1

green tide (Macro-algal bloom)

keyword

10cm

Sea lettuce!!

https://renote.jp/articles/5853/page/2

2

3 Contents

1. Motive & Purpose

3. Pre-expt.1

4. Expt.1 5. Expt.2

7. Future prospects

6. Conclusion

2. Significance

4

https://www.irasutoya.com/2014/06/blog-post_941.html

https://www.scmp.com/news/china/article/1284156/cause-qingdaos-green-tide-algae-mystery

at Takasago Seaside Park

Normal scenery Green Tide!!!

5

6 Contents

1. Motive & Purpose

3. Pre-expt.1

4. Expt.1 5. Expt.2

7. Future prospects

6. Conclusion

2. Significance

7

Causes of green tide

Reproduce in the bay

Float out beyond the bay

Significance

8

Reproduce in the bay

Nutrition of seawater

N

P

How about other elements??

Significance

9 Contents

1. Motive & Purpose

3. Pre-expt.1

4. Expt.1 5. Expt.2

7. Future prospects

6. Conclusion

2. Significance

10 Pre-expt.

Artificial seawater

Deionized water

-0.10

0.00

0.10

0.20

0.30

0.40

0.50

0.60

gro

wth

fro

m d

ay 0

Pre-expt.

Artificial seawater

Deionized water

［cm2］

11 Pre-expt.

Deionized water

↓ didn’t grow

Artificial sea water ↓

grew well

12 Pre-expt.

Growth of sea lettuce?

Artificial seawater

13 Contents

1. Motive & Purpose

3. Pre-expt.1

4. Expt.1 5. Expt.2

7. Future prospects

6. Conclusion

2. Significance

14 Expt.1

NaCl (aq) NaCl (aq)

N Fe

Mg

S

Ca

-0.20

0.00

0.20

0.40

0.60

0.80

1.00

gro

uth

fro

m t

he

firs

t d

ay

Expt.1

NaCl (aq)

NaCl (aq) + all the elements

［cm2］

15 Result

NaCl (aq) +

all the elements ↓

grew well

NaCl (aq) ↓

didn’t grow

16 Contents

1. Motive & Purpose

3. Pre-expt.1

4. Expt.1 5. Expt.2

7. Future prospects

6. Conclusion

2. Significance

17 Expt.2

⑤ -NH4Cl

① -MgCl2

⑥ -FeCl3

③ -KCl ② -CaCl2

④ -Na2SO4

S

Ca

Fe

K

N

N N

N N

Fe

Fe Fe Fe

K K

K

Mg Mg Mg

Mg Mg

S

S S

Ca

Ca

Ca

18

-0.20

0.00

0.20

0.40

0.60

0.80

1.00d

ay0

day

1

day

2

day

3

day

4

day

5

day

6

day

7

day

8

day

9

day

10

gro

wth

fro

m d

ay 0

Expt.2

-MgCl2

［cm2］

-NH4Cl，-FeCl3 ↓

grew well

→ not important

&

Result

-0.20

0.00

0.20

0.40

0.60

0.80

1.00d

ay0

day

1

day

2

day

3

day

4

day

5

day

6

day

7

day

8

day

9

day

10

gro

wth

fro

m d

ay 0

Expt.2

-MgCl2

［cm2］

19 Result

-MgCl2，-CaCl2， -KCl，-Na2SO4

↓

didn’t grow

→ important!

20 Contents

1. Motive & Purpose

3. Pre-expt.1

4. Expt.1 5. Expt.2

7. Future prospects

6. Conclusion

2. Significance

21 Conclusion

→ important!

We should focus on…

22 Contents

1. Motive & Purpose

3. Pre-expt.1

4. Expt.1 5. Expt.2

7. Future prospects

6. Conclusion

2. Significance

23 Future prospects

Solve green tide!!

What elements?

What concentration?

Apply in the sea

↑

↑

24

Acknowledgements

We deeply appreciate

Mr.Hanyuda

giving us invaluable advice.

25 References

• Ishii Yuichi. National Research and Development Institute of the National Institute for Environmental Studies: Seaweed environmental problems bring about - the generation of green tide and the constituent species of features. （海藻がもたらす環境問題–グリーンタイドの発生と構成種の特徴–）National Institute for Environmental Studies News. 2010, Vol.29, No.23, p465-470.

• Yauchi Eiji, Ishii Kenichi, Imoto Tatuya, Gomyo Michio: Feald study on proliferation of ulva sp. in Yatsu higata. （谷津干潟におけるアオサの繁茂特性に関する現地調査）Proceedings of civil engineering in the ocean. 2007, No.23, p465-470.

• Yabe Tohru: Are the extreme dominance phenomena caused by sea lettuce really reducing the ecosystem function of tidal flats? （アオサ類による極端な優占現象は干潟の生態系機能を本当に低下させているのか？）National Institute for Environmental Studies News. 2004, Vol.33, No.4.

• Nishikawa Tomoki, Takeda Shota, Yamochi Susumu: Prevention of Outbreaks of Green Tide occurring on the Artificial Tidal Flat and Salt Marsh. （人工干潟や塩性湿地で大発生するグリーンタイドの抑制に関する検討）Proceedings of the Japan Society of Civil Engineers B2 (Coastal Engineering). 2009, Vol.B2-65, No.1, p1221-1225.

• Nabata Shinichi: Classification and use of sea lettuce.（海藻アオサ類の分類と利用）Hokusuishi dayori. 2005,No.69,p1-12.

• Matsuoka Satoru, Yoshimatsu Sadaaki, Ono Akira, Ichimi Kazuhiko, Fujiwara Munehiro, Honda Kenji, Tada Kuninao: Discoloration of Nori (Porphyra) and Characteristics of Water Quality in Eastern Bisan Seto. （備讃瀬戸東部（香川県沿岸）におけるノリ色落ちと水質環境）Bulletin on coastal oceanography. 2005, Vol.43, No.1, p77-84.

• Yoshida Goro, Niimura Yoshiko, Tarutani Kenji, Hamaguchi Masami: Research review on the relationship between macroalgal-production and nutrients, and relative assessment of the nutrient conditions on macroalgae in the Seto Inland Sea. （海藻類の一次生産と栄養塩の関係に関する研究レビュー－および瀬戸内海藻場の栄養塩環境の相対評価－）Bulletin of Fisheries Research Agency. 2011, No.34, p1-31.

Thank you for listening!

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