"It can also affect the quality of the water."
He said he would not have minded if the people had left them further away from the river, and hidden in vegetation, as the pigs would naturally decompose "out of sight and out of smell".
However, it annoyed him someone had dumped them right by the river bank.
He said he would like to charge the people who had dumped the pigs.
"You just can't dump stuff at the river."
Central Hawke's Bay mayor Alex Walker was unhappy with the situation.
"I think that is incredibly sad, and incredibly disappointing."
"There are so many people working to improve our environment, and particularly around the quality of our waterways."
The remains were three pig heads, three carcasses, and three crates of offal (the internal organs).
A spokesperson for Hawke's Bay Regional Council confirmed they cleaned up the pigs on Wednesday morning after receiving a call through their pollution hotline.
They said if anyone saw rubbish dumped into rivers to call the pollution hotline on 0800 108 838.
They did not know who the dumper was and said any decision to fine them would have to come from the district council.