At least 112 North Atlantic right whales were spotted in Cape Cod bay. The number is the largest on any day, followed by 107 of them in 2011, Center for Coastal Studies (CCS) noted.

According to National Oceanic and Atmospheric Administration (NOAA), North Atlantic right whales remain critically endangered, with at least 465 left of them, as of 2011.

Although North Atlantic right whales can survive waters with temperate to subpolar latitudes, their population has declined over the years because of the previous rise in commercial whaling. At present, since right whale nursery areas are in shallow, coastal waters, they are prone to entanglement in fishing gears and ship collisions which result to serious injury and death.

Talking to Boston Globe, Charles "Stormy" Mayo, director of right whale habitat studies at the CCS, explained that North Atlantic right whales as well as other species are often found in Cape Cod bay during this season. However, he noted that the number they have recently seen on their aerial survey was remarkable given the North Atlantic right whales' challenged population.

"It's quite a remarkable sighting. These are animals that are a lot rarer than a lot of those that you and I watch on TV," he said.

Mayo added that the large number could be probably because the bay contains a lot of zooplankton, which is a typical food for these whales.

World Wildlife Fund noted that whales feed on the zooplankton by opening their mouths and filtering the food from the water. They can do this for hours. Once they are done filtering, they will dive and swallow their food. They can consume about 1,000 to 2,500 kilograms (2,200 to 5,500 pounds) of zooplankton every day.

Female North Atlantic right whales only breed once every three to five years. Cape Cod Times noted that only three right whale births were recorded this year. The number is far from the average calf births in 2009, which reached 39. The whale's average lifespan is only up to 30 years.

Despite the recent sighting, the center clarified that the North Atlantic right whales are still critically endangered. The center encourages boaters to travel under 10 knots to avoid fatal collision.