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Operation-Let's Return Fish Back to Lake Biwa –again in 201716 October, 2017

Fish return to Lake Biwa will be made again this year at the Niihama Biotope on October 22, 2017 from 10:00 to 12:00. This is an annual event held every year since 2009 and since 2012, school children and their parents and guardians have been invited to join this activity to learn the natural life of water cratures of Lake Biwa. They will be taught by Japan Water Agency, who manages the biotope about the current severe environmental situation, which Lake Biwa faces now, i.e. the decline of the number of its native fish species such as carps and crucian carps as well as drastic increase of foreign fish like black basses and blue gills. They will recognize that their actions will become a small but important help to conserver the natural environment as well.

1.Outline of this event

Date and Time October 22, 2017 from 10:00-12:00
Place Niihama Biotope by Lake Biwa by the side of Omi Bridge, Omi City, Shiga Prefecture
Participants School children (max. 20) and their parents or guardians
Event Briefing of Lake information and its natural environment will be made first. Then, school children will catch the fish in a small pond (hands-on training, of course) and release only the native fish of Lake Biwa back to the lake.

2.What is Niihama Biotope

Niihama Biotope is a spawning ground for carps and crucian carps. Native adult fish like carps and crucian carps move to inner lakes and paddy fields adjacent to Lake Biwa in spring and spawn there. Then newly born young fish return to Lake Biwa as they grow. When they become adult fish, they come back to those inner lakes and paddy fields for spawning. This is the regular life cycle of local fish in Lake Biwa. However in recent years, there are increasing nuber of foreign fish species like black basses and blue gills in this lake. In addition, there appears the decline of indigenous fish in the lake mainly due to fewer chances for fish to reach inner lakes or paddy fields because of the disconnection from the lake to them and the decline of appropriate spawing grounds because of the environmental degradation. To respon to such a situation, Lake Biwa Development Integrated Operation and Maintenance Office developed Niihama Biotope in 2007 as one of the spawning grounds for carps and crucian carps.

3.Number of catch in the past

Carps and crucian carps other fish *1
July 2009 approx. 900 2
July 2010 approx. 6500 approx. 100
Novemer 2011 approx. 2200 approx. 200
October 2012 approx. 5600 approx. 300
October 2013 approx. 1700 approx. 180
October 2014 approx. 1700 approx 40
October 2015 approx. 300 6 *2
October 2016 approx. 3000 20
Other fish species include cat fish, black bass, blue gill, and northern snakehead, etc.
Only indigenous fish of Lake Biwa have been released to the lake.
Fish count was only of the upper pond.

4.Location of Niihama Biotope


5.Some of the photoes taken last year

Explanation of types of fish
Explanation of types of fish
Release of fish
Release of fish

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