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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Fisheries Sciences / Faculty of Fisheries Sciences >
Peer-reviewed Journal Articles, etc >
瀬戸内海の生物生産に果たす陸起源のリン・窒素の役割(シンポジウム:沿岸海域に存在する外洋起源のリン・窒素)
| Title: | 瀬戸内海の生物生産に果たす陸起源のリン・窒素の役割(シンポジウム:沿岸海域に存在する外洋起源のリン・窒素) |
| Other Titles: | The Role of Land Derived Phosphorus and Nitrogen in Marine Biological Production in the Seto Inland Sea(Symposium: Open-ocean Originated Phosphorus and Nitrogen in the Coastal Sea) |
| Authors: | 門谷, 茂1 Browse this author →KAKEN DB |
| Authors(alt): | Montani, Shigeru1 |
| Keywords: | リン | | 窒素 | | 富栄養化 | | 赤潮 | | 基礎生産 |
| Issue Date: | 28-Feb-2006 |
| Publisher: | 日本海洋学会沿岸海洋研究会 |
| Journal Title: | 沿岸海洋研究 |
| Volume: | 43 |
| Issue: | 2 |
| Start Page: | 151 |
| End Page: | 155 |
| Abstract: | 瀬戸内海では,他の人口集中沿岸海域と同様に1950年代以降,流入する河川の栄養塩濃度(とりわけ,リン・窒素)は,上昇を続けその結果として,海域の栄養塩濃度を急上昇させた.とりわけ,60年代後半から赤潮の発生が頻繁に起こるようになり,1976年には年間299回を数えるまでになった.富栄養化は基礎生産の増大をもたらすだけでなく,光合成によって作られた膨大な有機物の多くが水柱内で消費されることなく海底に沈積し,そこで微生物分解されることにより溶存酸素濃度を減少させ,貧酸素水塊を作り出すことにも繋がった.この間の瀬戸内海における富栄養化を進行させてきたのは,陸からもたらされた窒素やリンであることは種々の環境モニター結果から明らかである.瀬戸内海の生物過程において決定的な役割を演じているのは,やはり陸上からの栄養塩負荷であった.一方,近年重要視されてきた外洋起源と言われる窒素やリンが,瀬戸内海の生物生産にどのように寄与しているかについての答えを得ることは,今後の環境行政を考える上でも,沿岸域の生物生産構造を理解する上でも極めて重要である.今後は,溶存無機態の窒素やリンがどのようなタイミングでどこからどれだけ流入しているのかについて,詳細に明らかにする必要がある. | | The 20^<th> century was one of Eutrophication of coastal waters. After the 1950s, the density of nutrients in rivers flowing into enclosed coastal seas kept rising; as a result, the densities of nutrients in enclosed coastal seas rapidly elevated. This nutrient load is very closely related to the amount of the fertilizer used in the hinterland region and to population increases in coastal areas. In the sea areas receiving loads of excessive nutrient, increases of phytoplankton occurred on the sea surface; the result of primary production increasing by several fold from levels found before the 1950s. These events occurred in parallel to the generation of red tides, which became frequent in the latter half of the 1960s, indeed occurring 299 times in 1976 in the Seto Inland Sea. Eutrophication connected with primary production not only increased, but also consumed many of the organisms resulting from photosynthesis in seawater, and created a poverty of oxygen in the water with its production. On the other hand, recently there has been active discussion regarding the influence of phosphorus and nitrogen, not only in the nutrient loads from the land but also in those of Pacific Ocean origin, on processes of living organisms in the Seto Inland Sea. It is the nitrogen and phosphorus coming from the land that has caused Eutrophication in the Inland Sea. The nutrient loads from the land have had a definite in the biological processes occurring in the Seto Inland Sea. It is extremely important to understand the structure of biological production of coastal areas; it is also important for future environmental administration to understand how nitrogen and phosphorus of Pacific Ocean origin contributes to the biological production in the Seto Inland Sea. Therefore, it will be necessary to clarify the details of how much and from where nitrogen and phosphorus flows into the Seto Inland Sea. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/56490 |
| Appears in Collections: | 水産科学院・水産科学研究院 (Graduate School of Fisheries Sciences / Faculty of Fisheries Sciences) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 門谷 茂
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