### 2. The State of Loss of Biodiversity in Japan

Japan Biodiversity Outlook (JBO), which was released in May 2010, was an assessment of the state of Japan's biodiversity from the late 1950s to the present, made by experts and based on specific information such as statistics and documents. JBO concluded that, "Loss of biodiversity as a result of human activities in Japan has affected all ecosystems including forests and mountains, cultivated land, urban areas, inland water, marine and coastal areas, and islands, and the loss is continuing on the whole" (Figure 3-2-6: Biodiversity Loss in Japan).

As causes for the loss, there are direct causes due to human activities and development, and indirect causes in the background, such as socio-economic changes. Among these, the direct causes are laid out as four crises in the National Biodiversity Strategy. As for the “First Crisis,” which was brought about by human activities and development, although the speed of development will further decline if there is population decline and low growth, it is expected that the effects of development done in the past will continue. However, the largest impacts as causes of extinction of species and endangered species in Japan are the ones caused by development.

On the other hand, there are reports of examples such as that sweetfish, which disappeared once, are returning to rivers in cities because of improvements in the water quality of the rivers due to the diffusion of sewerage systems. In recent years there are also fishing catch amounts that, although not the same as in the past, are starting to recover as a result of efforts for steady recovery of resources through resource management, including a complete ban on fishing for three years and then setting an allowable amount of catch after the ban was lifted, as was done with Sandfish fishing in Akita Prefecture (Figure 3-2-7: Shifts in Amounts of Sandfish Catches in Akita Prefecture). It can be said that there are cases when ecosystems still have the ability to recover, and it is possible to restore the habitats of living things and biological resources by alleviating effects from human activities such as development, or by conducting appropriate management of resources.

In places such as satochi-satoyama, the “Second Crisis” caused by reduction of human activities is a serious problem. Due to factors such as population decreases and aging in farming and mountain villages, it has become difficult to maintain and manage places such as satochi-satoyama, and there are concerns about

Figure 3-2-6 Biodiversity Loss in Japan

Biodiversity loss as of 2010	Current state of loss and trends	Causes of loss (degree of impact) and current trends
Degree of loss from original state	Degree of loss from state as of latter 1950s, and current trends	First Crisis	Second Crisis	Third Crisis	Crisis of climate change	Other
Development/change	Reduction in use and management	Invasive alien species	Chemical substances
Forest and mountain systems	☐	☑	☑	☑	☑	☑	*1
Cultivated systems	—	☑	☑	☑	☑	☑	Decrease in local varieties of crops and livestock
Urban systems	—	☑	☑	—	☑	☑
Inland water systems	☑	☑	☑	☑	☑	*2	☑
Marine and coastal ecosystems	☑	☑	☑	—	☑	*3	Outbreaks of coral predators/Coralline flat
Island ecosystems	☑	☑	☑	—	☑	☑

Assessment targets	States	Causes
Size of current losses	Trends of current losses	Degree of impact during assessment period	Current trend of degree of impact
Legend	Not lost	✓	Recovering	Weak	Decreasing	✓
Not significantly lost	✓	Same	Moderate	Same	✓
Lost	✓	Being Lost	Strong	Increasing	✓
Significantly lost	✓	Being rapidly lost	Very strong	Increasing rapidly	✓

Note: Dashed lines for assessment of the degree of impact indicate that the data is not sufficient.

Note: “ $ ^{*} $ ” indicates that there are multiple factors and data related to the indicator in question, and that there are factors and data that show trends that differ from the current assessments of the degrees, effects, and trends of overall loss.

$ ^{*} $ 1 : The degree of impact on alpine systems has been and continues to be serious.

$ ^{*} $ 2 $ ^{*} $ 3: While the problem of chemical compounds has been mitigated to some extent, the problem of invasive alien species is serious.