Wildlife

Wildlife Wednesday: invasive “vampire fish” exploding across Great Lakes

Plus: following a whale fall, encountering a great white shark in New Brunswick, pushing to protect the marbled murrelet, and uncovering a fossilized fight to the death

The sea lamprey, native to the Atlantic Ocean, originally entered the Great Lakes in the early 20th century through shipping canals before wreaking havoc on the Great Lakes fishery, killing fish in huge numbers. (Photo: T. Lawrence, Great Lakes Fishery Commission)
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Below the waters of the Great Lakes lurks the stuff of nightmares. The invasive sea lamprey, also known as the “vampire fish,” is a long snake-like creature with a suction cup mouth ringed with concentric rows of sharp teeth. Growing up to 60 centimetres long, the parasitic fish latches onto the side of other fish, then extends it’s tongue and drills a hole through the fish’s scales and skin. Once it’s in, the lamprey feeds on its prey’s blood and bodily fluids.

To make matters worse, the population in the Great Lakes exploded during COVID-19. Lake Huron alone has seen a dramatic increase from about 100,000 to nearly 200,000 sea lampreys. The sea lamprey, native to the Atlantic Ocean, originally entered the Great Lakes in the early 20th century through shipping canals before wreaking havoc on the Great Lakes fishery, killing fish in huge numbers. Since then, cross-border programs were put in place to control numbers using a lamprey-selective pesticide. But the program was curtailed in 2020 and 2021 because of travel restrictions related to the pandemic. 

While efforts are back underway to drive numbers down again, this could take a few years. Sea lampreys are extremely good at bouncing back, with females able to produce up to 100,000 eggs at a time. 

Sea lampreys are not a danger to humans and don’t feed on warm-blooded creatures. A sliver of good news, at least.

Eye-to-eye with a giant

The great white shark caught on video is assumed to be a 12-foot-long female. (Video: Andrew Jones)

It’s that time of year again. As great white shark season fast approaches (late summer to early fall), these notorious giants are making their way to Atlantic Canada in search of their favourite snack – the region’s abundant seal population. As a result, white shark sightings are becoming increasingly common in Atlantic waters, with one close encounter in Grand Manan, N.B.

On July 20, Andrew Jones was fishing with two friends on his boat, School’s Out, between Whale Cove and Wolf Island in the Bay of Fundy. After stopping to take a break, they turned the boat’s engine off and soon noticed the telltale sign of a great white – a sizeable dorsal fin cutting through the clear water. Jones reported that the shark was very large and circled the boat before slapping its tail against the side and then disappearing into the roughly 260-foot deep water.

Based on the size of his 27-foot boat, Jones estimates that the shark was roughly 10 to 12 feet long. Male great whites can measure up to 13 feet long, while the average female can be between 15 to 16 feet long.  

Jones took  a 19-second video showing the shark opening its mouth and diving below the boat’s dive platform. Within 24 hours, the video received more than 100,000 views. Chris Fischer, the founder of Ocearch, was one of those viewers and confirmed to CBC News that the shark was a mature female. Fischer also noted that it’s not unusual for great whites to be in the area, and his group has tagged about 40 in the same region. 

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Fossilized ferocity

The fossil shows the entangled skeletons of Psittacosaurus, a larger plant-eating dinosaur and Repenomamus, a smaller carnivorous mammal. (Photo: Gang Han)
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One hundred and twenty five million years ago, dinosaurs ruled the earth. But, as a new finding by Canadian and Chinese scientists has shown, they occasionally met their match.

The jaw-dropping fossil, discovered in 2012 in China’s Liaoning Province and later brought to the attention of Canadian Museum of Nature palaeobiologist Xiao-Chun Wu, shows the entangled skeletons of a larger plant-eating dinosaur and a smaller carnivorous mammal. “The two animals are locked in mortal combat, and it’s among the first evidence to show actual predatory behaviour by a mammal on a dinosaur,” explains Dr. Jordan Mallon, palaeobiologist with the Canadian Museum of Nature and co-author on the study published in the journal Scientific Reports.

Illustration showing Repenomamus robustus as it attacks Psittacosaurus lujiatunensis before a volcanic debris flow buries them both, ca. 125 million years ago. (Illustration: Michael W. Skrepnick)
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The dinosaur has been identified as a species of Psittacosaurus, a horned dinosaur about the size of a dog that lived 125 to 105 million years ago. The mammal, clearly getting the better of the dinosaur, is the badger-like Repenomamus robustus. The fossil challenges the view that dinosaurs had few threats from their mammal contemporaries during this period, when dinosaurs were the dominant animals.

The great condition of this fossil and the abrupt nature of the death of these creatures can be attributed to the fact the fossil comes from an area known as “China’s Dinosaur Pompeii.” Many fossilized animals have been found in the area that were buried suddenly by mudslides and debris following one or more volcanic eruptions.  

The big house

When a large marine mammal dies, whale fall is the description given to the act of its body slowly drifting down to the ocean floor and decomposing. (Photo: Andre Estevez/Pexels)
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The name sounds poetic: whale fall. The reality a little less so. When a large marine mammal dies, whale fall is the description given to the act of its body slowly drifting down to the ocean floor and decomposing. That massive carcass will sustain a succession of sea creatures for a whopping 10 years or more. It’s the circle of life writ large.

When researchers discovered a 16-metre-long grey whale carcass decomposing at the bottom of the Clayoquot Slope off the B.C. coast in 2009, they decided to monitor its decomposition. Ocean Networks Canada scientists, along with Ocean Exploration Trust’s EV Nautilus research vessel, returned to the site in 2012, 2020 and 2023, using a remotely operated vehicle to survey the skeleton, still teeming with life nearly 15 years after the carcass was discovered on the seafloor. 

They uploaded YouTube footage of the whale fall in 2020 and a more recent video of their work in 2023 in which the scientists use photogrammetry to explore the fall. A blog post explains the project and the researchers’ hope that this long-term project will provide a much better understanding of the fate of whale falls and their role in the nutrient cycle in deep ocean environments.

Tall order

Marbled murrelets need to nest in tall trees greater than 250 years old because fledglings need a high jumping-off point to avoid other trees and remain airborne as they head for the sea. (Photo: Kim Nelson and Dan Cushing/Oregon State University [CC BY-SA 2.0])
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Small but mighty, the marbled murrelet is also an anomaly among seabirds — rather than nesting cliffside by the sea, it sets up house inland in the treetops in B.C.’s old-growth forests. 

And there lies the problem. The robin-sized murrelet excels at flying, hitting speeds of more than 70 kilometres per hour as it heads out to sea to catch fish before returning in the darkness of night with its catch, to a nest carefully set atop a mossy tree limb. But logging is taking down the marbled murrelets’ nesting sites at an alarming rate.

Now it’s birders rather than blockaders taking up the fight to protect the forest around the Fairy Creek watershed. Avid birder Royann Petrell, a retired University of British Columbia professor, is making waves with a group of citizen scientists and researchers collecting data aimed at pushing the provincial government to create additional wildlife habitat areas to protect the murrelets’ nesting grounds. The group’s work has garnered publicity in news media throughout B.C. over the past six months and has been endorsed by U.S. researchers working on marbled murrelet conservation in Washington state. 

Marbled murrelets need to nest in tall trees greater than 250 years old because fledglings need a high jumping-off point to avoid other trees and remain airborne as they head for the sea on their initial flight.

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