By Clint Wright, Vancouver Aquarium executive vice president & chief operating officer
At dawn fog banks started to roll in from both up and down the Sound — wispy fingers, silently reaching out and creeping in from the stream valley behind us as if to envelop us from all sides. Although no polar bears have been spotted near camp since the first night, no one likes to do a bear patrol in the fog. Miraculously by some meteorological phenomenon we remained a fog free zone throughout the morning and although we could hear the narwhals occasionally trumpeting like some ghostly foghorn close by, not one slid out from behind the billowing damp grey blanket toward our net.
Apart from several near misses, we have not been able to tag any new narwhals since last week and our total remains the same. Conditions have been up and down all week alternating between glassy calm waters and gale force winds. On several occasions we’ve had to pull the nets due to heavy seas and last night for the first time we had to bring the net in for two hours because it was too dark to see the floats.
Although narwhal free for a few days the scientific studies still continue. Greenland shark have been in the news recently having been aged using radiocarbon dating. At an estimated 400 years old, one of the females is now the longest-living vertebrate on the planet, and by a long margin. Despite their longevity, large size (up to seven metres) and relative abundance we know very little about their life history.
Greenland shark are top predators in the Canadian Arctic and Dr. Nigel Hussey from the University of Windsor has been studying them along with other large fishes around the world. This is his third year in camp with us and he’s been out here doing field work on a regular basis. During this trip he is setting long lines with baited hooks and has caught 13 sharks to date. He is catching them on every set, sometimes in as little as two to three hours. The bottom of the Sound must be crawling with them, which is a daunting thought since they seem to have voracious appetites and deceptively small but razor-like teeth that can slice cleanly through any flesh.
Dr. Hussey is taking measurements and attaching a variety of tags including satellite tags, pop off and archival varieties to track the migration routes and swimming patterns of these animals, potentially for many years. Already, his work in previous field seasons has shown the sharks on long migrations from Canada to Greenland in a relatively short time. Are the sharks following herds of narwhals and opportunistically feeding on the dead and dying or are the deceptively languid sharks’ more active hunters perhaps hunting in packs? It is early in the studies but the six sharks released with tags so far this year will be helping to fill in the gaps.
Clint Wright, the Vancouver Aquarium Marine Science Centre’s executive vice president & COO, has ventured into Canada’s Arctic for the seventh year in a row, lending his marine mammal expertise to a multi-year project with Fisheries and Oceans Canada. The field work primarily focuses on tagging narwhals, which is part of a long-term strategy to understand this unique species. The tags allow scientists to follow the movements of the narwhals during their annual feeding and reproductive routines.