A Waikato University doctoral student is researching the recovery time for kaimoana in the Bay of Plenty following contamination from the Rena oil spill.
Julien Huteau has taken samples of a wide range of shellfish from the water around Motiti Island, Astrolabe reef, Papamoa and Mount Maunganui.
His supervisor, Chris Battershill, says the research, which is the first of its type ever done in New Zealand, will be especially valuable for iwi.
He says literature from overseas on the effects of heavy fuel oil on shellfish suggests the recovery time can be quite long.
However some of the preliminary results from Julien Huteau's work indicate it can take only a month or so.
Dr Battershill says the research is looking not only at the oil toxicity levels in the flesh of kaimoana, but also the long term effects of the oil on shellfish reproduction.