Irisept

Her arrival in the St. Lawrence a few weeks ago caused quite a stir: some privileged individuals spotted Irisept surface-feeding, her swollen mouth filled with salt water and krill. This feeding behavior is one of the many techniques used by humpback whales to feed. Known since 1997, the female humpback first ventured into the estuary in 2003. Last summer, the GREMM research team captured images of Irisept with a drone, as part of a project to assess the physical condition of the large rorqual whales that frequent the St. Lawrence. These images are also used to record entanglement and collision marks, and provide a better understanding of the impact of human activities on these individuals.

Speaking of markings: it’s the coloration patterns on Irisept’s fluke that have given it her name. In the Saguenay-St. Lawrence Marine Park, however, the community nicknames this individual Cocotte, due to a pine cone-shaped pattern visible on its right flank. So, although some whales have “official” names, this doesn’t stop observers from attributing nicknames to certain whales. After all, even humans have nicknames!

Since the beginning of the summer, Irisept has been seen several times in the estuary with a calf by her side. This prolonged association confirms that she’s a mother again! In 2017, Irisept caused quite a surprise, as it was the first time she had brought a calf into the St. Lawrence River in 20 years of observations. Indeed, she was first photographed in 1997 in Minganie. She was first seen in the Estuary in 2003, but is a regular in the Gulf. She and her calf were seen on the Mingan Islands 2 weeks ago. They are now back in the estuary.

Before becoming a mother, Irisept had a brief career as a research subject for a GREMM and Fisheries and Oceans Canada project. In the summer of 2012, scientists fitted her with a telemetric tag to study rorqual whale feeding in the Saguenay-St. Lawrence Marine Park. However, the suction cup beacon only lasted 2 h 44 min! It did, however, allow us to learn that Irisept had dived to a depth of 15 to 20 metres when the Parks Canada team had noticed the presence of krill near the surface. The installation of telemetric beacons provides invaluable data, including the speed of a whale, when it eats, and the depth of its descent.

Irisept, also nicknamed Cocotte, is a female who mostly frequents the Gulf of St. Lawrence. She was first observed in 1997. She has been seen a few times in the Saguenay-St. Lawrence Marine Park. She is recognizable by the black-and-white colour pattern on the underside of her tail. On her right lobe, there is a black iris-shaped spot and in the centre of her tail, a small white number 7, hence her name: Irisept. Her nickname Cocotte stems from a marking on her right flank that resembles a pine cone. She is also recognized by her truncated dorsal fin and the conspicuous vertebrae near her peduncle.

Irisept is not currently in the Estuary. She is in the Gaspé where the humpbacks Siam, Gaspar and Whip are also being observed.

Graph deducted from telemetric monitoring of Irisept in 2012. Earlier, in June, Irisept was noticed in the Gaspé by the Fisheries and Oceans Canada (DFO)-GREMM research team which was undertaking a project on krill production and consumption of krill by whales in the Gulf of St. Lawrence. This mission was carried out from June 18 to 30. The team attempted to place a radio tag on Irisept’s back to monitor her underwater movements, but they have not been successful.

In the Estuary, the DFO, in collaboration with the GREMM, kicked off this week the 4th year of the large rorqual monitoring project. This project aims to document the whales’ underwater activity as well as their diet in the Marine Park. In parallel to the telemetric monitoring, the Parks Canada team is attempting to determine the identity and concentration of prey in the water column with the help of an echo sounder. In 2012, Irisept was one of the whales tracked by the DFO-GREMM team. At the time they monitored the giant feeding at depths of 15 to 20 metros.

Locally, she’s known as Cocotte. Well-known to MICS, it has a pretty official name: Irisept: “Iris” for the black shape on its right lobe, and “sept” for the white 7 in the central region of the tail. The tip of her dorsal fin also has a peculiar shape, as if it were truncated.

First photographed in the Gulf in 1997, she was biopsied in 2000: it’s a female. Over the years, she has been photographed in Mingan, Gaspésie and Sept-Îles. Her last visit to the marine park was in 2004. This year, she was photographed in Gaspésie in early June, before arriving in our sector on July 12. On July 15, she spent most of the day in the company of Siam.

She has never been observed with a calf. Yet she has been photographed almost every year by MICS and its collaborators since 1997. In humpback whales, the bond between mother and calf remains close for about a year, unlike other whale species. In other words, if a female fin whale has never been seen with a calf on her summer feeding grounds, we can assume that this is due to early weaning: her calf is independent before summer. But a female humpback whale that gives birth in winter will necessarily be accompanied by her calf the following summer. So what’s going on with Irisept? A mystery…

How do you choose a humpback whale’s name? It’s based on the pattern under its tail, not on markings elsewhere on its body, its mother’s name or other details of its life. The name must not already be given to another individual. In the marine park, the name is often assigned following a competition organized in collaboration with MICS.