Research On The Impact Of Underwater Noise Radiated From Offshore Wind Farm On Chinese White Dolphin(Sousa Chinensis)

With the concept of "low carbon economy" is gradually accepted and advocated by human in recent years, It’s the new development tendency to minimize the burning of fossil fuels and intensify our efforts to develop the clean energy. In the development and utilization of clean energy, the technology of wind energy development is more mature, and offshore wind energy is an important component of the whole wind energy. However, offshore wind farms will radiate lots of noise to the sea during the construction period and operation period, especially the process of percussive piling operations to fixing the foundation piles, which will radiate high-intensitive, instantaneous and wideband pulse signals underwater. Some researches show the noise caused by percussive piling underwater can affect the behaviors of marine mammals, such as masking its acoustic signal, and even damaging its hearing organ.Chinese white dolphin(Sousa chinensis), which mainly distributes in the southeast coast in our country, is the first-class national protected animals. They use echolocation signal for underwater target detection and recognition and use acoustic signal to communicate between individuals, which is an important tool for them to survive in their living environment. The noise radiated from underwater pile-driving and offshore wind turbine may cause hearing damage to Chinese white dolphins and mask their underwater sound, which may finally affect their normal life activities.In order to protect the Chinese white dolphin, and mitigate the impact from underwater noise radiated from underwater pile-driving and operational offshore wind turbine,we need to monitor underwater noise radiated from underwater pile-driving and operational offshore wind turbine. through combining time and frequency domain analysis of noise radiated from underwater pile-driving and operational offshore wind turbine with acoustic signal characteristics of Chinese white dolphin, we can understand whether underwater noise radiated from underwater pile-driving and operational offshore wind turbine will affect the hearing and acoustic signal of Chinese white dolphin, and assess their impact on the scope and extent of Chinese white dolphins,thus we can provide reference basis for Chinese white dolphin acoustic protection. The main contributions of this paper are as follows:1.Introduce the acoustic characteristics of Chinese white dolphins,the acoustic characteristics of noise radiated from underwater pile-driving and operational offshore wind turbines and the impact on marine mammals in detail,And introducing the research equipment about monitoring of underwater noise and method of signal process.2.Recorde the clicks of wild Chinese white dolphin, analyse the time and frequency domain characteristics of their clicks and estimate its source level,compare characteristics of clicks from chinese white dolphin between Xiamen sea and Leizhou Bay.3.Record underwater pile-driving noise, analyze its time-frequency domain characteristics,calculate the acoustic parameters of underwater pile-driving noise,study the propagation characteristics of underwater pile-driving noise; Assess the impact of underwater pile-driving noise on hearing and behaviors of Chinese white dolphin base on the dBht (species) parameters, and discuss the masking effect of underwater pile-driving noise on them.4.Record underwater noise of operational offshore wind turbine,then analyze its time-frequency domain characteristics; Assess the impact of noise radiated from operational wind turbine on hearing and behaviors of Chinese white dolphin base on the dBht (species), discuss the masking effect of noise of operational wind turbine.