Evidence of meeting #35 for Fisheries and Oceans in the 41st Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was control.

A recording is available from Parliament.

On the agenda

MPs speaking

Also speaking

4:20 p.m.

Liberal

Lawrence MacAulay Cardigan, PE

You did indicate that there was a major reduction in the harvesting of salmon and trout. You also indicated that there was a major reduction in the sea lamprey at one time. What happened?

4:20 p.m.

Assistant Professor, Department of Biology, Algoma University, As an Individual

Dr. Istvan Imre

The fisheries did rebound. In the late 1950s and 1960s, we saw a collapse of several fish species.

Well, I wasn't completely clear, in the sense that sea lamprey contributed to it, but they weren't the sole factor. Overfishing was also part of it. We managed to bring sea lamprey densities in the 1960s under control, but that was done at the same time as a lot of lake trout and other species were being raised in hatchery operations and released into the Great Lakes to help those species rebound. That has happened, to some extent.

4:20 p.m.

Liberal

Lawrence MacAulay Cardigan, PE

Before my time is gone, could you also elaborate on the sea lamprey releasing a chemical when it's injured? Is that correct?

Are you about to do research on that? It would be better to ask you this question a year from now, probably. But you must feel that there must be some way that would be used as a control method.

4:20 p.m.

Assistant Professor, Department of Biology, Algoma University, As an Individual

Dr. Istvan Imre

Thank you for the question.

In the paper I mentioned, from 2010, I speculated that they have to have some kind of chemical within their tissues, because we know of a broad variety of other fish species, including some salmonids, that have a so-called alarm cue that is typically released from their skin when a pike, for example, comes and bites them. It's like a chemical warning signal to the other conspecifics—individuals of the same species—that it has been attacked and to watch out and go away.

We figure that sea lamprey must have something similar. In fact, Dr. Michael Wagner, who works at Michigan State University and is a permanent scientist for the Great Lakes Fishery Commission, has shown that they have shown avoidance behaviour toward decaying sea lamprey extract.

I'll be working with freshly killed sea lamprey as well as juvenile sea lamprey tissue extract. Basically, I'll take a certain amount of tissue, grind it up, dissolve it in water, release it in water, and see what they do. There is very positive science that shows that they avoid it. Of course, it doesn't kill them. It's not a control method; it's a behavioural manipulation method.

I'll give you an example of how it works. Imagine that the width of this room is a stream, and on one corner you have a dam—

4:20 p.m.

Liberal

Lawrence MacAulay Cardigan, PE

You could scare them out of the area.

4:20 p.m.

Assistant Professor, Department of Biology, Algoma University, As an Individual

Dr. Istvan Imre

Yes, that's what I'm getting at.

Assuming uniform distribution of animals moving up, if I were to release the repellent on the other side of the stream it would scare them over to this side and they would become more available for trapping. In the optimal scenario, if we were to put a pipe across that released that chemical into the water we could potentially set up a chemical barrier. It would be temporary in nature, but it might tell them to not enter this stream and to move on to the next one. Instead of using a huge amount of very expensive chemicals you could just release that and ring the alarm that this is a bad spot, so go away, if everything were to go well.

4:25 p.m.

Liberal

Lawrence MacAulay Cardigan, PE

It would also be natural.

4:25 p.m.

Assistant Professor, Department of Biology, Algoma University, As an Individual

4:25 p.m.

Liberal

Lawrence MacAulay Cardigan, PE

In some areas there has been a major increase in sea lamprey, and in some areas there has been very little increase in sea lamprey. Can we learn anything from that, as far as the different conditions in each area?

4:25 p.m.

Assistant Professor, Department of Biology, Algoma University, As an Individual

Dr. Istvan Imre

I presume you're talking about the St. Marys River.

4:25 p.m.

Liberal

Lawrence MacAulay Cardigan, PE

Yes.

4:25 p.m.

Assistant Professor, Department of Biology, Algoma University, As an Individual

Dr. Istvan Imre

We do know what the difference is. The habitat conditions have improved substantially, allowing the animals to successfully reproduce in that area. We are less efficient in controlling sea lamprey there because the chemical we normally release is very efficient in small streams, but we're dealing with a body of water that's 300 metres wide, several metres deep, and moving very fast in some locations. You would need a humongous amount to be effective in killing the larvae, and most of it wouldn't make it all the way to the bottom.

4:25 p.m.

Liberal

Lawrence MacAulay Cardigan, PE

And it's not very acceptable either.

4:25 p.m.

Assistant Professor, Department of Biology, Algoma University, As an Individual

Dr. Istvan Imre

That's another issue.

4:25 p.m.

Liberal

Lawrence MacAulay Cardigan, PE

Thank you, Mr. Chair.