You asked, we answered!
NAME OF OBJECT: Shark tracking satellite tag
Who uses this object?
Trophic ecologists like Aaron Fisk and Nigel Hussey, who both work in the University of Windsor’s Great Lakes Institute for Environmental Research.
Where is it used?
In the Arctic ocean, on Greenland sharks (tags like it are also sometimes in the Red Sea, off the coast of Sudan, on manta rays and sharks).
What does it do and why is that helpful/important in this field of study?
The tag is attached to a shark and programmed to remain in it for a specific time period – sometimes up to a year! It collects all kinds of data, such as water temperature, depth and distance travelled, then releases from the animal, floats to the surface and transmits all that information to a satellite in outer space. The researchers are able to access that satellite data from their labs.
How does the research related to this object affect me or why is it important to the public?
The research is important because it helps scientists understand the movement and behaviours of these animals. The sharks are often accidentally caught by commercial fishermen. If scientists can better understand their migratory patterns, they can help fishermen avoid catching them, and help preserve this species.
How is this object used at universities?
It’s actually very rare to get one back, so it’s not used in the university. But the scientists here are able to access and analyze the data from the satellite
Was this object invented in Ontario, or has its use helped with an Ontario research breakthrough?
It wasn’t invented in Ontario, but it has helped Ontario researchers better understand the behavior of various aquatic animals like sharks, seals and manta rays.
Why is this relevant to all Ontarians?
It’s relevant to Ontarians because the research may help the federal Department of Fisheries and Oceans develop new commercial fisheries for small Inuit communities in the Canadian Arctic – and we eat a lot of fish in Ontario!
Interesting facts, statistics or stories about this object?
This tag was planted in a shark in the fall of 2012. It came out near Baffin island and floated all the way across the North Atlantic to Wales where it was found washed up on a beach – more than 6,000 kms away! Here’s a story about it: http://www.uwindsor.ca/dailynews/2014-04-10/high-tech-message-bottle-travels-more-6000-km
Does tagging the shark hurt it?
We don’t think it really hurts the sharks – they feel a small pain when the attachment dart is inserted into the muscle (similar to humans with a needle), basically a flinch, but then they resume normal behaviour almost immediately following release. We have observed sharks and rays happily swimming around with other animals a few minutes after tagging and release. Also, when sharks mate the males bite the females to hold them down – following mating the females have many bite marks along their backs where the muscle tissue is formed of open wounds – attaching a tag is nothing compared to that!
How is the tag attached?
The tag is attached via a plastic umbrella dart that locks into the fibres of the muscle tissue and the spines that come down from the dorsal fin. The dart is attached to a monofilament fishing line that is fastened to the tag. We insert the umbrella dart using a needle on the end of a hand tagging pole.
How does the tag communicate with the scientist?
Via overhead satellites. We program the tag to stay on the animal recording data for defined period of time from weeks to months. At the specified time, a pin at the base of the tag burns off releasing the tag from the animal. The tag floats to the surface. The tag then starts transmitting all the data to satellites. The data is relayed from the satellites to the ARGOS satellite base and then via internet. We get to work in the morning, log on and can download the data!
Why does the jaw have so many teeth? What are they specialized for?
It has many rows of teeth because they are continually replaced, i.e. new teeth move forward to replace ones that fall out while feeding. For humans, we have baby teeth but then we have adult teeth that we need to clean and keep healthy as we don’t have replacements! Sharks are very luck that their teeth continually grow in new rows throughout their life – the rows of teeth keep moving forward on a conveyor belt system to replace teeth lost while biting things.
The Greenland sharks has small but very sharp teeth. Basically Greenland sharks feed by grabbing on to something and then turning in a corkscrew motion, backwards and forwards. By doing this their teeth rip out chunks of meat. Greenland sharks often scavenge from dead animals such as whales – this is a very good way for them to consume lots of food.