Hear them coming: right whales return to the Gulf of St. Lawrence
The North Atlantic right whale—Eubalaena glacialis—is a large marine mammal that is listed as one of Canada's Species at Risk. It was designated Endangered in 2005. Fisheries and Oceans Canada then began a program to re-establish the species, as required by the Species at Risk Act. In the context of this program, researchers at the Maurice Lamontagne Institute in Mont-Joli, Quebec launched a project to unravel the mystery behind its return to the Gulf of St. Lawrence.
The right whale is a migratory animal. Every year, it leaves its breeding and feeding grounds and travels along the east coast of the Atlantic Ocean, from Florida to the Gulf of St. Lawrence, and around Newfoundland and Labrador (see Figure 1). It was given the name "right whale" because it was easy to hunt: it isn't very fierce, moves rather slowly and tends to float to the surface when harpooned. Today, the population of right whales in the North Atlantic is estimated at 350 individuals. Though it was present in Quebec's waters for centuries, it almost disappeared from the Gulf of St. Lawrence in recent times. However, starting about 15 years ago, observers have reported sightings of right whales (at the end of the Gaspé Peninsula in particular). In 2001, a whale that got tangled in a fishing net was tracked as it entered the Gulf of St. Lawrence. In the same year, a right whale was found beached on the shores of the Magdalen Islands.
What are right whales doing in waters they frequented many years ago? Why are we seeing them once again in the Gulf of St. Lawrence, and in certain spots in the Gulf? When, exactly, do they come and how many are there? Here are some of the questions that are most interesting to oceanographer Yvan Simard, who heads a research project aimed at better understanding the movements of right whales through Quebec's waters and figuring out why they're attracted to certain places. But tracking the comings and goings of these rare animals through simple observation will not provide the answers; it simply cannot be done continuously, day and night, in weather good and bad, for all 12 months of the year. So the research team decided to use a new technology to observe these marine mammals: acoustic detection.
It's a technique that involves recording the regular vocalizations of these whales to verify their presence in the area. The equipment used is the hydrophone, a sort of underwater microphone that records whales' sounds and songs. Manufactured in Rimouski, Quebec, the hydrophones are designed to store a year's worth of data. Once the year is up, the data is extracted and the hydrophones are returned to the water for another year. Analysis of the acoustic data will help determine the times of year at which right whales enter Quebec's waters, as well as their migration routes from the Atlantic.
In addition to hydrophones, the researchers have installed instruments to measure food abundance and currents. The right whale is a picky eater: it feeds exclusively on zooplankton (tiny aquatic animals), unlike other whales that eat small fish as well. The researchers suspect that the right whale's presence in the Gulf of St. Lawrence is related to favourable currents carrying high concentrations of their preferred food into certain places at certain times. With the data gathered by these measurement instruments and other equipment on board research vessels, the scientific team will be able to map out the presence and abundance of zooplankton in the area and determine what mechanisms are behind the high concentrations that attract the whales. New observations will be compared to those of 12 years ago, offering a picture of how the whales' feeding ground has developed.
Sharing this new information means adding an important piece to the puzzle of tracking this population in the North Atlantic. Researchers already know that most individuals spend the summer in the Bay of Fundy and its surroundings, and along the American and Canadian coasts. Yet they lose track of about one-third of the whales. Do they migrate towards the North Atlantic? Since this a sizeable proportion of the total number, the mystery must be solved to truly understand the growth dynamics of this small, endangered population and find a way to protect the habitats essential to its survival.
A better understanding of the migratory habits of right whales will better equip us to protect them. Knowing when they will show up in certain areas means we can take measures to minimize the impact of human activity on the threatened population. The Bay of Fundy provides a good example. In 1993, Fisheries and Oceans Canada created a right whale conservation area in the Grand Manan Basin. Since the end of the whaling era, whales sustain the most damage from collisions with boats and entanglements in fishing gear. As such, awareness was raised among people in maritime communities about the presence of whales and new maritime routes established to minimize the impact of boat traffic in areas commonly used by whales.
The acoustic detection work carried out by Yvan Simard and his team in the Gulf of St. Lawrence is one of the very few research projects studying right whales in Canada. It will improve international knowledge of the species and contribute to the scientific efforts that are being carried out, in large part, by the United States. Understanding how the survival of this species is tied to particular places in the vast area right whales cover in their annual migrations is essential in developing measures to protect and re-establish the population. This is what the recovery strategy strives to do in Canada in response to the Species at Risk Act.