"Further wreck removal, particularly the bow sections, could assist to address safety, natural character, and ecological concerns.
Arguably, also on cultural grounds, given the significant impacts to the mauri (life force) of the reef.
"The Crown has Treaty obligations to all Maori groups that are before the panel ... but acknowledges that with the changing cultural dynamics, the matter is not straightforward."
Mr Stephen said even if the final decision called for retaining the bow pieces, it was important that "robust and enforceable" conditions were imposed to deal with contamination and ecological impacts.
Last week, the applicants had raised the heritage value of the wreck as a reason why it should remain in place.
Mr Stephen said the Crown did not support this as justification for the wreck to be left behind.
Reef ecology "compromised"
Deborah Freeman, a marine science adviser with Department of Conservation, described Astrolabe Reef's high ecological integrity pre-Rena, but said there was now evidence some species and habitats were in a "compromised state".
"Experts have agreed that the grounding of the Rena and subsequent contamination release had significant impacts on the ecological value of parts of the reef, particularly areas near to the wreck."
Dr Freeman noted salvage efforts had also impacted the reef, mainly physically.
It was likely the wreck and debris would break down and move in future, but Dr Freeman said there was disagreement between experts about how significant the ecological effects would be and what could be done to avoid, remedy or mitigate these.
Her view was movement of the wreck and debris would result in ongoing ecological effects over long periods of time.
"This includes those organisms that may become associated with or attached to the wreck and debris, and potentially also organisms in areas that may have been previously unaffected by the wreck or debris."
Continued movement of the wreck and debris as it degraded would change the composition of species at the site.
Species more resilient to disturbance and other "opportunistic" species would thrive in greater proportion.
Dr Freeman said contaminants like copper, TBT and fluoride related to the release of cryolite, posed a risk to the marine life on the reef.
She said further removal of the wreck and debris would help mitigate some effects and provide a more stable environment for marine life to recover.
Negative effects from removal of the wreckage depended largely on salvage methods and time frames of the operation.
High chance contaminants will be released
Chris Hickey, a principal scientist of ecotoxicology and environmental chemistry with NIWA, said there was a high chance significant amounts of contaminants could be released during a large storm.
Because of this, humans could be exposed to an increased amount of contaminants through the food chain.
Dr Hickey said because there was a high chance of this happening, conditions should be attached to the resource consent to mitigate and monitor risk.
Further collapsing of the ship's structure could result in some of the 16 tonnes of copper clove being released into the environment near the wreck.
To help prevent this happening, Dr Hickey suggested highly contaminated sites could be "capped" with a thick layer of coarse sand and additional layers of material.
