More than 30,000 tuatua and thousands of pipi, paua, kina, crabs and cockles had been tested for oil pollution. The tests show most of the Rena oil has dissipated.
"Shellfish are a key focus because they are one of the biggest concerns for the community," he said.
"They are also a good indicator of water quality because they sit on the sea floor and act as a filter. If there are contaminants in the water, it is likely you would trace these in common shellfish." Toi Te Ora Public Health Service last week extended a health warning regarding shellfish in the Bay, because of high levels of Paralytic Shellfish Poisoning, a toxin unrelated to the Rena oil spill. People are warned not to eat bi-valve shellfish collected between Tairua and the Whakatane Heads.
Rahera Ohia, iwi representative on the board overseeing the monitoring programme, said the scientific results were important and pleasing. However, there were other, less tangible, matters that needed to be considered.
"The fact that Western science is producing results that say our food basket is starting to repair itself and that soon we can safely go back to the food basket and gather what we want, that's very, very important to us.
"On the other hand, so are things that are not tangible. Things like how our relationship with this body of water is being repaired, and that's as much to do with people's hearts and minds, the hearts and minds of iwi and hapu along the coast, as it is to do with science."
Professor Schiel said oil spots may continue washing up on Bay of Plenty beaches for some years, however the way the Rena clean-up was handled minimised the amount of oil trapped in beach sands.
Other countries have responded to oil spills by driving heavy machinery on to beaches to quickly scoop up the contaminated sand, pushing oil deep into the sand in the process, he said.
The way thousands of Bay residents volunteered to clean up their beaches by hand was not only a good community response but the best environmental response as well.
"I think there are a lot of lessons from this and a lot of things that can be used elsewhere as models for how to deal with this sort of disaster in the future."
Fisherman Brett Keller, of Tauranga Marine Charters, said the latest news confirmed what was already known.
"They did surveys and tests three or four months after it happened and they found no signs of oil contamination then. It's been a non-event all the way through. The oil all ended up on shore after the first storm anyway."