An armada of whales head into the St.Lawrence

Written by: Richard Sears, Founder of MICS

On June 10th 2019, aerial surveys revealed a large group of baleen whales south of Bonaventure Island off the coast of Gaspé. A few days later, on the 18th and 19th of June, our collaborator René Roy, working from the Bay of Gaspé, found whales both inside the bay and 6-8 miles outside the northeast side of Cap Gaspé. René reported that he was surrounded by spouts and estimated nearly 100 baleen whales in the area. He observed several species including humpback, fin and blue whales, all in a moving front and feeding on krill. How was their prey determined? Simply by the fact that the animal’s feces was brick red, indicating that krill was the main prey being consumed at that time. This red coloration is due to the keratin found in euphausiids (krill). Blue whales are krill specialists, whereas humpback and fin whales are generalists and will feed on a combination of krill and fish such as herring, capelin, mackerel, and/or sand lance. 

New scars on the back of B194 (Hippocampe) ©René Roy, MICS  

Such a joint movement of mixed species of whales into the area is impressive and we were lucky enough to get photo-IDs of several humpback and blue whales. Based on preliminary matching within our photo identification catalogue, at least four of the blue whales observed had never been sighted by us previously. However, several blue whale individuals were identified:

• B189 (Bell), first sighted in 1985, with more regularity as of 2008.
• B194 (Hippocampe), a female known since 1992, appeared to have new scars on her back this year. The cause of these markings is uncertain.
• B201, an individual known since 1993 and last observed in 2017 before this most recent sighting.
• B311, first sighted in 1994 and sighted almost yearly since. This individual has been observed in the St. Lawrence from June to November in some years.
• B202 (Fender-Bender), a female known since 1988 and previously observed in 2006 with several scars resulting from entanglement in fishing gear. These scars seem to have faded since!
• B479, sighted once previously in 2012.
• B275 (Phoenix), a female known since 1993 that is regularly sighted in the estuary near Les Escoumins during the summer months.
• B292, a male known since 1993 and resighted previously in 2016.
• B332 (Dragonleaf), a male known since 2000 and named for mottling that resembles a species of sea dragon – the leafy sea dragon (Phycodurus eques) – famous for their leaf-like camouflage.
• B345, an animal first observed in 2002, and last sighted in 2015.
• B473, known since 2011, was previously observed in 2013.
• B499, sighted only once in 2015 and observed for a second time this year.
• B397 (Doru), a male known since 2006 was sighted with new scars on the front half of his body. Though we cannot be certain what caused this, based on the type of scaring observed, the scars may be due to ice entrapment.
  

  In springtime, whales feeding along the South coast of Newfoundland can get trapped by ice that is leaving the St. Lawrence during the ice break-up. Winds disperse the ice, giving whales the ability to move into these areas, however shifting winds can push the ice pack back against SW Newfoundland and trap cetaceans. This entrapment can be fatal, as was the case in 2014 when 9 blue whales were trapped in ice off the southwest coast of Newfoundland.

  However, had B397 (Doru) scar’s been caused by vessel contact, they would not have been as evenly distributed on the front part of the animal’s body and would most likely have resulted in deeper localized trauma. Furthermore, had the scaring been caused by fishing gear, deep grooves from rope cuts on the whale’s back, peduncle, and/or tail would have been visible. Since no visible signs of vessel collision or fishing entanglement were apparent, ice entrapment seems to be the most plausible cause of these new scars. Apparent ice entrapment seems to be the most plausible cause.

B397 (Doru) with new scars, probably caused by ice entrapment  ©René Roy, MICS  

The fieldwork carried out by MICS as the summer progresses will reveal more about the movements of the individuals mentioned above and others entering the St Lawrence. Hopefully we will be able to deploy satellite tags on several of these animals to learn more on the details of their dispersal within and outside the St. Lawrence.  

It is important to note that around this time last year, 7 blue whale calves accompanied by their mothers had already been sighted. This year, despite a good number of blue whale sightings, no calves have been reported to date. 

Why is there an apparent baby-boom last year but no evidence of calving in this population this year ? What could this mean for the blue whales ? These are the questions we are still striving to answer with our ongoing research.