared for a while after intrusion. Intrusion upwelled the bottom nutrient water, and made worse the upper water quality.(2)Hydrogen sulfide (H2S), which was produced at the bottom surface with the development of anoxic water, was transported to the upper layr through vertical mixing, and immediately oxidized. Oxidation of H2S reduced the dissolved oxygen (DO) concentration in the bottom layr by 2.4ppm during August, and further promoted the anoxidation.(3)Gymnodinium nagasakiense red tide plankton began to grow at the middle layr in the center of Uranouchi Bay with the development of anoxic water in the bottom. When external saline water intruded, abnormal multiplication immediately occurred in the whole layrs, red tide was formed at the surface.(4)Anoxidation in the subsurface was formed at the beginning of September, 1988, the middle of August and September, and the beginning of November, 1993. These were formed from just after the sudden decrease of daylight hours. At the beginning of anoxidation, red tides of dinoflagellates and outside water intrusion were developed.(5)Dinoflagellates were appeared in the surface in the daytime, but migrate into the depth of 8-15m in the nighttime, and consumed abundant DO in the subsurface and middle layrs.(6)DO concentration in the subsurface layr was controlled by the production due to phytoplankton and consumption in water. DO supply due to mixing and intrusion was negligible. When the daylight hours decreased, anoxidation were formed in the subsurface, because DO production in the subsurface layr decreased, and DO consumption were increased due to the migration of dinoflagellates.

在Uranouchi湾，在夏季，底部形成了强大的缺氧水质量，夏季形成了地下层。（1）底部的缺氧水杀死了大量培养的黄尾鱼。随着6月至9月的pycnocline的发展，底部的缺氧水生长出来，并在侵入后消失了一段时间。入侵使底部的营养水上升，使上水质的上流质量更糟。（2）通过垂直混合将硫化氢（H2S）在底部表面产生的氢（H2S），并通过垂直混合运输到上层层，并立即氧化。 H2S的氧化在八月期间将溶解的氧（DO）浓度降低了2.4ppm，并进一步促进了缺氧。（3）Nagasakiense nagasakiense Red Tide plankton开始在Uranouchi Bay中心的Layr中生长，随着底部氧化水的发育，底部的氧化物中心。当外部盐水侵入时，在整个层次中立即发生异常乘法时，在表面形成了红潮。（4）在1988年9月初，8月中旬，9月中旬，1993年11月初以及1993年11月初，在地下形成了缺氧。这些潮汐是由1993年11月初的。在缺氧开始时，开发了鞭毛藻的红潮和外部水入侵。（5）白天在表面出现了鞭毛鞭毛，但在夜间迁移到8-15m的深度，并在地下和中间的layrs layr layr中的浓度均在水面上进行了浓度。由于混合和入侵而供应可忽略不计。当白天小时减少时，在地下中会形成缺氧，因为地下Layr中的DO产生减少，并且由于鞭毛藻的迁移而增加了消耗。