New Jersey ? Authorities protecting a dolphin family in a New Jersey river are stepping up enforcement over the July Fourth holiday.

State police and federal officials monitoring the dolphins said there were no immediate reports of incidents between the dolphins and boaters on the Shrewsbury River in nearby Red Bank Thursday night during a fireworks display.

Authorities were worried because of the increased boat traffic on the river. They have said they will fine people as much as $10,000 if they enter an exclusion zone around the dolphins.

Authorities decided to keep people away from the 15 bottlenose dolphins after scrapping plans to try coaxing them back out to sea.

The dolphins have been in the river since mid-June.