keywords: mitigation. artificial ecosystem, environmental management,functions of environment, purification function
ABSTRACT
Coastal zones may be inevitably transformed to artificial ecosystems. One of the ecosystems is the human-made environment that is changed subsidarily by the development or the disaster prevention of coastal zones. Another is the one constructed for the purpose of harvesting.
In these cases. their environmental value has to be measured in the same quantitative unit as the value gained by the development. One measure is the economic one, in which we measure the functions of bio-environment. Another is the one concerning to the bio-environmental functions, such as the diversity of genes. bacteria and others. which we do not currently have a measure.
We may use a way of thinking, called "The no net loss development." However, we do not necessarily understand the meaning of " No net loss. " Hereafter, I will state the function of bio-environments.
1. Introduction
Japan' s concerns over her environments may fall into two categories: control of pollutants. and preservation of natural environments. Regarding the control of pollutants. Japan has carried out an enormous effort to hold pollution effects under strict numerical targets. successfully preventing its coastal waters from excessive degradation. On the other hand, the degree of success has been limited in an effort to preserve natural environments, due mainly to. among others. the difficulty of establishing quantitative criteria to be achieved.
We envision three sequential components in the mitigation policy; first to "avoid" negative impacts on environment; second to " minimize "impacts. and third to " compensate " unavoidable "impacts. Enforcement of environmental impact assessments in recent decades in Japan has led to a considerable success in "avoid" and "minimize" aspects of mitigation. The third aspect. the "compensatory" mitigation. is not yet implemented in Japan. The pros and cons for the compensatory mitigation are debated seriously in this country, and the government decision is still weighed regarding its implementation. Implications of "compensatory" mitigation are expected to reach beyond the Japanese borders; it may also affect many of our foreign aid programs to the developing countries which now rank the largest in the world.
2. The ocean may be bound to become artificial ecosystem
The man has nurtured the agro-ecosystem attempting to feed its growing population which now stands at 5.7 billion. It seems inevitable that the man is destined to rely continuously on habitat control technologies with progressively expanding scale. embracing eventually the aquaculture ecosystem. among others, as the source for sustained food supply.
・ Two pressing issues facing us today are: to feed the rapidly growing population, and to balance developments with preservation of natural environments.
