An associate science professor at Guam university says fears held by fishermen about the prospect of the Marianas Trench becoming a sanctuary are unfounded.
A group of Mariana Islands residents want the trench upgraded from a monument to a sanctuary to protect the water column above the sea bed.
Academic Joni Kerr said little recreational fishing happened in the trench because it was too far to travel.
She said commercial fishing in the trench failed in the past because there weren't enough fish.
"Here's another issue, with climate change some of the data points to fish migrating to cooler water or to refuges. Extending sanctuary protection to a certain area of are region will offer that refugia where fish can move and populate. There could be spill over affects into areas that could be fished."
She said recreational, sustenance and traditional fishing could still be allowed in the Marianas Trench if it is made a sanctuary.