A Greenpeace activist was thrown overboard when a Japanese whale harpoon was launched across an inflatable boat in the Antarctic seas on Saturday.
The harpoon from Japanese whaling vessel Yushin Maru No.2 was fired directly over the Zodiac inflatable boat, which was shadowing a minke whale in Antarctic seas.
It follows a series of confrontations involving environmentalists and whalers in the Southern Ocean.
Greenpeace activists say the incident won't deter them and they will continue to take risks.
Senator Campbell has called on both sides to show restraint.
"My own strong feeling is that if the activities of protesters become not sensible... then it risks putting what we're both trying to achieve - Greenpeace and the Australian government - backwards," he told ABC radio.
"I don't think people are going to have respect for tactics that are going to put human life at risk.
"We don't want to bring the whole cause of whale conservation into disrepute.
"They both need to understand that they have to respect human life.
"Greenpeace has said that they're going to do that, so do the Japanese fishing authorities - they need to walk that talk."
Senator Campbell effectively ruled out intervention by the Australian government, despite escalating tensions.
He said the Australian government had made its views on whale conservation very clear.
"But I think what is important is that we maintain our focus on the main game," Senator Campbell said.
"And that is that whaling will come to an end when the people of Norway and the people of Japan tell their governments unequivocally that the slaughter of whales -- that the cold-blooded destruction of whales -- needs to come to an end."
Greenpeace spokesman Shane Rattenbury said activists are aware of the dangers involved in their protests.
"The aggression shown over the weekend is a warning to us and we need to think hard about what our tactics are from here," he told ABC radio.
"We've got quite a few tricks up our sleeve yet."
Mr Rattenbury said the incident shows just how desperate the Japanese whalers are.
"For them to now be taking shots that are flying straight over the inflatable boat suggests that they are under pressure," he said.