MPA Protects Northern Bottlenose Whales in the Scotian Shelf

Photo copyright Anke KŸgler

Photo copyright Anke KŸgler

On the wild, rugged coastlines of Nova Scotia, lucky bystanders may occasionally catch a glimpse of a breaching Northern Bottlenose Whale. These large beaked whales spend their lives in the cold, deep waters of the North Atlantic, foraging for squid in submarine canyons up to 1450 meters deep. Scientists first began studying the Northern Bottlenose Whale population in the Scotian Shelf in 1988, providing an important baseline for assessing how the Gully MPA, set aside in 2004, protects these majestic creatures.

In the summer of 2010 and 2011, two Canadian scientists went out on the waters of the Scotian Shelf to determine the size of the Scotian Shelf bottlenose whale population, how many whales were using the Gully MPA, and if the MPA has affected long-term trends in population size. They took high-quality digital photographs of every Northern Bottlenose Whale they encountered, using unique features such as dorsal fin notches and indentations in the whale’s back to identify each individual. The shape of the whale’s forehead (known as a “melon”) also allowed them to identify each whale as either female, an immature male, or an adult male. By comparing these photos to others collected since 1988, the scientists were able to look at changes in the population over time.

With long-lived animals that reproduce late in life, decades of information are needed to accurately assess population trends and the impact of changes in management. Early results are promising. Over the last 23 years, the population has remained stable, and there seems to be no impact of whaling on the relative numbers of males and females in the population. The current population is still small, 143 individuals, but the majority of this population resides within the boundaries of the MPA most of the time. Over the coming decades, these whales will continue to reap greater and greater benefits from MPA protection, helping to restore this population to it’s pre-whaling levels.

For More Information: O’Brien K., H. Whitehead. 2013. Population analysis of endangered northern bottlenose whales on the Scotian Shelf seven years after the establishment of a Marine Protected Area. Endangered Species Research 21:273–284