Recently, an innovative materials research group at H漫画 jumped into the ocean technology game and teamed up with VEMCO, a local company that develops unique tracking solutions for the Ocean Tracking Network and researchers worldwide.
The collaboration will help scientists collect more accurate data on聽animal behaviour, movement, physiology and the survival of animals in marine and freshwater environments.
Mary Anne White, Harry Shirreff Professor of Chemical Research (Emerita) in the Department of Chemistry, led a small team of researchers on a project unlike any other her group had tackled before.
A new challenge
Dr. White鈥檚 lab usually focuses on materials that can be used to develop new or improved ways to store energy.
But in a chance conversation with a VEMCO employee at a Halifax Chamber of Commerce dinner, Dr. White learned scientists who study the movement and migratory patterns of fish would benefit from a new kind of acoustic telemetry tag鈥攁 tracking device inserted under the skin of a fish. This tag would somehow have to emit a signal when a larger fish ate a tagged fish. That way researchers could better interpret their data knowing the information coming from that tag is associated with a different species.
鈥淗e said, 鈥榳e have a problem that materials research might help us solve,鈥欌�� recalls Dr. White of the conversation over dinner. 鈥淪o, I wondered, how can my team help develop that signal?鈥�
Dr. White brought the problem to her research group. Kim Miller, a postdoctoral fellow at the time, jumped at the chance to get involved. With a natural 鈥渓ove of fish,鈥� Dr. Miller was a perfect fit, said Dr. White.
鈥淲e needed to make a coating for the tag that the stomach acid of another fish would dissolve 鈥� it would need to be stable and non-toxic while under the skin of the tagged fish, but unstable and still non-toxic in the stomach acid of the predator,鈥� says Dr. White.
Detailed approach
鈥淚t鈥檚 a fascinating project, chips in fish. We got to learn a lot about how VEMCO makes these tags. It鈥檚 a very intricate procedure,鈥� says Dr. White.
With funding from Natural Sciences and Engineering Research Council of Canada鈥檚 (NSERC) Engage program, Dr. White鈥檚 team identified that a derivative of a material called chitin provided the right combination of chemical properties for the coating. A product of nature, chitin helps form tough outer skeletons found on lobsters, beetles and spiders.
The placement of the tag was an important factor in the success of this project because tags are inserted under the skin so they can continuously send out information on location, activity and physiology. Dr. White鈥檚 modified chitin material would require particular mechanical properties, too. After considerable chemical testing, the team made a coating flexible enough to prevent cracking and swelling while the fish moves about.
When the coating of the tag encounters the predator鈥檚 stomach acid it degrades and triggers the release of a small magnet that emits the signal of predation, changing the output of the tag to indicate that it鈥檚 inside of a predator.
Dr. White and Kim Miller, along with former master鈥檚 student Ryan Fielden, hold a patent with VEMCO on the successful device now. Called the V5 Predation Tag and available on the company鈥檚 website, it reacts to a changing chemical environment on predation and within a matter of hours emits a signal to researchers.聽 聽
Eddie Halfyard, a former PhD student in the Department of Biology who was supported by the Ocean Tracking Network, is looking forward to what this new tag can do. Currently he鈥檚 a marine scientist with the Nova Scotia Salmon Association.
鈥淚t allows us to have more confidence in our data, but it also opens up a whole new avenue of research and application for telemetry data,鈥� says Dr. Halfyard. 聽
Flexible solutions
鈥淢aterials researchers have a lot of techniques at their fingertips. We look at a lot of materials to find solutions to diverse problems,鈥� said Dr. White.
鈥淚t doesn鈥檛 matter whether it鈥檚 a fish tag, pen ink, or energy storage materials 鈥� the ways we characterize materials and their properties are part of our toolkit and expertise. Training in materials research means you can be very flexible and tackle a wide range of problems.鈥�