Climate Justice Taranaki (CJT) said the development would threaten the survival of endangered marine mammals.
CRT's submission also said fossil fuels needed to be kept in the ground to avoid "catastrophic climate change" and that the projected economic benefits ignored the potential costs and opportunity loss.
Deep Sea Oil Free NZ reiterated the concerns around marine mammals including Maui's dolphin. It points to the EEZ Act's requirement that the EPA consider "the importance of protecting rare and vulnerable ecosystems and habitats of protected species".
Support for OMV's application came from Trans-Tasman Resources who are about to challenge the EPA's decision to decline their own marine consent in the High Court. It said the application was consistent with the purpose of the Exclusive Economic Zone and Continental Shelf Act 2012.
Meanwhile the Ministry of Business, Innovation and Employment submitted a neutral application but highlighted the government's intention to increase New Zealand's overall exports and utilise the country's natural resources.
It said Maari had contributed $77 million in royalties between 2011 and 2013 and projected the Maari Growth Project will generate $377 million in royalties and $449 million in corporate tax.
The majority of submissions from individuals asked for the application to be declined.
Submissions closed last week and the hearing will open on September 23 with EPA's decision being released soon after.