September 17th, 2007
This year's Estuary trip turned out to be shorter than usual but yielded valuable information about the Blue Whales that visit that part of the St. Lawrence. Richard Sears, Valentine Ribadeau Dumas, Sophie Comptois, and Sophie Bédel spent two weeks based out of Forestville to study behaviour and photo-identify a total of 15 Blue Whales. The trip was originally planned to last five weeks, but the late arrival of the animals compelled us to postpone. Here are a few notable observations made during the expedition:
B245, first seen in 1991, spent the greater part of the 2007 season in the Sainte-Anne-de-Portneuf area. This female is usually seen for only a few days near the end of the season and though most of her sightings come from the estuary, she was also seen in the Mingan area in October 1992. In 1994 she had also spent considerably more time in the St. Lawrence; that year, she was observed from mid-July to the end of September. Why did she stay for most of the season this year and in 1994 when she would normally only be observed for a few days or not at all? Are there changes in the environment, prey availability or social associations that affect her movements or are they simply random? These remain unanswered questions.
Another interesting observation was of B301. This male is an irregular visitor in the St. Lawrence and was first photographed in the estuary in 1993. B301 showed up in the vicinity of Les Escoumins only 6 days after René Roy had photographed it off Rivière-au-Renard along the Gaspé peninsula. As always, René was able to find himself at the right place and time! B301’s 180 nautical mile trip (324 kilometres) in 6 days is the quickest we’ve ever seen. This observation, combined with the frequent displacements that have been reported this year, only confirm our thoughts that the large rorquals that visit the St. Lawrence are not restricted to a particular location. As a threatened species in Canada, certain measures to protect Blue Whales in the estuary should also be applied along the Gaspé coast and in other regions of the gulf to take into account their seasonal movements.
During one of their days on the field, the estuary team witnessed impressive social interaction between three Blue Whales. As they were following a pair of blues, they noticed a change in behaviour and a third animal that had come in the vicinity. At their next surfacing, the three whales were side-by-side and they were speed-swimming out of the water! This abnormal behaviour lasted for almost 30 minutes during which the group would make sharp turns with their tails and pectoral fins showing at the surface or even gaining enough speed for a third of their body-length to come out of the water. Imagine: the largest animal species ever to have lived on the planet, up to 27 metres long and 120 tonnes in the St. Lawrence, jutting out and breaking through the surface! This observation was also remarkable for its length. After 29 years of working with Blue Whales, Richard claims never to have witnessed such behaviour last that long.
A Blue Whale charging out of the water!
Mysticetes - whales that have baleen plates instead of teeth that they use to filter small prey out of the water are generally solitary in their movements and may form temporary associations with other individuals in feeding aggregations. Though the broad consensus is that most social activity is limited to the winter breeding period, we have noticed that Finbacks and Blue Whales engage in what looks like breeding behaviour while on the feeding grounds. This is not the first time we have had the opportunity to observe such interactions. Our aim is to combine visual observations with photo-identification, acoustical, as well as environmental data to determine what triggers such displays.
MICS would like to thank the following people for their help and support throughout the two-week trip up-river. Our eyes-and-ears in the estuary: Yvon and Éric of Croisières du Grand Héron. Our hosts: Lise and Guy of La Maison du Havre. And our colleagues at the Mériscope: Dany Zbinden and Brian Kot. MICS would also like to give a special thank you to René Roy whose passion for Blue Whales brings him to areas we can’t cover.
Another tagging attempt.
During the first two weeks of September, MICS welcomed Becky Woodward of Woods Hole Oceanographic Institution and Jeremy Winn. Becky and Jeremy have been working over the last several years to deploy a digital acoustic recording tag (DTAG) on a variety of baleen whale species. The DTAG was developed by Mark Johnson at Woods Hole as a device to record the three-dimensional underwater movements of whales as well as their acoustic emissions. Originally designed as a tool to monitor Right Whale responses to acoustic stimuli, Becky and Jeremy have expanded the use of the tag to study locomotion patterns and underwater manoeuvring. Their tag has already been tried on Gray, Blue, and Humpback Whales as part of a cross-species comparative study and their goal while in Mingan was to deploy it on Finbacks. This is the second time in 2007 that we have collaborated with visiting scientists to try a data-logging tag. Unfortunately the weather has not been on our side! Both attempts, with Ruth Searle in late-July and Becky and Jeremy in September, have been unsuccessful. Becky and Jeremy only had one good day on the water with adequate conditions and were only able to make one attempt to deploy their tag on a Fin Whale, F155. The only two whales seen on that day were fairly uncooperative! The two researchers are now trying again with a different species and ORES, a research group that concentrates on Minke Whales in the St. Lawrence Estuary. Good luck and we hope the weather improves for you!
One last attempt as the crew on Twister just misses F155