Aquatic Species at Risk - Northern Bottlenose Whale (Scotian Shelf)
Species - Details
Whitehead Laboratories, Dalhousie University
Endangered, listed under SARA
Region: Atlantic Ocean
Did You Know?
The bottlenose whale dives deeper and longer than any other cetacean. Bottlenose whales have regularly made recorded dives of over 1,000 metres in the waters of the continental shelf and often remain at these depths for more than an hour in search of food.
At a glance
With its distinctive bulbous forehead, the northern bottlenose whale is relatively easy to spot. The Scotian Shelf population of this whale lives at the southern limit of the species’ range in the western North Atlantic Ocean and is threatened by commercial shipping, fishing, and oil and gas exploration. Today, it is believed that less than 200 Scotian Shelf northern bottlenose whales remain.
About the northern bottlenose whale
In the offshore waters of Atlantic Canada, there are several known centres of abundance of northern bottlenose whales – on the edge of the Scotian Shelf and the Davis Strait, off Labrador. The Scotian Shelf population is distinct from the Labrador population. An inquisitive whale that often approaches boats, the Scotian Shelf northern bottlenose population spends both summer and winter months close to the entrance of the underwater canyon they call home. The whales are usually found in small groups of one to four, with males and females usually associating with members of their own sex. Mixed groups of whales do not stay together for more than 20 days, and usually occur in the spring. Scientists assume that the mixed groups are mating herds.
Northern bottlenose whales eat mainly deep water squid, but also feed on other animals. Once the whales dive into the dark waters, they rely on more than vision for navigation. Northern bottlenose whales have highly developed vocal and hearing abilities, allowing them to communicate, navigate and locate prey in deep areas.
How to recognize a northern bottlenose whale
A medium-sized whale, the northern bottlenose grows to between six and nine metres in length, and weighs between six and eight tonnes. The whale’s bulbous forehead sits above a distinctive beak, with the lower jaw extending slightly further than the upper. Male whales generally have much larger but flatter foreheads than females; males also have teeth, which in females rarely erupt through the gums.
Young bottlenose whales are dark brown to black in colour; older whales are light to yellowish brown with whitish beaks and foreheads. Occasionally, old males can become entirely yellow-white to grey.
Where northern bottlenose whales live
The Scotian Shelf population of bottlenose whales lives in relatively small deep water areas at the entrance to prominent underwater canyons—such The Gully—off the southeast coast of Nova Scotia. The whales rarely inhabit waters less than 800 metres deep.
Why it’s at risk
The Scotian Shelf population was targeted by whalers in the 1960s. Current threats to the northern bottlenose are poorly understood. Increased commercial shipping and fishing have led to increased numbers of collisions with ships and entanglements in fishing gear. Because of how the northern bottlenose whales are thought to use sound to communicate and navigate, activities that create noise in their habitat are a concern. For example, oil and gas exploration on the Scotian Shelf might harm this population through noise from drilling and seismic surveying, although no long-term effects to such noise pollution are established. Chemical pollution and oil spills are other potential threats.
Read about: Does Seismic Exploration Harm Whales and Fish?
What’s being done
The Scotian Shelf Population of northern bottlenose whales is designated as endangered under both COSEWIC and SARA. Several initiatives have been undertaken to protect this population of northern bottlenose whale. The northern bottlenose whale is a major beneficiary of the Gully Marine Protected Area (MPA) and its regulations which prohibit the disturbance, damage, destruction or removal of any living marine organism or habitat within the Gully. The deep-water portion of the canyon is designated as a critical habitat to northern bottlenose whales and has received the highest level of protection in the management of the MPA. Some oil and gas operators have instituted their own codes of practice to minimize operational impacts on the whales.
Fisheries and Oceans Canada in Halifax has also worked to reduce the amount of traffic passing through the Gully by requesting that vessels avoid the area. Reducing ship traffic will lessen the chances of collisions, the amount of noise, and the risk of oil spills and other pollution.
Current research is attempting to identify the links between the bottlenose whales that live in on the Scotian Shelf and other whale population centres in the western North Atlantic.
What can you do?
The northern bottlenose whale will get the protection it needs only if all Canadians work together to reduce threats. Find out more about bottlenose whales and be aware of human-induced threats. Do your best to reduce these threats wherever possible to better protect the whale’s critical habitat. Get involved with the Habitat Stewardship Program for Species at Risk (HSP) or another conservation organization.
For more information, visit the SARA Public Registry at: www.SARAregistry.gc.ca
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