PORTLAND — Federal officials have agreed to reduce drastically the size of no-fishing buffers around some underwater cables.

The decision came at the request of Casco Bay fishermen, Central Maine Power Co. and Maine state officials and is effective nationwide for all cables with locations that have been pinpointed by satellite technology.

“That doesn’t just affect Maine,” said Tim Vrabel, a CMP official. “That affects 34 seaboard states.”

The order changing the buffer around underwater cables — which carry phone signals, electricity and the like — was signed this month by Capt. David MacFarland, chief of the marine chart division for the National Oceanic and Atmospheric Administration.

It eliminates the old standard buffer of 1,000 feet for cables located by satellite-based geographical positioning system, or GPS. Buffers around such cables now must be 330 feet, said Dennis Romesburg, chief of NOAA’s nautical data section.

In the case of the most accurately pinpointed cables, Romesburg said, the required buffer will shrink to virtually nothing. The government said it agreed that mariners can navigate safely with the smaller buffers. The buffers are designed to protect both the mariners from being injured if they pull up a cable and the cables from being damaged.

The decision has the potential of opening up a substantial amount of ocean bottom that was previously off-limits to fishermen.

Also, the move has provided an important morale boost to fishermen at a time they feel beleaguered by tightening government restrictions.

“Fishermen right now need every piece of (ocean) bottom they can fish on to make a living,” said John Stuart, a local fisherman and consultant who worked on the project.

“In the fishing community, when we win one like this, it just brings a smile to people’s faces. It’s kind of one of those the-little-guys-make-a-big-impact type of stories.”

The 1,000-foot buffer was established decades ago.