Key legislation to regulate deep-sea oil drilling and other activity in New Zealand's vast offshore ocean areas is to be toughened up, Environment Minister Amy Adams says.

Ms Adams told the Environmental Defence Society conference yesterday that the Government had listened to submitters and stakeholders and would make a number of changes to the Exclusive Economic Zone and Continental Shelf (Environmental Effects) Bill.

The bill establishes rules for oil, gas and mineral exploration and extraction along with other activities taking place in New Zealand's exclusive economic zone (EEZ), which lies between 12 and 200 nautical miles off the coast.

Critics, including Opposition parties, the Parliamentary Commissioner for the Environment and the Law Commission, as well as environmentalists, say the legislation's environmental protections are too weak and don't comply with New Zealand's international obligations.


Ms Adams said key changes included amending the underlying purpose of the bill "to incorporate the concept of sustainable management to reflect the Resource Management Act".

The maximum penalty for companies that breached marine consents would also rise from $600,000 to $10 million.

Labour's environment spokesman Grant Robertson welcomed the amendment to the purpose clause.

"We've said from the beginning we want to see more consistency with the Resource Management Act and so introducing the idea of sustainable management is good although obviously we need to see the actual wording."

However, Labour still maintained the law needed to be consistent with international obligations.

Greens oceans spokesman Gareth Hughes said it was good the Government planned to increase the "woefully small" original maximum penalty figure copied from the Resource Management Act "which was shown to be inadequate in the Rena catastrophe".