In direct contrast to Israel's western flowing streams, Lake Kinneret is used for a multiplicity of beneficial uses. The lake supplies 45% of the country's total water supply, 6% of its fish catch, a vacation spot for 1½ million tourists a year, a purification plant for 3 million cubic metres of sewage yearly, an annual supply of tons of smooth, decorative pebbles, and a source of income for at least 70 scientists. Again in contrast to Israel's streams and wadis, data are available to those interested in preventing pollution of the Kinneret. Scientific studies of the lake began as far back as 1847. Beginning in the 1950's Israel scientists concentrated their efforts on solving a myriad of problems in the lake and its watershed. In the 1950's geographic surveys of the watershed were completed which described the type of land, its quality, texture and suitability for agricultural use. By 1964, scientific studies included the quality of lake water for drinking, lake currents, salt concentrations in the lake, sources of radiation, the lake's temperature, phytoplankton, zooplankton, algal blooms, floating plants, organisms living at the bottom of the lake, the lake's water level, thematodes and nematodes in the lake, water birds, chiromed flies, pesticides, commercial fish, and, last but not least, the Tabgha blind prawn, the only unique species endemic to the lake's waters.