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Post doc receives grant to study invasive species

By Kelly Foss

The New Zealand government will give a postdoctoral fellow studying at Memorial one of two international grants valued at $200,000.

Dr. Daniel Bassett, who is working with Dr. Mark Abrahams, dean of Science and a researcher at the Ocean Sciences Centre, will now be covered for salary and research costs for the next three years.

The Foundation of Research, Science and Technology provides 12 grants annually, 10 to residents studying at home, and two for New Zealanders studying abroad who are conducting research benefit that will benefit their home country. Dr. Bassett is a native of Auckland, N.Z.

Dr. Bassett’s research involves a new theory behind invasion pathways. He says there are plenty of theories why invasive species take over an area and none of them are mutually exclusive. But he is hoping to develop one theory that could prove to be a piece of the puzzle.

“Humans negatively impact our waterways through erosion, contaminants, and pollution, so those freshwater rivers and lakes become really turbid, meaning murky,” he explains. “Over 90 per cent of fish are visual, so they find it hard to see their food in these murky ecosystems, and their numbers start to drop.
Dr. Bassett says when these fish get introduced into a murky environment, they tend to do well and displace the native species.

“I’m going to be looking at this research in three ways. I want to look at native and exotic species using brain morphology to establish that exotic species tend to have enlarged non-visual regions of the brain, while the visual area is very small. I also want to show that native species predominately have big visual areas and smaller non-visual areas.

“Then I’ll be going in the field and looking at turbid sites and non-turbid sites and show that in turbid sites you will have more exotic species than the clear water sites. That’s definitely the case in Auckland, which is the hub of invasions in New Zealand, and I want to see if that’s the case in the Great Lakes as well. That’s the hub of invasions in North America.”

Finally, he will be conducting lab work and testing non-visual fish against visual fish and looking at their ability to feed in turbid or non-turbid water.

“I hope to show that once the water becomes more turbid non-visual fish can continue to feed where the visual fish will stop,” he said.

Dr. Bassett will be doing his field work in both areas while he develops his theory. He hopes that his research might ultimately change the focus of conservation.

“People tend to think that in order to save a native species, you have to get rid of all the exotic species,” he said. “If you do that they think the native species will naturally recover due to a lack of competition. But this research could show that you actually have to change physical habitat characteristics, such as turbidity, in order to swing the home team advantage back in favour of the native fish.”

“It might not be that both species are in competition. If I determine at what turbidity level native fish can feed, or no longer feed, government agencies and conservation groups can work to make those changes through habitat restoration.”
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