Marine biologists are giving the Astrolabe Reef a cautious, qualified, clean bill of health after the cargo ship Rena struck the reef in October 2011, and subsequently broke up.

Keith Gregor and Phil Ross made the announcement in a seminar at the Bay of Plenty Polytechnic yesterday where the pair shared findings collected from a two-day dive around the Rena wreck conducted by scientists and divers in August 2012.

Marine scientists Phil Ross and Keith Gregor.

'The prognosis is preliminary only and made from limited sampling,” says Phil.

'There's no way are we able to grasp the whole impact of the Rena, all we are trying to do at this stage is get an indication.”

Discussed during the 20 minute seminar was the fact scientists were not able to take samples off the reef until August 2012 – more than a year after the wreck occurred.

Video and photos also taken over the two days of diving show the reef near the wreck was still in recovery, but marine life has picked up away from the debris field.

'By the time you get 100 metres from the wreck there's kelp, sponges and invertebrates on the reef, so it's not looking too bad,” says Phil.

'But that's preliminary data from limited sampling.”

Phil says scientists scrambled to get baseline data in the days immediately after the wreck and before the oil began to pollute local seawater.

They visited all nearby islands and reefs, taking samples of kelp, brown algae and sea urchins for refrigeration to be used later as the standard the pollution would be measured by.

The seminar was part of the polytechnic's annual research symposium.