"When you've only got 55 of these left, they're the smallest and rarest dolphins in the world, we need every possible piece of information we can get our hands on so we can try and understand the species."
The World Wildlife Fund's Milena Palka says if the cause of death was human activity, it could have been catastrophic for the remaining population of just 55 adults.
"These dolphins are slow to breed they produce one calf every two to three years at best and that equates to about a 1.8 per cent population growth if all human-induced deaths would be removed."
She says more restrictions need to be placed on fishing near the Maui's habitat, along the North Island's west coast.
"And if we're not going to be really precautionary with the protection that we afford them then they're not really going to stand a chance given there's so few of them left."