Submissions against an application from Shell Taranaki Ltd to drill at Maui gas field will be heard in New Plymouth today.
Climate Justice Taranaki is asking the Environment Protection Authority to decline the application.
Dr Lyndon DeVantier said the application is very inadequate.
"Shell has not identified which jack-up rig their going to use. They haven't identified which chemicals they're going to use, but of the chemicals that they could potentially use hundreds of them are highly eco-toxic."
DeVantier said the area is home to many threatened marine creatures.
"Six species endangered, one vulnerable and another eighteen of them are data deficient. We don't know enough about about their biology to even to be able to determine what status their populations are in."