富山湾深層水のかけ流し条件におけるスラグ系施肥材のマコンブに対する効果実証実験(Effects of an iron-enriched fertilizer on Saccharina japonica in tank with running Toyama Bay deep seawater)
- 標題
- 富山湾深層水のかけ流し条件におけるスラグ系施肥材のマコンブに対する効果実証実験(Effects of an iron-enriched fertilizer on Saccharina japonica in tank with running Toyama Bay deep seawater)
- 作者
- 小杉知佳・熊谷敬之・小林美樹・藤田大介(Chika Kosugi, Takayuki Kumagai, Miki Kobayashi and Daisuke Fujita)
- 文件屬性
- 日本研究
- 知識分類
- 精緻農業
- 出版年
- 2016
- 刊名
- 海洋深層水研究
- 卷
- 16
- 期
- 3
- 頁
- P69-81
- 點閱數
- 2501
摘要
スラグ系施肥材の海産藻類への影響を調べるため，入善町アワビ養殖施設で，清浄，水質安定，栄養塩豊富で鉄濃度が低い富山湾深層水（水深394 mから取水）を用い，マコンブの胞子体と配偶体の屋外流水培養を行った．深層水は1次水槽（容量50 L）から2次水槽（80 L, 1基に施肥材2 kgを2日おきに投入）に分水し，各々から培養水槽（70 L, 施肥した実験区2基と対照区1基）に注水してオーバーフローさせた．実験区と対照区の間に，胞子体（葉長10 cm以上）では葉長や葉幅に有差はなかったが，実験区では葉厚，SPAD値（体色の指標）と藻体中のChl. a量が有意に高い値を示し，一部の胞子体が成熟した．配偶体は両区とも成熟し，得られた幼胞子体の密度と初期生長は実験区で有意に大きかった．
To test the e ects of the iron-enriched fertilizer (mixture of converter-derived steelmaking slag and humus soil), young sporophytes and immature gametophytes of Saccharina japonica were cultured in outdoor tanks with running deep seawater (DSW) pipelined from 394 m in Toyama Bay, which is known as clean, stable, and nutrient-rich with less iron concentration than surface water. DSW was poured through the 1st collecting tank (50 L in volume) prior to pumping into two 2nd tanks (80 L in volume, one with 2 kg fertilizer every 2 d and another without fertilizer as the control). DSW from the 2nd tanks was piped and allowed to over ow in three aquaria (70 L in volume, two fertilized and one control) for culture. As the result, young sporophytes grew with no signi cant di erences in the thallus length and width among aquaria, but thallus thickness, SPAD value, and chlorophyll a contents at thallus tips were signi cantly higher in fertilized aquaria. In fertilized aquaria, some sporophytes formed sori. Immature gametophytes matured in all aquaria, but density and early growth of young sporophytes were signi cantly higher and faster in fertilized aquaria. These results con rmed the positive e ect of iron enrichment even in nutrient-rich
condition.
To test the e ects of the iron-enriched fertilizer (mixture of converter-derived steelmaking slag and humus soil), young sporophytes and immature gametophytes of Saccharina japonica were cultured in outdoor tanks with running deep seawater (DSW) pipelined from 394 m in Toyama Bay, which is known as clean, stable, and nutrient-rich with less iron concentration than surface water. DSW was poured through the 1st collecting tank (50 L in volume) prior to pumping into two 2nd tanks (80 L in volume, one with 2 kg fertilizer every 2 d and another without fertilizer as the control). DSW from the 2nd tanks was piped and allowed to over ow in three aquaria (70 L in volume, two fertilized and one control) for culture. As the result, young sporophytes grew with no signi cant di erences in the thallus length and width among aquaria, but thallus thickness, SPAD value, and chlorophyll a contents at thallus tips were signi cantly higher in fertilized aquaria. In fertilized aquaria, some sporophytes formed sori. Immature gametophytes matured in all aquaria, but density and early growth of young sporophytes were signi cantly higher and faster in fertilized aquaria. These results con rmed the positive e ect of iron enrichment even in nutrient-rich
condition.