Even though I am mostly in the lab these days, somehow I am still subject to the unpredictability of working with wild animals. The research project I am currently working on uses yellow perch eggs collected within under 24 hours after fertilization. I was lucky to find a fish farm in central Ontario that had “wild” yellow perch. I say “wild” because although they live on this fish farm, they still live in a fairly natural habitat. Achieving the right timing of egg development was the tricky part. I had to wait until I heard that the adult yellow perch were spawning and drive up there to collect the eggs within a day. Essentially I was like a doctor on call waiting for a delivery (of yellow perch eggs).
Natural ponds at the fish farm are a great habitat for yellow perch.
I originally spoke with the owner at the end of February and he said he would give us some perch eggs. However, he was reluctant to give up much detail about the fish. When I asked when they usually spawn, he replied, “I can’t tell you when those little buggers are going to spawn; I’m not God”. Yellow perch in this area typically do not spawn until mid April so I was not surprised, given the cold February we had, that they would not be near ready.
At the end of March, I received a phone call from the owner who explained that he had caught two females that were “as big as footballs” and that they could spawn any day now. (Side note – I think it is very interesting how people describe their study species. For example, the seabirds I was studying for my master’s thesis were often described as “flying tennis balls with wings”.) I was not ready for the fish to be ready; I thought I had two more weeks to prepare for the experiment! I scrambled to get all of the equipment together so that at any point I was ready to go collect the eggs.
From eggs to fry: the yellow perch are collected and kept in big tanks until they are old enough to be put back into the ponds.
And then I waited. The owner told me not to call him for updates as it would take a lot of his time. But no sign of eggs. So I waited longer. Still no eggs. At this point, it was now the end of April and I started to get worried. Did the owner forget to call me? Did he lose my number? Would the perch ever lay their eggs? Was the project ruined!? (Questions in field biologists’ heads often escalate quickly).
The owner finally called me last week and told me that the yellow perch had spawned and there were a few strands of eggs that I could collect.
Scooping eggs out of the pond. Don’t fall in!
The next day I drove a total of 6 hours to retrieve the eggs and bring them back to our lab (Believe it or not, 6 hours driving for 1 hour of fieldwork does sound appealing when you sit behind a lab bench most of your time!). However, even though I had over a month to prepare, I still forgot my rain boots and ended up with a wet foot. The owner kept saying “This is a fish farm you know. You’re going to get wet.” and “Don’t you go falling in there, I don’t want to have to come in after you!”.
Yellow perch eggs come out in long gooey strands.
Although it seemed that I was an inconvenience to the owner most of the time, when I arrived at the fish farm, he was surprisingly very interested in the research that we do and said “I just want to know that you are learning something”. In addition to learning more about yellow perch, it turns out that interactions with people in the field can also surprise you!
Dispatches from the Field 