This summer, as right whales seemingly continued to underutilize their historic summer feeding grounds and as the death toll in the Gulf of St. Lawrence rose to at least 12 whales, our research team collaborated with old and new partners to maximize survey efforts in the gulf. While planes contracted under the National Marine Fisheries Service (NMFS), Department of Fisheries and Oceans (DFO) Canada, and Transport Canada covered extensive territory via the air and Mingan Island Cetacean Study continued vessel surveys north and west of Anticosti Island and around Perce, Quebec, the Shelagh crew (representing the Canadian Whale Institute, Dalhousie University, DFO, New England Aquarium’s Anderson Cabot Center for Ocean Life, and NMFS) focused on surveying the Orpheline Trough (western side of the gulf) for two weeks in both July and August.
In addition to the usual data collected, we made an effort to get a more complete picture of the habitat by collecting oceanographic information through CTD and plankton tows.
Unlike last year, when we started surveys several weeks later, the Shelagh crew found this area to be densely populated with fishing gear and vessels, and therefore much less of a safe haven for right whales. The July cruise logged a total of five survey days and so far has identified at least 15 individual right whales from 24 sightings. However, our team was repeatedly pulled away from documentation to respond to entangled right whales found by the NMFS aerial survey team.
There were a few familiar faces from the previous GSL season, including Flare (Catalog #4092), Bocce (Catalog #3860), and Clipper (Catalog #3450). It is interesting to note that approximately one-quarter of the identified whales seen on this cruise were female and about half have been seen in the gulf in previous years.
The first trip was tragically cut short, but a resilient crew returned for the August cruise a few weeks later and found drastically less fishing gear and fewer vessels in the area due to the closure of the snow crab fishery. This trip logged five survey days, and so far we have identified at least 24 individual right whales from 35 sightings, most of which were seen on the first day. We witnessed the right whales move out of the Orpheline Trough area (plankton tows confirmed the decline of their main prey), while other baleen whales moved in (along with different plankton, including krill). Aerial surveys later confirmed that the aggregation had moved further north. Three of the whales seen on this trip, Silver (Catalog #2705), Cream (Catalog #1149), and Comet (Catalog #1514), were also seen on the July cruise, and Harmonia (Catalog #3101) was another repeat from last summer. One whale (Catalog #4123) was seen a few weeks later in the Bay of Fundy. For this second cruise, about half of the identified whales were female and about two-thirds have been seen in the Gulf of St. Lawrence before.
It was an extremely tough season mired in loss, but it was also an informative one that proves the importance of dedicated survey effort and collaboration among research institutions. The number of right whales seen by multiple platforms in the Gulf of St. Lawrence this season constitutes quite a chunk of the population and essentially insures that this will be a budding research habitat for years to come.
Tags: entanglement, field work, Gulf of St. Lawrence, Gulf of St. Lawrence 2017, plankton, right whales