Lab Business Magazine | Fall Edition

Cover Story : 
Diving Into Aquatic
Animal Health

By: Jason Hagerman


The resilient red and black fishing boat pitches sharply to the left, then just as aggressively to the right as the waves of the North Atlantic Ocean assail it as though it were an unwelcome guest. The sun shows no sign of breaking through the blackened clouds now occupying the sky as far as the eye can see in all directions. The deck seems submerged. Salty mists and powerful waves dance back and forth across the rubberized surface.
This could easily be a scene out of The Deadliest Catch, and indeed a few days earlier it may have been just that. But today, this crab fishing vessel has a different objective. Today it searches for snow crab not for the purpose of human consumption, but for study. Snow and queen crab are, according to Fisheries and Oceans Canada, a more than $500 million economy in Canada, making these cold-water dwellers the second-largest seafood product by value in the Canadian economy, lagging behind only lobster with a reported value of $803 million in 2009.
This vessel’s job for the week is to ferry a team of field researchers from the aquatic section of the Atlantic Veterinary College (AVC) at the University of Prince Edward Island to a destination where they can collect samples, test them in the field for any of a number of ailments and bring a few back to the wet lab for further investigation. This particular team is looking into bitter crab disease (BCD), led by 25-year veteran of AVC, Dr. Rick Cawthorn, Professor of Parasitology in the Lobster Science Centre. 

 

“Our primary goal with this right now will be to determine whether or not BCD is a significant mortality factor in snow crab populations and how it’s causing disease among these populations,” says Cawthorn. “This will allow fisheries managers to look at BCD in a way that better allows them to manage populations.” Cawthorn also plans to work with colleagues at the UPEI Food Technology Centre to determine the cause of the bitter taste associated with the disease, and methods to remove it.   In order to do this, Cawthorn’s field workers transport sample crabs from the field to AVC’s aquatic animal facility. As part of a soon-to-be-completed $45-million expansion and renovation project, AVC is growing its aquatic holding facility by 8,000 square-feet, with the new addition expected to open in 2011.

“Our expanded aquatics holding facility is an important step forward in achieving our goal of becoming the world’s leading academic-based aquatics health institution,” says Dr. Jeff Wichtel, Associate Dean of Research. The aquatic facility contains a series of standalone salt-water recirculation units. Salt-water is necessary because the majority of subjects studied here are ocean dwellers, which presented a problem when building the facility in 1985. “We’re not close enough to the ocean to get salt water pumped in to our facility,” says Wichtel. Economically, building a pipeline to the ocean and maintaining water quality, disinfection and temperature control from that source didn’t make sense. Salt-water wells exist in the area, but not necessarily with the degree of salinity needed to maintain living samples. “Our salt water is made from a package that you basically dump into the water,” says Cawthorn. Substantial fresh water wells provide all the water needed and allow for precise control of the salinity in the interior tanks.

 “Our crabs, for example, are held at salinity of 34 parts per thousand,” Cawthorn explains. “The facility people do regular water quality testing and we work closely with them because they’re taking care of our animals and aquarium systems, really the most important part of our work here.” Taking care of the animals also means maintaining precise temperature control. One recirculation unit, for example, may contain crabs that must be held at a temperature of 0 C. Lobsters would be housed in a different unit, with their optimal temperature sitting between 1 C and 10 C. Lobsters are also a significant research focus at AVC and the Lobster Science Centre (LSC) is the only lobster research centre in the world that is part of a veterinary college. In 2000, scientists at LSC pioneered a new, humane method of euthanizing lobsters for study. Dr. Andrea Battison observed lobsters under imaging ultrasound and ended the use of pesticide baths in euthanizing the animals by introducing an injection that stops the heart very quickly. Studying animals such as snow crab, lobsters and shrimp will provide critical information allowing this industry to continue to grow, but there are a number of other fisheries critical to the Canadian and global economies in which AVC plays a pivotal role.

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