When the environment is damaged, biotechnology can be used to protect the environment from secondary damage. Biology is highly specific and can eliminate special pollution sources. For example, a cruise ship transporting crude oil pollutes the sea area with heavy oil due to an accident. The special microbial strains that decompose heavy oil are used to decompose the heavy oil and metabolize it into environmentally acceptable short chain fatty acids to eliminate the pollution. In addition, if the soil is polluted by heavy metals, specific plants can also be used to absorb pollution sources.