Project B.I.G. – Bypass ramp Installation Gift
What is Project B.I.G.?
Project B.I.G. (Bypass ramp Installation Gift) is a conservation initiative focused on protecting the Japanese Giant Salamander (Andrias japonicus) by restoring river connectivity. Our initial efforts are centred on the Nawa River Basin in Mount Daisen, Tottori Prefecture.
Why Bypass Ramps Are Needed
Across Japan, thousands of rivers and streams have been modified with concrete weirs and channelisation under national river management programmes. While these structures were built for flood control, they have become one of the greatest threats to the survival of the Japanese Giant Salamander.
Weirs block natural movement corridors, cutting salamanders off from essential breeding and shelter habitats.
During heavy rain, individuals are flushed downstream over one or more weirs until they reach brackish river mouths where they cannot survive.
The concrete walls provide few natural shelters and often cause injuries when salamanders attempt to climb them.
Our surveys in the Nawa River have documented severe eye damage and foot injuries in salamanders trapped below weirs. In contrast, individuals in feeder streams with natural substrates are healthier and successfully breeding — evidenced by the larvae we have recorded.
The Uniqueness of the Nawa River
The Nawa River system is particularly significant:
It is a very short river fed mainly by snowmelt from Mount Daisen, delivering oxygen-rich, cool water all the way to the mouth.
This creates the lowest known altitude breeding habitat for any giant salamander species anywhere in the world.
Its global importance means the population deserves extra conservation measures — yet, aside from our work, almost no protection is currently in place.
Phase One: The Nawa River
Working with renowned JGS researcher Dr. Taguchi, we conducted intensive surveys on a one-kilometre stretch of the Nawa River identified for Phase One. This section contains 11 weirs that block access to a pristine feeder stream. Installing bypass ramps here would allow trapped salamanders to reach cleaner water with natural breeding habitat.
Population estimates from these surveys are being finalised, but early findings show that opening this single kilometre could significantly improve the health and long-term survival of the local population.
Phase One focuses on this section of the Nawa River. Phases Two and beyond will expand to other weirs further along the river system.
Cultural Protection – in Name Only
The Japanese Giant Salamander is classed as a Special Natural Treasure under the Agency for Cultural Affairs, yet active protection in the Nawa River system has been limited. When the issue was first raised, we were told that if evidence of a problem existed, action could be considered. However, no significant surveys had been conducted to provide that evidence.
This lack of data is what led myself and Dr. Taguchi to undertake detailed surveys. With clear evidence now in hand, there is a strong case for urgent action in cooperation with the relevant authorities.
The ‘Gift’ in Project B.I.G.
When we presented our findings to local politician Ryohei Akazawa, he acknowledged the severity of the issue and agreed that bypass ramps are a viable solution. However, he explained that a lack of public interest in the Japanese Giant Salamander makes it nearly impossible to secure government funding for such a project under current conditions.
That conversation made it clear that waiting for public budgets is not an option. Project B.I.G. proposes to move ahead with private funding. Once completed, the ramps will be formally gifted to the river and the local community, creating a lasting conservation legacy for Mount Daisen.
Partnerships and Support
We are working with Tottori Prefecture to secure the necessary permissions and ensure the project meets all environmental standards. Bypass ramps already exist in some feeder streams in other regions, so there is precedent — this time, the funding will come directly from people who care.
Local Action and Responsibility
There is often discussion about Japanese Giant Salamander conservation being “locally led.” In reality, many rural communities lack the resources to take on large-scale conservation projects alone.
Our NPO, Sustainable Daisen, is rooted in this community. I have lived and worked here for nearly 20 years.
To strengthen local relationships, we have been actively helping farmers with seasonal tasks such as cleaning drainage channels, cutting grass along rice fields, and clearing vines from river fences. These efforts have been warmly received and help build trust — something that will be vital if any temporary disruption arises during ramp installation.
Project B.I.G. bridges the gap, combining local roots with global support and scientific expertise to take action while there is still time.
How You Can Help
Sponsor a Ramp: Fund one bypass ramp and directly open up a section of river for the salamanders.
Donate to the Fund: Every contribution supports the installation of ramps and the survival of this ancient species.
Share the Story: Help us build the public interest needed to show that the Japanese Giant Salamander is worth saving.
The Vision
Project B.I.G. starts in the Nawa River, but it doesn’t end there. Our goal is to create a model for bypass ramp installation and private–public partnerships that can be replicated across Japan to reconnect fragmented river systems and give the Japanese Giant Salamander a fighting chance.