ジャパン・ウォーター・ガード

Japan Water Guard
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●To conserve 21st century environment and water front●
Save our Earth!!
地球の水をまもろう!

1.Basic of Water

2.Water Condition

§1.World Water Crisis
Health damage by
  lack of water

Change of Water resources
  site due to global warming

Lack of agricultural water
  by underground drought

Decline of biodiversity due to
  water shortage and pollution.

Area conflicts by
  lack of water

Virtual water trade
Future prospects

§2.World Water Aspect
●China
●Japan

§3.Water Issue
Cause and current condition
  of water issue

Water issue in rivers
Waterissue in lakes・marshes
Water issue in ocean
  -Red tide

§4.Cause and Condition
Global warming
Ozone layer depletion
Deforestation
Desertification

3.Environment Measure

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Chapter 2 Water Condition

§3.Red tide

What is red tide?

 Red tide is the phenomenon which red color covers the surface of ocean due to overgrowth of phytoplankton. Depending on the type, the color changes reddish brown or pink. Because of nutrient enrichment, it emerges in freshwater environment such as lakes and marshes. Such type of red tide is called freshwater red tide.


The factor fo red tide

 Due to human daily activities, daily and industrial wastewater contained lots of nitrogen and phosphorous are discharged to the ocean. Moreover, ocean becomes nutrient enrichment if the area changed to closed-area because of harbor development. Nutrient enrichment is the situation which the water contains lots of nitrogen and phosphorous that are nutrient salts for plankton. Thus, countries established environment standards and regulate the waste amount of nutrient salt though red tide occurs in many places. As the factor rather than daily and industrial wastewater, nutrient salts from non-point source, long time bottom sediment, overfeeding in farms, decrease of tideland and natural coast have been reported.

Why does red tide emerge?
  What is measure for red tide

Growth mechanism of red tide

 Phytoplanktons which are the cause of red tide grow by nutrient salt in the ocean similar to land plants which obtain nutrient from soils. In nutrient enrichment condition, because phytoplankton increased by absorbing rich nutrient salts, it grows rapidly. Moreover, due to increase ocean temperature or other factors such as change of ecosystem balance, red tide emerges.


Damage by red tide

 Due to red tide, large amount of oxygen are used. Because of lack of DO in the water, fishes die lack of air. Moreover, there are plankton which have poison, fishes also die by the poison, as well as that affects on land organisms and human which eat these fish. Therefore, red tide causes serious problems such as decrease of fish industry.


Red tide type and organisms which causes red tide

1)Large growth red tide: In case it grows in high density, fish die due to lack of DO.
2)Harmful algal bloom: It produces strong poison, it might affects on humans. In case which the color of ocean doesn't change much, it can be found the poison phenomenon (especially in bivalve).
3)Harmful red tide: Although it doesn't affect on human, it causes the large amount of death in farming fishes.
4)Red tide by diatom: Diatom is usually helpful as the basic producers in the ocean. However, it grows at the time of porphyra culture and consume nutrient salts in the water. That causes decrease of quality of seaweed and affects on fish industry.

Type. Classification of red tide
Type factor organism
Large growth red tide Gonyaulax polygramma
Noctiluca scintillans

Trichodesmium erythraeum
Scrippsiella trochoidea
Harmful algal bloom Paralytic shellfish poisoning:Alexandrium tamarense, Gymnodinium catenatum
Diarrheal shellfish poisoning :Dinophysis fortii, D. acuminata, Prorocentrum lima
Amnesic shellfish poisoning:Pseudo-nitzschia multiseries, P. australis
Neurotoxic shellfish poisoning :Gymnodinium breve
Ciguatera:Gambierdiscus toxicus
Harmful red tide Chattonella antiqua, C. marina, C. ovata, C. verruculosa,
Heterosigma akashiwo, Heterocapsa circularisquama, Karenia mikimotoi,
Cochlodinium polykrikoides, Chrysochromulina polylepis
Red tide by diatom Eucampia zodiacus, Coscinodiscus wailesii,
Chaetoceros spp., Skeletonema costatum,
Thalassiosira spp., Rhizosolenia imbricata
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