Symposium Introduction

Slightly more than 100 years ago has disappeared wild horse Tarpan, living in the south Russia. Many animal species are on the verge of extinction or preserved only in the reserves. Such is the fate of the bison, tens of millions inhabiting prairies of North America and bison, particularly widespread in the forests Europe. In the Far East is almost completely exterminated by sika deer.

Amplified fishing cetaceans led to the brink of destruction several species whales: gray, bowhead, blue. On the number of animals has impact and human activities unrelated to fishing.

Sharply reduced the number of Ussuri tiger - as a result of development areas within its range and reduce the forage base. In the Pacific die each year tens of thousands of dolphins: for the period of fishing, they enter the network and can not escape from them.

The disappearance of the relatively small number of species of animals and plants can not seem very significant. However, the main value of the now living species is not in their single value.

Each species occupies a special place in biocoenosis in the food chain, and replace it nobody can. Disappearance of a species leads to reduce the stability biotsenozov .