Federal officials have alerted operators of small boats as well as large ones that there are dozens of humpback whales off Marin’s coast.

Humpbacks are considered endangered and boats represent a threat to them, not to mention the danger humpbacks pose to boaters if they collide. About 115 humpbacks were documented in just one hour near the Farallon Islands on July 4th, according to a San Jose Mercury-News report.

Federal officials are telling large ships that they need to slow down to a speed of 10 knots in boat traffic lanes as they approach the Bay Area, and recreational boaters have been told to stay 300 feet away from the whales, which is the federal minimum distance.

All species of whales are protected from harassment, including blue and fin whales, which are listed under the Endangered Species Act.

The humpback whales are in the area en masse in order to feed on large waves of krill as well as anchovies. Even for these whales, however, these are unusual numbers.

Sometimes, blue whales are spotted in the midst of the humpbacks, and whales often get close to boats that are nearby.

Humpback whales are a species of baleen whale that can reach between 39 and 52 feet in length and weigh 79,000 lbs, making it one of the largest creatures on the planet. Its distinct body shape gives it its name, as it has long pectoral fins and “hump” like head. They are found in oceans around the world, but are threatened by whaling and other human activities.