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Establishment and progress of the airport
History of the Kansai International Airport
Environment chronology
Outline diagram for the efforts in regard to the environment

Environment considerations with the second phase
Creation of an abundant environment
Monitoring of the influence onto the environment
Environment preservation measures during the construction work
Together with the people in the surrounding area
Environment influence evaluation

Environment considerations with the second phase

Creation of an abundant environment


Creation of seaweed beds under consideration of the ecology
In order to create a fertile marine environment and to improve water quality, positive efforts towards seaweed bed creation on the breakwater of the second airport island has been made in the same way as for the breakwater of the first airport island.

What is a seaweed bed ?
This is the general name for places where large
groups of seaweed plants live.Young fish live in these seaweed beds,they serve as spawn-ing grounds for coastal fish, and they support many marine lives.They also take in nitrogen and phosphorus from the sea water, increase the amount of oxygen, and provide a water purification function

Gently sloping rubble mound type seawall
Gently sloping rubble mound type seawall has been adopted widely for the seawall of airport island, and the seaweed beds which have formed over many years on the airport island form a diverse ecosystem with many marine lives which provide food for fish and shellfish,and it has become that this is becoming an important ecosystem in Osaka Bay.

Efforts toward the formation of seaweed beds

The second phase of the seaweed bed formation used seaweed blocks,nets with grown
seaweed leaves (spore bags), etc. to grow seaweeds.
In order to accelerate the growth of these seaweed beds,Special blocks for seaweeds have been developed and placed to improve the attachment of seaweeds.
Approximately 100,000 wave dissipating blocks were used for the seawall of the second airport island,and these newly developed blocks were used for a part of these (a total of 3,200 blocks have been installed at five locations of the sea wall).
These blocks are conventional blocks with a total of 18 grooves with a length of approximately 60 cm and a depth of approximately 5 cm in the surface, and it is expected that seaweed beds would form on them faster than on conventional blocks.
In addition,18 seaweed blocks with Eisenia bicyclis from the first airport island had been redeployed to 6 locations on the seawall of the second airport island.

Kansai International Airport(KIX) is the huge artifical island with large scale of gently sloping rubble mound type seawall. Seaweed beds which have formed on the airport island is about 50ha , which is about 10% as large as total seaweed in Osaka bay.

green seaweed      
green seaweed01 green seaweed02    

brown seaweed      
brown seaweed01 brown seaweed02   brown seaweed03

red seaweed      
red seaweed01 red seaweed02    

Utilization of seaweed blocks
Seaweeds blocksUnder consideration of the monitoring for the seawall of the first airport island, seaweed blocks (wave-eliminating blocks with grooves to facilitate seaweed attachment and holding of spores) was adopted.

Seaweed blocks are placed for approximately 15% of the wave-dis-sipating block installation length, and they have been installed under consideration of the suitable water depth for growing of Eisenia bicyclis and other seaweeds which grow well on the seawall of the first airport island.

Planting on seaweed blocks
18 seaweed blocks from the first airport island have been moved to the seawall of the second airport island to serve as core for seaweed beds.

Seeding with spore bags
Spore bags were introduced nuclei seaweed banks.

Seeding by utilization of female rope and seeding rope
(to be carried out during AprilÅ] June:Wakame and Shidamoku, to be carried out during October-December:kajime)

Utilization of juvenile adhesion plate
(to be placed during October-December :Oobamoku, Yoremokumodoki and Nokogirimoku)
A plate to which juvenile of seaweed is attached is placed to form a multi generation seaweed bed from the early stage of formation.

Arrangement plan for seaweed blocks etc.
Under consideration of the monitoring investigation results for the first airport island,installation was made as shown below.The formetion of seaweed beds was constructed over approximately three years.

Efforts for formation of seaweed beds of the first airport island (reference data)

Placement of seaweed blocks (4 locations)
In order to form seaweed beds in short time, blocks with seaweed spores were placed on the seawall to promote the formation of seaweed beds.