Just meters from the Yellow River Delta nature reserve in eastern China's Shandong province, farmers are feeling the pain of pollution caused by a petrochemical industry park.

Su Qing, 63, said his five goats died after drinking water near a biotech company in Dongying city's Economic Development Zone. Four of the goats were close to giving birth, according to the farmer.

The company has subsequently paid Su 7,000 yuan ($1,124) in compensation.

Dongying, a city in the center of the Yellow River delta, has become a battlefield for petrochemical developers and environmental campaigners over the past decade because of its rich oil reserves.

When the development zone was first planned, China's environmental experts called for careful construction and robust protection within the delta due to its vulnerable ecological condition.

However, there are now around twelve chemical and petrochemical enterprises near the nature reserve, with two companies located just 10 meters from the protected areas, Southern Metropolis Daily reported.

A previous environmental assessment by the reserve administrator found high environmental risks, but considered them acceptable.

However, Hezhen township, about 10 kilometers from the development zone, has witnessed dramatic changes to its environment, including decreased wetlands and increasingly polluted air.

Hezhen residents have also survived two industrial accidents of hydrogen sulfide leakage, in 2010 and 2013.

The local government has said that efforts have been made to safeguard the environment.

Li Aitao, head of environmental protection at the development zone, said that more than 40 projects with investment totaling over 20 billion yuan ($3.2 billion) have been turned down in recent years due to environmental concerns.

But researchers are still worried about possible environmental damage.

Liu Gaohuan, a researcher with the Institute of Geographic Sciences and Natural Resources, has been researching wetland protection in the Yellow River Delta for years.

He said that legally unprotected wetland in the Yellow River Delta nature reserve has become a major base for the petrochemical industry.

Liu also warned against overdevelopment of coastal areas, which would negatively impact the environment, especially in terms of biodiversity.

The Yellow River is often referred to as the "Mother River" or cradle of Chinese civilisation.