Mercury Bay locals were appalled at the council's actions, it said, and demanded the council become more attuned and responsive to the community.
This morning 740 supporters had signed the petition, which would be delivered to the council.
Those commenting on the petition said Collicott had done the right thing and shouldn't be punished.
DOC yesterday said staff with the appropriate training were on an island on the western side of the peninsula when the stricken orca was reported. They were only able to leave by late afternoon.
By that time DOC had a second report from the fisherman that he thought the orca was not in imminent danger.
Communications adviser Nick Hirst yesterday said the DOC staff struck rough seas and strong winds as they headed for the orca and as it was not in imminent danger and they were unable to reach it before it got dark, they returned to Whitianga.
DOC today said it was investigating all the circumstances of the incident, including its own response time.
Acting communications adviser Steve Brightwell said the process could take some time and it was too early to say what outcomes, if any, might result.
Council chief executive Vaughan Payne yesterday confirmed Collicott would not be performing operational duties while inquiries continued.
He said council acknowledged Collicott's good intent. However, it was checking whether any regulations were breached or operational procedures not followed during the rescue.
Payne said Collicott was leaving the role today, having resigned some time ago.