Many of them are regulars at it now and, despite the time that has lapsed since the oil first came to shore, they're still at it.
Maybe it's not a choice for them, as one of the team leaders, Mate Samuels, explains in today's paper.
"I'm from Matakana Island. I've grown up with the sea at my doorstep and I just think the job has to be done - and who else is going to do it? Someone has to," he said.
Reporter Kiri Gillespie came back from Matakana Island on Tuesday with the story of how locals were doing all they could to make the clean-up faster.
She wrote about how people were gathering pieces of smashed-up timber from the beach and using them to make circles around the dead birds they found on their beach.
The birds were then quickly located by Department of Conservation rangers, making their job easier.
We've also heard of tourists mucking in and giving up their beachside holidays to get the sand looking golden again.
What an incredible sacrifice.
The rewards will come for these volunteers when the beaches are clean.
Given Rena is going to be talked about well into the future, they will also be able to say that they were there on the beaches and they pitched in.